Plants

34 pages, 6991 KB

Open AccessReview

Interactive Effects of Heavy Metals and Co-Occurring Abiotic Stresses in Plants: Shared Response Mechanisms and Mitigation Approaches

by Maurizio Capuana and Emily Rose Palm

Plants 2026, 15(14), 2245; https://doi.org/10.3390/plants15142245 - 22 Jul 2026

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Abstract

Heavy metal (HM) contamination of soils frequently occurs in combination with other environmental stressors, resulting in a cumulative effect that interferes with plant physiology, biochemistry, and development in a more severe and complex manner than the individual stressors alone. While there are many [...] Read more.

Heavy metal (HM) contamination of soils frequently occurs in combination with other environmental stressors, resulting in a cumulative effect that interferes with plant physiology, biochemistry, and development in a more severe and complex manner than the individual stressors alone. While there are many reviews that consider abiotic stress combinations broadly, this review focuses specifically on combined HM + abiotic stress conditions and classifies in terms of the effect on symptoms or induced defense mechanisms as additive, synergistic (exacerbated) or even antagonistic (counteracted). It is revealed that the combined stress response may depend on the way that each of the stresses presents itself to plant tissues, i.e., whether it is a chemical compound whose accumulation into roots may be regulated or a stress whose application is more general, such as heat stress or flooding (localized versus systemic, respectively). Combined localized stresses such as HMs and hydrocarbons tend to elicit synergistic responses, while localized + systemic stresses are more variable, tending toward antagonistic, such as HM and drought. Modern analysis tools indicate an overlap in or induction of unique response pathways that may alter depending on the conditions (intensity, duration and timing of exposure; greenhouse versus field conditions). The latest findings in mitigation techniques, ranging from chemical amendments and biological treatments, such as biochar and phytohormones, respectively, to genetic engineering, as also summarized. It is revealed that biochar and genetic approaches are both the most-widely used and the most effective. Full article

(This article belongs to the Special Issue Plant Ecotoxicology and Remediation Under Heavy Metal Stress)

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32 pages, 18124 KB

Open AccessReview

The Dual Role of Lignin in Fruit Trees: Unraveling Regulatory Networks from Stress Resilience to Quality Control

by Yun Shao, Wenfang Li, Muhammad Mobeen Tahir, Juan Mao and Baihong Chen

Plants 2026, 15(14), 2244; https://doi.org/10.3390/plants15142244 - 22 Jul 2026

Viewed by 671

Abstract

Lignin deposition in fruit trees represents a fundamental physiological trade-off: essential for structural integrity and stress adaptation, yet excessive or mistimed activation compromises fruit texture, palatability, and market value. This review synthesizes advances in lignin biosynthesis and its multilayered regulation in commercial fruit [...] Read more.

Lignin deposition in fruit trees represents a fundamental physiological trade-off: essential for structural integrity and stress adaptation, yet excessive or mistimed activation compromises fruit texture, palatability, and market value. This review synthesizes advances in lignin biosynthesis and its multilayered regulation in commercial fruit species. We describe how abiotic (drought, salinity, temperature extremes) and biotic (pathogens, pests) stresses trigger lignification through transcriptional, post-transcriptional, hormonal, and epigenetic mechanisms, centered on the conserved NAC-MYB cascade. This core module integrates WRKY/ERF transcription factors (TFs), microRNA networks, and hormone signaling. Transcriptional programs are further refined by microRNAs, alternative splicing, DNA methylation, histone acetylation, and phytohormone crosstalk (abscisic acid, ABA; jasmonic acid, JA; salicylic acid, SA; and brassinosteroids, BRs). We emphasize molecular crosstalk integrating abiotic and biotic stress signaling via shared TFs, reactive oxygen species (ROS), and epigenetic memory. We critically examine lignification’s dual nature during development and postharvest storage, contributing to desirable traits (stone formation and skin toughness) but also driving defects (stone cell gritty texture and chilling-induced wooliness). Finally, we propose a strategic framework leveraging molecular breeding, targeted gene editing, and precision horticulture to fine-tune lignification, enabling climate-resilient cultivars without compromising fruit quality. Full article

(This article belongs to the Special Issue Plant Gene Families and Functional Regulation in Crop Development)

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20 pages, 6067 KB

Open AccessArticle

Deciphering the Olive Fruit Volatilome: A Multivariate Approach to Assess Cultivar Variation and Biotic Stress Response in a Changing Agroclimatic Context

by Araceli Sánchez-Ortiz, José Manuel Muñoz-Redondo, Juan Cano Rodríguez, Enrique Quesada-Moraga and José Manuel Moreno-Rojas

Plants 2026, 15(14), 2243; https://doi.org/10.3390/plants15142243 - 22 Jul 2026

Viewed by 355

Abstract

Understanding olive tree metabolism and its interactions with biotic and abiotic factors is crucial for the sustainability and resilience of olive cultivation in a changing agroclimatic context. In response to biotic stress, plants activate complex signaling pathways that trigger the production of specialized [...] Read more.

Understanding olive tree metabolism and its interactions with biotic and abiotic factors is crucial for the sustainability and resilience of olive cultivation in a changing agroclimatic context. In response to biotic stress, plants activate complex signaling pathways that trigger the production of specialized metabolites, particularly volatile organic compounds (VOCs). This study investigates the volatolomic profile naturally emitted by whole olive fruits using an integrated metabolomic strategy that combines design of experiments (DoE), targeted and untargeted analyses, and multivariate statistics. Optimal headspace solid-phase microextraction (HS-SPME) conditions were established using 30 g of sample, a 50 °C extraction temperature, a 50 min extraction time, and a 3 min injection at 250 °C, identifying extraction time and temperature as the most critical factors influencing VOC recovery. The data demonstrated significant cultivar-dependent variation in the volatile emissions from healthy olive fruit among six representative varieties. Furthermore, robust partial least squares-discriminant analysis (PLS-DA) and random forest models provided a clear separation between healthy and damaged olive fruits, achieving high predictive accuracy (90%) and identifying key volatile biomarkers derived from the lipoxygenase (LOX) pathway. This novel multivariate optimization approach (SPME–GC/MS) represents a powerful tool for establishing a reliable chemical fingerprint of the olive fruit “volatilome” under evolving agroclimatic challenges. Full article

(This article belongs to the Special Issue Update on Olive Tree Cultivation: Sustainable Innovative Techniques and Mitigation Strategies Against Climate Change—2nd Edition)

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19 pages, 1907 KB

Open AccessArticle

Drought, Ash and Soil Legacies Shape Seed Germination Responses in Pinus canariensis C. Sm. & DC. Forests

by María A. Pérez-Fernández, Irene de Lara del Rey, Cristina González-Montelongo and José Ramón Arévalo

Plants 2026, 15(14), 2242; https://doi.org/10.3390/plants15142242 - 22 Jul 2026

Viewed by 413

Abstract

Fire plays a central role in shaping regeneration dynamics in Pinus canariensis C. Sm. & DC. forests, yet the relative importance of different fire-related cues and post-fire environmental filters remains poorly understood. We experimentally evaluated the effects of drought, heat, smoke, ash and [...] Read more.

Fire plays a central role in shaping regeneration dynamics in Pinus canariensis C. Sm. & DC. forests, yet the relative importance of different fire-related cues and post-fire environmental filters remains poorly understood. We experimentally evaluated the effects of drought, heat, smoke, ash and soil microbial extracts on the germination of seven co-occurring species representing the main functional groups of these forests. Germination responses varied markedly among species, revealing that no single cue dominates early recruitment. Drought emerged as the strongest and most consistent filter, sharply reducing germination success and slowing emergence in P. canariensis and Fabaceae, while Poaceae remained largely insensitive under the imposed water potentials. Ash enhanced germination in P. canariensis and Cynosurus echinatus L., indicating that nutrient-rich post-fire substrates can facilitate emergence when moisture is available. Soil and microbial extracts accelerated germination in fast-emerging grasses, providing the first experimental evidence that post-fire soil legacies influence recruitment in Macaronesian pine forests. In contrast, heat acted as a species-specific cue, with only limited stimulation at moderate temperatures and widespread declines under extreme heat, while the smoke treatment used in this study produced negligible effects across all species. Across treatments, germination timing emerged as a key functional axis, structuring regeneration niches, with rapid-germinating Poaceae favoured under increasing aridity. Our findings highlight the dominant role of hydric stress, the selective relevance of ash and soil legacies, and the functional divergence among species, offering new mechanistic insights into post-fire regeneration under current and future climate scenarios. Full article

(This article belongs to the Section Plant Response to Abiotic Stress and Climate Change)

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18 pages, 2470 KB

Open AccessArticle

Traditional Medicinal Uses and Ethnopharmacological Significance of Alchemilla L. Species in Azerbaijan

by Javanshir Isayev, Elvin Nagiyev, Gunay Jafarova, Nilufar Safarova and Vagida Mammadova

Plants 2026, 15(14), 2241; https://doi.org/10.3390/plants15142241 - 22 Jul 2026

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Abstract

The present ethnopharmacological study investigated the traditional medicinal uses of Alchemilla species distributed across different geobotanical regions of Azerbaijan. Field surveys were conducted in five mountainous regions of the country during 2024–2025, and ethnopharmacological data were collected from 125 informants through semi-structured interviews [...] Read more.

The present ethnopharmacological study investigated the traditional medicinal uses of Alchemilla species distributed across different geobotanical regions of Azerbaijan. Field surveys were conducted in five mountainous regions of the country during 2024–2025, and ethnopharmacological data were collected from 125 informants through semi-structured interviews and questionnaire surveys. A total of 21 Alchemilla species belonging to the Rosaceae family were documented. Quantitative ethnobotanical indices, including Use Value (UV), Relative Frequency of Citation (RFC), Fidelity Level (FL), and Informant Consensus Factor (ICF), were applied to evaluate the ethnobotanical significance of the recorded species. The results revealed that Alchemilla species are mainly used for the treatment of digestive, hepatobiliary, respiratory, and skin disorders, as well as for the management of diabetes. The highest ICF value was recorded for antipyretic use (ICF = 1.00), whereas the greatest number of use reports was documented for digestive system disorders (Nur = 278). Alchemilla sericea, A. sericata, A. caucasica and A. grossheimii exhibited the highest UV and RFC values. The high quantitative ethnobotanical indices reflect the relative local importance of these species and the strong consensus among informants regarding their traditional medicinal uses. The findings demonstrate the important role of Alchemilla species in the traditional medicine of Azerbaijan and indicate that species with high ethnobotanical indices represent promising candidates for future phytochemical and pharmacological investigations. Full article

(This article belongs to the Special Issue Antimicrobial, Enzyme Inhibitory and Wound-Healing Properties of Plant Extracts and Phytochemicals)

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17 pages, 15323 KB

Open AccessArticle

Exploring Genetic Diversity in a Temperate Bamboo: A Study Using SSR Markers

by Khin Nyein Chan, Janka Bedő, Kitti Andrea Tóth-Lencsés, András Neményi, Csilla Mihályfi, Szilvia Kisvarga, László Orlóci and Anikó Veres

Plants 2026, 15(14), 2240; https://doi.org/10.3390/plants15142240 - 22 Jul 2026

Viewed by 293

Abstract

Molecular markers have been employed for decades to assess genetic diversity in the Phyllostachys genus. However, a more comprehensive understanding of genetic variation among Phyllostachys species is still needed to carry out accurate germplasm identification, clarify genetic relationships among taxa, and support the [...] Read more.

Molecular markers have been employed for decades to assess genetic diversity in the Phyllostachys genus. However, a more comprehensive understanding of genetic variation among Phyllostachys species is still needed to carry out accurate germplasm identification, clarify genetic relationships among taxa, and support the conservation and management of bamboo genetic resources. High genetic diversity within bamboo populations enhances their resilience and adaptability to environmental changes. In this study, we evaluated genetic variation across 96 genotypes representing 44 Phyllostachys species using eight simple sequence repeat markers. These markers detected 47 alleles in total, ranging from 3 to 11 per locus. A private allele (201 bp) was identified in Phyllostachys edulis and its associated forms using the PBM019 marker. Cluster analysis grouped the samples into three clusters: 22 genotypes in Cluster I, 54 in Cluster II, and 21 in Cluster III. Principal coordinate analysis (PCoA) corroborated these clusters, revealing interspecific genetic divergence alongside high intraspecific and intra-form similarity, except in Phyllostachys arcana where two related forms exhibited clear genetic differentiation and clustered separately in both analyses. The PBM021 marker showed the highest polymorphism, amplifying eight alleles in select genotypes (Phyllostachys angusta, P. mannii, P. bissetii, P. heteroclada). Overall, this research provides insights into genetic diversity and relationships among 96 bamboo genotypes. Full article

(This article belongs to the Special Issue Bamboo Growth and Development for Sustainable Industries in the Industry 5.0 Revolution)

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24 pages, 4733 KB

Open AccessArticle

Chemical Components of Volatile Oils and Hydrosols Derived from Different Plant Organs of Three Scutellaria L. Species

by Tatiana Rodideal, Nina Ciocârlan, Lăcrămioara Carmen Ivănescu, Mădălina-Elena Frunzete, Maria-Magdalena Zamfirache, Violeta Alexandra Ion and Liliana Bădulescu

Plants 2026, 15(14), 2239; https://doi.org/10.3390/plants15142239 - 22 Jul 2026

Viewed by 443

Abstract

The genus Scutellaria L. occupies an isolated position within the family Lamiaceae, whereas the aerial organs of many species remain largely unexplored despite their potential as sources of bioactive metabolites. This study provides the first comprehensive comparison of 20 volatile oils and their [...] Read more.

The genus Scutellaria L. occupies an isolated position within the family Lamiaceae, whereas the aerial organs of many species remain largely unexplored despite their potential as sources of bioactive metabolites. This study provides the first comprehensive comparison of 20 volatile oils and their corresponding 20 hydrosols obtained by hydrodistillation from different organs of three Scutellaria species cultivated at NBGI (Republic of Moldova). GC–MS analysis identified eleven classes of secondary metabolites. S. altissima L. was characterized by linalool as the principal constituent in volatile oils (20.24–29.96%) and hydrosols (55.36–61.72%). S. baicalensis Georgi produced sesquiterpene-rich volatile oils primarily composed of β-caryophyllene (23.44–37.99%) and germacrene D (6.83–22.42%), whereas its hydrosols contained high relative abundances of 1-octen-3-ol (24.54–59.32%). The volatile oils of S. supina L. were characterized by high relative abundances of germacrene D (up to 33.16%), β-caryophyllene (up to 21.72%), linalool (up to 21.95%), and spathulenol (up to 11.36%). In contrast, hydrosols contained high relative abundances of 1-octen-3-ol (17.39–71.10%) and linalool (5.86–45.49%). Hierarchical cluster analysis distinguished volatile oils from hydrosols and revealed species-specific volatile profiles, with organ-related variation being primarily quantitative. These results underscore the potential of aerial organs and hydrosols for future investigations. Full article

(This article belongs to the Special Issue Research on Plant Biology)

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16 pages, 2046 KB

Open AccessArticle

Phylogenetic Relationships and Genetic Diversity of Thai Nepenthes (Nepenthaceae) Revealed by Integrative Molecular Analyses

by Yaowaphan Sontikun, Sunya Nuanlaong, Tim Böhnert, Maximilian Weigend and Potjamarn Suraninpong

Plants 2026, 15(14), 2238; https://doi.org/10.3390/plants15142238 - 22 Jul 2026

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Abstract

Accurate assessment of phylogenetic relationships is essential for understanding the evolution, taxonomy, and conservation of the carnivorous genus Nepenthes. In Thailand, species delimitation remains challenging because of extensive morphological variation and the occurrence of several closely related taxa. This study integrated genome-wide [...] Read more.

Accurate assessment of phylogenetic relationships is essential for understanding the evolution, taxonomy, and conservation of the carnivorous genus Nepenthes. In Thailand, species delimitation remains challenging because of extensive morphological variation and the occurrence of several closely related taxa. This study integrated genome-wide single nucleotide polymorphisms (SNPs) generated by Genotyping-by-Sequencing (GBS), chloroplast trnK intron sequences, nuclear ITS sequences, and AFLP markers to investigate phylogenetic relationships and genetic diversity among Thai Nepenthes taxa. Genome-wide SNP analysis recovered three principal clades, whereas trnK and ITS datasets provided complementary resolution at deeper and intermediate phylogenetic levels. The molecular datasets revealed broadly congruent phylogenetic patterns and improved resolution among several closely related Thai taxa. AFLP analysis of Nepenthes mirabilis populations revealed moderate polymorphism despite relatively high overall genetic similarity. Across all datasets, N. mirabilis var. globosa was consistently recovered within the broader N. mirabilis lineage and showed limited genetic differentiation from sampled N. mirabilis accessions. These findings provide an integrated molecular framework for understanding phylogenetic relationships among Thai Nepenthes and support future taxonomic, evolutionary, and conservation studies in the region. Full article

(This article belongs to the Topic New Insights in Plants Diversity and Conservation)

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25 pages, 8751 KB

Open AccessArticle

A Multilocus Integrative Framework to Reassess Species Boundaries Within the Cystoseira Sensu Stricto Complex (Fucales, Phaeophyceae)

by Sara D’Ambros Burchio, Alberto Pallavicini, Lucia Muggia, Ilaria Pagana, Giovanni Furnari, Samuele Greco, Elettra Chiarabelli, Fiorella Florian, Jose Valdazo, Ricardo Haroun, Anna Maria Mannino, Zahira Belattmania, Raquel Sanchez de Pedro, Polytimi Ioli Lardi, Maria Salomidi, Ljiljana Iveša, Claudio Battelli and Annalisa Falace

Plants 2026, 15(14), 2237; https://doi.org/10.3390/plants15142237 - 22 Jul 2026

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Abstract

Cystoseira sensu lato (s.l.) (Fucales, Phaeophyceae) form structurally complex marine forests along the warm-temperate coasts of the Mediterranean Sea and the eastern Atlantic Ocean. They are experiencing widespread decline, yet their conservation and restoration are hindered by taxonomic uncertainty. Within Cystoseira sensu stricto [...] Read more.

Cystoseira sensu lato (s.l.) (Fucales, Phaeophyceae) form structurally complex marine forests along the warm-temperate coasts of the Mediterranean Sea and the eastern Atlantic Ocean. They are experiencing widespread decline, yet their conservation and restoration are hindered by taxonomic uncertainty. Within Cystoseira sensu stricto (s.s.), species boundaries among taxa traditionally referred to as C. compressa, C. foeniculacea, C. humilis (including the C. canariensis morphotype), and C. pustulata have long been debated due to the high plasticity and partial overlap of diagnostic morphological traits. Here we reassess species boundaries within the Cystoseira s.s. complex using an integrative approach combining morphology, ecology, and multilocus genetic data. We collected specimens from 20 sites spanning the Mediterranean–Atlantic distribution. Genomic DNA was extracted from 220 specimens and Sanger sequencing generated 243 new sequences (ITS2: n = 99; cox1: n = 88; rbcL–rbcS: n = 56). We inferred single-locus and concatenated phylogenies, reconstructed haplotype networks, and applied multiple single-locus species delimitation approaches to test the robustness of inferred boundaries. We consistently recovered two primary lineages corresponding to C. foeniculacea and a C. compressa complex, the latter including specimens historically identified as C. pustulata and the C. humilis with the C. canariensis morphotype. Within an integrative framework that prioritises cross-locus concordance and diagnosability, we recognise two species-level lineages in Cystoseira s.s. and treat the morpho-ecologically coherent entities within C. compressa at the variety rank. Accordingly, we propose the new status and combination Cystoseira compressa var. pustulata (Ercegović) D’Ambros Burchio & Falace, comb. et stat. nov. Full article

(This article belongs to the Section Plant Systematics, Taxonomy, Nomenclature and Classification)

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23 pages, 9370 KB

Open AccessArticle

Co-Application of Trichoderma harzianum and the Strigolactone Analog GR24 Enhances Wheat Tolerance to Cadmium Stress: Effects on Growth, Photosynthesis, Antioxidant Defense, and Cd Accumulation

by Xueping Su, Fangzhao Qin, Cheng Huang and Fasih Ullah Haider

Plants 2026, 15(14), 2236; https://doi.org/10.3390/plants15142236 - 22 Jul 2026

Viewed by 427

Abstract

Cadmium (Cd) contamination threatens wheat productivity by impairing growth, redox homeostasis, and metal partitioning. Beneficial fungi and phytohormones improve plant stress tolerance, but the combined role of Trichoderma harzianum and the synthetic strigolactone analog GR24 in wheat Cd tolerance remains unclear. This study [...] Read more.

Cadmium (Cd) contamination threatens wheat productivity by impairing growth, redox homeostasis, and metal partitioning. Beneficial fungi and phytohormones improve plant stress tolerance, but the combined role of Trichoderma harzianum and the synthetic strigolactone analog GR24 in wheat Cd tolerance remains unclear. This study evaluated whether co-application of T. harzianum and GR24 enhances Cd tolerance by improving growth, photosynthetic activity, and antioxidant defense, and by reducing Cd accumulation. A greenhouse pot experiment was conducted with two Cd levels (Cd₀ and Cd₁), two GR24 treatments (H₀, without GR24; H₁, 100 mg L⁻¹ GR24), and two T. harzianum treatments (TH₀ and TH₁; 2 g kg⁻¹ soil), using five biological replications. Cd stress markedly inhibited wheat growth, photosynthetic performance, and antioxidant defense while increasing oxidative injury and Cd accumulation in plant tissues. Under Cd stress, the combined GR24-T. harzianum treatment increased shoot growth and biomass by 53.04–80.43%, reduced EL, MDA, and H₂O₂ by 18.70–30.36%, enhanced SOD, POD, and CAT activities by 24.01–44.50%, and lowered Cd concentrations in roots, shoots, and leaves by 41.09–56.19%. These responses strengthen the treatment’s practical relevance. Collectively, these findings indicate that T. harzianum-GR24 co-application offers a promising biological approach to improve wheat resilience and reduce Cd accumulation in wheat tissues. Full article

(This article belongs to the Section Crop Physiology and Crop Production)

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29 pages, 5879 KB

Open AccessReview

Lathyrane Diterpenoids: Half-Century of Chemical Insights and Therapeutic Potential

by Diego Caprioglio, Daniela Imperio and Alberto Minassi

Plants 2026, 15(14), 2235; https://doi.org/10.3390/plants15142235 - 22 Jul 2026

Viewed by 548

Abstract

Despite being discovered over a century ago, lathyrane diterpenoids have only recently attracted significant attention from the organic chemistry community due to their distinctive carbon framework, characterized by a 5/11/3 tricyclic system. The conformational rigidity of these scaffolds promotes close spatial proximity between [...] Read more.

Despite being discovered over a century ago, lathyrane diterpenoids have only recently attracted significant attention from the organic chemistry community due to their distinctive carbon framework, characterized by a 5/11/3 tricyclic system. The conformational rigidity of these scaffolds promotes close spatial proximity between functional groups, making transannular reactions a powerful tool for the construction of new complex polycyclic architectures. In parallel, compounds from the genus Euphorbia have emerged as versatile molecular frameworks in medicinal chemistry, exhibiting a wide range of biological activities, including cytotoxic, antiviral, and neuroprotective effects. This review summarizes recent advances in the field, with particular emphasis on synthetic strategies, structural diversity, and medicinal chemistry aspects of this intriguing class of secondary metabolites. Full article

(This article belongs to the Special Issue Plant-Derived Natural Products: Chemistry, Synthesis and Medicinal Applications)

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22 pages, 2871 KB

Open AccessArticle

Synergistic Interactions Between Plant Growth-Promoting Bacteria and Trichoderma virens Enhance Arabidopsis Growth and Suppress Fusarium brachygibbosum

by Paulina Guzmán-Guzmán, María D. Ramírez-Ramos, Ma. del Carmen Orozco-Mosqueda, Juan Francisco Jiménez-Bremont, Paola Fincheira, Mauricio Schoebitz, Eduardo Valencia-Cantero and Gustavo Santoyo

Plants 2026, 15(14), 2234; https://doi.org/10.3390/plants15142234 - 22 Jul 2026

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Abstract

Trichoderma virens and plant growth-promoting bacteria (PGPB) are well-known agents that promote plant development and control pathogens. This study assessed the compatibility, biocontrol potential, and plant growth promotion of T. virens in combination with four PGPB strains (Pseudomonas fluorescens UM270, Rouxiella badensis [...] Read more.

Trichoderma virens and plant growth-promoting bacteria (PGPB) are well-known agents that promote plant development and control pathogens. This study assessed the compatibility, biocontrol potential, and plant growth promotion of T. virens in combination with four PGPB strains (Pseudomonas fluorescens UM270, Rouxiella badensis SER3, Bacillus velezensis AF12, and Bacillus halotolerans AF23) against Fusarium brachygibbosum and Arabidopsis thaliana. The results showed that single inoculations significantly inhibited the growth of F. brachygibbosum by the 7th day of confrontation. However, co-inoculating T. virens with PGPB exhibited synergistic effects on the inhibition percentages for the consortia Tv + UM270 (48.94%), Tv + AF12 (67.04%), and Tv + SER3 (78.63%). Plant assays demonstrated that most microorganisms enhanced root development and plant height, with UM270 having the strongest beneficial effect. Expression analysis of T. virens effector genes (sm1, tvsep3, and tvhydii1) indicated early induction of tvhydii1 in the condition of Fb + AF12 at day 3, while sm1 was downregulated. No significant changes in the expression of these genes were detected during interaction with A. thaliana and PGPB. These findings demonstrate that T. virens–PGPB can simultaneously promote plant growth and suppress pathogens, with effector genes such as tvhydii1 contributing to these interactions, highlighting their potential for sustainable agriculture. Full article

(This article belongs to the Special Issue Plant–Microorganism Interactions)

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19 pages, 2704 KB

Open AccessArticle

Phytochemical Analysis and Bioactivities of Dombeya rotundifolia and Lippia javanica

by Matsilane L. Mashilo, Mashilo M. Matotoka, Ofentse Mazimba and Peter Masoko

Plants 2026, 15(14), 2233; https://doi.org/10.3390/plants15142233 - 22 Jul 2026

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Abstract

Tuberculosis (TB) remains a major global health challenge, compounded by rising drug resistance. Traditional medicinal plants used for TB-related symptoms represent a valuable yet underexplored source of potential antimycobacterial agents. In this study, the phytochemical content and biological activities of Dombeya rotundifolia and [...] Read more.

Tuberculosis (TB) remains a major global health challenge, compounded by rising drug resistance. Traditional medicinal plants used for TB-related symptoms represent a valuable yet underexplored source of potential antimycobacterial agents. In this study, the phytochemical content and biological activities of Dombeya rotundifolia and Lippia javanica were evaluated, and antimycobacterial compounds were isolated through bioassay-guided fractionation. Plant leaves were collected, extracted with solvents of varying polarity, and screened for phenolics and flavonoids. Antioxidant activity was assessed using DPPH and ferric reducing power assays, antimycobacterial activity was tested against Mycobacterium smegmatis, anti-inflammatory activity was determined by the egg albumin denaturation method, and cytotoxicity was evaluated in THP-1 cells using the MTT assay. Extraction yields varied, with water extracts of L. javanica showing the highest yield and hexane extracts of D. rotundifolia the lowest. Both plants contained bioactive phytochemicals with measurable antioxidant activity, while acetone and dichloromethane extracts of D. rotundifolia displayed the strongest antimycobacterial activity with MIC values of 0.16 mg/mL. Cytotoxicity assays indicated moderate toxicity at higher extract concentrations. Bioassay-guided isolation led to the identification of two fatty acid fractions with tentative characterization, which showed notable antimycobacterial activity (MIC 0.25 mg/mL). These findings provide preliminary support for the ethnomedicinal use of D. rotundifolia in respiratory conditions traditionally associated with tuberculosis and suggest a potential contribution of its fatty acids to its observed antimycobacterial activity. Full article

(This article belongs to the Special Issue Medicinal Plants: Advances in Phytochemistry and Ethnobotany (3rd Edition))

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12 pages, 998 KB

Open AccessArticle

Growth Characteristics, Growing Medium Properties, and Leaf Nutrient Contents of Silene compacta Fisch. Seedlings at Two Growing Periods Under Standardized Nursery Conditions

by Selma Kösa and Sibel Mansuroğlu

Plants 2026, 15(14), 2232; https://doi.org/10.3390/plants15142232 - 22 Jul 2026

Viewed by 359

Abstract

Despite the increasing interest in Silene compacta Fisch. as a landscape plant, its greenhouse cultivation protocols remain poorly explored, leaving a critical gap in optimizing seedling production duration and efficiency. Therefore, this study aimed to compare the growth characteristics, growing medium properties, and [...] Read more.

Despite the increasing interest in Silene compacta Fisch. as a landscape plant, its greenhouse cultivation protocols remain poorly explored, leaving a critical gap in optimizing seedling production duration and efficiency. Therefore, this study aimed to compare the growth characteristics, growing medium properties, and leaf nutrient contents of S. compacta seedlings grown for two different periods (2.5 and 4.5 months) under standardized nursery conditions using a single pot type, a uniform growing medium, and a fixed fertilization program. Seedlings were grown simultaneously under greenhouse conditions, and final measurements were made at the end of each assigned growing period. Differences between the two growing periods were evaluated using independent samples t-tests based on replicate means. Several growth traits, including leaf number, leaf area, root number, stem diameter, and root and shoot biomass, were significantly higher at 4.5 months than at 2.5 months, whereas plant height, plant width, lateral branching traits, leaf dimensions, and root length did not differ significantly between the two periods. In the growing medium, pH was higher at 4.5 months, whereas total nitrogen and several micronutrients were higher at 2.5 months. Leaf N, P, K, Mn, and Cu concentrations were also higher at 2.5 months, whereas leaf Ca concentration was higher at 4.5 months. Overall, the results indicate that the 2.5-month growing period provided sufficient seedling development within a shorter production time and may offer significant economic and practical advantages in terms of compact appearance, lower input requirement, and earlier saleable seedling production under the nursery conditions tested. Full article

(This article belongs to the Section Horticultural Science and Ornamental Plants)

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10 pages, 7823 KB

Open AccessArticle

The STOP1-MATE-Citrate Axis Confers Inorganic Sn Tolerance in Plants

by Zixuan Zhao, Ting He, Yi Fan, Hongxia Chang, Zhixuan Du, Longfei Zhu and Guanping Feng

Plants 2026, 15(14), 2231; https://doi.org/10.3390/plants15142231 - 22 Jul 2026

Viewed by 337

Abstract

Inorganic tin (Sn) is an emerging pollutant whose phytotoxicity and plant detoxification mechanisms remain poorly understood. Here, we demonstrate that inorganic Sn severely inhibits root growth and triggers ROS accumulation in Lemna minor and Arabidopsis. We identified the transcription factor STOP1 as a [...] Read more.

Inorganic tin (Sn) is an emerging pollutant whose phytotoxicity and plant detoxification mechanisms remain poorly understood. Here, we demonstrate that inorganic Sn severely inhibits root growth and triggers ROS accumulation in Lemna minor and Arabidopsis. We identified the transcription factor STOP1 as a critical regulator of Sn tolerance. Mechanistically, STOP1 confers Sn tolerance primarily by activating the citrate transporter MATE, contrasting sharply with Al tolerance which relies heavily on the malate transporter ALMT1. Inorganic Sn stress strongly induced root citrate exudation, and the mate mutant displayed severe Sn hypersensitivity. Exogenous citrate application effectively rescued root growth by impeding Sn uptake and attenuating ROS overaccumulation. Our study reveals that the STOP1-MATE-citrate axis constitutes a pivotal detoxification mechanism against inorganic Sn, providing novel insights into how plants adapt to heavy metal stress through distinct organic acid secretion pathways. Full article

(This article belongs to the Section Plant Response to Abiotic Stress and Climate Change)

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21 pages, 6356 KB

Open AccessArticle

Is Early Tobacco–Rice Rotation Associated with Soil Nutrient Legacy and Shifts in Bacterial Ecological Potential in a Subtropical Paddy System?

by Xiang-Bin Yao, Yong-Yu Liang, Ya-Jun Cheng, Chun-Yan Li, Jie-Yu-Xin Kang and Jian-Ying Qi

Plants 2026, 15(14), 2230; https://doi.org/10.3390/plants15142230 - 21 Jul 2026

Viewed by 371

Abstract

In subtropical double-rice regions, replacing early-season rice with tobacco may alter the soil environment inherited by subsequent paddy cultivation. We conducted a one-year field experiment in 2023 to compare rice–rice (RR) and tobacco–rice (TR) pathways. Soils from the 0–10 and 10–20 cm layers [...] Read more.

In subtropical double-rice regions, replacing early-season rice with tobacco may alter the soil environment inherited by subsequent paddy cultivation. We conducted a one-year field experiment in 2023 to compare rice–rice (RR) and tobacco–rice (TR) pathways. Soils from the 0–10 and 10–20 cm layers were sampled during the early-season pathway-differentiation period and the late-season rice-growing period, and soil properties, bacterial 16S rRNA communities, predicted functional profiles, and rice agronomic traits were analyzed. Relative to RR, TR was associated with 4.12% lower grain yield but 5.10% higher 1000-grain weight and 23.74% higher aboveground dry matter, indicating altered yield formation rather than uniform growth suppression. TR was also associated with lower soil organic carbon (SOC), total nitrogen (TN), alkali-hydrolyzable nitrogen (AN), and available phosphorus (AP). Bacterial communities differed between pathways, with stronger Chloroflexi/Actinobacteriota and 16S-predicted aerobic, stress-tolerant, and chemoheterotrophic signals under TR. Together, these findings indicate that early TR was associated with lower measured C-, N-, and P-related soil pools, bacterial community reorganization, and altered late-season rice yield formation; therefore, nutrient and residue management should be planned across the tobacco–rice year rather than only during the rice season. Full article

(This article belongs to the Special Issue Agricultural Soil Management for Crop Cultivation and Productivity)

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21 pages, 1824 KB

Open AccessArticle

Phytochemical Characterization and High-Speed Countercurrent Chromatography-Assisted Isolation of Flavonoids from Leaves of Talisia esculenta Radlk

by Katia Castanho Scortecci, Letícia Barbosa Santos, Luís Felipe Costa Gatis, Verônica Giuliani de Queiroz Aquino-Martins, Nathalia Maira Cabral de Medeiros, Wirginia Kukula-Koch, Sarah Stiegeler, Garance Coquant, Fabio Boylan and Sinéad C. Corr

Plants 2026, 15(14), 2229; https://doi.org/10.3390/plants15142229 - 21 Jul 2026

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Abstract

Talisia esculenta Radlk (Sapindaceae) is a tropical tree species native to Brazil, whose leaves are traditionally consumed as herbal infusions. However, the secondary metabolite composition of its foliage remains poorly characterised. In this study, the phytochemical profile of T. esculenta leaf infusions was [...] Read more.

Talisia esculenta Radlk (Sapindaceae) is a tropical tree species native to Brazil, whose leaves are traditionally consumed as herbal infusions. However, the secondary metabolite composition of its foliage remains poorly characterised. In this study, the phytochemical profile of T. esculenta leaf infusions was investigated using HPLC–ESI–QTOF–MS/MS, leading to the annotation of 20 compounds. Subsequent liquid–liquid partitioning and high-speed counter-current chromatography (HSCCC) enabled the targeted isolation of two major constituents. The analysis revealed a flavonoid-rich profile dominated by glycosylated flavonols, with rutin and quercitrin identified as the principal compounds and structurally confirmed by NMR spectroscopy. They were both quantified in the aqueous infusion of the leaves, being 1.42 ± 0.02% (w/w) and 1.54 ± 0.01% (w/w) for rutin and quercitrin, respectively. The metabolite pattern found is consistent with that reported in other members of the Sapindaceae family and contributes to the chemotaxonomic characterisation of the genus. Fractionation enhanced the enrichment of phenolic constituents and allowed assessment of their functional properties such as antioxidant activity (including DPPH assay: from 43.4% for the aqueous infusion to 92.9% for the ethyl acetate fraction) and inhibition of microbial biofilm formation (from 37.4% for the aqueous infusion to 83.4% for the butanolic fraction at 6.25 µg/mL against Staphylococcus aureus). The MIC and MBC were also calculated for the aqueous infusion (12.5 mg/mL for both), its partitions as well as rutin and quercitrin. Anti-inflammatory effects were also observed, with inhibition of NF-κB activity reaching 56.9% for the aqueous infusion and 47.7% for the butanolic fraction. These findings expand current knowledge of secondary metabolite diversity in T. esculenta and demonstrate the applicability of HSCCC as an efficient technique for flavonoid isolation from complex plant extracts. Overall, this study provides new insights into the phytochemical composition of an underexplored tropical species within the Sapindaceae family. Full article

(This article belongs to the Special Issue Botanical, Chemical, Pharmacological, and Potential Health Benefits of Plants)

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24 pages, 9972 KB

Open AccessArticle

Pine-Extracted Volatile Oils Suppress Root Rot in Psammosilene tunicoides Through Direct Antifungal Activity and Rhizosphere Microbiome Modulation

by Li-Juan Wang, Fei Ji, Shu-Yun Qi, Qiao-Feng Li, Min Zhao, Chun-Ju Xu, Ying-Tao Li and Ai-Li Zhang

Plants 2026, 15(14), 2228; https://doi.org/10.3390/plants15142228 - 21 Jul 2026

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Abstract

Frequent outbreaks of root rot in Psammosilene tunicoides W. C. Wu & C. Y. Wu severely compromise the quality of its medicinal materials and hinder its large-scale cultivation. Interestingly, wild P. tunicoides growing under pine trees rarely experience this disease. To explore the [...] Read more.

Frequent outbreaks of root rot in Psammosilene tunicoides W. C. Wu & C. Y. Wu severely compromise the quality of its medicinal materials and hinder its large-scale cultivation. Interestingly, wild P. tunicoides growing under pine trees rarely experience this disease. To explore the potential basis of root rot suppression, we evaluated the direct antifungal activity of pine-derived volatile oils and the associated changes in the rhizosphere microbiome. GC-MS showed that pine turpentine was dominated by α-pinene (45.50%) and longifolene (28.20%). In vitro assays confirmed its highly efficient inhibition (81.65–94.71%) against major root rot pathogens in P. tunicoides. Beyond direct antifungal effects, metagenomic analysis indicated that volatile oil (SYR) treatment was associated with shifts in the rhizosphere microbiome, including increased relative abundances of potentially beneficial taxa, such as Paenibacillus, Trichoderma, and Geosiphon. Pine volatiles might be associated with shifts in the rhizosphere microbial community of P. tunicoides, potentially involving plant-mediated changes in root exudation and the enrichment of certain beneficial microbes. However, it remains to be further elucidated regarding the specific mechanisms underlying these community changes. Functional prediction of the microbial community suggested a predominance of metabolic pathways, secondary metabolite biosynthesis, and flagellar assembly in the SYR group. Conclusively, pine volatiles may contribute to root rot suppression through two potential processes: direct pathogen inhibition and beneficial microbiome enrichment. This study provides a theoretical basis for establishing sustainable agroforestry co-planting systems for P. tunicoides. Full article

(This article belongs to the Section Plant Protection and Biotic Interactions)

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27 pages, 8802 KB

Open AccessReview

Research Progress on Preparation, Transformation and Application of Protoplasts Derived from Medicinal Plants

by Zijin Fang, Yanheng Hu, Zijing Zhou, Huijie Ma, Lingxiao Zhang, Yuting Peng, Xiaori Zhan, Yiming Sun and Chenjia Shen

Plants 2026, 15(14), 2227; https://doi.org/10.3390/plants15142227 - 21 Jul 2026

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Abstract

As unicellular systems, protoplasts derived from medicinal plant cells exhibit high totipotency and hold significant value in applications such as gene function analysis, genetic improvement, and cell engineering optimization. This review focuses on how protoplast technology addresses longstanding bottlenecks in medicinal plant research [...] Read more.

As unicellular systems, protoplasts derived from medicinal plant cells exhibit high totipotency and hold significant value in applications such as gene function analysis, genetic improvement, and cell engineering optimization. This review focuses on how protoplast technology addresses longstanding bottlenecks in medicinal plant research by systematically collating recent advances in the study of medicinal plant protoplasts. It explores the multifaceted factors influencing protoplast preparation, including the intrinsic and extrinsic properties of medicinal plant materials, pretreatment methods prior to enzymatic hydrolysis, the composition of enzymatic solutions, enzymatic hydrolysis parameters, external environmental conditions, and protoplast purification techniques. Additionally, the review summarizes the significance and value of medicinal plant protoplasts in gene function verification, gene editing, genetic transformation, single-cell sequencing, and cell fusion regulation. By comprehensively synthesizing the optimization of the preparation of medicinal plant protoplasts and their application in transient expression, gene function research, and plant regeneration, this work aims to provide critical guidance for subsequent research in genetic modification, germplasm resource breeding, spatiotemporal programming of active substances, and regulatory network analysis. Ultimately, it serves as a valuable reference for advancing research in the plant sciences. Full article

(This article belongs to the Topic New Trends and Innovations in Medicinal and Aromatic Plants, and Specialty Crops, 2nd Edition)

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15 pages, 5569 KB

Open AccessArticle

Early Dynamics of Zinc-Based Nanofertilizer Absorption in Plants of Glycine max L. (Fabaceae): Short-Term Ultrastructural and Functional Changes and Subcellular Localization

by Emilio de Castro Miguel, Sergimar Kennedy de Paiva Pinheiro, Alex Natã Bazzanezi, Karlos Eduardo Pianoski, Bruno Sousa Araújo, Barbara M. Santos, Michele A. S. Nobrega, Gilberto J. Arruda, Etenaldo F. Santiago, Montcharles S. Pontes and Thaiz Batista Azevedo Rangel Miguel

Plants 2026, 15(14), 2226; https://doi.org/10.3390/plants15142226 - 21 Jul 2026

Viewed by 420

Abstract

This study investigated the initial absorption dynamics and ultrastructural responses of soybean leaf tissue to foliar application of zinc-based (Zn²⁺) nanofertilizer, using brightfield light microscopy, electron scanning and transmission microscopy (SEM and TEM), and Raman spectroscopy. Anatomically, no relevant structural changes [...] Read more.

This study investigated the initial absorption dynamics and ultrastructural responses of soybean leaf tissue to foliar application of zinc-based (Zn²⁺) nanofertilizer, using brightfield light microscopy, electron scanning and transmission microscopy (SEM and TEM), and Raman spectroscopy. Anatomically, no relevant structural changes were detected in the roots or stems in any of the treatments. However, leaves treated with ionic Zn²⁺ (T1) exhibited thickening of the palisade parenchyma with Zn²⁺ accumulation in the adaxial epidermis. Samples treated with T2 and T3 revealed epidermal precipitates and intracellular deposits within leaf cells, as evidenced by brightfield optical microscopy and Raman spectroscopy. These aggregates were absorbed and subsequently dissolved, being no longer observed at the 30 min time point. Ultrastructural analysis confirmed the presence of nanofertilizers within the vacuoles and cytoplasm, suggesting absorption and translocation of Zn²⁺, reinforcing the ability of nano-enabled materials to overcome biological barriers. Our results indicate that zinc-based (Zn²⁺) nanofertilizers can alter cellular features without evident short-term phytotoxicity. Theoretically, this study provides mechanistic insights into nanoparticle dissolution dynamics, biological barrier penetration, and subcellular compartmentalization pathways in crop plants. From an applied perspective, the rapid absorption (<30 min) and preferential organelle targeting suggest potential for precision nutrient delivery systems, though long-term and efficacy evaluations are required before agricultural deployment can be recommended. Full article

(This article belongs to the Special Issue Microscopy Techniques in Plant Studies—2nd Edition)

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30 pages, 7173 KB

Open AccessReview

Degradation and Regeneration of Soil Structure in Intensified Paddy Fields: Plant–Soil Interactions, Ecological Effects, and Restoration Pathways

by Meng Fang, Jiahao Shen, Gan Liu, Chirui Zhang and Zhong Tang

Plants 2026, 15(14), 2225; https://doi.org/10.3390/plants15142225 - 21 Jul 2026

Viewed by 366

Abstract

Intensified paddy production plays a crucial role in sustaining rice productivity and food security; however, long-term high-frequency puddling, heavy machinery operations under wet soil conditions, simplified cropping systems, and insufficient organic matter inputs have progressively degraded the physical structure of paddy soils. Such [...] Read more.

Intensified paddy production plays a crucial role in sustaining rice productivity and food security; however, long-term high-frequency puddling, heavy machinery operations under wet soil conditions, simplified cropping systems, and insufficient organic matter inputs have progressively degraded the physical structure of paddy soils. Such structural degradation not only weakens soil water movement, nutrient supply, and aeration but also restricts rice root penetration, alters rhizosphere processes, and disrupts plant–soil feedbacks. Previous studies have largely focused on individual aspects such as soil compaction, amendment-based improvement, water management, or root responses, whereas an integrated understanding of the multi-source drivers, functional consequences, and restoration pathways of soil structural degradation in intensified paddy fields remains limited. Following the overarching theme of soil degradation and regeneration, this review systematically synthesizes the indicator framework, formation mechanisms, degradation typology, ecological consequences, and regulation strategies of paddy soil structural degradation. We further clarify the transition of degraded paddy soils from single physical constraints to the coupled decline of physical, chemical, and biological functions, and compare the agronomic performance, environmental implications, implementation feasibility, and trade-offs of different restoration pathways. Existing evidence indicates that soil structural degradation in paddy fields can impair root-zone pore connectivity, rhizosphere oxygen supply, nutrient acquisition, microbial-mediated carbon and nitrogen cycling, and greenhouse gas regulation, thereby affecting rice growth, yield stability, and the ecological sustainability of paddy systems. Accordingly, the restoration of degraded paddy soils should move beyond short-term loosening or single-factor amendment toward integrated regeneration strategies that maintain soil structural health, reconstruct plough-layer functions, enhance root–soil interactions, and promote the synergistic recovery of pore networks, aggregates, organic carbon, and microbial processes. This review provides a theoretical basis and research reference for the precise restoration of soil structural constraints and the sustainable management of plant–soil systems in intensified paddy fields. Full article

(This article belongs to the Section Plant–Soil Interactions)

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20 pages, 23720 KB

Open AccessArticle

Identification of the SET Family and Key Role of ZmSET9 in Drought Tolerance in Maize (Zea mays)

by Huixin Zhang, Xinyu Wang, Zhengyu Wei, Xueyu Cui, Yujiao Peng, Baoqing Hu, Xiaoyu Zhang and Fulei Mo

Plants 2026, 15(14), 2224; https://doi.org/10.3390/plants15142224 - 21 Jul 2026

Viewed by 447

Abstract

Maize (Zea mays L.) productivity is severely constrained by drought stress. Although the maize SET domain-containing gene family has previously been investigated, the earlier analysis was based on the incomplete B73 RefGen_v2 genome assembly, and the drought-responsive functions of individual ZmSET members [...] Read more.

Maize (Zea mays L.) productivity is severely constrained by drought stress. Although the maize SET domain-containing gene family has previously been investigated, the earlier analysis was based on the incomplete B73 RefGen_v2 genome assembly, and the drought-responsive functions of individual ZmSET members remain largely uncharacterized. In this study, 47 ZmSET genes were identified using the updated B73 RefGen_v5 genome and systematically analyzed for their physicochemical properties, chromosomal distribution, gene structures, conserved motifs, and promoter cis-acting elements. The ZmSET family exhibited substantial evolutionary conservation, while its promoters contained numerous stress- and hormone-responsive elements. Transcriptome analysis identified ZmSET9 as a drought-responsive gene, and RT-qPCR showed that it maintained relatively high expression throughout drought treatment. Heterologous overexpression of ZmSET9 in Arabidopsis thaliana enhanced drought tolerance and supported plant growth under drought stress. Compared with wild type plants, the transgenic lines exhibited higher superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activities and lower malondialdehyde (MDA) contents, indicating enhanced antioxidant capacity and reduced membrane lipid peroxidation. Under PEG induced osmotic stress, AtCAT1 and AtMYC2 were more strongly induced in the transgenic lines. Protein–protein interaction prediction and yeast two-hybrid assays further demonstrated that ZmSET9 physically interacts with FERTILIZATION-INDEPENDENT ENDOSPERM 1 (FIE1), a core component of Polycomb repressive complex 2. These findings update the genomic characterization of the maize SET family and suggest that ZmSET9 contributes to drought tolerance by enhancing antioxidant defense and regulating stress-responsive gene expression. Full article

(This article belongs to the Special Issue Molecular Regulation of Maize Abiotic Stress Resilience)

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18 pages, 2287 KB

Open AccessArticle

Antisense Oligonucleotides as a Gene-Silencing Strategy Regulating Cytosolic G6PDH in Hordeum vulgare

by Antonella Aquilone, Maryanna Martina Perrotta, Simone Landi and Sergio Esposito

Plants 2026, 15(14), 2223; https://doi.org/10.3390/plants15142223 - 21 Jul 2026

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Abstract

Antisense oligonucleotides (ASOs) are short, synthetic DNA fragments able to modulate gene expression. In this work, the cytosolic isoform of glucose-6-phosphate dehydrogenase (Cyt-G6PDH) was selected as a target for ASOs to induce transient gene silencing in barley (Hordeum vulgare). G6PDH is [...] Read more.

Antisense oligonucleotides (ASOs) are short, synthetic DNA fragments able to modulate gene expression. In this work, the cytosolic isoform of glucose-6-phosphate dehydrogenase (Cyt-G6PDH) was selected as a target for ASOs to induce transient gene silencing in barley (Hordeum vulgare). G6PDH is the most important enzyme of the oxidative pentose phosphate pathway (OPPP), supplying NADPH and regulating the entire cycle. Different ASOs were tested at different concentrations on the leaf surface. Their effects were evaluated by measuring enzymatic activity, gene expression, and protein abundance. Treatment with 30 µM ASOs for 6 h represented the optimal condition, inducing a 40–60% reduction in G6PDH total activity in barley leaves, with a specific decrease in the cytosolic isoform, as determined by DTT-sensitive enzymatic assays. ASOs designed on the main regulator of cyt-G6PDH, the shaggy-like kinase (SK11), led to an analogous effect in terms of G6PDH activity, confirming the involvement of HvSK11 in the regulation of cyt-G6PDH in barley. Consistently, qRT-PCR analyses showed that ASO treatment simulates an abiotic stress condition obtained by the down-regulation of Cyt-G6PDH. These results support the use of ASOs as a rapid and efficient method for the functional analysis of key metabolic regulators in plants to overcome complications in recalcitrant organisms or lethal genes. Full article

(This article belongs to the Special Issue Resilient Plants and Algae: New Environmental Challenges and Innovative Technological Approaches)

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19 pages, 12405 KB

Open AccessArticle

Functional Analysis of the GH16 Domain-Containing XTH2 Homologs in Mediating Sunflower Response to Orobanche cumana Parasitism

by Yannan Li, Ruonan Yu, Rui Xu, Hada Wuriyanghan and Fang Yan

Plants 2026, 15(14), 2222; https://doi.org/10.3390/plants15142222 - 21 Jul 2026

Viewed by 325

Abstract

Sunflower (Helianthus annuus) is highly susceptible to infection by the root parasitic plant Orobanche cumana during its growth. In establishing connections with the sunflower root system, O. cumana induces the hydrolysis and remodeling of the host cell wall. Xyloglucan endotransglucosylase/hydrolase (XTH), [...] Read more.

Sunflower (Helianthus annuus) is highly susceptible to infection by the root parasitic plant Orobanche cumana during its growth. In establishing connections with the sunflower root system, O. cumana induces the hydrolysis and remodeling of the host cell wall. Xyloglucan endotransglucosylase/hydrolase (XTH), a member of glycoside hydrolase family 16 (GH16), is a key enzyme involved in the hydrolysis and synthesis of xyloglucan, playing a critical role in cell wall modification and reconstruction. However, the involvement of XTH families in the interaction between sunflower and O. cumana remains unclear. In this study, we showed that the expression level of HaXTH2 was upregulated in sunflowers following O. cumana infection. Overexpression of HaXTH2 loosens host primary cell walls and represses lignin-based defense responses at the early infection stage, thereby facilitating haustorial penetration across cortical tissues and xylem bridge formation to support normal parasitism of O. cumana. Functional analysis revealed that HaXTH2 and its homolog, HaXTH2-1, facilitate O. cumana infection, whereas OcXTH2, an O. cumana homolog, suppresses this process. Furthermore, HaXTH2, HaXTH2-1, and OcXTH2 are localized to the cell wall. Domain truncation analysis revealed that the GH16 domain alone from HaXTH2 and HaXTH2-1 enhance parasitic susceptibility, while the xyloglucan endotransglycosylase C-terminal domain (XET_C) domain does not. Mutation analysis identified Y20 in HaXTH2 and H96 in HaXTH2-1 as key amino acid sites regulating O. cumana parasitism. This study expands our understanding of the functions of XTHs in plant–plant interactions and provides a theoretical basis for further development of O. cumana-resistant sunflower cultivars. Full article

(This article belongs to the Section Plant Molecular Biology)

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49 pages, 1078 KB

Open AccessArticle

The Ethnobotanical Heritage of Olea europaea L. in Italy: Continuity of a Millenary Mediterranean Tradition

by Rosalucia Mazzei, Luca Lombardo, Samanta Zelasco, Marianna Rizzo and Giuseppe Tagarelli

Plants 2026, 15(14), 2221; https://doi.org/10.3390/plants15142221 - 21 Jul 2026

Viewed by 478

Abstract

The olive tree (Olea europaea L.) is a quintessential symbol of the Mediterranean basin, representing a profound intersection of ecological adaptation, agricultural evolution, and cultural identity. Italy, where the olive has shaped dietary habits, traditional medicine, folklore, and landscape from prehistory to [...] Read more.

The olive tree (Olea europaea L.) is a quintessential symbol of the Mediterranean basin, representing a profound intersection of ecological adaptation, agricultural evolution, and cultural identity. Italy, where the olive has shaped dietary habits, traditional medicine, folklore, and landscape from prehistory to the present, serves as a primary macro-region for studying the co-evolution of human societies and this iconic plant. In this vein, this paper examines the ethnobotanical trajectory of O. europaea on the Italian peninsula through an analysis of traditional knowledge concerning its medicinal and ritual uses, reported in ethnographic literature dating from the second half of the 19th century to the first half of the 20th century. In addition, we conducted a review of Italian ethnobotanical fieldwork published between 2000 and 2025. Accordingly, olive leaves (used as antihypertensives, febrifuges, hypoglycemic and apotropaic agents), bark and roots (to treat various pathologies) and oil (in rituals for spiritual healing and against evil eye, as an emollient for dermatological pathological and cosmetical conditions and as a vehicle for infusing other therapeutic herbs) have found a central place in the Italian popular pharmacopeia and magic-religious practices. The roots of these traditions have been contextualized within a wider Mediterranean oleo-culture rising from the second millennium BCE. By identifying knowledge gaps, documenting regional ethnobotanical diversity, and connecting historical and contemporary evidence, this work provides a novel framework for future comparative ethnobotanical research. Eventually, a discussion on how contemporary Italy is reframing this botanical legacy through the lenses of agrobiodiversity conservation and the safeguarding of historical rural landscapes against modern threats such as climate change and phytosanitary crises is presented. Full article

(This article belongs to the Special Issue Ethnobotany and Botany in the Euro-Mediterranean Region)

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23 pages, 27228 KB

Open AccessArticle

Co-Overexpression of Geissoschizine Synthase and Catharanthine Synthase Increases Catharanthine Biosynthesis in Catharanthus roseus Hairy Roots

by Xiaohua Li, Gongqiang Li, Zhiwei Hu, Jiacheng Wang, Yang Chen, Kunhong Zhu, Zichen Huang, Mingyu Wang and Jiayi Sun

Plants 2026, 15(14), 2220; https://doi.org/10.3390/plants15142220 - 21 Jul 2026

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Abstract

Plant-based platforms remain vital for producing anticancer vinca alkaloids. However, one major challenge in plant-based metabolic engineering is that target metabolite yields are often hindered by the presence of multiple competing pathway branches that disperse metabolic flux. To overcome these bottlenecks, we first [...] Read more.

Plant-based platforms remain vital for producing anticancer vinca alkaloids. However, one major challenge in plant-based metabolic engineering is that target metabolite yields are often hindered by the presence of multiple competing pathway branches that disperse metabolic flux. To overcome these bottlenecks, we first implemented a competitive branch-point diversion strategy by co-overexpressing geissoschizine synthase and catharanthine synthase under an inducible promoter in Catharanthus roseus hairy roots. This targeted intervention successfully shifted metabolic partitioning, driving a peak relative increase of 67% in catharanthine accumulation at the 96 h time point, while significantly reducing competing by-products such as ajmalicine, serpentine, and tabersonine. Targeted qPCR analysis revealed a transient upregulation of core monoterpene indole alkaloid biosynthetic genes and a coordinated suppression of some competing branch genes. Despite this effective downstream diversion, overall yield enhancement was constrained by tight regulation, notably the downregulation of BIS transcriptional activators, which restricts the supply of upstream terpenoid precursors. Furthermore, untargeted metabolomic profiling highlighted a widespread metabolic shifts featuring the significant enrichment of phenylalanine-derived secondary pathways. Ultimately, this study demonstrates the efficacy of competitive branch-point diversion for target alkaloid enrichment, while highlighting the complex regulatory dynamics and broad metabolic alterations within the C. roseus network. Full article

(This article belongs to the Section Plant Physiology and Metabolism)

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15 pages, 4395 KB

Open AccessArticle

Climate and Soil Constraints Shape Vegetation-Zone-Dependent Leaf C:N:P Stoichiometry of Quercus variabilis

by Yanqi Yuan, Kaixi Chen, Xue Wang, Xinrui Liu, Zemeng Ma, Shuoxin Zhang, Fan Hao and Zhouping Shangguan

Plants 2026, 15(14), 2219; https://doi.org/10.3390/plants15142219 - 21 Jul 2026

Viewed by 291

Abstract

Leaf C:N:P stoichiometry provides a functional link between plant nutrient composition and environmental adaptation. However, whether widely distributed tree species maintain consistent leaf stoichiometric patterns across contrasting vegetation zones remains unclear. Here, we investigated the leaf C:N:P stoichiometry of Quercus variabilis, a [...] Read more.

Leaf C:N:P stoichiometry provides a functional link between plant nutrient composition and environmental adaptation. However, whether widely distributed tree species maintain consistent leaf stoichiometric patterns across contrasting vegetation zones remains unclear. Here, we investigated the leaf C:N:P stoichiometry of Quercus variabilis, a widely distributed tree species in China, across the subtropical evergreen broad-leaved forest zone (SEF) and the warm-temperate deciduous broad-leaved forest zone (WDF). We aimed to clarify between-zone differences in leaf stoichiometric traits and the role of climate and soil constraints in shaping vegetation-zone-dependent stoichiometric variation. Our results showed that leaf C:N:P stoichiometry of Q. variabilis differed between the SEF and WDF, with significant differences detected only for leaf N and leaf C:N. Overall, leaf C varied little across zones (CV = 3.13–3.42%), leaf N and leaf C:N showed moderate variation (CV = 10.07–13.26%), whereas leaf P, leaf C:P, and leaf N:P showed greater variability (CV = 33.28–39.93%). Environmental analyses further indicated contrasting patterns between zones: leaf stoichiometry in the SEF was jointly associated with climate and soil factors and showed a positive leaf C–N relationship, whereas that in the WDF showed a stronger soil association and a negative leaf N–P relationship. These findings suggest that Q. variabilis may adjust its leaf stoichiometry in a zone-dependent manner in response to contrasting climate and soil conditions. This study provides a theoretical basis for understanding nutrient-use strategies and environmental adaptation of widely distributed tree species under heterogeneous climate and soil conditions. Full article

(This article belongs to the Section Plant Nutrition)

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24 pages, 4710 KB

Open AccessArticle

Comprehensive Analysis of Annexin Family from Tetragonia tetragonoides and Its Initial Functions in Abiotic Stress Responses

by Lihua Chen, Fuying Xie, Shuguang Jian, Zhengfeng Wang, Tingyao Li and Mei Zhang

Plants 2026, 15(14), 2218; https://doi.org/10.3390/plants15142218 - 21 Jul 2026

Viewed by 389

Abstract

Tetragonia tetragonoides is a valuable medicinal and nutritional wild plant and a typical tropical euhalophyte, exhibiting strong tolerance to salinity, alkalinity, drought, and heat. Plant annexins play critical roles in plant growth, development, and stress responses; however, the characteristics and stress-responsive patterns of [...] Read more.

Tetragonia tetragonoides is a valuable medicinal and nutritional wild plant and a typical tropical euhalophyte, exhibiting strong tolerance to salinity, alkalinity, drought, and heat. Plant annexins play critical roles in plant growth, development, and stress responses; however, the characteristics and stress-responsive patterns of the annexin (TtAnn) gene family in T. tetragonoides remain largely unclear. This study aimed to systematically characterize the TtAnn family and explore its functions in abiotic stress tolerance. A total of 15 TtAnn members were identified at the genome-wide level, followed by phylogenetic classification, chromosomal distribution analysis, duplication pattern characterization, cis-acting element prediction, and organ-specific as well as stress-induced expression profiling. Five TtAnn genes were further cloned and heterologously expressed in yeast for stress tolerance validation. The 15 TtAnns were classified into four subgroups and unevenly distributed across nine chromosomes, with whole-genome duplication serving as the predominant mechanism driving gene expansion. Their promoter regions contained multiple cis-elements related to light, hormones, and transcription factors. TtAnns exhibited root-preferential expression and showed distinct differential expression patterns under salt, alkali, osmotic, and heat stresses. Transgenic yeast assays further confirmed their roles in stress resistance. This study elucidates the fundamental features of the TtAnn family and provides valuable gene resources and a theoretical basis for dissecting abiotic stress mechanisms and genetically improving stress-tolerant crops. Full article

(This article belongs to the Special Issue ‘Omics’ and ‘Multi-Omics’ Insights into Plant Responses to Abiotic Stresses (2nd Edition))

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21 pages, 661 KB

Open AccessArticle

Effects of N Application Rates and Ratios on Photosynthetic Characteristics and Dry Matter Production of Different Rice Varieties

by Jinghong Ji, Jingfang Xue, Xingzhu Ma, Yongsheng Cai, Shuangquan Liu, Xiaoyu Hao, Yu Zheng, Yue Zhao, Yuqi Xia and Shuqiang Chen

Plants 2026, 15(14), 2217; https://doi.org/10.3390/plants15142217 - 21 Jul 2026

Viewed by 284

Abstract

Nitrogen (N) fertilizer regulates leaf photosynthesis and dry matter production in rice, and extensive genotypic differences in N responsiveness exist among cold-region japonica rice cultivars. A two-year field experiment was conducted in the city of Jiamusi, Heilongjiang Province, during 2023–2024, using two representative [...] Read more.

Nitrogen (N) fertilizer regulates leaf photosynthesis and dry matter production in rice, and extensive genotypic differences in N responsiveness exist among cold-region japonica rice cultivars. A two-year field experiment was conducted in the city of Jiamusi, Heilongjiang Province, during 2023–2024, using two representative japonica cultivars: the small-panicle cultivar Longjing 47 (LJ47) and the large-panicle cultivar Longjing 3010 (LJ3010). A split-plot design was adopted with four N application rates (0, 110, 138, and 166 kg N·ha⁻¹) and four basal–tiller to panicle–grain N ratios (10:0, 8:2, 7:3, and 6:4). The results showed that increasing N supply significantly enhanced SPAD values, photosynthetic capacity, leaf area index, and total dry matter accumulation in both cultivars. LJ47 maintained high photosynthetic capacity under moderate N supply, whereas LJ3010 required higher N input to sustain superior photosynthetic performance. From heading to maturity, dry matter accumulation, photosynthetic potential, crop growth rate, net assimilation rate, N uptake, and grain yield all increased with an increasing ratio of panicle–grain N fertilizer, with more pronounced improvements observed in LJ3010. LJ47 achieved optimal physiological performance and grain yield at 138 kg N·ha⁻¹ (moderate N), with no further promotion under high-N supply. In contrast, LJ3010 required 166 kg N·ha⁻¹ (high-N) to maintain photosynthetic advantages and achieve higher grain yield in the late growth stage. Increasing the proportion of basal–tiller N fertilizer favored the source sink balance of LJ47, while increasing panicle–grain topdressing delayed leaf senescence and promoted post-heading dry matter translocation in LJ3010. For a target grain yield of 9 t·ha⁻¹, the recommended N rate is 138 kg·ha⁻¹ with a basal–tiller to panicle–grain N ratio of 8:2–7:3 for LJ47, and 166 kg·ha⁻¹ with a ratio of 7:3–6:4 for LJ3010. This study provides a theoretical basis and data reference for the formulation of precise N fertilization strategies that match fertilizer management with rice cultivar characteristics in cold regions. Full article

(This article belongs to the Section Crop Physiology and Crop Production)

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Open AccessArticle

Water Content Variation Patterns of Fruits During Development and Their Effects on Fleshiness or Dryness for Fruits at Maturity

by Shunli Yu, Canran Liu, Hui Liu, Xiuli Gao, Chang’en Shang and Carol C. Baskin

Plants 2026, 15(14), 2216; https://doi.org/10.3390/plants15142216 - 21 Jul 2026

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Abstract

The ecological origins of diverse fruit types remain unresolved due to lack of knowledge about variation patterns in fruit water content during fruit development and after fruit maturity. We hypothesized that distinctive water content variation patterns during fruit development mainly determine fleshiness or [...] Read more.

The ecological origins of diverse fruit types remain unresolved due to lack of knowledge about variation patterns in fruit water content during fruit development and after fruit maturity. We hypothesized that distinctive water content variation patterns during fruit development mainly determine fleshiness or dryness of fruits at maturity. Controlled water evaporation experiment of fruits of 188 species (belonging to 144 genera and 72 families) was conducted to measure fruit drying days and water content. A phylogenetic tree was built for 29,760 seed plants of China using the R package V.PhyloMaker2 and phylogenetic generalized linear models and Pearson correlation analysis were used to explore the variation patterns of drying days of various fruit types and their mechanism. Water content in dry fruits decreases gradually during fruit development (i.e., prior to maturity, and before dehiscent fruits split), while water content in fleshy fruits (berries, at least the pericarp of drupes and rosehips) increases slightly or remains constant during fruit development. Significant correlations were found between fruit drying period and fruit height, surface area and fruit size. In general, the development of dryness for dry fruits at maturity is primarily attributed to declining fruit water content due to pericarp lignification and consequent fast water loss. Also, possible water imbalance between supply and loss especially for elongated or flaky dry fruits due to allometric growth between pedicel diameter (or fruit mass) and fruit surface area helps account for fruit dryness. Development of dry fruits may be induced by cold, dry and open habitats with strong light. Conversely, fleshiness of mature fleshy fruits is attributed to slow pericarp water loss rate due to low cuticle permeability and high fruit thickness, combined with stable high-water content maintained during fruit development. The evolution of fleshy fruits was induced by warm and humid habitats with weak or possibly strong light. Full article

(This article belongs to the Section Plant Physiology and Metabolism)

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Plants, Volume 15, Issue 14 (July-2 2026) – 142 articles

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