Ascorbic acid (AsA) is one of the most abundant and versatile free-radical scavengers in plants, playing a crucial role in protecting cellular defense mechanisms by mitigating oxidative stress. Under stress conditions, plants undergo physiological and biochemical modifications, primarily due to the excessive production of reactive oxygen species (ROS), which disrupt cellular homeostasis and damage nucleic acids, proteins, and cellular membranes. Cellular AsA serves as both a non-enzymatic antioxidant and an enzymatic cofactor, maintaining the pro-oxidant-antioxidant balance by scavenging ROS and promoting detoxification via the ascorbate–glutathione cycle, xanthophyll cycle, and antioxidant enzyme activity. Beyond its antioxidant role in stress tolerance, cellular AsA also serves as a cofactor for enzymes, an electron donor to the photosystem, and plays a role in plant ontogenesis by regulating cell cycle progression, enzyme activity, hormonal signaling, and plant defense mechanisms. The cellular ascorbate pool is regulated by several biosynthetic genes, including GMP, GGP, and VITAMIN C DEFECTIVE (VTC), and also by ascorbate recycling genes such as APX, GR, MDHAR, and DHAR. Under stress conditions, various regulatory proteins, such as ABI4, PTPN, CSN5B, COP9, HY5, and the KONJAC protein, also regulate the cellular ascorbate pool by interfering with the AsA biosynthesis and recycling pathways, thereby helping to develop climate-resilient crops. Recent advances in genome-editing technologies, such as CRISPR-Cas9, facilitate increased cellular AsA levels, improving stress tolerance and supporting crop productivity. This review highlights the regulation of the AsA biosynthetic pathway, the role of AsA in physio-biochemical mechanisms, hormonal crosstalk, and the molecular aspects of AsA in mitigating stress-induced effects in plants.
Enhancing tomato productivity and fruit quality under changing environmental conditions has become a critical objective in agricultural research. As climate-induced stresses and food security concerns intensify, there is growing emphasis on understanding the complex traits that govern tomato resilience and fruit characteristics. The integration of multi-layered ‘omics’ approaches, including genomics, transcriptomics, proteomics, metabolomics, and phenomics, enables the dissection of complex traits from genome to phenome. These technologies have enabled the identification of candidate genes, regulatory networks, and key metabolic pathways associated with biotic, abiotic stress tolerance and essential fruit quality traits such as flavor, texture, and nutritional value. Coupled with genome editing technologies, high-throughput phenotyping platforms facilitate predictive trait analysis and accelerate the selection of desirable genotypes. Altogether, this review synthesizes recent progress in omics-assisted tomato breeding, highlights key case studies, and explores the potential of integrating advanced computational and biotechnological approaches to improve tomato productivity and modern breeding strategies for sustainable tomato production.
Powdery mildew (PM), a worldwide disease affecting more than 10,000 plant species, is caused by obligate biotrophic fungi of the order Helotiales. It is identified by the presence of greyish powdery patches on aerial plant parts and leads to impaired photosynthesis, vegetative strength and yield which cause significant economic losses in various species. This review provides an overview of recent advancements in PM research, focussing majorly on taxonomy, causative agents, symptoms, disease cycle, molecular diagnosis and disease management strategies. The review also highlights the diversity of the family Erysiphaceae along with host specificity and morphological variations among different genera. Disease cycle in terms of disease spread via asexual conidia and inter-season survival via sexual chasmothecia is also explored. Further, this review also suggests that advancements in early detection technologies like PCR-based diagnostics, hyperspectral imaging and machine learning-assisted phenotyping as potential tools for pre-symptomatic identification and management. It also discusses molecular approaches such as QTL (Quantitative trait loci) mapping, genome-wide association studies (GWAS), genomic prediction and transcriptomics that are used for identifying resistance genes or non-coding RNAs (ncRNAs) in plants. Innovations in functional genomics approaches such as overexpression of defense-related transcription factors, editing of susceptibility genes via CRISPR-Cas, RNA interference (RNAi) have further enhanced PM resistance in host plants. Despite such breakthroughs, certain challenges such as pathogen adaptability, emerging fungicide resistance and environmental concerns still persist. Future research integrating multi-omics approaches, precision phenotyping and environmentally sustainable RNA-based approaches will be crucial for achieving durable and eco-friendly PM management in various agroecosystems.
Efforts to improve water-use efficiency (WUE) and drought resilience in rice have generated a large catalog of candidate stomatal traits, yet no principled basis exists for deciding which traits merit the cost of selection. Recent syntheses recommend balancing stomatal and non-stomatal trade-offs but describe the problem's structure without supplying a classification, while the optimization-theory and molecular-genetic literatures that could provide one have developed in parallel. Here, we deploy stomatal optimization theory not as a descriptive background but as a quantitative prioritization filter. We reduce the theory to four axes consequential for the carbon–water trade-off: the steady-state setpoint (g₁/λ), response speed, hydraulic supply (Kleaf/Lpr), and the developmental ceiling on maximum conductance (gmax). Mapping the rice molecular toolbox onto these axes, rather than onto gene families, yields a tractability-ranked shortlist scored by phenotyping feasibility, genetic architecture, and yield-penalty risk. This ranking is not fixed but inverts with drought regime: the setpoint axis is the highest-value target under intermittent stress but is demoted under terminal stress, where reducing gmax becomes protective; response speed gains value with severity yet is not yet selectable; and hydraulic supply becomes limiting only under high-VPD terminal stress. This inversion follows because the constant-λ assumption underlying optimization holds under recoverable deficit but fails once hydraulic limitation becomes non-recoverable. We frame regime-dependence temporally: intermittent versus terminal, vegetative versus reproductive stress, not by production system. The review closes with testable predictions, each naming a measurable contrast and its phenotyping bottleneck to direct future work.
Mungbean (Vigna radiata) is a short-duration legume crop, and identifying suitable housekeeping genes is crucial for accurate gene expression analysis under both normal and stress conditions, as they enable proper normalization of target gene expression data. To address this gap, we carried out a comparative analysis of ten housekeeping genes to determine the most appropriate reference genes for assessing target gene expression. Among the ten genes, EF-1 ALPHA, CYP1, and GAPDH showed the most stable expression across different tissues compared with the other reference genes. All three genes exhibited lower Ct values and better stability scores across different algorithms than the other genes tested. Further, the suitability of these selected reference genes was validated by examining the expression of PHENYLALANINE AMMONIA LYASE (PAL), CINNAMOYL ALCOHOL DEHYDROGENASE (CAD), IRREGULAR XYLEM 14 (IRX14), and RIBULOSE-1,5-BISPHOSPHATE CARBOXYLASE/OXYGENASE (RuBisCO) in three different mungbean genotypes and tissue types. We further tested the expression of RuBisCO in seedlings under salt and osmotic stress and found that its expression was lower than that in control plants, which correlated with the seedling phenotype. Moreover, we validated the efficacy of these reference genes by examining the expression of selected target genes and found that all were upregulated in mungbean yellow mosaic virus-infected leaves compared with non-infected leaves. Based on these findings, we propose that EF-1 ALPHA is the best reference gene, followed by CYP1 and GAPDH, for analyzing gene expression across different tissues and developmental stages under both normal and stress conditions in mungbean.
Eco-physiological traits are key to understanding how plants cope with environmental stress, yet their integrated variation along altitudinal gradients in Himalayan tree species remains poorly understood. This study investigated leaf functional trait variation and plasticity in Quercus griffithii across three altitudinal zones between 1000 and 2800 m a.s.l. in the Eastern Himalaya. Nine leaf traits namely leaf length (LL), leaf breadth (LB), leaf area (LA), chlorophyll a (Chl_a), chlorophyll b (Chl_b), relative water content (RWC), stomatal density (SD), stomatal length (SL), and stomatal breadth (SB)—were quantified using coefficients of variation (CV), plasticity indices (PI), correlation analysis, and PCA. Leaf morphometric traits declined progressively with altitude, whereas stomatal traits showed greater variability and plasticity than physiological traits, indicating a stronger contribution of structural adjustments to altitudinal responses. RWC decreased with altitude, while chlorophyll and stomatal traits showed trait-specific variation across the gradient. Correlation analysis revealed reduced trait coordination at higher altitudes, and PCA identified distinct axes associated with physiological and stomatal traits. Collectively, these findings demonstrate that Q. griffithii responds to altitudinal variation through integrated but trait-specific adjustments, offering new insights into intraspecific functional trait variation in heterogeneous Himalayan environments.
Soil salinity stress limits crop productivity by disrupting plant physiological processes, water uptake, creating ionic imbalance, and interrupting cellular homeostasis, causing oxidative damage. The present study investigates the potential of a habitat-adapted endophytic fungus, Fusarium isolates, to confer salinity stress tolerance in tomato. Amongst three isolates (K23, SF-5, and N-14) tested, symbiosis with SF-5 exhibited beneficial effects at early seedling growth under NaCl-induced stress. The beneficial effects of endophyte inoculation were maintained at the whole-plant level under greenhouse conditions subjected to 10 dS m⁻¹ salinity stress, with SF-5-inoculated plants exhibiting superior growth-related traits compared to uninoculated plants under the same stress conditions. Endophyte colonization significantly increased chlorophyll content and photosynthetic rate, reflecting enhanced photosynthetic efficiency under stress conditions. Histochemical analysis showed reduced accumulation of reactive oxygen species (O2⁻ and H2O2) and improved membrane stability in SF-5 inoculated stressed plants, suggesting enhanced antioxidant defense mechanisms. However, despite improvements in early vegetative and physiological processes, average fruit weight and total fruit yield did not show any improvement under high salinity in SF-5 inoculated plants. Fruit quality parameters showed differential responses, with reduced total soluble solids under stress. Overall, the results suggest that SF-5 confers salinity stress tolerance primarily by enhancing cellular tolerance via the alleviation of oxidative damage and the maintenance of higher photosynthetic efficiency. These findings demonstrate the potential of the fungal endophyte as a sustainable biological elicitor for enhancing resilience to salinity stress.
Temperature-sensitive genic male sterility (TGMS) is the foundation of two-line hybrid rice breeding, with fertility transition primarily regulated by temperature during the thermosensitive stage of microsporogenesis. Although temperature is the primary regulator of fertility transition, photoperiod modulates sterility expression by influencing the duration of exposure during the thermosensitive phase. This study investigated the interactive effects of temperature and photoperiod on a tms5-derived TGMS red rice line (EC720903 and derivatives) through integrated morphological, biochemical, and targeted metabolomic analyses. Elevated temperature induced complete male sterility, which wasaccompanied with increased reactive oxygen species (ROS) accumulation, lipid peroxidation, membrane damage, hormonal imbalance, and metabolic reprogramming of amino acids and phenolic compounds. Photoperiod extension alone induced moderate pollen sterility, while its combination with elevated temperature further intensified oxidative and metabolic perturbations, resulting in the greatest reduction in pollen viability. The combined temperature × photoperiod treatment was characterized by enhanced accumulation of H₂O₂, and malondialdehyde, together with pronounced hormonal dysregulation and coordinated changes in amino acid and phenylpropanoid metabolism, indicating disruption of tapetal function and pollen development. Collectively, the findings demonstrate that temperature and photoperiod interact to regulate fertility expression through coordinated physiological and metabolic responses, with temperature acting as the primary determinant and photoperiod functioning as a complementary regulator of sterility. The observed interaction further suggests that photoperiod management may help maintain sterility expression when environmental temperatures fluctuate near the critical sterility threshold, thereby improving the stability of TGMS-based hybrid seed production under variable climatic conditions.
Seed coat colour can be an important practical and non-destructive indicator of physiological seed quality in many crop species. This review compiles current knowledge on the genetic, biochemical, and physiological mechanisms underlying seed coat colour and critically examines its relationship with major seed quality traits. Seed coat colour is primarily governed by the phenylpropanoid-flavonoid biosynthetic pathway, which regulates the accumulation of flavanols, anthocyanins, and proanthocyanidins by the MYB-bHLH-WD40 (MBW) transcriptional complex. These compounds not only determine the seed coat colour but also influence permeability, antioxidant capacity, membrane stability, and stress adaptations. Darker-seeded genotypes generally accumulate higher levels of these phenolic compounds and are frequently associated with regulated water imbibition, enhanced dormancy, improved germination, greater seed vigour, superior storability, increased resistance to biotic and abiotic stresses, and better field emergence than lighter-seeded genotypes. Recent evidence further suggests that interactions among pigment compounds contribute to the regulation of seed germination and longevity. This review also highlights recent advances in digital phenotyping, including colorimetry, hyperspectral imaging, and machine learning. These advances enable an objective, high-throughput assessment of seed coat colour, strengthening its application in seed quality evaluation. Overall, seed coat colour is a reliable, rapid, and cost-effective morphological marker for assessing seed quality and using in breeding programmes.
The present study deals with genetic diversity study among 22 pomegranate genotypes using 25 informative markers viz., 19 SSRs, 2 Pre_miRNA-SSRs, 1 Pg_PIP and 3 InDels with distributions. A total of 64 alleles were amplified with an average of 2.56 alleles per primer. Based on polymorphism information content (PIC), 13 highly polymorphic markers with PIC ≥ 0.5 were shortlisted for clonal fidelity testing. The micropropagation of Bhagwa cultivar was achieved using nodal explants on modified MS medium to produce 20 true to type planting materials. Clonal fidelity was assessed among 20 micro-propagated plantlets using 13 highly polymorphic markers with known chromosome locations. As a result, all the 13 markers revealed highly uniform monomorphic bands among in vitro raised Bhagwa saplings as that of mother plant. The clonal fidelity analysis revealed high genetic uniformity among the micro propagated Bhagwa plantlets and their mother plant. Also, underscore efficiency of identified genic and genomic markers for systematic monitoring of somaclonal variations for future sustainable and profitable pomegranate cultivations.
The Sarawak Gold (SG1) pineapple is a premium Malaysian variety valued for its golden flesh, natural sweetness, and potential health-promoting properties. This study evaluated the phytochemical characteristics, antioxidant activity, bromelain properties, and nutritional composition of SG1 pineapples cultivated on mineral soil in Mantin, Negeri Sembilan, across different maturity indices. Physicochemical properties were assessed at maturity indices 0–7, while total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity, bromelain content, and bromelain activity were determined at representative maturity stages (Index 1, 3, and 6). The results showed that bromelain content was highest at index 1 (104.39 mg/100 mL), whereas bromelain activity peaked at index 3 (3769 GDU/g). Antioxidant activity increased from Index 1 and remained high at index 3 and 6. Total phenolic content was highest at index 6 (282.90 µg GAE/mg), while total flavonoid content reached its maximum at index 3 (24.82 µg QE/mg). Nutritional analysis revealed sucrose as the predominant sugar (5.6 g/100 mL) and potassium as the most abundant mineral (807 mg/kg). Fruit maturity also influenced pH, total soluble solids, and overall fruit quality. These findings indicate that index 3 may be suitable for bromelain-related applications, whereas index 6 may be preferred for antioxidant-rich products. The study provides new information on the phytochemical, biochemical, and nutritional characteristics of SG1 pineapple and may be useful to support harvest management and value-added product development.
The present investigation evaluated the impact of pruning on yield, fruit quality, leaf nutrient composition and disease incidence in mango cv. Amrapali. Pruning significantly influenced fruit weight, yield dynamics, biochemical quality attributes, leaf nutritional status and disease infestation. Although fruit yield of pruned trees declined during the first year following pruning compared with that of unpruned trees, a marked increase was recorded in the subsequent year, indicating a strong compensatory response. Leaf nutrient analysis revealed greater concentrations of K, Mg, S, Cu, Zn and Mn in pruned trees, whereas N, P, Ca and Fe concentrations were higher in unpruned trees. Pruning also noticeably decreased the incidence of major diseases, including anthracnose and stem-end rot in fruits and anthracnose and red rust in leaves. Strong positive correlations were observed among ascorbic acid, carotenoids, antioxidant activity, and total phenolic content (r = 0.87–0.99). The beneficial effects of pruning were attributed to improved light penetration, enhanced air circulation, stimulation of new vegetative growth and more efficient nutrient redistribution. This study demonstrates that strategic pruning improves fruit nutritional quality, plant health and long-term productivity in mango cv. Amrapali, highlighting the importance of regular and judicious pruning for sustainable mango orchard management.
Porang (Amorphophallus muelleri) is a high-value tuber crop prized for its glucomannan, yet seed-based propagation is constrained because its compound fruit ripens unevenly. This study examined how the physiological ripening stage of green fruit affects seed size, germination, seed health, and embryo type (mono- versus poly-embryonic). Fruits were harvested at four weekly stages—T0 (early physiological ripeness), T1, T2, and T3 (T0 + 7, + 14, and + 21 days)—and the seeds were surface-sterilised (25
A set of 121 intersubspecific-derived rice lines was evaluated during Kharif 2024 and Summer 2025 at the Department of Rice, Tamil Nadu Agricultural University, Coimbatore, to assess genetic variability, genotype × environment interaction, inter-trait associations, and phenotypic diversity. The experiment was conducted in an alpha lattice design with three replications, and observations were recorded for twelve quantitative traits. Combined ANOVA across seasons revealed highly significant variation among the genotypes for all traits, demonstrating substantial variability. Higher genotypic and phenotypic coefficients of variation were observed for single plant yield, number of filled grains per panicle, flag leaf length, grain breadth, and productive tillers. High broad-sense heritability coupled with substantial genetic advance as a percentage of the mean was recorded for GB, GL, L/B ratio, NFP, and SPY. Correlation analysis revealed a positive relationship of SPY with FL and NFP. Principal component analysis extracted five principal components with eigenvalues exceeding unity, accounting for 75.35
Reliable regeneration systems are critical for biotechnological applications and for genetic improvement in tissue-culture recalcitrant sorghum. This study used mature seeds as explants to establish a reproducible and season-independent regeneration system for M35-1, an important native Indian Maldandi genotype. Different concentrations of 2,4-D (1–3 mg/L) in combination with Kinetin (0.5 mg/L) were tested for efficient induction of embryogenic callus. The maximum callus induction frequency (82.5 ± 3.7
Aluminum (Al) toxicity, is a major yield-limiting factor in acid soils, reducing the yield of crop plants including lentil through its adverse effects on the root system. In the present study, a diverse set of 50 genotypes including wild was phenotyped at the seedling stage using root length, root staining score, and root regrowth after staining as well as callose deposition. All traits, except root staining score exhibited significant genetic variability among the genotypes under Al stress condition. Al-tolerant genotypes displayed greater root length and increased root re-growth after root staining, and increased secretion of organic acids such as citrate and malate, which corresponded to lower accumulation of Al and callose in their roots The secretion of organic acids showed strong and positive correlation with root centric traits, while significant negative association with callose and Al accumulation was notices in response to Al stress. These findings indicate that coordinated regulation of organic acid secretion and root-associated traits confers Al tolerance in lentil.
Biological Nitrification Inhibition (BNI) trait provides a promising way to enhance NUE in wheat by reducing nitrification losses. 246 lines of F5 generation from a cross DBW-371/BNI-MUNAL were screened with the genome specific SSR marker 24_s81287 linked to BNI trait, and 35 lines were found positive. Based on nitrogen balance index and thousand-grain weight 23 lines out of 35 were selected for morphological, physiological, and quality traits evaluation under 75
Soil salinity significantly limits rice production in Africa, necessitating the development of salt-tolerant varieties. This study evaluated 206 rice genotypes (201 from Eastern and Southern Africa (ESA) and 5 standard checks from IRRI) for seedling-stage salinity tolerance. Thirteen genotypes were further characterized under salinity stress, including eight from ESA and five tolerant and sensitive checks. Salinity reduced both root and shoot dry weights across genotypes. Spearman’s correlation identified sodium content, Na+: K+ ratio, and leaf temperature at later stress stages as strongly associated with salinity tolerance. Principal component analysis (PCA) revealed that Na⁺: K⁺ ratio, root and shoot dry weights, and shoot length were key contributors to tolerance, accounting for 56.95
A study was conducted with clonal and seedling-derived trees of Pongamia pinnata in the field conditions at the ICAR-Central Agroforestry Research Institute, Jhansi, India, with an objective to unravel the mechanistic insights for drought stress tolerance in clonal and seedling trees of Pongamia pinnata through comparative physio-biochemical determinants. Photosynthetic CO2 assimilation (PNmax) and its associated parameters, along with chlorophyll fluorescence traits were analysed. Leaf water potential (LWP) was measured with the PSΨPRO water potential system. Findings of the study showed that clonal plants performed better than seedling plants during dry heat summer (DHS) by maintaining higher PNmax and its associated traits and PNmax was supported by a higher LWP. Additionally, elevated peroxidase (POD) activity and diminished malondialdehyde (MDA) levels in clonal plants as compared to seedling plants during DHS were validated by photosynthetic and chlorophyll fluorescence traits, thereby affirming their superior performance. In addition, clonal plants also recorded higher plant height, diameter at breast height (DBH) and 100-seed weight, signifying their higher resilience during DHS. Principal component analysis (PCA) unveiled that LWP, PNmax and Gs were major contributors to total variance. The study inferred that clonal plants of Pongamia pinnata maintained relatively higher physiological functioning during DHS.
