Plants

16 pages, 7963 KB

Open AccessArticle

Combining Ability and Hybrid Performance of Cowpea Landraces Under Semiarid Conditions

by Maria Joelma da Silva, Samandra Silva de Lima, Mateus de Souza Silva, Vitor Emanuel Conrado da Silva, Taís Borges da Silva, Rubens Rangel Rolim, João Henrique Constantino Sales Silva, Helder Farias Pereira de Araújo, Edna Ursulino Alves, Lenyneves Duarte Alvino de Araújo and Naysa Flávia Ferreira do Nascimento

Plants 2026, 15(20), 3145; https://doi.org/10.3390/plants15203145 - 14 Oct 2026

Abstract

Cowpea (Vigna unguiculata (L.) Walp.) plays a key role in food security and income generation in semiarid regions, particularly for smallholder farming systems in the Brazilian semiarid. However, productivity remains low because of environmental limitations, genetic constraints, and traditional crop management practices. [...] Read more.

Cowpea (Vigna unguiculata (L.) Walp.) plays a key role in food security and income generation in semiarid regions, particularly for smallholder farming systems in the Brazilian semiarid. However, productivity remains low because of environmental limitations, genetic constraints, and traditional crop management practices. We evaluated diallel crosses among cowpea landraces to identify superior parents and cross combinations in terms of earliness and grain yield under semiarid conditions. Six landrace accessions, previously selected through participatory prospecting for adaptability and yield stability, were crossed in a complete diallel design to produce 15 F₁ hybrids and their reciprocal crosses. The hybrids were evaluated under field conditions in the semiarid region during the 2023 growing season using a randomized complete block design with ten replications. The evaluations were conducted according to each genotype’s developmental stage and immature pod formation. Early-maturing varieties were harvested at 60 days, intermediate and late varieties between 65 and 75 days. At physiological maturity, early and intermediate genotypes were harvested at 80 days, while late genotypes were harvested between 85 and 90 days. General combining ability (GCA) and specific combining ability (SCA) were estimated using Griffing’s Method I (fixed-effects model), and treatment means were compared using the Scott–Knott test at the 5% significance level. Significant GCA and SCA effects (p < 0.05) were detected for 12 of the 14 evaluated traits, whereas reciprocal effects were significant for seven traits. The hybrid combinations L1 × L4, L1 × L5, and L4 × L5, and their reciprocal crosses, exhibited superior agronomic performance, highlighting their potential as valuable genetic resources for cowpea breeding under semiarid environments. Full article

(This article belongs to the Special Issue Genetic Diversity of Phenotypic Traits in Crops)

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28 pages, 6000 KB

Open AccessArticle

Genome-Wide Identification and Functional Characterization of the Carboxylesterase (CXE) Gene Family in Melon (Cucumis melo L.): CmCXE7 as a Cold-Responsive Regulator of Ester Metabolism

by Yongjie Xia, Jie Liu, Huijun Zhang, Zhuoran Huang, Xiuxiu Zhu and Hu Li

Plants 2026, 15(20), 3144; https://doi.org/10.3390/plants15203144 - 14 Oct 2026

Abstract

Melon fruit aroma depends on the balance between ester biosynthesis and hydrolysis, yet the carboxylesterase (CXE) family responsible for hydrolysis remains uncharacterized in this crop. Here, a genome-wide identification of the CXE gene family in melon revealed 22 CmCXE genes. Phylogenetic analysis revealed [...] Read more.

Melon fruit aroma depends on the balance between ester biosynthesis and hydrolysis, yet the carboxylesterase (CXE) family responsible for hydrolysis remains uncharacterized in this crop. Here, a genome-wide identification of the CXE gene family in melon revealed 22 CmCXE genes. Phylogenetic analysis revealed that Group III members cluster with functionally validated ester-hydrolyzing CXEs from peach, tomato, and strawberry, and their expression peaks during the climacteric and post-climacteric stages—the same window when melon aroma volatiles accumulate. We further functionally characterized CmCXE7, a cold-responsive member, through subcellular localization and heterologous overexpression in tomato. CmCXE7 localized predominantly to the plasma membrane with a weak nuclear signal. Non-targeted metabolomics revealed 776 differentially accumulated metabolites (DAMs) based on VIP > 1 and p < 0.05, with 11 of 14 high-magnitude ester-related changes being downregulated. These results identify Group III genes as candidate regulators of melon ester metabolism and identify CmCXE7 as a cold-responsive CXE candidate that may participate in ester metabolism. The potential relevance of CmCXE7 to fruit ripening and postharvest storage warrants further investigation, providing a candidate gene for future functional studies and molecular breeding of melon aroma quality. Full article

(This article belongs to the Section Plant Genetics, Genomics and Biotechnology)

22 pages, 8191 KB

Open AccessArticle

Physiological and Transcriptomic Insights into Melatonin-Mediated Alleviation of Cadmium Stress in the Endangered Plant Plantago fengdouensis

by Yang Peng, Bin-Ru Wang, Jia-Bin Zhang, You-Wei Zuo, Xin Liang, Sheng-Mao Zhou, Shi-Qi You and Hong-Ping Deng

Plants 2026, 15(20), 3143; https://doi.org/10.3390/plants15203143 - 14 Oct 2026

Abstract

Plantago fengdouensis is an endangered species threatened by habitat loss, population fragmentation, and cadmium (Cd) contamination. This study evaluated the effects of exogenous melatonin (MT) on Cd tolerance from seed germination to the seedling stage. In Petri-dish assays, 50–100 mg L⁻¹ Cd [...] Read more.

Plantago fengdouensis is an endangered species threatened by habitat loss, population fragmentation, and cadmium (Cd) contamination. This study evaluated the effects of exogenous melatonin (MT) on Cd tolerance from seed germination to the seedling stage. In Petri-dish assays, 50–100 mg L⁻¹ Cd markedly inhibited germination; 50 mg L⁻¹ was selected as the lowest concentration producing severe inhibition while retaining sufficient germination for mitigation testing, and 100 μM MT provided the strongest alleviation. In pot experiments, MT promoted seedling growth, shoot and root biomass accumulation, and root and leaf development while reducing Cd accumulation and root-to-shoot translocation. Physiological analyses showed that 200–250 μM MT most effectively alleviated Cd-associated damage by maintaining photosynthesis, enhancing antioxidant and osmotic-adjustment responses, and modulating endogenous hormones. Transcriptome analysis identified 4871 differentially expressed genes (DEGs) between C50M200 and C50M0, with prominent enrichment in plant hormone signaling, cell-wall/plasma-membrane functions, secondary metabolism, and photosynthesis. Exploratory weighted gene co-expression network analysis (WGCNA) further identified treatment-associated modules and candidate hub genes. Overall, the data support coordinated MT-associated responses involving stronger antioxidant defense, reduced Cd accumulation/translocation, and hormone-signaling remodeling. Because transcriptomes were obtained from leaves and WGCNA included nine samples, the inferred molecular mechanisms should be regarded as candidate pathways pending targeted expression and functional validation. Full article

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

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25 pages, 16373 KB

Open AccessReview

Engineering Drought-Responsive ABA Signaling: Linking Physiological Stress Cues to Metal–Organic Framework-Mediated ABA Delivery and SnRK2 Activation

by Muhammad Faheem Jan, Muhammad Ali Shah, Imran Azeem, Haseeb Ahmad, Rehmat Ullah, Waqas Liaqat, Muhammad Aasim and Muhammad Tanveer Altaf

Plants 2026, 15(20), 3142; https://doi.org/10.3390/plants15203142 - 14 Oct 2026

Abstract

Drought induces coordinated physiological, biochemical, and molecular responses that extend beyond changes in phytohormone concentrations. Rapid alterations in reactive oxygen species (ROS), apoplastic pH, Ca²⁺ and ionic dynamics, tissue hydration, and cellular redox status provide spatial and temporal information on developing water [...] Read more.

Drought induces coordinated physiological, biochemical, and molecular responses that extend beyond changes in phytohormone concentrations. Rapid alterations in reactive oxygen species (ROS), apoplastic pH, Ca²⁺ and ionic dynamics, tissue hydration, and cellular redox status provide spatial and temporal information on developing water deficit and regulate stomatal behavior, photosynthesis, water relations, and stress-responsive gene expression. This review explores whether endogenous drought-associated signals can serve as biological triggers for stimulus-responsive metal–organic frameworks (MOFs) designed to regulate abscisic acid (ABA) delivery. We integrate drought-induced changes in redox state, apoplastic pH, ionic composition, and hydration with MOF transformation, host–guest interactions, ABA release, uptake, transport, metabolism, and engagement of the PYR/PYL/RCAR–PP2C–SnRK2 signaling pathway. We propose a framework in which responsive MOFs generate a temporally controlled ABA pulse that follows drought progression, activates protective signaling during water limitation, and attenuates after rewatering to facilitate recovery. Particular emphasis is placed on ROS-Ca²⁺ crosstalk, SnRK2/OST1-dependent guard-cell regulation, hydraulic adjustment, photosynthetic protection, and recovery dynamics. Current studies demonstrate MOF-mediated phytohormone protection, controlled release, and drought-related physiological improvement. Current advances have established the feasibility of MOF-based ABA protection and controlled delivery; however, the integration of drought-responsive carrier activation with receptor-accessible ABA delivery and PYR/PYL/RCAR–PP2C–SnRK2 pathway validation remains an emerging research frontier. We therefore outline a claim-matched validation framework integrating spatial drought-signal analysis, isotope-resolved ABA tracing, carrier localization, phosphorylation-based pathway assays, drought–rewatering experiments, and physiological assessment. This integration of plant stress physiology with responsive nanomaterials provides a conceptual basis for developing more precise ABA delivery strategies for crop resilience under increasingly variable water availability. Full article

(This article belongs to the Special Issue Physiological and Molecular Responses of Plants to Abiotic Stress)

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21 pages, 3056 KB

Open AccessArticle

An Indirect Organogenesis-Based Citrus Transformation System Monitored Using Visible Reporter Markers

by Sameena Ejaz Tanwir, Tao Jiang, Anandi Karn, Carlos D. Messina and Heqiang Huo

Plants 2026, 15(20), 3141; https://doi.org/10.3390/plants15203141 - 14 Oct 2026

Abstract

Genetic transformation of citrus is essential for functional genomics and trait improvement, yet remains limited by prolonged regeneration cycles, genotype-dependent responses, and inefficient screening of transformed tissues. Here, we established an Agrobacterium-mediated indirect organogenesis-based transformation system for Carrizo citrange and evaluated two [...] Read more.

Genetic transformation of citrus is essential for functional genomics and trait improvement, yet remains limited by prolonged regeneration cycles, genotype-dependent responses, and inefficient screening of transformed tissues. Here, we established an Agrobacterium-mediated indirect organogenesis-based transformation system for Carrizo citrange and evaluated two visible reporter systems, the anthocyanin regulator ROSEA1 and the betalain biosynthetic cassette RUBY, for monitoring transformed tissues throughout regeneration. The regeneration protocol enabled visible callus initiation within 7 days following a 5-day pre-culture treatment and recovery of PCR-confirmed transgenic plantlets within 5 months. Both visible reporters were compatible with callus development and shoot regeneration throughout the indirect organogenesis workflow. During callus proliferation, visible pigmentation closely corresponded with GFP fluorescence, enabling rapid, non-destructive identification of transformed tissues. However, reporter performance diverged during shoot regeneration: RUBY maintained stable pigmentation throughout regeneration, whereas ROSEA1-associated pigmentation progressively declined despite continued GFP fluorescence. Consequently, RUBY showed an approximately 4.7-fold higher pigment-positive shoot fraction than ROSEA1 at week 17, and the RUBY-positive fraction was similar to the GFP-positive fraction in the same treatment. Putative transgenic events were confirmed by PCR in independent lines of both constructs, together with GFP fluorescence in leaves and root tips. Together, these findings describe a practical indirect organogenesis-based transformation platform for citrus and demonstrate that both ROSEA1 and RUBY are effective visual reporters during callus proliferation, whereas RUBY provides more reliable visual identification during shoot regeneration. RUBY is therefore recommended as the visible reporter of choice for citrus transformation extending beyond the callus stage. The workflow was established in Carrizo citrange, among the most readily transformed citrus genotypes, and extension to other varieties remains to be demonstrated. Full article

(This article belongs to the Topic Genome Editing and Genetic Transformation in Woody Plants: Methodological Innovations and Applications)

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20 pages, 1976 KB

Open AccessArticle

Preliminary Study to Compare the Antimicrobial Efficacy of Aqueous and Ethanolic Ultrasound-Assisted Aloe vera Extracts

by Luis Cabanillas-Chirinos, Moisés Gallozzo-Cárdenas, Magali Tantaleán Pérez, María Mondéjar Barrios and David García-Cedrón

Plants 2026, 15(20), 3140; https://doi.org/10.3390/plants15203140 - 14 Oct 2026

Abstract

The growing threat of antimicrobial resistance has driven the search for natural alternatives, such as Aloe vera extracts, whose phytochemical composition and biological activity depend on the extraction solvent. This preliminary study compared the antimicrobial efficacy of aqueous and ethanolic (99%) A. vera [...] Read more.

The growing threat of antimicrobial resistance has driven the search for natural alternatives, such as Aloe vera extracts, whose phytochemical composition and biological activity depend on the extraction solvent. This preliminary study compared the antimicrobial efficacy of aqueous and ethanolic (99%) A. vera extracts obtained by ultrasound-assisted extraction (UAE) under identical conditions, and explored their FTIR spectroscopic profiles. The extracts were characterized by FTIR and evaluated against Staphylococcus aureus ATCC 12493 and Escherichia coli ATCC 33876 using the agar well diffusion method and broth macrodilution to determine the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). In the well diffusion assay, the ethanolic extract produced larger inhibition halos than the aqueous extract (22.3 and 20.0 mm vs. 20.6 and 17.4 mm against S. aureus and E. coli, respectively, at 200 mg/mL), and two-way ANOVA showed significant effects of extract type and microorganism (p < 0.001). The ethanolic extract also showed a trend toward lower mean MIC values (62.0 and 85.6 mg/mL) than the aqueous extract (90.7 and 145.0 mg/mL); however, given the high standard deviations and the limited number of replicates (n = 3), the MIC/MBC results are inconclusive, as no specific statistical analysis was applied to them. Likewise, the FTIR spectra showed a relatively higher intensity of bands consistent with polysaccharides (O–H and C–O–C) in the aqueous extract and of the 1600–1650 cm⁻¹ band (C=O/C=C), a spectral feature potentially associated with compounds such as anthraquinones and flavonoids, in the ethanolic extract; nevertheless, owing to band overlap, the semi-quantitative nature of the comparison and the absence of complementary analyses (e.g., HPLC-MS or NMR), these results are also inconclusive regarding the specific compound classes involved. Overall, the findings indicate a trend toward higher antimicrobial activity of the ethanolic extract against the two reference strains evaluated, which should be confirmed in future studies using broth microdilution with a larger number of replicates, identification of bioactive compounds, and a broader panel of microorganisms, including resistant clinical isolates, together with cytotoxicity assays. Full article

(This article belongs to the Special Issue Phytochemistry and Bioactivities of Plant Extracts)

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20 pages, 4585 KB

Open AccessArticle

Effects of Stubble Height and Mulching on Wind Erosion in Maize–Peanut Intercropping Farmland

by Ping Zeng, Yuhang Wei, Jiaxin Chen, Yajun Su, Shuyao Wang, Naijia Wang, Yubo Meng, Chen Feng, Wuyan Xiang, Yunqing Wang, Meiling Zhang, Xining Gao and Liwei Wang

Plants 2026, 15(20), 3139; https://doi.org/10.3390/plants15203139 - 14 Oct 2026

Abstract

To clarify the effectiveness of different stubble heights and mulching patterns for wind erosion control in maize–peanut intercropping systems, this study was conducted in the black soil region of Northeast China using a combination of wind tunnel simulation and field wind erosion monitoring. [...] Read more.

To clarify the effectiveness of different stubble heights and mulching patterns for wind erosion control in maize–peanut intercropping systems, this study was conducted in the black soil region of Northeast China using a combination of wind tunnel simulation and field wind erosion monitoring. Monocropped peanut bare land was used as the control (CK). Four wind tunnel treatments were established: maize stubble with mulching (WT-1), maize stubble without mulching (WT-2), and peanut strip with maize straw mulching (WT-3). Additionally, seven field treatments were established, comprising mulched and non-mulched plots at three stubble height levels (low, medium, and high), as well as a mulched peanut plot without stubble (T7). Wind erosion intensity and amount were systematically measured across all treatments. The results showed that: (1) Wind erosion intensity increased exponentially with wind speed (R² = 0.90–0.96, p < 0.001). Over the full range of wind speeds, wind erosion intensity was consistently greater in CK and WT-2 than in WT-3 and WT-1. The three mulching treatments exhibited distinct protective characteristics across different wind speed intervals: rapid response of surface mulching at low wind speeds, enhanced wind erosion control of standing stubble at moderate wind speeds, and diminished stubble protection but sustained mulching advantage at high wind speeds. The WT-1 treatment maintained an anti-wind erosion efficiency of 70.15% even at the extreme wind speed of 18 m·s⁻¹. (2) Field wind erosion amounts ranked as CK > T6 > T2 > T4 > T1 > T7 > T5 > T3. The medium stubble with mulching treatment (T3) showed a net dust deposition effect with a wind erosion amount of −0.35 g, demonstrating the optimal erosion reduction performance. (3) Standing stubble and surface mulching synergistically increased aerodynamic roughness by 22.86–394.44%, effectively reducing near-surface wind speed by 30.32–55.55%. Meanwhile, straw mulching reduced soil water evaporation, increased pre-sowing surface soil water content by 5.4–126.01%, and enhanced inter-particle cohesion, thereby effectively suppressing soil wind erosion. Therefore, after harvest in the maize–peanut intercropping system in the black soil region of Northeast China, the combined application of maize straw mulching on peanut strips (T7) and medium stubble (40–50 cm) with mulching on maize strips (T3) is recommended as an optimal technical strategy for wind erosion control in the study area and similar brown soil-dominated wind erosion-sensitive regions after autumn harvest. Full article

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

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25 pages, 5699 KB

Open AccessArticle

Developmental Stage Shapes the Leaf-Associated Bacterial Community of Eugenia uniflora and Reveals Shared Bacterial Taxa with Other Myrtaceae Species

by Isabel Cristina Cadavid Sánchez, Dámaris Esquén Bayona, Belkys Brianna Medrano Salazar, Rogerio Margis and Frank Guzman Escudero

Plants 2026, 15(20), 3138; https://doi.org/10.3390/plants15203138 - 14 Oct 2026

Abstract

The phyllosphere microbiome contributes to plant health and adaptation, yet bacterial communities associated with Eugenia uniflora remain poorly characterized. This study investigated how developmental stage shapes the E. uniflora phyllosphere microbiome and assessed bacterial taxa and associations shared with other Myrtaceae species. The [...] Read more.

The phyllosphere microbiome contributes to plant health and adaptation, yet bacterial communities associated with Eugenia uniflora remain poorly characterized. This study investigated how developmental stage shapes the E. uniflora phyllosphere microbiome and assessed bacterial taxa and associations shared with other Myrtaceae species. The V3–V4 region of the 16S rRNA gene was sequenced from 19 E. uniflora samples representing young and mature trees, as well as 13 samples from mature trees representing three additional Myrtaceae genera (Myrcianthes, Plinia, and Psidium) and other Eugenia species. Community diversity, predicted functional potential, co-occurrence networks, and core taxa were analyzed. In E. uniflora, 1428 bacterial ASVs belonging to 17 phyla and 135 genera were identified, and bacterial community composition differed significantly between developmental stages. Young and mature trees showed distinct taxonomic profiles and predicted functional patterns. Network analysis revealed more connected bacterial communities in young plants and simpler networks in mature plants. Comparison with other Myrtaceae identified 17 core genera, including Methylobacterium–Methylorubrum, Hymenobacter, Sphingomonas, Bdellovibrio, and Terriglobus, which occurred in all 21 mature trees. Overall, developmental stage was associated with changes in the taxonomic, predicted functional potential, and network organization of the E. uniflora phyllosphere microbiome, while shared bacterial taxa and associations across the sampled Myrtaceae genera suggest conserved features of phyllosphere community assembly. Full article

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

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26 pages, 3066 KB

Open AccessReview

Smart Agriculture Research in Date Palm (Phoenix dactylifera L.) Production: A Comprehensive Bibliometric Study

by Sajid Safeer, Adnan Nadeem, Sajid Maqsood and Cataldo Pulvento

Plants 2026, 15(20), 3137; https://doi.org/10.3390/plants15203137 - 14 Oct 2026

Abstract

The date palm (Phoenix dactylifera L.) is fundamental to food security, livelihoods, and agro-ecosystem sustainability across the Arabian Peninsula, yet its production is increasingly constrained by water scarcity, salinity, climate change, and biotic stresses. Smart agriculture technologies offer opportunities to improve crop [...] Read more.

The date palm (Phoenix dactylifera L.) is fundamental to food security, livelihoods, and agro-ecosystem sustainability across the Arabian Peninsula, yet its production is increasingly constrained by water scarcity, salinity, climate change, and biotic stresses. Smart agriculture technologies offer opportunities to improve crop monitoring, resource-use efficiency, and decision-making; however, their application in date palm production remains fragmented and insufficiently validated. This study evaluates the development, geographic distribution, technological focus, research approaches, and thematic structure of smart agriculture research on date palms in the Arabian Peninsula and other major date-producing countries. A bibliometric analysis was conducted using peer-reviewed English-language articles and reviews indexed in Scopus and Web of Science from 2016 to 2026, with 2026 representing a partial year. Following screening and duplicate removal, 164 published studies were retained. Publication output increased gradually, although the trend was not statistically significant (β = 1.25 articles year⁻¹, p = 0.068; Mann–Kendall τ = 0.489, p = 0.060). The literature was concentrated in the Gulf Cooperation Council (GCC) region, with Saudi Arabia contributing 54 publications (32.9%). General agronomy/other topics accounted for 46.3% of publications, while remote sensing/UAVs (17.1%), GIS/geospatial technologies (14.0%), IoT/sensors (13.4%), and AI/machine learning (9.8%) represented the leading specific technology categories. Water and irrigation management dominated thematic applications (46.3%), whereas Smart Farming/IoT accounted for only 11.0%. Observational and monitoring studies comprised 50.0% of publications, compared with only 6.1% involving field experiments, indicating limited field-scale validation. Internationally co-authored studies received significantly more citations than domestically authored studies (16.55 vs. 8.68; p = 0.0007). Thematic analysis identified four major clusters: geospatial monitoring, water management, pest control, and sustainability, with AI/machine learning showing marked growth after 2022. Altogether, the field is expanding but remains fragmented, highlighting the need for integrated IoT and sensor networks, rigorous field trials, AI-driven decision-support systems, and stronger regional and international collaboration to enable scalable, context-specific smart agriculture for date palm production. Full article

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26 pages, 6358 KB

Open AccessArticle

Metabolic Regulation of Phenanthrene-Degrading Strain Sphingobium abikonense GHP1 in Response to Phenanthrene Stress and Its Effects on Endorhizosphere Microbiota of Lettuce

by Lihang Zhang, Zhangkai Wang, Yizhen Jia, Ling’en Liu, Yi Yang, Weizheng Ren and Haiping Gu

Plants 2026, 15(20), 3136; https://doi.org/10.3390/plants15203136 - 14 Oct 2026

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants with high ecotoxicity and bioaccumulation potential, and plant-microbe-assisted remediation is a promising green strategy for their removal. This study investigated Sphingobium abikonense GHP1, a phenanthrene-degrading bacterium isolated from a municipal solid waste incineration site, to [...] Read more.

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants with high ecotoxicity and bioaccumulation potential, and plant-microbe-assisted remediation is a promising green strategy for their removal. This study investigated Sphingobium abikonense GHP1, a phenanthrene-degrading bacterium isolated from a municipal solid waste incineration site, to elucidate its potential remediation mechanism using untargeted metabolomics and root endophytic bacterial community analysis. GHP1 completely degraded phenanthrene (50 mg L⁻¹) within 3 days using it as the sole carbon source. During degradation, aromatic intermediates, including 1-hydroxy-2-naphthoic acid, salicylic acid, and hydroxybenzoic acid derivatives, accumulated, while central carbon metabolism, 2-oxocarboxylic acid metabolism, aromatic compound degradation, and benzoate degradation pathways were activated. Increased levels of NAD, purine metabolites, phosphatidylcholine, and phosphatidylethanolamine suggested enhanced redox regulation, energy metabolism, and membrane homeostasis under phenanthrene stress. In lettuce, GHP1 inoculation promoted plant growth, increased biomass and chlorophyll content, and reduced phenanthrene residues in roots and leaves. Moreover, GHP1 increased the richness of the root endophytic bacterial community and enriched Actinobacteriota, Firmicutes, and other bacterial taxa. These findings demonstrate that GHP1 enhances phenanthrene remediation through coordinated pollutant degradation, metabolic regulation, and plant-microbe interactions, providing a promising microbial resource for the remediation of PAH-contaminated environments. Full article

(This article belongs to the Special Issue Plant Responses to Metal Contamination and Other Pollutants: From Molecular Adaptation to Phytoremediation)

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18 pages, 7201 KB

Open AccessArticle

Integrated Transcriptomic and Metabolomic Analysis Reveals MeJA-Mediated Flavonoid Biosynthesis in Cyclocarya paliurus Callus

by Yilin Gao, Kaidi Gao, Yiting Wang, Zhuosui Li, Jian Qin and Xulan Shang

Plants 2026, 15(20), 3135; https://doi.org/10.3390/plants15203135 - 14 Oct 2026

Abstract

Cyclocarya paliurus is a rare Chinese endemic medicinal tree with high-value bioactive metabolites in its leaves, but wild resource scarcity and growth constraints limit large-scale utilization. Callus culture combined with methyl jasmonate (MeJA) elicitation is a promising strategy for sustainable bioactive compound production. [...] Read more.

Cyclocarya paliurus is a rare Chinese endemic medicinal tree with high-value bioactive metabolites in its leaves, but wild resource scarcity and growth constraints limit large-scale utilization. Callus culture combined with methyl jasmonate (MeJA) elicitation is a promising strategy for sustainable bioactive compound production. However, the metabolic responses of C. paliurus callus to MeJA and the underlying molecular regulatory mechanisms remain unclear. Here, in vitro C. paliurus callus treated with gradient concentrations of MeJA was analyzed by integrating untargeted metabolomics and transcriptomics. Exogenous MeJA significantly induced the accumulation of major flavonoids in C. paliurus callus, including dihydrokaempferol, dihydroquercetin, and quercetin. Twelve key structural genes involved in flavonoid biosynthesis (two 4CL genes, two CHS genes, one CYP73A gene, three HCT genes, one CCoAOMT gene, one CHR gene, one CYP75A gene, and one ANS gene) were co-upregulated. Two hub transcription factors (TFs), CpbHLH162 and CpNAC073, were identified as potential upstream regulators of flavonoid synthesis. These findings indicate that MeJA enhances flavonoid production in C. paliurus callus by activating multiple structural genes and key transcription factors, providing candidate genes for metabolic improvement and theoretical support for the large-scale industrial production of bioactive compounds in C. paliurus. Full article

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

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17 pages, 2481 KB

Open AccessArticle

Synergistic Effects of Maize Growth and Soil Respiration on Yield Under Tillage Regime Conversion

by Jingkun Lu, Tianhao Luan, Nan Wang, Chen Xu, Haoran Liu, Hongjun Wang and Baoyu Chen

Plants 2026, 15(20), 3134; https://doi.org/10.3390/plants15203134 - 14 Oct 2026

Abstract

Soil respiration is a major pathway of carbon loss from agricultural soils and is substantially influenced by tillage practices. However, the short-term effects of different tillage system transitions on soil respiration and maize yield remain unclear. A field experiment was therefore conducted with [...] Read more.

Soil respiration is a major pathway of carbon loss from agricultural soils and is substantially influenced by tillage practices. However, the short-term effects of different tillage system transitions on soil respiration and maize yield remain unclear. A field experiment was therefore conducted with five treatments: conventional tillage–conventional tillage (CK), mulching–mulching (CS), conventional tillage–rotary tillage (NR), rotary tillage–rotary tillage (RS), and mulching–rotary tillage (CRS). Soil respiration, maize growth, and yield were monitored throughout the growing season. The results showed that tillage transition significantly altered the soil respiration rate and its component structure. Higher soil respiration increased CO₂ release, raised canopy CO₂ concentration, and accelerated dry matter accumulation. The RS exhibited the highest soil respiration, with a peak rate of 16.83 μmol m⁻² s⁻¹, of which root respiration accounted for 64.16%, and improved soil porosity and promoted aboveground biomass accumulation. The CRS treatment achieved the highest leaf area index, dry matter accumulation, and yield, representing a 51.49% increase over the control, and had the lowest Q₁₀ value (2.97), indicating that respiration under this treatment was more regulated by substrate availability than by temperature. The CS treatment minimized carbon loss while maintaining grain yield. Overall, tillage transitions that improve soil aeration and root activity were generally associated with higher maize yields, but different pathways created distinct trade-offs among respiration, carbon turnover, and harvestable yield. These findings suggest that conservation tillage transitions have considerable potential for balancing yield maintenance with soil respiration regulation, providing useful guidance for sustainable high-yield maize production in semi-arid regions. Full article

(This article belongs to the Special Issue Advances in Synergistic Research of High-Yield Maize Cultivation, Stress Response and Smart Agriculture)

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14 pages, 1709 KB

Open AccessArticle

Grafting of Black Pepper onto Native Piper Species

by Basílio Cerri Neto, Vinicius de Souza Oliveira, Johnatan Jair de Paula Marchiori, Jeane Crasque, Thayanne Rangel Ferreira, Simone Alves Fernandes, Carla da Silva Dias, Lúcio de Oliveira Arantes, Elmo Pereira Ramos, Antelmo Ralph Falqueto, Edilson Romais Schmildt and Sara Dousseau-Arantes

Plants 2026, 15(20), 3133; https://doi.org/10.3390/plants15203133 - 14 Oct 2026

Abstract

Brazil is the third largest producer of black pepper in the world. Although Brazil is prominent in black pepper production, the average yield is low. The main stressful factors in Brazilian black pepper crops directly affect the root system, such as water deficit, [...] Read more.

Brazil is the third largest producer of black pepper in the world. Although Brazil is prominent in black pepper production, the average yield is low. The main stressful factors in Brazilian black pepper crops directly affect the root system, such as water deficit, flooding and diseases. One strategy to enable the cultivation of black pepper in contaminated areas is the planting of seedlings grafted onto wild Piper species resistant to fusariosis, drought or flooding. Grafting consists of the union of plant tissues from at least two different plants to generate a single organism. However, many factors influence graft incompatibility, the main ones being botanical affinity, which is directly linked to genetic and morphological factors, environmental conditions and physiological factors. The objective of this work was to investigate the compatibility and physiology of grafted seedlings of ‘bragantina’ black pepper, using three rootstocks. The experiment was conducted at the Linhares Experimental Farm, of the Capixaba Institute for Research, Technical Assistance and Rural Extension. Piper aduncum, Piper caldense and the cultivar bragantina (Piper nigrum) were evaluated as rootstock. The native species were propagated by seeds and the bragantina cultivar by cuttings, both propagules collected from mother plants in the Active Germplasm Bank located on the farm. The full cleft top method was carried out. The rootstocks were decapitated just below the fourth node, in which a slit was made, 3 cm deep, and after insertion of the graft, it was tied with a rubber band. The grafts were covered with plastic bags. After grafting, the plants were kept in a nursery. Four months after grafting, survival, chlorophyll a fluorescence, gas exchange, hydraulic conductivity of the stem and root, shoot and root anatomy were assessed. At the end of the experiment, the survival rate was higher in plants grafted onto Piper caldense. P. aduncum showed an increase in the number of active FSII reaction centers by cross sections (RC/CS0). The photosynthetic performance index relative to absorption (PIabs) was increased in P. aduncum. P. caldense and bragantina showed no significant difference. Water use efficiency (WUE) was higher in P. caldense plants, followed by bragantina plants. P. aduncum showed a decrease in WUE. P. aduncum showed an increase in the length of the vascular bundle and root xylem, however P. caldense showed reduced values. Regarding the number of root xylem vessels, the highest values were observed in bragantina plants. The diameter of the root xylem vessels was higher in P. aduncum. P. caldense and bragantina showed no difference. It is concluded that among the species studied, P. caldense was the species that presented the most characteristics that make it compatible with being used as a rootstock using the bragantina genotype as a graft. Full article

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

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20 pages, 6672 KB

Open AccessArticle

Integrated Flame Weeding and Biochar Reutilization Enhance Soybean Yield by Promoting Soil Microbial Abundance

by Ziyang Qu, Hongbin Cheng, Qiyun Xu, Mengru Su, Mingniang Qi, Meishuang Li, Yongkang Chen, Chunping Jian, Yongpeng Wang and Xiaorong Fan

Plants 2026, 15(20), 3132; https://doi.org/10.3390/plants15203132 - 14 Oct 2026

Abstract

Weed interference and crop residue are major constraints on sustainable soybean production, particularly in intensive tropical agriculture. Flame weeding provides a non-chemical approach for weed management, but the agronomic value of carbonized residues generated during this process remains largely unexplored. In this study, [...] Read more.

Weed interference and crop residue are major constraints on sustainable soybean production, particularly in intensive tropical agriculture. Flame weeding provides a non-chemical approach for weed management, but the agronomic value of carbonized residues generated during this process remains largely unexplored. In this study, flame-weeding temperatures ranging from 300 to 800 °C were first screened based on weed carbonization efficiency and air-quality condition, after which 500 and 600 °C were selected for field evaluation. A two-season field experiment was conducted using a 3 × 2 treatment structure combining three pre-sowing flame-weeding temperatures (0, 500, and 600 °C) with or without biochar from flame-weeding (BFW) foliar spraying. Each treatment included four replicates. Flame weeding was applied before soybean sowing, whereas BFW foliar spraying was performed at the V4, R2, R4, and R6 growth stages. Flame weeding altered the soil environment, increasing electrical conductivity and reducing soil nematode abundance. Combined treatments produced the highest yields in soybean. In particular, T600-BFW increased the yield per plant by 73.32% and 32.43% relative to the CK in the two seasons, respectively. Flame weeding exerted a significant lethal effect on soil nematodes. Soil nematode density declined from 149.75 to 2.92 ind·20 g⁻¹ of soil at week 10 following T600 treatment. Compared to CK, T600-BFW increased the root nodule number by 31.71%. The quantities of bacteria, fungi, and actinomycetes in T500 and T600 increased significantly after flame weeding. Redundancy analysis identified soil temperature, electrical conductivity, and pH as major variables associated with microbial community variation. The PLS-PM model showed that soil microorganisms exerted a significant positive effect on soybean yield. These findings indicate that flame weeding and BFW reutilization enhance soybean yield through complementary soil–microbe–root and leaf physiological improvement. This integrated strategy provides a potential pathway for simultaneously managing weeds, reutilizing field-derived carbonized biomass, and improving soybean production. Full article

(This article belongs to the Topic Ammonium Biology: From Molecular Response to Fertilization)

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28 pages, 5687 KB

Open AccessArticle

Storage-Dependent Responses of KDML 105 Rice (Oryza sativa L.) Seeds Across Dynamic Magnetic-Field Treatment Conditions: Germination, Seedling Growth, and Dual-Phase Hydration Modelling

by Tiwanat Gaewsondee, Phirayot Khaengkhan, Cherdpong Chiawchanwattana and Suphan Yangyuen

Plants 2026, 15(20), 3131; https://doi.org/10.3390/plants15203131 - 13 Oct 2026

Abstract

Seed ageing reduces germination and seedling performance, but variation in these responses and hydration kinetics across dynamic magnetic-field exposure (DMFE) conditions is poorly defined. Khao Dawk Mali 105 rice seeds (Oryza sativa L.) stored for 10–13 months were treated for 3, 6, [...] Read more.

Seed ageing reduces germination and seedling performance, but variation in these responses and hydration kinetics across dynamic magnetic-field exposure (DMFE) conditions is poorly defined. Khao Dawk Mali 105 rice seeds (Oryza sativa L.) stored for 10–13 months were treated for 3, 6, or 9 min at nominal maximum surface flux densities of 150, 270, 370, or 470 mT. Untreated controls were excluded from the factorial analyses and used as descriptive references. Water uptake was modelled kinetically, and germination, vigour, and seedling growth by response surfaces; for early germination the arcsine-square-root scale was adopted after grouped cross-validation. Storage duration dominated every endpoint, especially early germination (η_p² = 0.991), declining approximately 28 percentage points per month. DMFE-associated differences were concentrated during early imbibition: treated seeds took up 2.9–4.9 percentage points more water than controls at 6 h, narrowing to 0.6–1.2 points by 42 h. The Reduced Dual-Phase Gompertz model was decisively favoured (ΔAICc = 260.2–347.2). Flux density was retained in the earlier hydration amplitude and all six seedling-growth models, and on the arcsine scale in a shallow early-germination profile whose selection was sensitive to design support and which did not improve cross-validated prediction. Independent seed lots, airflow-only controls, and field validation are required before practical recommendations. Full article

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

22 pages, 4666 KB

Open AccessArticle

Heat Stress Responses During Grain Filling in Two Korean Wheat Cultivars as Affected by Developmental Stage and Exposure Duration

by Ju-Young Choi, Junseok Choi, Jae-Han Son, Yurim Kim, Han-Yong Jeong, Jinhee Park, Goeun Lee, Sookjin Kim, Chon-Sik Kang and Chuloh Cho

Plants 2026, 15(20), 3130; https://doi.org/10.3390/plants15203130 - 13 Oct 2026

Abstract

High temperature can impair grain development and storage compound accumulation during wheat grain filling, with responses depending on stress intensity, timing, duration, and cultivar. In this study, Saekeumkang and Hwanggeumal were selected from among major Korean wheat cultivars because they differ in grain [...] Read more.

High temperature can impair grain development and storage compound accumulation during wheat grain filling, with responses depending on stress intensity, timing, duration, and cultivar. In this study, Saekeumkang and Hwanggeumal were selected from among major Korean wheat cultivars because they differ in grain quality- and starch-related characteristics, providing a basis for comparing cultivar-specific responses to heat stress during grain filling. Plants were exposed to 25/15, 35/25, and 40/30 °C (day/night) temperature regimes for 5 d beginning at 10 or 20 days after heading (DAH), and changes in grain morphology, endosperm and embryo development, 100-grain weight, protein concentration, and storage-related gene expression were evaluated. High temperature altered grain developmental traits and generally reduced 100-grain weight, while the magnitude of these effects differed between cultivars and treatment stages. Grain protein concentration and the expression of starch- and storage protein-related genes also showed cultivar- and stage-dependent responses. In a separate RNA-seq experiment initiated at 10 DAH, plants were exposed to the temperature treatments for either 5 or 10 d, and transcriptomic analysis revealed that heat intensity and exposure duration affected both the number and functional characteristics of differentially expressed genes, particularly those associated with protein folding and quality control, chromatin-related processes, and carbohydrate metabolism. These results indicate that heat responses during wheat grain filling are jointly influenced by developmental stage, exposure duration, and cultivar-specific molecular regulation. Full article

(This article belongs to the Special Issue Molecular Mechanisms Associated with Plant Tolerance upon Abiotic Stress—3rd Edition)

16 pages, 1307 KB

Open AccessArticle

Testing the Geometric Series Hypothesis for the Ascending Leaf Length Sequence per Culm in Six Indocalamus Bamboo Species

by Yimin Zhu, Weihao Yao and Peijian Shi

Plants 2026, 15(20), 3129; https://doi.org/10.3390/plants15203129 - 13 Oct 2026

Abstract

The distribution of leaf sizes along a shoot is a fundamental aspect of plant architecture, but a simple quantitative rule for this pattern has not been widely tested. We examined whether the ascending leaf length sequence per culm in six Indocalamus bamboo species [...] Read more.

The distribution of leaf sizes along a shoot is a fundamental aspect of plant architecture, but a simple quantitative rule for this pattern has not been widely tested. We examined whether the ascending leaf length sequence per culm in six Indocalamus bamboo species follows a geometric series. This hypothesis is particularly plausible for Indocalamus bamboos because their leaves are concentrated near the culm apex, resulting in relatively uniform light exposure across the leaf cohort. However, the culm architecture is not entirely uniform: some leaves arise from smaller, thinner branches, which could naturally generate a geometric size sequence. To test this hypothesis, we measured the lengths of all leaves from 602 culms across the six species. After excluding culms with fewer than three or more than 90 leaves and those with estimated common ratios exceeding 1.2, we retained 577 culms for final analysis, representing 95.8% of the initial sample. For each culm, we fitted a geometric series model to the ascending leaf length sequence using nonlinear least-squares regression. The goodness of fit was evaluated using the mean absolute percentage error (MAPE) between observed and predicted cumulative leaf lengths. The results showed that the geometric series model fitted the data remarkably well, with 75.39% of the 577 culms having a MAPE below 5% and 96.53% below 10%. The estimated common ratios ranged from 1.01 to 1.19, with a mean of 1.05, indicating a modest but consistent geometric increase in leaf length. Significant differences in both the estimated common ratio and the estimated minimum leaf length were found among species, reflecting interspecific variation in growth strategies. These findings provide strong support for the geometric series as a robust descriptor of leaf length organization per culm in bamboos, offering new insights into the architectural structures that constrain the leaf size distribution per culm. Full article

(This article belongs to the Section Plant Modeling)

21 pages, 5527 KB

Open AccessReview

Tylosema esculentum (Marama Bean) as a Climate-Resilient Opportunity Crop: A Review of Nutritional, Medicinal, andGenomics Insights and Drought Adaptation

by Pfunzo Gavhi, Mulisa Nkuna, Gumani Luidney Nemauluma, Lindokuhle Mogwaduba, Nndamuleleni Romeo Murovhi and Takalani Mulaudzi

Plants 2026, 15(20), 3128; https://doi.org/10.3390/plants15203128 - 13 Oct 2026

Abstract

Tylosema esculentum (Burch.) A. Schreib. (also known as marama) is a perennial legume native to the arid and semi-arid regions of southern Africa, where it thrives under extreme climatic conditions, particularly in hot and water-limited environments and nutrient-poor soils. This review outlines current [...] Read more.

Tylosema esculentum (Burch.) A. Schreib. (also known as marama) is a perennial legume native to the arid and semi-arid regions of southern Africa, where it thrives under extreme climatic conditions, particularly in hot and water-limited environments and nutrient-poor soils. This review outlines current knowledge on marama’s nutritional and medicinal potential, as well as genomic insights and drought adaptation mechanisms, to ensure sustainable food systems. Marama has added advantages since the entire crop, including grains/beans, stems and tubers, can be used as a source of food for animals and humans. However, the nutritional value and safe consumption of different tissues are dependent on developmental stages and appropriate processing to reduce anti-nutritional compounds and improve digestibility. Marama beans possess exceptional nutritional value, being rich in protein; unsaturated lipids; essential micronutrients; and health-promoting phytochemicals including phenolics, flavonoids, saponins and phytosterols. To date, the chloroplast and mitochondrial genomes of Tylosema esculentum (marama) have been sequenced and assembled, while its nuclear genome size has been estimated at approximately 1 gigabyte, providing valuable genomic resources for further research. Marama exhibits a predominantly drought-avoidance strategy characterized by the development of deep tubers for water and nutrient storage, reduction in transpiration through leaf senescence and stomatal regulation, and maintenance of plant water status during prolonged dry periods. Marama also exhibits osmotic adjustment, which further enhances cellular protection and stress tolerance under water-deficit conditions. Despite these promising attributes, marama remains largely underutilized due to limited agronomic data to support its cultivation and insufficient data on its metabolic and genetic architecture that drives drought adaptation and socio-economic potential. Thus, there is an urgent need for integrated research efforts that will facilitate the transition of this crop from a wild-harvested resource to a sustainable, climate-resilient crop suited to arid and semi-arid agroecosystems. Full article

(This article belongs to the Special Issue Advances in Wild Relatives and Neglected Crops: Physiology, Ecology, Genetics and Beyond)

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21 pages, 8501 KB

Open AccessArticle

Multi-Objective Optimization of Nitrogen Management for Oat Production in the Agro-Pastoral Ecotone of China Using NSGA-II to Balance Yield, Quality, Nitrogen Use Efficiency and Environmental Sustainability

by Ying Wang, Xue Han, Yanli Zhang, Xiaorong Wu and Lijun Li

Plants 2026, 15(20), 3127; https://doi.org/10.3390/plants15203127 - 13 Oct 2026

Abstract

Oat is a staple cereal in semi-arid regions and requires eco-friendly nitrogen management to stabilize yield and mitigate environmental risks. A two-year field experiment was conducted to investigate the impacts of nitrogen rate and topdressing timing on oat grain yield, β-glucan yield, economic [...] Read more.

Oat is a staple cereal in semi-arid regions and requires eco-friendly nitrogen management to stabilize yield and mitigate environmental risks. A two-year field experiment was conducted to investigate the impacts of nitrogen rate and topdressing timing on oat grain yield, β-glucan yield, economic return, nitrogen agronomic efficiency, and soil mineral nitrogen residue. Jointing stage topdressing at 105–140 kg·ha⁻¹ markedly raised grain yield and β-glucan yield. Physiological mechanism analysis revealed that appropriate nitrogen topdressing at the jointing stage effectively maintained a high chlorophyll content and nitrogen balance index by significantly improving the activities of nitrate reductase and glutamine synthetase during the grain-filling stage, thereby promoting the accumulation of dry matter and nitrogen. With the increase in nitrogen application rate and the delay of topdressing time, the soil mineral nitrogen accumulation increased significantly. Furthermore, a multi-objective optimization framework integrating regression models with the NSGA-II algorithm identified the optimal strategy as 140.68 kg·ha⁻¹ with topdressing 32 days after emergence. This study constructed a multi-objective optimization system for oat nitrogen application suitable for the agro-pastoral ecotone of northern China, which can provide a theoretical basis and practical methods for the synergistic achievement of high-yield, high-quality oat production and ecological conservation. Full article

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

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