International Journal of Plant Biology

22 pages, 5604 KB

Open AccessArticle

Genome-Wide Identification and Analysis of the PHD Family Members in Gossypium tomentosum and Their Potential Roles in Response to Abiotic Stress

by Yu Lyu and Wenbing Han

Int. J. Plant Biol. 2026, 17(9), 96; https://doi.org/10.3390/ijpb17090096 - 21 Sep 2026

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Abstract

Plant homeobox domain (PHD) proteins are a class of zinc-finger proteins that play pivotal regulatory roles in plant responses to environmental stresses. Research on the identification and analysis of PHDs in Gossypium tomentosum (G. tomentosum) remains limited. The present study [...] Read more.

Plant homeobox domain (PHD) proteins are a class of zinc-finger proteins that play pivotal regulatory roles in plant responses to environmental stresses. Research on the identification and analysis of PHDs in Gossypium tomentosum (G. tomentosum) remains limited. The present study conducted a genome-wide analysis of the PHD members in G. tomentosum and examined their properties and functions. A total of 71 PHDs have been identified, designated as GtPHD1–GtPHD71, through a combination of profile HMM-based searches, BLAST searches, and canonical features of PHD domains. Multiple sequence alignment of the G. tomentosum PHD domains revealed a characteristic signature: X(0,1)-C-X(1,2)-C-X(6,12)-[VLI]-X-C-X(0,2)-[DPK]-X(1,2)-C-X(4,5)-H-X2-C-X(9,18)-[YWF]-X-C-X2-C. A comprehensive investigation encompassing RT–qPCR, promoter analysis, and transcription factor analysis concluded that G. tomentosum PHDs likely play critical regulatory roles in response to abiotic stresses, including drought, hypoxia, and low temperature. Full article

(This article belongs to the Special Issue Hormone and Gene Regulatory Networks in Plant Stress Resistance)

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22 pages, 9112 KB

Open AccessReview

From Lipid Shuttling to Signaling Hubs: The Multifaceted Roles of Non-Specific Lipid Transfer Proteins in Plant Adaptation

by Mouna Ghorbel, Kamel Jebreen, Abdalmenem I. M. Hawamda and Faiçal Brini

Int. J. Plant Biol. 2026, 17(9), 95; https://doi.org/10.3390/ijpb17090095 - 20 Sep 2026

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Abstract

Non-specific lipid transfer proteins (nsLTPs) are small cysteine-rich proteins belonging to the cysteine-rich peptide (CRP) antimicrobial peptide superfamily, widely distributed across land plants and involved in key physiological processes including fertilization, cell wall organization, wax deposition, and responses to biotic and abiotic stresses. [...] Read more.

Non-specific lipid transfer proteins (nsLTPs) are small cysteine-rich proteins belonging to the cysteine-rich peptide (CRP) antimicrobial peptide superfamily, widely distributed across land plants and involved in key physiological processes including fertilization, cell wall organization, wax deposition, and responses to biotic and abiotic stresses. Recent genomic and evolutionary analyses have revealed an extensive diversification of nsLTPs across plant lineages, which has led to multiple classification systems based on molecular mass, cysteine spacing, intron structure, and GPI (glycosylphosphatidylinositol-anchored proteins)-anchor motifs. This diversity reflects their adaptive expansion during plant terrestrialization. This review proposes that nsLTPs act as central nodes connecting lipid metabolism, developmental signals, and stress response networks, functioning as integrative signaling hubs rather than simple lipid carriers. Building on this central thesis, we synthesize current knowledge on nsLTP structure, classification, and evolution, and examine their multifaceted roles in plant development and defense. We also highlight emerging biotechnological applications and identify key gaps that warrant further investigation. Full article

(This article belongs to the Section Plant Response to Stresses)

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Graphical abstract

16 pages, 4472 KB

Open AccessArticle

Combined Biostimulant Treatment Is Associated with PSII Energy Partitioning and Leaf Anatomy in Cucumber Leaves and Fruits

by Georgia Ouzounidou, Niki-Sophia Antaraki, Antonios Anagnostou, George Daskas and Ioannis-Dimosthenis S. Adamakis

Int. J. Plant Biol. 2026, 17(9), 94; https://doi.org/10.3390/ijpb17090094 - 19 Sep 2026

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Abstract

Plant biostimulants may alter photosynthetic energy use and leaf structure, but their effects on complementary PSII energy partitioning in both cucumber leaves and fruits remain insufficiently characterized. Using plant material from a commercial greenhouse trial previously reported for agronomic outcomes, we evaluated a [...] Read more.

Plant biostimulants may alter photosynthetic energy use and leaf structure, but their effects on complementary PSII energy partitioning in both cucumber leaves and fruits remain insufficiently characterized. Using plant material from a commercial greenhouse trial previously reported for agronomic outcomes, we evaluated a combined CropBioLife^®, KeyPlex 120^®, and Key Eco Oil^® application protocol relative to conventional management. Chlorophyll Content Index (CCI), chlorophyll fluorescence imaging, and leaf anatomical traits were assessed. Under low light (LL; 455 μmol photons m⁻² s⁻¹), the combined-treatment greenhouse showed higher ΦPSII than the conventional-control greenhouse by 22% in fruits and 50% in leaves; fruit ΦNPQ was 17% higher, whereas ΦNO was 12% lower in fruits and 26% lower in leaves. Under high light (HL; 973 μmol photons m⁻² s⁻¹), differences in ΦPSII were smaller, while leaf ΦNO remained 17% lower. CCI was 38% higher in fruits and 52% higher in leaves. In leaves, spongy parenchyma thickness increased from 110 ± 3.4 to 135 ± 4.1 μm, palisade parenchyma thickness from 75 ± 2.1 to 78 ± 1.8 μm, total leaf thickness from 230 ± 4.6 to 245 ± 5.2 μm, and intercellular air-space area from 420 ± 18 to 610 ± 22 μm². The parallel physiological and anatomical differences are consistent with a possible functional association, but gas exchange, mesophyll conductance, ROS, and water-use efficiency were not measured in the present dataset. Because the two management regimes occupied separate, non-replicated greenhouses and received different crop-protection inputs, the findings should be interpreted as treatment-associated differences rather than causal effects attributable to individual products. Full article

(This article belongs to the Section Plant Physiology)

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18 pages, 1661 KB

Open AccessArticle

Integrating Boron and Zinc Foliar Fertilization with Mineral Nutrition Improves Growth, Nutrient Acquisition, and Productivity of Sugar Beets

by Almagul Malimbayeva, Azamat Khidirov, Erbol Zhusupbekov, Batyrgali Amangaliev, Akerke Soltanayeva, Aigul Raiymbekova, Erbolat Berdibek and Maksat Batyrbek

Int. J. Plant Biol. 2026, 17(9), 93; https://doi.org/10.3390/ijpb17090093 - 18 Sep 2026

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Abstract

Sugar beet (Beta vulgaris L.) is an economically important industrial crop, and its productivity and sugar accumulation depend heavily on effective nutrient management. This study investigated how mineral fertilization combined with foliar applications of boron (B) and zinc (Zn) influences plant growth, [...] Read more.

Sugar beet (Beta vulgaris L.) is an economically important industrial crop, and its productivity and sugar accumulation depend heavily on effective nutrient management. This study investigated how mineral fertilization combined with foliar applications of boron (B) and zinc (Zn) influences plant growth, photosynthetic performance, nutrient uptake, yield, and sugar production under irrigated alkaline soil conditions in southeastern Kazakhstan during the 2024 and 2025 growing seasons. The field experiment was conducted using a randomized complete block design with three replications and five treatments: (1) control (CK), (2) N₃₀₀P₁₅₀K₃₀₀ (NPK), (3) NPK + B, (4) NPK + Zn, and (5) NPK + B + Zn. Mineral fertilization substantially enhanced plant growth and productivity compared with the unfertilized control, while foliar supplementation with B and Zn provided further improvements. Across both growing seasons, the combined NPK + B + Zn treatment consistently produced the greatest leaf area (55.6 × 10³ m² ha⁻¹), dry biomass (4.9 t ha⁻¹), photosynthetic potential (1631.5 × 10³ m² day ha⁻¹), and net photosynthetic productivity (7.7 g m⁻² day⁻¹). It also resulted in the highest total uptake of nitrogen, phosphorus, and potassium, reaching 431.5, 64.7, and 761.4 kg ha⁻¹, respectively. Foliar application of the combined micronutrients markedly increased their accumulation in plant tissues, with total B and Zn uptake rising to 874 and 1005 g ha⁻¹, respectively. Sugar content improved from 17.1–17.2% in the control to 17.9–18.1% under the combined micronutrient treatment. As a result, the NPK + B + Zn treatment achieved the highest mean sugar yield (15.12 t ha⁻¹), representing a 76.4% increase over the control and a 12.5% increase compared with NPK fertilization alone. The results demonstrate that foliar application of boron and zinc effectively complements mineral fertilization by enhancing photosynthetic activity, nutrient acquisition, and sugar accumulation. The combined application of NPK with foliar B and Zn can therefore be recommended as an effective nutrient management strategy for improving sugar beet productivity and sugar yield under alkaline soil conditions. Full article

(This article belongs to the Section Plant Physiology)

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11 pages, 657 KB

Open AccessCommunication

Hormone Treatments Affect Stem Cutting Propagation Strategies of Four Interspecific Hybrid Southern Grape Cultivars

by Jenny B. Ryals, Eric T. Stafne, Haley N. Williams and Patricia R. Knight

Int. J. Plant Biol. 2026, 17(9), 92; https://doi.org/10.3390/ijpb17090092 - 18 Sep 2026

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Abstract

Improving stem cutting propagation of grapevine species (Vitis sp.) is important for supporting growing interest in southern grapevine production, particularly for lesser-known cultivars. More efficient and reliable propagation techniques can help nurseries increase the availability of grapevine plants for local growers and [...] Read more.

Improving stem cutting propagation of grapevine species (Vitis sp.) is important for supporting growing interest in southern grapevine production, particularly for lesser-known cultivars. More efficient and reliable propagation techniques can help nurseries increase the availability of grapevine plants for local growers and support development of the southern U.S. wine industry. Hardwood and semi-hardwood cuttings of four winegrape cultivars, ‘Mamont Noir’, ‘MidSouth’, ‘Miss Blanc’, and ‘Norton’, were subjected to 10 hormone treatments consisting of indole-3-butyric acid (IBA) alone or in combination with ascorbic acid (ASC). Treatments were applied as a three-second basal quick dip. Sixty days after treatment, total shoot and root number, average shoot and root length, rooting percentage, and cutting and root quality were evaluated. Based on the results, semi-hardwood or hardwood ‘Mamont Noir’ cuttings can be propagated using 50 ppm ASC or 50 ppm ASC + 500 ppm IBA. For nurseries where hardwood cuttings better fit the production schedule, ‘Miss Blanc’ cuttings rooted well regardless of hormone treatment. Additional research is needed to optimize hormone treatments for ‘MidSouth’ and ‘Norton’. Full article

(This article belongs to the Section Plant Physiology)

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19 pages, 10651 KB

Open AccessArticle

Deciphering Microprotein–TF Regulatory Crosstalk: An Integrative Transcriptomic and Evolutionary Analysis of MIF1–ZHD Interaction in Brassica napus Seed Development

by Khadijeh Shokri, Naser Farrokhi, Amir Mousavi, Pär K. Ingvarsson and Asadollah Ahmadikhah

Int. J. Plant Biol. 2026, 17(9), 91; https://doi.org/10.3390/ijpb17090091 - 17 Sep 2026

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Abstract

Seed development in Brassica napus is tightly regulated at many stages. Microproteins (miPs), small regulatory peptides derived from larger ancestral proteins, have emerged as key post-translational modulators in plants; however, their role in seed development remains poorly understood. Here, a genome-wide screen for [...] Read more.

Seed development in Brassica napus is tightly regulated at many stages. Microproteins (miPs), small regulatory peptides derived from larger ancestral proteins, have emerged as key post-translational modulators in plants; however, their role in seed development remains poorly understood. Here, a genome-wide screen for putative miPs in B. napus was performed, identifying 32 candidates. Among these, MIF1 (BnaC06g35530D), with domain similarity to ZF-HD transcription factors (TFs), showed robust expression dynamics. The integration of RNA-seq profiling, qRT-PCR, co-expression network modeling, and protein–protein interaction revealed a strong regulatory association between MIF1 and its predicted TF partner, i.e., ZHD (BnaC01g16510D), particularly at the zygote and bending cotyledon stages. Promoter analysis identified shared cis-elements among co-expressed genes, while structural modeling supported a stable MIF1–ZHD interaction interface. Evolutionary analysis demonstrated the conservation of zinc finger motifs, syntenic neighborhoods, and purifying selection on MIF1 across Brassicaceae species. Collectively, our findings suggest that MIF1 potentially functions as a conserved post-translational repressor of ZHD during seed development, contributing to fine-tuned transcriptional regulation in polyploid oilseed crops. This study provides a testable hypothesis about the interaction between MIF1 and ZHD and also paves the way for the future functional characterization of miP-TF modules in plant development. Full article

(This article belongs to the Section Plant Biochemistry and Genetics)

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14 pages, 6886 KB

Open AccessArticle

Efficacy of a Calcium Functional Fertiliser with a Calcium Transport Stimulant in Managing Cavity Spot of Carrot (Daucus carota subsp. sativus)

by Jolyon Dodgson, Nicole Pereira, John Clarkson, Anna K. Marks and David J. Marks

Int. J. Plant Biol. 2026, 17(9), 90; https://doi.org/10.3390/ijpb17090090 - 16 Sep 2026

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Abstract

The marketable yield of carrot is reduced by carrot cavity spot disease (Pythium violae and P. sulcatum). In the UK, metalaxyl-M is the only approved fungicide. Good calcium nutrition can manage cavity spot, but calcium is not generally mobilised to the [...] Read more.

The marketable yield of carrot is reduced by carrot cavity spot disease (Pythium violae and P. sulcatum). In the UK, metalaxyl-M is the only approved fungicide. Good calcium nutrition can manage cavity spot, but calcium is not generally mobilised to the maturing carrot root. We report field-based studies testing the effect of Albina, a novel calcium functional fertiliser, which contains a calcium transport stimulant (MCAS) LoCal^TM (Levity Crop Science, UK) that mimics the effect of auxin in relation to the transport of calcium across cell membranes. Its effect on cavity spot was compared with calcium nitrate (calcium fertiliser without MCAS) and metalaxyl-M in an inoculated ‘macrocosm’ plot experiment (cv. Nairobi), and in grower-managed field trials where it was compared with standard fertiliser and fungicide applications over two years (cvs. Nairobi and Octavo). In the macrocosm trial, the functional fertiliser gave significantly reduced cavity spot (12% incidence) compared with the inoculated (untreated) control (24% incidence) and had similar efficacy to the fungicide. In the grower-managed field trials, the functional fertiliser resulted in significantly improved cavity spot control with a mean reduction of 14%. The functional fertiliser could provide a cost-effective and environmentally friendly means for reducing cavity spot in carrots. Full article

(This article belongs to the Special Issue Plant Health in the Context of Fungal and Other Microbial Threats: Systematics, Pathogenesis and Integrated Management)

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17 pages, 7457 KB

Open AccessArticle

The Response of Juvenile Dichrostachys cinerea and Terminalia sericea Savanna Plants to Cutting Disturbances in the Nylsvley Nature Reserve, South Africa

by Maanda Ligavha-Mbelengwa, Humbulani Munzhelele, Peter Tshisikhawe, Alphonce Bere and John Ogola

Int. J. Plant Biol. 2026, 17(9), 89; https://doi.org/10.3390/ijpb17090089 - 16 Sep 2026

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Abstract

Bush encroachment by woody species threatens biodiversity, ecosystem functioning, and rangeland productivity in savanna ecosystems. Understanding how juvenile woody plants respond to cutting at different times of the year is essential for developing effective management strategies. This study evaluated the seasonal resprouting responses [...] Read more.

Bush encroachment by woody species threatens biodiversity, ecosystem functioning, and rangeland productivity in savanna ecosystems. Understanding how juvenile woody plants respond to cutting at different times of the year is essential for developing effective management strategies. This study evaluated the seasonal resprouting responses of juvenile individuals of Dichrostachys cinerea and Terminalia sericea following cutting disturbances. The study was conducted in the Nylsvley Nature Reserve using line transects and plot-based sampling because of challenges associated with protecting experimental sites in communal lands. Juvenile plants of each species were allocated into groups comprising thirty-five individuals and subjected to seasonal cutting treatments. Resprout height, leaf production, and root sugar concentrations were measured to assess seasonal recovery patterns. Both species successfully resprouted after cutting regardless of season. T. sericea produced taller resprout heights than D. cinerea, whereas D. cinerea generally produced more leaves. Seasonal differences significantly affected recovery, with winter cutting producing the tallest resprout heights and greatest leaf production, while summer cutting resulted in the shortest resprouts and fewest leaves. Winter-cut plants produced more than twice as many leaves as summer-cut plants. Winter cutting drastically boosts plant regeneration capacity and cannot effectively curb bush expansion, whereas summer cutting achieves better suppression effects. Root sugar concentrations were lower during winter in both species, indicating reduced metabolic activity. Summer is the most effective season for cutting juvenile individuals of D. cinerea and T. sericea to suppress bush encroachment, whereas winter is the least effective. These findings provide evidence to support seasonally informed bush management strategies that promote biodiversity conservation, ecological integrity, and sustainable savanna ecosystem management. Full article

(This article belongs to the Section Plant Ecology and Biodiversity)

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16 pages, 1929 KB

Open AccessArticle

Genetic Diversity and Population Structure of Sweet Orange (Citrus sinensis) Germplasm in Inhambane Province, Mozambique

by Milton Sebastião Zavale, Arsénio D. Ndeve, Winfred N. Muteti and Rogério M. Chiulele

Int. J. Plant Biol. 2026, 17(9), 88; https://doi.org/10.3390/ijpb17090088 - 10 Sep 2026

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Abstract

Background/Objectives: Sweet orange (Citrus sinensis (L.) Osbeck) is an economically important fruit crop that contributes substantially to food security and smallholder income in Mozambique. Despite this, the genetic diversity of the locally grown germplasm has not been characterized at the molecular level, [...] Read more.

Background/Objectives: Sweet orange (Citrus sinensis (L.) Osbeck) is an economically important fruit crop that contributes substantially to food security and smallholder income in Mozambique. Despite this, the genetic diversity of the locally grown germplasm has not been characterized at the molecular level, limiting its improvement and conservation programs. This study assessed the genetic diversity and population structure of germplasm from 94 sweet orange trees sampled across four districts of Inhambane Province using DArTSeq single-nucleotide polymorphism (SNP) markers. Methods: After filtering 8111 SNPs for call rate (≥0.80) and minor allele frequency (≥0.01), 1263 markers were retained, of which 1144 were anchored to the nine chromosomes of the reference genome. Results: Sparse non-negative matrix factorization identified K = 1, indicating a single undifferentiated gene pool, supported by a smooth PCA scree with one weak axis. DAPC assigned individuals to their district only 38.3% of the time (random expectation = 25%; maximum a-score = 0.10), and the first two PCoA axes explained 10.33% of variation with complete district overlap, indicating no detectable geographic structure. Diversity was low, with observed heterozygosity (Ho = 0.247) exceeding expected heterozygosity (He = 0.138) and a negative inbreeding coefficient (Fis = −0.222). The pattern indicated a heterozygote excess consistent with the fixation of the heterozygous interspecific-hybrid genome under clonal propagation. A hierarchical analysis of molecular variance showed that differentiation among districts was negligible (0.04%), whereas 4.16% of variation was partitioned among orchards (farms) within districts, indicating that the little of the existing structure resides at the orchard level, confounded with propagation method and cultivar, rather than among districts. Most variation was partitioned within individuals (76.0%), and pairwise FST values (0.0005–0.0035) were uniformly low. Conclusions: These results indicate that the sweet orange orchards stem from a single, highly heterozygous gene pool redistributed through the exchange of seed and vegetative planting material. This underscores the need to introduce diverse external germplasm to broaden the genetic base for sustainable improvement in Mozambique. Full article

(This article belongs to the Section Plant Ecology and Biodiversity)

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23 pages, 2114 KB

Open AccessArticle

Climacteric and Non-Climacteric Ripening Patterns of Melons with Focus on Carbohydrate Metabolism and Osmotic Potential

by Maria Raquel Alcantara de Miranda, Luiz Ferreira Coelho Junior, Gabrielle Glayssa Lopes de Oliveira Holanda, Rute Xavier Franca, Elenilson Godoy Alves Filho, Sueli Rodrigues, Izabella Maria Costa Oliveira, Fernando Antônio Souza Aragão and Ricardo Antonio Ayub

Int. J. Plant Biol. 2026, 17(9), 87; https://doi.org/10.3390/ijpb17090087 - 10 Sep 2026

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Abstract

This study investigated the differences between ripening patterns of two homozygous lineages of melons, yellow A5, a non-climacteric inodorus, and Charentais C1, a climacteric cantalupensis, regarding the physiological processes related to postharvest quality with a focus on carbohydrate metabolism and osmotic [...] Read more.

This study investigated the differences between ripening patterns of two homozygous lineages of melons, yellow A5, a non-climacteric inodorus, and Charentais C1, a climacteric cantalupensis, regarding the physiological processes related to postharvest quality with a focus on carbohydrate metabolism and osmotic potential. Melons underwent significant changes as maturation progressed from 24 to 34 days after pollination (DAP) for the non-climacteric A5 lineage and from 18 to 28 DAP for the C1 climacteric lineage. The most discriminant variables for the non-climacteric pattern of A5 melons were the higher activity of cell wall hydrolase PME and lower firmness, the higher activity of enzymes involved in carbohydrate metabolism, and sucrose accumulation. In contrast, climacteric C1 melons reach physiological maturity at 24 DAP, do not accumulate sucrose, and enzyme β-GAL plays a key role in cell wall breakdown, contributing to softening and to soluble solids content. A5 melons exhibited greater TSS and soluble solids content, and even though the osmotic potential did not change significantly, the VIP results highlighted it as an important variable for discriminating between its maturation stages. Meanwhile, in the C1 melon, the increase in soluble solids content influences the more negative values of osmotic potential, not by changes in TSS content, and thus may be associated with fruit growth. Full article

(This article belongs to the Section Plant Physiology)

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30 pages, 28314 KB

Open AccessArticle

Cultivar-Specific Transcriptional and Biochemical Responses of In Vivo-Grown Camellia sinensis Plants to Long-Term Nitrogen Deficiency

by Karina A. Manakhova, Lidiia S. Samarina, Lyudmila S. Malyukova, Lada V. Zhokhova, Alexey V. Ryndin and Evgeny I. Rogaev

Int. J. Plant Biol. 2026, 17(9), 86; https://doi.org/10.3390/ijpb17090086 - 9 Sep 2026

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Abstract

Nitrogen (N) availability strongly influences tea growth and the accumulation of quality-related metabolites, but long-term responses to withdrawal of external N can vary among cultivars. In this study, we characterized phenotypic, spectral, biochemical, and transcriptomic responses of four Camellia sinensis accessions—‘Kolkhida’, ‘Karatum’, and [...] Read more.

Nitrogen (N) availability strongly influences tea growth and the accumulation of quality-related metabolites, but long-term responses to withdrawal of external N can vary among cultivars. In this study, we characterized phenotypic, spectral, biochemical, and transcriptomic responses of four Camellia sinensis accessions—‘Kolkhida’, ‘Karatum’, and γ-irradiation-derived mutant forms #582 and #619—during two, four, or six months of complete withdrawal of exogenous NH₄NO₃ in greenhouse sand culture. Phenotypic, spectral, and biochemical measurements included all four accessions at all three time points; RNA-seq data were available for all four accessions were represented at four and six months, whereas two-month point were available only for ‘Kolkhida’ and ‘Karatum’. Nitrogen withdrawal decreased L-theanine and caffeine and generally increased simple and gallated catechins, consistent with a change in carbon/nitrogen balance towards phenolic metabolism. The four cultivars exhibited markedly distinct responses. ‘Karatum’ showed the optimum resilience, with minimal phenotypic alteration and a neutral transcriptional response, while #582 demonstrated a stronger stress-associated phenotype and metabolic response. Within the available RNA-seq comparisons, DEG counts were lower at four months than at six months, while the two-month datasets for ‘Kolkhida’ and ‘Karatum’ contained the largest DEG sets for those two cultivars, suggesting a phased acclimation process. CsELIP1, CsSRG1, CsHHO2/4, CsNRT2.4, and CsTAT2 were identified as potential candidate genes associated with nitrogen limitation, flavonoid regulation, and amino acid metabolism. Our findings show that N-deficiency reactions in tea are highly cultivar- and time-dependent, making single-time-point evaluations insufficient. We propose ‘Karatum’ as a promising candidate for further evaluation in low-nitrogen dose–response and field trials based on our combined biochemical and transcriptional findings. Full article

(This article belongs to the Section Plant Biochemistry and Genetics)

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22 pages, 3525 KB

Open AccessArticle

Physiological, Biochemical, and Molecular Responses of Potato Cultivars to Osmotic Stress Under In Vitro Shoot Culture

by Aidana K. Argumbayeva, Balnur R. Kali, Laura S. Abeuova, Beibit N. Nasiyev, Aisulu Orken, Dilnur Tussipkan and Shuga A. Manabayeva

Int. J. Plant Biol. 2026, 17(9), 85; https://doi.org/10.3390/ijpb17090085 - 9 Sep 2026

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Abstract

Drought is a major limiting factor for potato productivity. This study examined two Kazakh potato cultivars, Tokhtar and Aksor, under osmotic stress induced by polyethylene glycol (PEG)-6000 using an integrated physiological, biochemical, and molecular approach. We evaluated plant growth, total chlorophyll content, catalase [...] Read more.

Drought is a major limiting factor for potato productivity. This study examined two Kazakh potato cultivars, Tokhtar and Aksor, under osmotic stress induced by polyethylene glycol (PEG)-6000 using an integrated physiological, biochemical, and molecular approach. We evaluated plant growth, total chlorophyll content, catalase activity, malondialdehyde content, and the transcript levels of six stress-associated genes (StMYB306-like, StuNAC, TRE, OST2, and EPF1, and EPF2) across increasing PEG concentrations. PEG treatment significantly inhibited growth and reduced total chlorophyll content while increasing CAT activity and MDA accumulation. The magnitude and statistical significance of the morphological and biochemical responses varied between cultivars and among PEG concentrations. Transcript levels of StMYB306-like, StuNAC, TRE, and OST2 generally increased with increasing PEG concentration, while EPF1 and EPF2 levels decreased. The absence of significant cultivar × PEG interactions for all six genes indicated that their transcriptional responses to PEG did not differ statistically between Tokhtar and Aksor. Correlation and multivariate analysis revealed contrasting associations between growth and chlorophyll-related traits and CAT activity, MDA accumulation, and stress-responsive gene expression. To our knowledge, the expression patterns of TRE, OST2, and EPF1 and EPF2 in potatoes under PEG-induced osmotic stress have not been characterized previously. Taken together, these findings characterize the coordinated morphological, biochemical, and transcriptional responses of potato plantlets to PEG-induced osmotic stress. They also identify candidate response traits for validation across genetically diverse germplasm and under soil-based and field drought conditions. Full article

(This article belongs to the Special Issue Hormone and Gene Regulatory Networks in Plant Stress Resistance)

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14 pages, 1841 KB

Open AccessArticle

Modulation of Maize Yield Response to Vapor Pressure Deficit by Nitrogen Nutrition and Phenological Stress Windows

by Miroslav Salaić, Zvonimir Zdunić, Antun Jambrović, Domagoj Šimić, Sonja Petrović, Andrija Brkić and Vlatko Galić

Int. J. Plant Biol. 2026, 17(9), 84; https://doi.org/10.3390/ijpb17090084 - 8 Sep 2026

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Abstract

This study explored how nitrogen fertilization modulates the grain yield response of maize to atmospheric stress across distinct phenological windows. Field trials were conducted from 2023 to 2025 under three nitrogen regimes (N0, N69, and NFull) with 237 maize testcrosses. Atmospheric stress was [...] Read more.

This study explored how nitrogen fertilization modulates the grain yield response of maize to atmospheric stress across distinct phenological windows. Field trials were conducted from 2023 to 2025 under three nitrogen regimes (N0, N69, and NFull) with 237 maize testcrosses. Atmospheric stress was quantified as the cumulative number of hours with a vapor pressure deficit (VPD) exceeding 3.0 kPa. Data were analyzed using linear mixed-effects models. The 15-day pre-silking window was identified as the most sensitive among the three evaluated phenological windows, exhibiting a strong negative scaled effect of −0.390. The interaction between nitrogen treatment and pre-silking stress was highly significant. Elevated VPD did not operate as an independent determinant of final yield, as the highest mean grain yield was achieved during the hydrothermally intense 2025 season (8.319 t ha⁻¹). NFull effectively mitigated the physiological impact of stress, securing the shallowest yield decline slope (−0.038 t ha⁻¹ per hour). Conversely, the intermediate N69 treatment exhibited the highest statistical sensitivity (−0.109 t ha⁻¹ per hour), reflecting phenotypic plasticity. Random-effects analysis revealed substantial genetic variability for pre-silking VPD sensitivity. The lack of correlation between absolute yield potential and stress sensitivity enables simultaneous selection for both high yield and phenotypic stability within this germplasm. Full article

(This article belongs to the Section Plant Response to Stresses)

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16 pages, 11238 KB

Open AccessArticle

Foliar Application of Se and TiO₂ Nanoparticles Induces Physiological Stability and Stem Anatomical Remodeling Without Affecting Vegetative Growth in Lilium cv. Concador

by Sergio Rubén Pérez-Ríos, Nayla Tamara Sánchez-Granados, Juan Ocampo-López, Mariana Saucedo-García, Fabián Fernández-Luqueño, María Fernanda Cenobio-Galindo, Macario Vicente-Flores, Ma Isabel Reyes-Santamaría, Cristián Raziel Delgado-González and Iridiam Hernández-Soto

Int. J. Plant Biol. 2026, 17(9), 83; https://doi.org/10.3390/ijpb17090083 - 4 Sep 2026

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Abstract

Lilium sp. is one of the most commercially important ornamental species; however, improving its ornamental quality remains a challenge for production systems. In this context, nanoparticles have been proposed as an innovative alternative to optimize the agronomic performance of ornamental crops. The objective [...] Read more.

Lilium sp. is one of the most commercially important ornamental species; however, improving its ornamental quality remains a challenge for production systems. In this context, nanoparticles have been proposed as an innovative alternative to optimize the agronomic performance of ornamental crops. The objective of this study was to determine how the foliar application of selenium nanoparticles (SeNPs) and titanium dioxide nanoparticles (TiO₂NPs) modifies the physiological response and stem morphoanatomy of Lilium cv. Concador. Plants were grown under greenhouse conditions using conventional agronomic management for commercial Lilium production. We evaluated vegetative growth variables, relative chlorophyll content (SPAD), root biomass, flowering characteristics, and quantitative stem anatomy using histological, morphometric, and multivariate statistical analyses. Most agronomic variables, including plant height, number of leaves, shoot biomass, and flower opening, did not differ significantly between treatments, indicating that the nanoparticles did not compromise vegetative development. In contrast, root biomass and stem anatomical organization responded differently depending on nanoparticle type and applied dose. SeNPs, particularly at the highest dose, promoted greater development of parenchyma and vascular tissue, while TiO₂NPs induced dose-dependent anatomical responses, with less parenchyma expansion and less pronounced vascular remodeling. Taken together, these results demonstrate that foliar application of nanoparticles induces early remodeling of the stem’s functional architecture without affecting vegetative growth and show that quantitative anatomy is a sensitive tool for detecting early responses to nano-inputs in ornamental species. Full article

(This article belongs to the Section Plant Physiology)

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16 pages, 6540 KB

Open AccessArticle

De Novo Transcriptome Assembly and Differential Gene Expression Analysis of the Global Invader Thunbergia alata Under Varying Light Conditions

by Juan Camilo Alvarez-Diaz, Daniela Marin, Mariana Espinal-Guzman, Esteban Felipe Loaiza-Jaramillo and Mario Alberto Quijano-Abril

Int. J. Plant Biol. 2026, 17(9), 82; https://doi.org/10.3390/ijpb17090082 - 2 Sep 2026

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Abstract

Biological invasions threaten tropical biodiversity, yet the molecular mechanisms underlying successful invaders remain poorly understood. Thunbergia alata (Black-eyed Susan) is an aggressive “genomic orphan” invader in Andean forests, causing significant ecological disruption. This study contributes as one of the few transcriptomic profiles of [...] Read more.

Biological invasions threaten tropical biodiversity, yet the molecular mechanisms underlying successful invaders remain poorly understood. Thunbergia alata (Black-eyed Susan) is an aggressive “genomic orphan” invader in Andean forests, causing significant ecological disruption. This study contributes as one of the few transcriptomic profiles of light vs. shade responses in T. alata, providing a foundational molecular resource for this species. We performed differential expression analysis under varying light conditions, revealing a massive transcriptomic shift involving over 4000 differentially expressed genes. Our findings suggest a robust and stable homeostatic adaptation mechanism, characterized by the up-regulation of SnRK1 subunits for energy sensing and strategic management of Reactive Oxygen Species (ROS) within the thylakoid membrane. Furthermore, the fine-tuning of PIF/Auxin modules and the condition-specific induction of NAC and WRKY transcription factors facilitate shade avoidance and rapid vertical growth. The identification of a substantial reservoir of species-specific “not classified” genes suggests that novel genetic elements contribute to T. alata’s adaptive success. By elucidating these key regulatory networks, this research provides an important genomic baseline for future studies on adaptive evolution and the development of molecularly informed strategies for managing and controlling this invasive species in new environments. Full article

(This article belongs to the Section Plant Biochemistry and Genetics)

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37 pages, 431 KB

Open AccessReview

Single-Nucleotide Polymorphism Chip Platforms in Rice (Oryza sativa) Genomics and Their Potential for Precision Breeding

by Ha Duc Chu, Trung Quoc Nguyen, Anh Quynh Ho, Gioi Huy Dong, Hong Viet La, Nguyen Thi Phuong Thao and Linh Hong Ta

Int. J. Plant Biol. 2026, 17(9), 81; https://doi.org/10.3390/ijpb17090081 - 31 Aug 2026

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Abstract

Single-nucleotide polymorphism (SNP) arrays provide reproducible, accurate, and scalable genotyping for rice research and cultivar development. This review critically evaluates the design and development of major rice SNP platforms and defines their value within a rapidly changing genotyping landscape. In contrast to earlier [...] Read more.

Single-nucleotide polymorphism (SNP) arrays provide reproducible, accurate, and scalable genotyping for rice research and cultivar development. This review critically evaluates the design and development of major rice SNP platforms and defines their value within a rapidly changing genotyping landscape. In contrast to earlier platform-centered summaries, this review connects array selection with the complete breeding pathway from germplasm assessment and locus discovery to functional validation, marker-assisted transfer, genomic selection, varietal authentication, and pre-breeding. SNP arrays are compared with genotyping-by-sequencing, double-digest restriction site-associated DNA sequencing, low-pass sequencing, whole-genome resequencing, targeted sequencing, and long-read sequencing in terms of cost, throughput, data completeness, computational demand, marker discovery, and population transferability. Candidate-locus validation through gene-expression analysis, haplotype analysis, near-isogenic lines, RNA interference, transgenic complementation, clustered regularly interspaced short palindromic repeats/CRISPR-associated protein (CRISPR/Cas) editing, and field evaluation is also examined. Pangenome resources and the contributions of structural variants, presence/absence variations, and copy number variations to probe design and trait analysis receive particular attention. The review further assesses ascertainment bias, weak detection of rare alleles, genotype-cluster errors, limited portability across distant germplasm, and reduced genomic prediction across populations or environments. Future priorities include multi-omics integration, climate-resilient rice improvement, modular panels, imputation anchor loci, and economical deployment through low-density assays, shared facilities, and kompetitive allele-specific polymerase chain reaction conversion. The value of SNP arrays is greatest when stable genotype calls, large sample numbers, and repeated use across breeding cycles are required. Their practical contribution should be judged by prediction accuracy, selection cost, cycle duration, donor-segment control, realized genetic gain, and cultivar deployment. Full article

(This article belongs to the Section Plant Biochemistry and Genetics)

27 pages, 3426 KB

Open AccessArticle

Image-Based Identification of Crop and Weed Species at the Seedling Stage: Deep Learning Classifiers Rely on Acquisition Context Beyond Plant Morphology

by Lyna Miloudi, Khaled Rezeg and Mohamed Kotoub Miloudi

Int. J. Plant Biol. 2026, 17(9), 80; https://doi.org/10.3390/ijpb17090080 - 29 Aug 2026

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Abstract

Distinguishing crop from weed species at the seedling stage is a fine-grained morphological discrimination problem. We study it on the public Plant Seedlings benchmark, which contains twelve species (three crops and nine weeds) imaged at the seedling stage. Automated classifiers report near-ceiling accuracy [...] Read more.

Distinguishing crop from weed species at the seedling stage is a fine-grained morphological discrimination problem. We study it on the public Plant Seedlings benchmark, which contains twelve species (three crops and nine weeds) imaged at the seedling stage. Automated classifiers report near-ceiling accuracy on this benchmark. Yet its images are acquired in controlled trays containing soil, gravel, rulers, barcodes, and printed labels, so a model may identify a species from its acquisition context rather than its morphology. We audit two architectures, EfficientNet-B7 and ViT-B/16, trained on the V2 dataset (5539 images) and probed with plant-only, background-only, and background-swapped inputs. Near-ceiling models (96.1% and 96.4% over three seeds) recover the correct species for up to 47.7% of samples from the background alone (chance 8.3%) and lose about 60 points under background swapping. Context reliance is therefore a property of the benchmark, not any single architecture. Tracing this to its source, an independent learned representation of the plant-free background alone identifies the species at 72.4%. The reliance is correctable end to end: a consistency-regularisation scheme retains 92.1% full-image accuracy for the transformer with no segmentation at inference, at an architecture-dependent cost. Reported accuracy thus partly measures acquisition context, not morphology; morphological grounding should be measured and reported alongside accuracy. Full article

(This article belongs to the Section Application of Artificial Intelligence in Plant Biology)

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21 pages, 1076 KB

Open AccessArticle

Medicinal Herbs and Spices from Mount Athos, Greece: Phenolic Content, Antioxidant Activity, and Qualitative Effects on Oxidative DNA Damage

by Efthymios Poulios, Sousana K. Papadopoulou, Evmorfia Psara, Agathi Pritsa and Constantinos Giaginis

Int. J. Plant Biol. 2026, 17(9), 79; https://doi.org/10.3390/ijpb17090079 - 29 Aug 2026

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Abstract

Background/Objectives: Medicinal and aromatic plants are important sources of phenolic compounds with antioxidant properties. This study evaluated the total phenolic content (TPC) and antioxidant activity of 19 commercially available medicinal herb and spice products of reported Mount Athos provenance and investigated the influence [...] Read more.

Background/Objectives: Medicinal and aromatic plants are important sources of phenolic compounds with antioxidant properties. This study evaluated the total phenolic content (TPC) and antioxidant activity of 19 commercially available medicinal herb and spice products of reported Mount Athos provenance and investigated the influence of extraction solvent on these properties. Methods: Extracts were prepared by ultrasound-assisted extraction using water, 50% aqueous methanol, or 50% aqueous acetone. TPC was determined using the Folin–Ciocalteu assay, while antioxidant activity was evaluated using DPPH, ABTS, FRAP, and a qualitative supercoiled plasmid DNA relaxation assay. Solvent effects were assessed using Friedman and post hoc Wilcoxon signed-rank tests, and associations between TPC and antioxidant activity were examined using correlation and regression analyses. Results: TPC and antioxidant activity varied considerably among botanical products and extraction conditions, with Origanum spp. generally exhibiting among the highest TPC values and strong antioxidant responses. Aqueous acetone yielded significantly higher TPC than aqueous methanol and water. Both aqueous organic solvents produced greater DPPH inhibition than water, whereas aqueous methanol produced greater ABTS activity than water; no significant solvent effect was observed for FRAP. TPC was positively associated with antioxidant activity, particularly ABTS and FRAP, explaining up to 78% of its variability. Several extracts also preserved the supercoiled plasmid DNA form under hydroxyl radical-generating conditions, although this observation requires quantitative confirmation. Conclusions: Medicinal herbs and spices of Athonite provenance exhibit considerable phytochemical and antioxidant variability. Extraction solvent influences phenolic recovery and antioxidant activity in an assay-dependent manner, with no single solvent being uniformly superior. These findings provide baseline data supporting further phytochemical characterization and quantitative evaluation of the antioxidant and DNA-protective properties of these botanical materials. Full article

(This article belongs to the Section Plant Biochemistry and Genetics)

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15 pages, 2225 KB

Open AccessArticle

Bioactivity of Ascophyllum nodosum in Mitigating Water Stress Induced by PEG-6000 in Maize Seeds

by Janyne Soares Braga Pires, Francine Bonomo Crispim Silva, Maria Eduarda da Silva Barbosa, Geovana Ribeiro Cavilha, Mateus Moura Coelho, Samile Mardegan Otilia, Fernando Gomes Hoste, Ana Júlia Câmara Jeveaux-Machado, Lúcio de Oliveira Arantes, Vinicius de Souza Oliveira, Simone Alves Fernandes, Johnatan Jair de Paula Marchiori, Adriano Alves Fernandes and Sara Dousseau-Arantes

Int. J. Plant Biol. 2026, 17(9), 78; https://doi.org/10.3390/ijpb17090078 - 22 Aug 2026

Cited by 1 | Viewed by 318

Abstract

Water deficit is one of the main limiting factors for crop establishment and productivity, particularly during seed germination and early seedling development. This study aimed to evaluate the biostimulant potential of Ascophyllum nodosum extract applied to maize (Zea mays L.) seeds subjected [...] Read more.

Water deficit is one of the main limiting factors for crop establishment and productivity, particularly during seed germination and early seedling development. This study aimed to evaluate the biostimulant potential of Ascophyllum nodosum extract applied to maize (Zea mays L.) seeds subjected to osmotic stress induced by polyethylene glycol (PEG-6000). Three independent bioassays were conducted under controlled conditions. In the first assay, osmotic potentials ranging from 0 to −0.8 MPa were evaluated to characterize stress levels and identify conditions representative of moderate and severe water deficit. In the second assay, increasing doses (0 to 2.0 mL kg⁻¹ of seeds) of a commercial A. nodosum-based extract and its isolated mineral fraction were evaluated to determine the optimal application range. In the third assay, the selected treatment was evaluated under control conditions and under moderate (−0.6 MPa) and severe (−0.8 MPa) osmotic stress. Germination percentage, normal and abnormal seedlings, radicle and epicotyl length, and seedling vigor index were assessed. Osmotic stress progressively reduced germination and seedling growth, with the strongest effects observed at −0.6 and −0.8 MPa. Seed treatment with A. nodosum extract did not impair final germination but improved seedling development in a dose-dependent manner. The highest efficiency was observed at intermediate doses, with maximum normal seedling percentage predicted at 0.45 mL kg⁻¹ and maximum radicle growth at approximately 0.66 mL kg⁻¹. Under water deficit conditions, the complete extract promoted greater improvements in seedling performance than the mineral fraction, indicating that the beneficial effects were mainly associated with bioactive organic compounds rather than mineral nutrition alone. These findings provide new evidence that dose optimization is essential for maximizing the efficiency of seaweed-based biostimulants and demonstrate the potential of A. nodosum seed treatment as a sustainable strategy to improve maize establishment under water-limited conditions. Full article

(This article belongs to the Section Plant Response to Stresses)

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Int. J. Plant Biol., Volume 17, Issue 9 (September 2026) – 19 articles

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