Plant Stress

Bluebunch wheatgrass (Pseudoroegneria spicata) exhibits substantial variation in its response to salt stress, making it a valuable model for studying salinity-tolerance mechanisms for use in crop improvement. In this study, we identified two P. spicata genotypes with contrasting responses to salt stress: the tolerant W6 56551, which maintained growth with green foliage under saline conditions, and the susceptible PI693916, which exhibited severe leaf chlorosis and stunted growth. To better understand the molecular basis of salt tolerance in blue-bunch wheatgrass, we conducted RNA-sequencing at 0, 1, and 4 days (D0, D1, and D4) after salt treatment at 160 mM level to examine changes in gene expression of salt-tolerant and salt-susceptible genotypes. Comparative analysis across time points identified 6,154 and 1,086 differentially expressed genes (DEGs) at D4 and D1 in PI693916, and 4,638 and 3,302 DEGs at D4 and D1 in W6 56551, respectively, relative to control (D0). Functional analysis of these DEGs showed that the salt-tolerant geno-type displayed an early and broad transcriptional reprogramming, including induction of photosynthesis, carbon metabolism, and flavonoid biosynthesis pathways, whereas the salt-susceptible genotype exhibited delayed and less coordinated responses, with enrichment of cyanoamino acid metabolism and repression of antioxidant-associated pathways. Notably, calcium signaling, ion transporter regulation, and osmolyte biosynthesis genes showed contrasting expression between genotypes, highlighting distinct strategies for ionic and osmotic homeostasis. Collectively, these results demonstrate that salt tolerance in P. spicata is associated with rapid metabolic adjustment, enhanced photosynthetic stability, and differential regulation of ion transport and osmoprotectant pathways.

Tomato production, yield and fruit quality face major challenges due to several factors, including the complex polygenic inheritance of agronomically relevant traits, biotic and abiotic stresses, and increasingly stringent regulations limiting the use of phytosanitary products. In this context, bioinoculants have emerged as a sustainable strategy capable of enhancing yield without compromising fruit quality, conferring protection against different stresses and exerting a minimal or no impact on environment and human health. In this study, we evaluated the effects and the underlying mechanisms by which Streptomyces sp. N2A, an actinobacteria isolated from soybean rhizosphere, promotes seed germination, vegetative growth and yield in tomato, without modifying fruit quality. The obtained results demonstrated that the bacterial treatment significantly improved seedlin[g]s emergence and growth and development in vegetative stage. At harvest, yield was also significantly enhanced, mainly driven by increased individual fruit weight, which was positively correlated with a thicker pericarp in fruits from N2A-treated plants. Transcriptional analysis during fruit development revealed a coordinated induction of auxin and cytokinin signaling pathways before and after anthesis, providing a hormonal framework that underlies the promotion of pericarp growth. This study provides evidence of the beneficial effect of inoculation with Streptomyces sp. N2A on tomato yield and constitutes the first report describing the modification of fruit morphology and expression of genes involved in phytohormonal modulation during early growth and development, induced by a plant growth-promoting Streptomyces.

Heavy-metal accumulation in cereal grains is becoming critical for European food safety, regulation and plant breeding. In the EU, Cd maximum levels in certain foodstuffs have been revised, including lowering or establishing limits for relevant food categories, while new maximum levels for nickel (Ni) have recently been introduced for several foodstuffs, including cereal categories, with limits for oats and selected cereals applying from 2026. Together, these developments create an urgent need to identify genetic and physiological mechanisms that reduce Cd and Ni accumulation in cereal grains while maintaining crop quality and productivity. Against this regulatory and food-safety background, our broader RNA-seq experiment investigates early transcriptional responses to Cd and Ni in oat F2 segregants contrasting for metal accumulation. The full dataset includes low- and high-accumulating segregants, roots and developing caryopses sampled at 3 h and 7 h after treatment. In the present pilot analysis, we focus on the Cd response in developing caryopses of the low-Cd accumulating segregant AS131 to identify candidate processes associated with reduced grain Cd accumulation. The strongest transcriptional responses were not dominated by canonical Cd-detoxification pathways. At 3 h after Cd exposure, differentially expressed transcripts were mainly associated with cell-wall functions, endosperm transfer-cell-specific PR60 proteins, DUF239-containing proteins and cysteine proteinase inhibitors, whereas several dehydration-, pathogen-, defence-, cell-wall-loosening- and ROS- related genes were repressed. By 7 h, the response suggested a shift towards homeostatic acclimation, with induction of TIP2 aquaporins, thiamine thiazole synthases, EF-Tu proteins, coatomer-related genes and carbohydrate metabolism-associated genes, together with repression of LEA/SMP/dehydrin genes, FRO7-like genes, EF-hand calcium-binding proteins and stress-regulatory transcription factors. Pathway-level analyses were broadly consistent with these transcript-level patterns, highlighting structural, nucleosome-associated, translation-related, metabolic and developmental processes. Several Cd-responsive transcripts were also associated with broader abiotic-stress responses, suggesting recruitment of shared stress-regulatory modules rather than Cd-specific detoxification pathways alone. Overall, these results support a working hypothesis in which low Cd accumulation in developing oat grain may involve regulation of solute-transfer interfaces, cellular protection, intracellular homeostasis, trafficking pathways and caryopsis developmental programmes. These findings provide candidate processes for future comparison with high-Cd accumulating segregants, root tissues and Ni responses in the broader dataset.

Stomata are the pores on plant surface, and these tiny pores are responsible for the flow of gas between plants and atmosphere. Currently, what effects of the broad and continuous increase in stomatal density achieved via genetic engineering on plant growth and development remain poorly understood. The 9 Arabidopsis transgenic lines with increased stomatal density were acquired through overexpressing FSTOMAGEN (the homologs of STOMAGEN, which are in Flaveria). The intermediate stomatal density (SD) lines exhibited increased trend in biomass. Compared with the lines with low SD, the biomass of Arabidopsis lines with intermediate SD (484 mm-2) significantly increased. There was a positive and significant correlation between biomass and relative water content. Across these transgenic lines, only during the earlier phase of growth, the leaf area exhibited a gradually increased trend as stomatal density increased, and there was both a significant linear relationship between SD and leaf growth rate and a strong linear relationship between SD and leaf area. In contrast, a clear relationship during the later phase wasnt observed. Under lower growth light intensity, there was an increased trend of biomass from other lines to the lines with intermediate SD, and the photosynthetic rate and stomatal conductance of the intermediate line were significantly increased. This study reveals plant-growth alterations that correspond to broad and near-continuous increases in stomatal density achieved via genetic engineering. Our study sheds light on the prerequisites for elevated stomatal density achieved via genetic engineering to promote plant growth.

Potato (Solanum tuberosum L.), the worlds fourth most cultivated crop, suffers yield losses of up to 40-50% from early blight caused by the necrotrophic fungal pathogen Alternaria solani. In this study we performed gas chromatography-mass spectrometry (GC-MS)-based untargeted metabolomics to characterize temporal alterations in metabolite composition, metabolic pathway regulation, and discriminatory biomarker metabolites in the susceptible Indian potato variety Kufri Jyoti, analyzing infected leaves, non-infected leaves, and lesion-associated necrotic tissues across four days post-inoculation (DPI).Metabolite annotation identified 58 compounds, including sugars, organic acids, amino acids, and secondary metabolites.. Multivariate analyses resolved distinct, largely non-overlapping metabolic clusters for control, infected leaves (1-4 DPI), and lesion tissue (Bs1-Bs3). A biphasic metabolic response was observed: early infection (1-2 DPI) was characterized by general suppression of primary metabolism, while late infection (3-4 DPI) showed pronounced upregulation of glycolysis, the TCA cycle, GS/GOGAT, and the shikimate pathway. Key discriminatory metabolites included asparagine, oxoproline, GABA, phenylalanine, and aromatic amino acids. Lesion tissues exhibited distinct metabolic fingerprints, with early disruption of amino acid recycling followed by a late rebound of defense-associated metabolites. Notably, defence-associated phenolics were detected exclusively within lesion tissue and were absent from whole-leaf profiles, demonstrating that spatially resolved lesion sampling captures defence chemistry that whole-leaf analysis alone would miss. The identified biomarker metabolites, particularly those linked to the shikimate and GS/GOGAT pathways, represent promising candidates for metabolite-assisted breeding and targeted crop protection strategies against early blight in potato. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=115 SRC="FIGDIR/small/745268v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@18131edorg.highwire.dtl.DTLVardef@f4fbe6org.highwire.dtl.DTLVardef@1c5db61org.highwire.dtl.DTLVardef@c5ef6d_HPS_FORMAT_FIGEXP M_FIG C_FIG

Per- and polyfluoroalkyl substances (PFAS) pose significant environmental risks, yet their impact on food crops like legumes remain insufficiently understood. This study investigated the developmental and physiological responses of hydroponically grown mung bean (Vigna radiata) to varying concentrations of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). High concentrations (1 mM) of PFOA severely impaired early plant development, significantly delaying seed germination, reducing leaf emergence, and suppressing root hair formation compared to PFOS and controls. Over a narrower concentration range (5-500 {micro}M), both compounds caused transient growth stunting at early timepoints (48 h), though plants exhibited partial recovery over time. High-dose exposure (500 {micro}M) significantly decreased seedling wet weights, leaf area, and leaf biomass without affecting dry weights, indicating disrupted water retention and homeostasis rather than reduced biomass accumulation. Spectrophotometric analysis revealed a dose- and compound-dependent effect on photosynthesis, with low-dose PFOA (5 {micro}M) significantly increasing leaf chlorophyll absorbance. Furthermore, quantification of callose deposition revealed that high-dose PFOA (500 {micro}M) and medium-dose PFOS (50 {micro}M) raised baseline immune stress responses, which were not further elevated by subsequent flagellin-22 (flg22) challenge, suggesting a contaminant-induced immune priming mechanism. These findings highlight distinct, chemical-specific toxicological impact of PFAS on legume growth, water dynamics, and defence priming, underscoring critical implications for agricultural productivity and food safety.

Arsenic (As) poses a major threat to rice productivity and food safety due to its high bioaccumulation potential and subsequent entry into the human food chain. In rice, As impairs seed germination, disrupts morpho-anatomical development, and induces oxidative stress. This study evaluates seed priming with an aqueous extract of the agricultural weed Amaranthus viridis (AvE) as a sustainable strategy to alleviate As-induced phytotoxicity. AvE priming significantly improved germination (71-75%) and morpho-physiological performance under As stress. It reduced oxidative stress markers, including H2O2 (21-38%), malondialdehyde (13-26%), and proline (18.9-44.7%), while increasing antioxidant metabolites, polyphenols and glutathione by up to 2.34-fold and 41%, respectively. Microscopy confirmed restoration of cellular integrity and anatomical organisation in primed seedlings. ICP-OES analysis showed that AvE priming reduced root As uptake by up to 39%, root-to-shoot translocation by up to 58%, and grain As accumulation by up to 95% compared with unprimed plants. qRT-PCR revealed modulation of genes involved in As homeostasis, indicating coordinated physiological and transcriptional responses. Importantly, improved agronomic performance further demonstrated the translational potential of this approach. This study provides the first evidence that A. viridis extract is a cost-effective, sustainable biostimulant for producing low-As rice in contaminated regions.

Salinity tolerance is commonly associated with whole leaf Na exclusion and maintenance of K homeostasis, but whether spatial ion partitioning among functional leaf compartments contributes to stress adaptation remains unclear. Here, we investigated the relationship between bulk leaf and stomatal complex ionomes and gas exchange performance under salinity using two contrasting genotypes in both maize and faba bean crops. Maize generally maintained higher photosynthesis and stomatal conductance than faba bean under salt stress, which was associated with lower Na accumulation, stronger K retention and distinct ion partitioning patterns between bulk leaf tissue and the stomatal complex. Enrichment analysis revealed that stomatal complex ion composition provided information beyond bulk leaf ion concentrations, with Na and Cl- showing distinct distribution patterns associated with photosynthetic performance. Integrating physiological and ionomic traits further demonstrated that stomatal-complex ion traits captured additional variation in salinity responses. These findings identify the stomatal complex as a functionally distinct ionomic compartment and reveal compartment-specific ion partitioning as an important mechanism underlying species-specific salinity tolerance.

Ultraviolet-C (UV-C) radiation can be highly damaging to plants, yet its effects on gibberellin (GA) homeostasis are not well understood. In this study, we show that short daily UV-C pulse treatments (12 s, 1,200 J m-2) applied for seven days reduce plant height and delay flowering in Arabidopsis thaliana. Endogenous levels of the GA biosynthesis precursors GA12, GA53, GA15, and GA24, the bioactive GA4, and the GA catabolites GA34 and GA110 are all lower in UV-C treated plants than in untreated controls. These changes were accompanied by lower transcript levels of the GA biosynthesis genes KS, GA13ox1, GA20ox1, and GA3ox1, together with opposing changes in the expression of GA2ox genes. Exogenous GA4 restores growth in UV-C-treated plants, suggesting that reduced GA availability contributes to UV-C-induced growth inhibition. Consistent with this finding, the GA-signalling mutant gdella and the GA-biosynthesis mutants kao1 and kao2 show strongly reduced UV-C responses. Together, these findings highlight the importance of GA metabolism and signalling in the developmental response to repeated UV-C exposure, and suggest that exposure regimen influences the dynamics of UV-C-induced hormonal responses.

Context. Barley production requires advanced knowledge of its response to changing environmental conditions in order to keep it competitive and sustainable. Aim. Advance in the understanding of barley phenology and foliar development under South American field conditions. Methods. 8 spring barley genotypes with differential phenology were studied in four field experiments under different temperature (through years and sowing dates) and photoperiod (through sowing dates) conditions. Time to anthesis, emergence to onset of stem elongation, stem elongation to anthesis, photoperiod response (PR) in these three traits, number of final leaves at anthesis (FLN) and phyllochron were measured. Key Results. Time to anthesis and its subphases were shorter in late plantings but under similar photoperiod, temperature increased them. Cultivars have differential responses but with magnitude interactions and not crossover ones. Cultivar effects defined PR with no interaction with year (temperature). Temperature and photoperiod affected FLN, phyllochron and their relationship with time to anthesis. Under the shorter photoperiod, FLN and phyllochron were negatively correlated, FLN was higher in the warmer year and positively correlated with time to anthesis while phyllochron was not affected by temperature and had no correlation with time to anthesis. Under longer photoperiod, phyllochron was higher in the warmer year and time to anthesis was positively correlated with both FLN and phyllochron. Conclusions. Cultivar basal thermal requirements and PR were consistent under the different studied conditions. Changes in temperature and photoperiod affected the relationship between time to anthesis, FLN and phyllochron suggesting that, although the three traits are arithmetically related, environmental conditions affect their balance.

Concurrent exposure to heat and drought stress compromises legume productivity, yet their combined effects are rarely quantified systematically. We compiled a database of 18 studies covering seven legume species. From these, we extracted 929 physiological, biochemical, and yield-related traits and calculated actual-to-additive ratios to classify heat-drought interactions as antagonistic (ratio < 1), additive (ratio = 1), or synergistic (ratio > 1). Additive heat-drought relationships accounted for 59 % of all classifiable observations, 37% relationships were antagonistic, and 4% synergistic. The relationship varied with species, genotype, trait, and experimental conditions highlighting the complexity of combined abiotic stress effects. The results challenge the common assumption that concurrent stresses invariably exacerbate damage and underscore the need for more realistic, quantitatively defined stress treatments as well as frameworks that integrate trait-level responses into predictive models of crop growth and development. Our synthesis provides a quantitative foundation to understand legume phenotypes under the increasingly frequent co-occurrence of heat and drought stress and identifies research areas where further work is needed to improve insight into combined stress responses. HighlightsO_LICombined heat and drought responses were mainly additive or antagonistic. C_LIO_LIEvidence is biased toward few legumes and controlled environments. C_LIO_LIField-based, multi-species studies are needed to identify adaptive traits. C_LI

Background Strigolactones (SLs) regulate diverse aspects of plant development and have been implicated in promoting leaf senescence. However, senescence phenotypes associated with SL deficiency have not been consistently observed across species, suggesting that this function may be species- or context-dependent. Moreover, the contribution of endogenous SL biosynthesis to senescence in leafy vegetable crops remains unclear. Here, we investigated the role of the SL biosynthetic gene MORE AXILLARY GROWTH1 (MAX1) in dark-induced leaf senescence in lettuce (Lactuca sativa). Results We found that endogenous SL biosynthesis plays a major role in dark-induced senescence in lettuce. SL pathway genes were induced during dark storage, while exogenous GR24 accelerated senescence and lettuce MAX1 (LsMAX1) complemented the delayed-senescence phenotype of the Arabidopsis max1 mutant. Consistent with these findings, CRISPR/Cas9-generated Lsmax1 mutants exhibited a pronounced stay-green phenotype during prolonged darkness, accompanied by strongly reduced induction of key senescence-associated genes. Despite this delayed visible senescence, Lsmax1 retained a substantial transcriptional response to dark storage. Strikingly, loss of LsMAX1 did not simply weaken the wild-type senescence program, but redirected part of the response toward a distinct stress-associated transcriptional state that was largely absent from wild type. Loss of LsMAX1 did not affect vegetative rosette architecture, although increased branching emerged after bolting. Conclusions Our findings establish MAX1-dependent SL biosynthesis as an important regulator of leaf senescence in lettuce and reveal a role that extends beyond controlling the rate of senescence. Rather than simply delaying the wild-type program, loss of LsMAX1 alters the transcriptional trajectory of senescence, favoring an alternative stress-associated state during prolonged darkness. The strong stay-green phenotype without detectable changes to vegetative rosette architecture further highlights SL biosynthesis as a potential target for extending postharvest longevity in lettuce and other leafy crops.

Fungal and oomycete plant pathogens are major drivers of yield losses worldwide and are spurring the search for sustainable alternatives to synthetic pesticides. Algae, in general, and microalgae, in particular, represent a promising source of bioactive compounds for crop protection. Despite this, their efficacy across different host-pathogen systems remains poorly characterised. This study evaluated the biocontrol potential of the aqueous extract of Chlorella sorokoniana against three economically important phytopathogens using complementary in vitro, ex vivo, and in planta assays. The strongest activity was observed against Magnaporthe oryzae, with the extract reducing fungal growth by approximately 70% in vitro, inhibiting appressorium formation by 55%, suppressing lesion development on detached rice leaves by more than 75%, and reducing rice blast severity by 64.5% as a preventive foliar treatment. In contrast, the extract showed little or no direct in vitro antifungal activity against Pythium ultimum and Rhizoctonia solani, yet it significantly reduced disease severity in planta by 13-37% and 48-55%, respectively. The contrasting responses among pathosystems suggest that C. sorokoniana aqueous extracts act through different mechanisms depending on the pathogen and the crop, combining direct antifungal activity against M. oryzae with plant-associated protective effects against soil-borne pathogens. These findings highlight the importance of evaluating candidate biocontrol products using complementary in vitro and in planta approaches, as laboratory antimicrobial assays alone may substantially underestimate their agricultural potential. The broad-spectrum protection achieved with an unrefined aqueous extract further supports C. sorokoniana as a promising source of sustainable crop protection products and provides a strong foundation for future mechanistic studies, formulation development, and field validation. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=115 SRC="FIGDIR/small/742703v1_ufig1.gif" ALT="Figure 1"> View larger version (45K): org.highwire.dtl.DTLVardef@394716org.highwire.dtl.DTLVardef@6a208corg.highwire.dtl.DTLVardef@17f0724org.highwire.dtl.DTLVardef@adda96_HPS_FORMAT_FIGEXP M_FIG C_FIG

High temperature during grain filling increases rice grain chalkiness and deteriorates grain appearance under climate warming. Although several loci that reduce chalkiness have been identified, breeding strategies that integrate grain level heat tolerance with panicle level heat avoidance remain limited. Here we characterized SL2033, a chromosome segment substitution line carrying a long IR64 derived segment on chromosome 10, and evaluated the combination of the chromosome 10 segment with Appearance quality of brown rice 1 (Apq1), a quantitative trait locus associated with reduced heat induced chalkiness that acts at the grain level. Compared with its recurrent parent Koshihikari, SL2033 had longer flag leaves, altered vertical plant architecture, and lower panicle temperature. Total starch and protein contents were comparable between the two genotypes, whereas RNAseq analysis of the developing endosperm identified specific differences in heat, stress, and cell wall related transcripts. In a two year field trial, a pyramided line combining the SL2033 derived segment with Apq1 had the highest proportion of perfect grains and lowest frequencies of multiple chalky kernel types during the year with hotter grain filling conditions, with no detectable yield penalty. The pyramided line combined longer flag leaves, as in SL2033, with shorter panicle exsertion, as in an Apq1 near isogenic line, and had the lowest panicle temperature among the tested genotypes. Time series unmanned aerial vehicle imaging also detected genotype dependent differences in plant height during early grain filling, supporting distinct temporal patterns of plant development among the lines. These findings demonstrate that pyramiding genetic loci that confer panicle level and grain level heat tolerance is a promising strategy for improving rice grain appearance under high temperature field conditions, which are becoming increasingly prevalent.

Optimum irrigation and fertilizer nitrogen (N) rates are important to improve crop yield at reduced environmental risks in the form of NO3-N leaching losses, without any financial loss. The study aimed to investigate the impact of rational irrigation and nitrogen management on wheat and maize crop yield vs. NO3-N leaching losses, with field experiments conducted at the experimental station, University of Agriculture Faisalabad, Pakistan, for two years, with wheat-fallow-corn seasons each year. Suction lysimeter were installed for collection of leachates while soil water balance was computed using the HYDRUS-1D model. We explored the various management strategies, including three irrigation and N levels (sub-optimal, optimal, and supra-optimal, referred to as I1, I2, and I3 for irrigation, and N1, N2, and N3 for nitrogen, respectively) for wheat and maize crops. The three irrigation levels were 325, 400, and 475 mm for wheat, and 375, 525, and 675 mm for maize crops. The three N-levels were 100, 130, and 160 kg ha-1 for wheat, and 220, 270, and 320 kg ha-1 for maize. The results indicated that increasing the irrigation and nitrogen levels significantly improved the growth and yield of both crops during both seasons. The highest grain yield of wheat (4.0 t ha-1) and maize (7.8 t ha-1) was observed with I3N3; however, I2N3 showed statistically no difference in yield, while showing significantly reduced (28.6%) annual NO3-N leaching losses of 23.8 kg ha-1, and the highest financial benefits of 780$. Sub-optimal levels of irrigation and N, though reduced the NO3-N leaching losses, caused significant yield losses, generally unacceptable to the farmers. Irrigation water use efficiency (WUEi) also improved by 12% in wheat and 20% in maize under I2 than that of the I3 level. Besides, considering economic profit, the highest value cost ratio (1.64 and 2.04 in wheat and maize, respectively) was achieved under the I2N3 treatment, as opposed to the other treatments. Based on comprehensive analysis, the I2N3 treatment is recommended for sustainable yield and minimal environmental risk in the wheat-maize cropping system. Moreover, it was observed that the rainy fallow period contributes 14.0-31.5% of the total NO3-N leaching losses. Further investigation is needed to minimize NO3-N leaching losses, especially during the rainy fallow period, by early maize sowing and increasing the efficiency of N fertilizer (such as fertilizer coating) under the flood irrigation system, to achieve the potential goals of sustainable productivity and environmental security.

Salinity stress affects rice productivity due to reduced growth and sodium ion toxicity. Previously, we identified a splice variant of RADIATION SENSITIVE23a (RAD23a) as the potential basis for variation in salt-tolerance in rice germplasm. RAD23 is a known moonlighting protein associated with protein degradation. To validate the role of RAD23a in salt stress response, we characterized gene edited mutant lines that targeted the UBL and UBA2 domains of this protein. Mutation in either domain promoted shoot growth under saline and control conditions. The mutants also differed from wildtype plants in Na and K accumulation in roots and shoots under salt stress. Transcriptome analysis of mutants versus wildtype showed differential transcript abundance of multiple inorganic phosphate (Pi) starvation related genes, including OsSPX2 and OsPHO2. As a result, mutants accumulate higher Pi compared to wildtype plants. The two allelic groups for RAD23a locus also differ in root and shoot phosphorus (P) content. Further, we show that RAD23a interacts with OsSPX2, a negative post-translational regulator of OsPHR2, the master regulator of Pi starvation response. Mutants have higher shoot growth and Pi levels under low Pi conditions, linking enhanced growth of mutants to increased Pi uptake. The UBA2 domain specific mutants have higher single grain weight and per plant grain weight than wildtype. In summary, we show that the RAD23a regulates differential growth, salt response and Pi uptake in rice in a domain-specific manner supporting the moonlighting roles of RAD23a in salt tolerance and phosphorus-dependent shoot growth.

Continuous-wave (CW) 450 nm blue diode-laser irradiation was evaluated as a physical seed-priming treatment for improving lettuce (Lactuca sativa L.) germination and early seedling establishment under reduced water availability. Dry seeds were irradiated at 50-250 mW for 2 min and at 100 mW for 0.5-10 min; each condition included three independent Petri-dish replicates with 100 seeds per replicate, and the replicates were monitored for 72 h. Laser treatment produced a dose-dependent biological response. The optimized condition, 100 mW for 2 min, increased final germination from approximately 65-70% to 90-95%, increased the germination speed index, and promoted root elongation more strongly than shoot elongation. Longer exposures reduced germination and seedling growth. Under reduced water availability (0.5-6 ml per Petri dish), laser-treated seeds germinated earlier, maintained final germination of 83-93% compared with 57-72% in controls, and produced better-developed seedlings. The relative benefit increased as water availability decreased, indicating that optimized blue laser priming partially compensated for low water supply during germination and early establishment. These results identify CW blue laser priming as a contactless, chemical-free approach for improving lettuce seed performance and early seedling vigor under limited water availability.

Tropospheric ozone (O) is a major atmospheric pollutant that affects plant carbon metabolism, redox homeostasis, and secondary metabolism, including the biosynthesis and emission of biogenic volatile organic compounds (BVOCs). However, the contribution of BVOCs to O3 tolerance, particularly in tropical woody species, remains poorly understood. Here, we investigated whether acute O exposure (cumulative AOT40 of 3497.82 ppb h) induces alterations in photosynthetic performance, redox homeostasis, and BVOC partitioning in Eugenia uniflora. We evaluated gas exchange, photosynthetic pigments, ascorbate and glutathione pools, emitted BVOCs, modeled intercellular BVOC concentrations, and the relative carbon cost associated with BVOC emissions. O exposure significantly increased net CO2 assimilation without affecting stomatal conductance, transpiration, leaf water status, or chlorophyll concentrations, indicating maintenance of photosynthetic performance. Carotenoid concentrations and total glutathione decreased, whereas glutathione redox status was maintained. O induced marked compound-specific changes in BVOC composition and partitioning. Several monoterpenes appeared exclusively under O exposure, {gamma}-elemene emission increased significantly, and the relative distribution of individual BVOCs between the modeled intercellular and emitted pools was altered. These findings show that the response of E. uniflora to acute O exposure was characterized by interplay among carbon assimilation, glutathione redox regulation, and BVOC partitioning rather than by increased total volatile emission. Enhanced carbon assimilation occurred without additional carbon loss through BVOC release, while changes in the modeled intercellular pool indicate that part of the volatile response remained within the leaf. Our findings highlight BVOC partitioning as an important dimension of the plant response to oxidative stress and demonstrate that emission measurements alone may not fully capture the fate and potential physiological role of volatile carbon under O exposure. O_FIG O_LINKSMALLFIG WIDTH=178 HEIGHT=200 SRC="FIGDIR/small/743946v1_ufig1.gif" ALT="Figure 1"> View larger version (52K): org.highwire.dtl.DTLVardef@653af1org.highwire.dtl.DTLVardef@ca5forg.highwire.dtl.DTLVardef@1e641bforg.highwire.dtl.DTLVardef@1e68fae_HPS_FORMAT_FIGEXP M_FIG C_FIG BVOC Partitioning Contributes to Oxidative Stress Defence Under Acute O Exposure

Drought stress is the major yield limiting factor in upland rice production where the moisture availability is highly variable. Understanding and evaluating how upland rice responds to drought stress is critical to improving resilience and yield stability. In this study performance of sixteen upland rice varieties were evaluated under non-stressed, moderately stressed and highly stressed conditions. Drought stress was introduced by irrigating upland rice at 70% and 50% field capacity (FC) whereas non-stress treatment was irrigated at 100% FC. Irrigation in moderately stressed and highly stressed conditions was also withheld for six days at lateral crop stages to observe temporary wilting by inducing a stress interval. Data on agronomic traits of upland rice was collected in three experimental replications. Results indicated that performance of upland rice varieties was significantly altered under stress conditions and highest performance was observed under non-stressed conditions. Yield losses for short duration and long duration varieties ranged 35-60% and 24-62% under moderate stress whereas it ranged 43-78% and 52-73% under highly stressed conditions, respectively. Overall varieties Dawk Kha, Khao/ Sai and Dawk Pa-yawm, indicated higher stability under stressed conditions therefore, these long duration varieties could be used for obtaining better yields under diverse agroclimatic conditions and under unpredicted weather patterns. Short duration Ma-led-nai-fai and long duration Goo Meung Lung and Bow Leb Nahag could be used for acquiring traits for higher tillering and panicle bearing capacity. Short heighted varieties such as Jao Daeng, Sahm Deuan and Ma-led-nai-fai could be used in breeding for short heighted new varieties to overcome lodging concerns. Strong significant association of GMP, STI, MPRO, MHAR with grain yield under non-stressed, moderately stressed and highly stressed conditions indicated that these indices were appropriate for their use as selection criteria for drought resilience.

Micronutrient deficiencies remain a major public-health challenge, and genetic improvement of grain iron and zinc concentrations in wheat offers a sustainable biofortification strategy. We evaluated 563 CIMMYT advanced wheat lines and six checks under restricted irrigation (two irrigations) and well-watered conditions (five irrigations) at Ciudad Obregon, Mexico. Grain iron and zinc concentrations were quantified by energy-dispersive X-ray fluorescence spectrometry. Best linear unbiased estimates were calculated, and genome-wide association analyses were conducted using 8,687 high-quality single-nucleotide polymorphisms and a multi-locus mixed model that accounted for population structure. Five marker-trait associations were detected in at least two datasets. For grain zinc concentration, S3B_811421507 was detected under both irrigation regimes and in the combined analysis, whereas S3B_814372642 was detected under well-watered conditions and in the combined analysis. For grain iron concentration, S2B_73321328 and S4B_20679079 were associated with variation under restricted irrigation and in the combined analysis, while S2B_72162723 was detected under well-watered conditions and in the combined analysis. Individual loci explained 0.34% to 3.36% of phenotypic variance, consistent with the quantitative inheritance of grain micronutrient concentration. The identified alleles provide candidate targets for validation and marker-assisted biofortification breeding, while their environment-dependent effects emphasize the need to evaluate micronutrient traits across contrasting moisture conditions.