Physiologia Plantarum

Transgenerational plasticity can shape plant phenotype and influence plant response to environmental changes in interaction with the current conditions. While how past stress interact with either current optimal or stress conditions is increasingly documented within a single plant, transgenerational plasticity remains particularly poorly understood especially at the metabolome level. In our study, we investigated whether heat stress induces transgenerational metabolic and phenotypic modifications along two successive clonal ramet generations of the sub-Antarctic aquatic plant Limosella australis. We performed untargeted metabolomic approaches and measured morphologic and performance traits, to assess both transgenerational plasticity of the metabolome and the phenotype. We found that heat stress remodelled the metabolic profile and influenced the foraging strategy of our clonal plant, and that some of these metabolic changes persisted into the first clonal generation. This one therefore adopted an intermediate growth strategy, even though culture conditions were optimal. By comparing differentially accumulated features between daughter ramets from heat stressed mother ramets and from unstressed mother ramets, we identified common and specific metabolites accumulation to heat stress response, belonging to diverse compound families. However, we did not observe any adaptative advantage and any metabolic imprint during another heat stress applied on the second clonal generation. This work provides especially new clues into how plant metabolome integrates and transfers previous stressed clonal generation's information.

Micro-dwarf tomato cultivars are increasingly considered for urban and controlled-environment agriculture due to their compact architecture and suitability for high-density planting. However, optimal canopy management strategies for these cultivars remain poorly defined. In this study, we evaluated the effects of different leaf removal intensities on leaf-level physiological performance, fruit yield, and fruit quality in three micro-dwarf tomato cultivars (Mohammed, Hahms Gelbe Topftomate, and Red Robin) grown under contrasting seasonal light conditions. Plants were subjected to low (15%), moderate (30%), or severe (90%) leaf removal, and leaf-level gas exchange was measured across canopy layers, along with yield and fruit quality assessments. Severe leaf removal (90%) increased carbon assimilation, transpiration, and stomatal conductance in middle and lower canopy leaves by up to approximately twofold compared with control plants, indicating improved light availability at the leaf level. However, these physiological enhancements did not consistently translate into higher yield, reflecting reduced whole-plant source capacity under excessive leaf removal. Low to moderate leaf removal (15-30%) generally increased or maintained yield and fruit number, whereas severe leaf removal reduced yield in Hahms Gelbe and Red Robin, particularly under low seasonal radiation. In contrast, Mohammed exhibited yield increases of up to 220% under low leaf removal and maintained increased yield even under severe leaf removal under high-light conditions. Fruit quality was largely unaffected by leaf removal, except for total soluble solids, which declined by approximately 12% under severe leaf removal across cultivars, consistent with sugar dilution under source limitation. Overall, these results demonstrate that optimal leaf removal in micro-dwarf tomatoes requires balancing improved canopy light distribution with maintenance of sufficient leaf area for carbon assimilation. Leaf removal thresholds are strongly cultivar- and light-dependent, emphasizing the need for cultivar-specific canopy management strategies in compact tomato systems and controlled-environment agriculture.

ContextUnderstanding how and when environmental conditions influence overall crop performance is crucial for optimising the development of genotypes to a specific breeding target environment. We focused on economically important traits of Australian rain-grown cotton including fibre yield and quality traits, which have not been investigated comprehensively. The aim of the study was to identify relevant environmental factors, and the timing and extent of their impact on rain-grown cotton production. MethodsWe used a data driven approach to analyse the relationship between ten climate related environmental factors across various plant growth stages and eight fibre yield and quality traits, using a large-scale field dataset of 9,283 records collected over 23 years at 4 locations, with 53 unique year-location combinations. We applied eight complementary statistical models including stepwise, penalised and Bayesian linear regression, regression-tree based ensemble methods and deep learning frameworks to (1) select the most essential environmental covariates affecting rain-grown cotton production, and (2) evaluate the predictive performance of these models. ResultsThe environmental impacts on rain-grown cotton production were trait and growth-stage specific. Number of rainy days and solar radiation were identified as the most influential environmental factors for fibre yield traits, vapour pressure deficit at maximum daily temperature was the most influential factor for majority of fibre quality traits. However, each analysed trait was influenced by multiple environmental factors across multiple growth stages (rather than a single factor or a single growth stage). These influential covariates explained a wide range of variation in the traits, accounting for 5.8% to 68.2%. Using the best-fit random forest model, our findings revealed non-linear relationships between key environmental covariates and the traits. ConclusionsEnvironmental factors at different rain-grown cotton growth stages are key determinants for the performance of end-of-season fibre yield and fibre quality parameters. These findings highlight the need to account for environment conditions when developing cotton varieties optimised for rain-grown production systems. Potential strategies are proposed whereby these key environmental factors can be used to increase the rate of genetic gain in rain-grown cotton production systems. ImplicationsThe results of this study will be crucial for future genetic evaluations and analyses of genotype-by-environment interaction effects in rain-grown cotton, which must account for the influence of the environment on plant performance. Furthermore, these methods can be applied to other species to identify critical growth stages and environmental factors which most influence crop performance.

BackgroundControlled-environment cultivation of medicinal cannabis (Cannabis sativa L.) typically optimizes light conditions to enhance the biosynthesis of pharmaceutically important metabolites like cannabinoids. Such experimental strategies may also influence other specialized metabolites like terpenoids, flavonoids, alkaloids, among others. Previous untargeted metabolomics studies testing short wavelength conditions like UV and blue light have shown that terpenoids and prenylated flavonoids in cannabis leaves respond differentially. However, since metabolomic studies in cannabis have so far mostly focused on floral cannabinoids, a comprehensive untargeted study into cannabis floral metabolome response to short wavelengths is currently lacking. ObjectivesOur study investigates the impact of short wavelength usage on cannabis specialized metabolism, and in particular the influence of UVB, UVA, and blue light on the cannabis floral flavonoid metabolome and associated glycosylation moieties. MethodsCannabis plants were grown under a white background light and exposed to supplemental UVB, UVA, or blue light during the generative phase of the cultivation cycle. Treatments were compared to a reference white background light without UV or blue light. Metabolites from floral tissue were extracted and analyzed via ultra-performance liquid chromatography-tandem mass spectrometry. A comparative metabolomics workflow was designed and used to characterize the floral flavonoid metabolome and associated glycosylation moieties. ResultsOur results demonstrate how short wavelengths differentially affect the metabolism of natural product compound classes including polyketides and phenylpropanoids/shikimates. Blue light induced flavonoids similarly to how UVB did, while both UVA and blue light specifically induced flavanones accumulation. UVB showed the strongest regulatory effect on flavonoids production and glycosylation patterns. ConclusionsUVB reshapes the cannabis floral flavonoid metabolome by selectively stimulating the accumulation and structural modification of flavonoids. Therefore, UVB application in cannabis cultivation represents a useful horticultural strategy to increase inflorescence medicinal quality without affecting cannabinoid levels.

Far-red light (FR; 700-750 nm) is increasingly incorporated into controlled-environment lighting because it can improve photosynthetic efficiency when combined with comparatively shorter wavelengths. In long-day leafy crops such as spinach, however, FR may also promote the transition from vegetative to reproductive growth and thereby reduce marketable yield. Most studies have evaluated FR fraction, intensity or end-of-day exposure, whereas the developmental timing of FR has rarely been tested, particularly in spinach. Here, we evaluated six commercial spinach cultivars (Amador, Harp, Renegade, Responder, Rubino and Santa Cruz) in an indoor vertical farm under a common red-green-blue background (PPFD 260-264 {micro}mol m-{superscript 2} s-{superscript 1}, 12 h photoperiod, 24 {degrees}C) and four FR timing treatments: no FR (Control), FR throughout production (FullFR), FR during early development only (EarlyFR), and FR during late development only (LateFR). LateFR increased marketable fresh weight relative to Control (244 vs 224 g) and reduced flowering incidence, whereas far-red supplied during early development reduced fresh weight (158 g) and increased flowering. The magnitude of the timing response differed among cultivars: switching from EarlyFR to LateFR recovered 0 % fresh weight in Amador but 107 % in Renegade and Rubino, with the largest penalties occurring in otherwise bolt-resistant cultivars. EarlyFR also increased total chlorophyll and reduced the chlorophyll a:b ratio. These results show that FR response in spinach is strongly conditioned by developmental stage and cultivar. Although LateFR received more total far-red than EarlyFR, it behaved like the Control, indicating that the penalty was set by far-red timing rather than dose. Treatment differences in bolting and yield tracked an estimated phytochrome photostationary-state deficit during early development: a phytochrome-deficit model markedly outperformed a cumulative-dose model ({Delta}AIC = 441), and the deficit x cultivar interaction was strong (p < 0.001), with bolt-resistant cultivars losing most yield when far-red coincided with the early developmental window. We therefore propose that FR should be treated as a genotype-dependent management variable rather than as a fixed spectral input, with late application and bolt-resistant cultivars offering the most favourable combination for vertical-farm spinach production. Framed within the breeders equation, the close match between the trial and production environment and the scope for shorter breeding cycles indoors suggest that genotype and far-red timing can be optimised jointly to accelerate genetic gain.

Biotechnological applications of oxygenic photosynthetic organisms depend on conversion of light energy into chemical energy through photosystems (PS). This energy can then be used to drive engineered metabolic pathways that are designed as strong electron sinks. For optimal performance, the engineered host metabolism must also be balanced with the native photoprotective electron transfer network. This includes the energy-consuming function of flavodiiron (Flv) proteins, which are universal to cyanobacteria and all other oxygenic photosynthetic organisms except angiosperms. In the cyanobacterium Synechocystis sp. PCC 6803, four different Flv proteins have been shown to function in a Mehler-like reaction within two heterodimeric forms (Flv1/Flv3 and Flv2/Flv4), donating electrons to O2 without generating oxidative stress. Previously, deleting Flv3 in the Synechocystis sucrose-producing (S02) strain was shown to cause drastic metabolic changes in S02{Delta}flv3, shifting it from photoautotrophic to mixotrophic growth (Muth-Pawlak, et al., 2024). In this study, we took an opposite approach by complementing S02 with Flv3 overexpression at different levels using RBS tuning. Interestingly, this resulted in S02oeFlv3 strains with significantly increased overall photosynthetic activity and sucrose production, enhanced cell growth, and storage compound accumulation. However, these outcomes are shown not to be due to conventional O2 photoreduction activity catalysed by Flv1/Flv3. Instead, we postulate that the observed changes are linked to the previously unidentified function of homomeric Flv3/Flv3 and the strongly increased sulphate redox metabolism. Based on extensive proteomic and metabolite analyses, we hypothesise that the Flv3 homooligomer uses sulfate metabolites directly or indirectly as the final electron acceptor instead of O2. This would also explain the upregulation of sulfate-related enzymes, as well as SQR, which passes the electrons back to the PQ pool in the Flv3 overexpression strain.

Bread wheat (Triticum aestivum) is a staple food crucial for global caloric intake and food security. The current climate emergency demands the development of sustainable agricultural practices, particularly in the context of drought-induced yield reductions in bread wheat. Microalgae-based biostimulants have emerged as promising tools to enhance crop tolerance to drought stress while concurrently mitigating atmospheric CO2 accumulation. This study characterizes the transcriptomic responses to the foliar application of the microalgae-based biostimulant LRMTM in drought-stressed and fully irrigated wheat plants unveiling its mode of action. Drought stress at the tillering stage significantly altered gene expression activating key pathways related to phosphate starvation response (PSR), inositol phosphate signaling, and tocopherol biosynthesis. The application of the microalgae-based biostimulant LRMTM in drought-stressed plants further enhanced the expression of drought-responsive genes, particularly those involved in PSR and carbon fixation. Specific responses to LRMTM treatment in drought-stressed plants were also found related to abscisic acid (ABA) signaling activating genes involved in stomata closure, which plays a critical role in drought tolerance. In fully irrigated plants, LRMTM treatment was also beneficial modulating circadian rhythms, shade avoidance and attenuating stress responses. Phenotypic analysis showed that LRMTM-treated plants exhibited enhanced drought tolerance, increased height and spike length even under fully irrigated conditions. These results indicate that the microalgae-based biostimulant LRMTM not only enhances wheat response to drought but also promotes growth and productivity in both stressed and non-stressed conditions which could contribute to the development of sustainable agriculture in the face of the current climate challenges.

RNA-seq datasets from medicinal yews are crucial for studying paclitaxel biosynthesis. However, cross-study data analyses are hindered by pronounced batch effects. Here, we compiled 45 RNA-seq samples from three studies across four tissues (bark, leaf, root, stem) and assessed 35 preprocessing pipelines combining six normalization strategies with five batch-effect correction approaches. Unsupervised clustering (HCA, k-means, Grade-of-Membership), evaluated using Jaccard and Adjusted Rand indices, revealed significant variability in batch effect removal. Supervised classification of tissue and project labels (Random Forest and linear/radial SVM) demonstrated improved accuracy in tissue type prediction, highlighting the effectiveness of correction methods. The processed data facilitated the identification of 189 putative ABC transporters across samples, six of which showing a strong correlation to the gene encoding 10-deacetylbaccatin-III-10{beta}-O-acetyltransferase, a key biosynthetic enzyme in the taxol pathway. High expression levels in leaf and bark further support their role in taxane intermediates trafficking in taxol biosynthesis. Structural analysis and molecular docking further supported the selection of these candidates, and the agreement between transcriptomic ranking and docking-based prioritization suggests that these transporters may participate in taxane intermediate recognition, trafficking, or export. These findings demonstrate the importance of normalization and batch effect correction in RNA-seq analysis to advance gene discovery in Taxus species and, more broadly, in plant research. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=152 SRC="FIGDIR/small/723993v1_ufig1.gif" ALT="Figure 1"> View larger version (54K): org.highwire.dtl.DTLVardef@1469162org.highwire.dtl.DTLVardef@1f2c4deorg.highwire.dtl.DTLVardef@15ad821org.highwire.dtl.DTLVardef@123676d_HPS_FORMAT_FIGEXP M_FIG C_FIG

Compound droughts, i.e. the co-occurrences of heat and drought, represent a serious challenge for temperate forest trees leading to significant losses in forest biomass. We studied the physiological response of Norway spruce (Picea abies) saplings to heat and drought individually, and in combination. Continuous measurements of leaf gas exchange and VOC emission allowed us to identify fast-response reactions, while discrete VOC and root exudate samplings added qualitative information on compositional changes. Additionally, we used 13CO2 and 2H2O label pulses to investigate C-allocation and root water uptake in response to stress. Heat as well as drought reduced assimilation rates in the saplings, whereas transpiration, leaf VOC emission and root exudation rates increased in response to heat. Drought alone increased VOC emission but decreased exudation rates. Combined heat and drought triggered an amplified response in both processes despite negative net CO2 assimilation rates. Label incorporation showed compromised water uptake capacity of drought-stressed plants and illustrated de novo C-allocation to VOC emission and root exudates. The results point at the high susceptibility of Norway spruce saplings to drought and heat. Combined stress resulted in synergistic responses in VOC emissions and root exudates, showing the detrimental effect of compound droughts on Norway spruce. HighlightIn this study, we found synergistic effects of heat and drought on carbon losses from leaf VOC emission and root exudates despite negative assimilation rates in Norway spruce saplings.

As extreme heat events increase in frequency and intensity worldwide, understanding how woody perennial crops respond to higher maximum temperatures is critical. Perennials face distinct challenges, persisting across many seasons under increasingly variable and extreme conditions, and heat waves threaten the viability of wine grape cultivars through impacts on yield, wine quality, and long-term vine health. To test whether irrigation practices before and during heat waves affect grapevine carbon (C) storage and health, we experimentally manipulated irrigation regimes surrounding heat waves from 2019-2021 in a commercial Cabernet Sauvignon vineyard in the Lodi AVA of Californias Central Valley. Vine physiological traits and yield were measured throughout, and whole-vine nonstructural carbohydrate (NSC) concentrations were quantified after three growing seasons. Although lower supplemental irrigation reduced photosynthesis, stomatal conductance, and fruit yield, whole-vine NSCs did not differ significantly in any perennial organ by the experiments end, indicating that reproductive output and final NSC status responded to irrigation on different timescales. These results suggest that moderate supplemental irrigation during heat events is sufficient to mitigate negative impacts on yield and quality while supporting recovery of NSC reserves, though longer-term monitoring is needed to confirm that this short-term resilience persists.

Soil salinization threatens global agriculture reducing yields, yet the metabolic signals controlling salt-sensitive root plasticity in alfalfa remain unclear. We hypothesize that salinity transiently uncouples the sucrose-trehalose-6-P (Tre6P)- Sucrose non-fermenting kinase 1 (SnRK1) nexus, aligning with a biphasic root metabolic response and altered root architecture. Alfalfa seedlings were grown in a hydroponic system and exposed to 200 mM NaCl, with root samples collected from 1 h to 7 d. While primary root growth and biomass remained unchanged, lateral root development was enhanced under salinity. Early response (1 h-1 d) was characterized by reduced carbon metabolites, low Tre6P, increased malondialdehyde, and SnRK1 activation, with a decline in glycolytic and TCA intermediates. During this phase, sucrose was negatively correlated with both Tre6P and SnRK1. Late response (3-7 d) showed a SnRK1 reactivation, Tre6P recovery, and osmoprotectant accumulation, including increased antioxidant capacity (+75% at 3dpt), proline (+178%), and sucrose (+18%) and starch depletion (-57%) at 7dpt respect to control. These metabolic changes coincided with the enhanced lateral root emergence. These findings indicate a two-phase response: early metabolic downscaling with transient Suc-Tre6P-SnRK1 disruption, followed by recovery with Tre6P restoration, SnRK1 reactivation, osmoprotection, and sustained root plasticity under salinity. HighlightSalinity triggers a temporary metabolic shift in alfalfa roots: plants first conserve energy, then adapt to stress, maintaining lateral root growth and flexible root architecture.

Recent studies have demonstrated the presence of kynurenine (KYN) and kynurenic acid (KYNA) in several plant species, but the metabolic function of these metabolites remains undefined. We hypothesized that KYN and KYNA are metabolites of auxin and play a role in plant morphogenesis. To test our hypothesis, we developed a plant tissue-culture-based bioassay using Hypericum perforatum (St. Johns wort; SJW), a model system for auxin and indoleamine metabolism and pharmacological inhibitors (PF-04859989, RO-61-8048, and KMO inhibitor II, JM6) of human kynurenine pathways enzymes. SJW is an interesting model system because explants root in the absence of plant growth regulators but supplementation of the culture media with 10 M IAA induces a callus response without de novo root organogenesis. Supplementation of the culture media with 10 M KYN increased root number and internodal length relative to basal media. We used a previously validated high-resolution mass spectrometry analytical method to quantify KYN, KYNA, and 3-hydroxyanthranilic acid (3-HAA). KYN, KYNA and 3-HAA were quantified in roots and shoots of SJW grown on basal media. Supplementation of the culture media with 10 M KYN increased the concentration of KYN, KYNA and 3-HAA in roots and shoots. Treatment with 10 M IAA increased KYN and 3-HAA concentration in shoots. Three pharmaceutical candidates that are kynurenine pathway inhibitors in humans were taken up into the tissues from the culture media and increased KYN content as compared to basal control. Together, these data propose a role for KYN in IAA metabolism, shoot and root organogenesis. HighlightsO_LIKynurenine metabolites are detected and accumulate in H. perforatum tissue culture C_LIO_LIIAA redirects metabolism towards accumulation of KYN and 3-HAA in shoots C_LIO_LIExogenous KYN promotes KYNA accumulation C_LIO_LIPharmacological inhibition alters kynurenine pathway metabolite profiles in a tissue-specific manner C_LIO_LIKynurenine and IAA differentially regulate root development C_LI

The current understanding of Crassulacean Acid Metabolism (CAM), including semi-controlled studies in pineapple, does not fully explain outcomes observed under commercial field conditions. Although empirical agronomy confirms a strong climatic influence on growth and development, mechanistic explanations at the metabolic level--particularly for photosynthate allocation--remain scarce. This study evaluated how environmental variation affects diel CAM outputs and how such effects can be agronomically interpreted. MD-2 pineapple plants were cultivated in contrasting natural environments across Costa Rica. Leaf samples were collected at defined phenological stages and at the end of CAM Phases I and IV. Field data revealed distinct metabolic balances between soluble sugar accumulation and nocturnal malic acid content. Under high radiation and temperature, sucrose concentrations increased markedly, reflecting shifts toward leaf growth over stem reserve storage. These shifts were associated with differences in harvest index, highlighting the role of sucrose dynamics in phenotypic plasticity. From a seed selection perspective, integrating CAM diel profiling into research protocols--together with physiological age (thermal units)--could provide a stronger basis for classifying planting material beyond current fresh-weight standards. Such integration would improve the prediction of photosynthetic performance, early establishment success, and ultimately, crop uniformity at harvest. Approximately 38% of diel metabolic patterns deviated from the classical CAM model, indicating dynamic regulatory mechanisms under field conditions. Understanding these patterns could improve the interpretation of yield variability, natural flowering incidence, and harvest index across agroecosystems. Recognizing these CAM particularities offers a path to bridge the gap between fundamental CAM biochemistry and agronomic application, enabling the development of precise management strategies that respond to metabolic plasticity under real-world conditions. Closing this gap is essential to enhance productivity, uniformity, and sustainability in pineapple agroecosystems.

Indica rice, being a tropical crop, is highly sensitive to cold temperature. Cold stress affects vegetative growth, photosynthetic efficiency, along with reproductive features. Genetic resource screening in diverse landraces is an approach for identifying cold-tolerant traits. Here, we have characterised a boro germplasm, CB1, with an efficient germination rate and growth vigour when treated at chilling temperatures. CB1 seedlings show a higher survival rate compared to IR36 when subjected to prolonged chilling stress. Biochemical analyses indicated efficient ROS modulation, higher chlorophyll content, enhanced photosystem II efficiency and unique stomatal traits, leading to higher relative water content in CB1 plants during stress and recovery. Transcriptome analysis supported upregulation of chlorophyll biosynthesis, photosystem, & light harvesting complex and ROS scavenger genes in CB1 seedlings. Interestingly, high D1 protein turnover in CB1 promotes damage-repair of PSII for efficient photosynthesis. Furthermore, key transcription factors for stomatal development and expression of photosynthetic genes were upregulated in CB1 during stress recovery. Notably, higher expression of OsGLK1 and enrichment of GLK1 targets were observed in CB1 plants during chilling stress and recovery. Taken together, our results suggested that CB1 plants exhibit cold tolerance by modulating photosynthesis efficiency and stomatal behavior for better adaptability and survival against chilling temperature. HIGHLIGHTSThe efficient photosynthetic recovery, active ROS scavenging system and maintenance of water content through regulating stomatal traits, enhance the survival of indica germplasm CB1 against chilling stress.

Increasing global temperatures and the rising frequency of heat waves pose a significant threat to plant reproduction. The reproductive phase is particularly sensitive to heat stress, yet the underlying mechanisms regulating thermotolerance during this stage remain insufficiently understood, despite significant advcances in its understanding during vegetative growth. Heat stress responses are largely controlled by heat shock factors (HSFs) and their downstream targets, including heat shock proteins (HSPs). Among these, HSP101 is essential for acquired thermotolerance and recovery from stress, while HEAT SHOCK BINDING PROTEIN (HSBP) acts as a negative regulator of HSF activity, modulating the heat shock response. Here, we investigated the impact of elevated temperature regimes on the reproductive development of Arabidopsis thaliana, with a particular focus on pollen development and fertility. Our results show that heat stress negatively affects pollen development in a dose-dependent manner, leading to reduced reproductive success. We confirmed the critical role of HSP101 in reproductive thermotolerance using the hot1-3 mutant, deficient in HSP101. Furthermore, we provide evidence that the hot1-3 mutant is tetraploid. The origin of this event is unknown, but it is tempting to speculate that disruption of heat stress responses and interference with meiotic processes may lead to whole genome duplication. Overall, this study provides new insights into the regulation of plant reproductive development under heat stress and highlights the importance of HSP101 in maintaining fertility. These findings contribute to a better understanding of plant responses to rising temperatures and may inform strategies to enhance crop resilience under climate change. Main ConclusionFlowering Arabidopsis plants adapt to long-term high temperature by shortening the flowering period and reducing their fertility. The study also demonstrated that the commonly used hot1-3 mutant is tetraploid.

Drought is a major abiotic stress threatening plant productivity and agricultural sustainability, yet the molecular mechanisms underlying adaptive root responses to water deficit in the water use strategies continuum remain insufficiently understood, particularly in perennial crops. In this study, we explored drought responses in nine accessions belonging to three wild Vitis species (V. acerifolia, V. candicans, and V. doaniana) displaying varying drought-response strategies. Plants were subjected to moderate drought stress (40% soil water content) for three weeks under greenhouse conditions. By integrating physiological, metabolic, and transcriptomic analyses, we aimed to identify both conserved and species-specific mechanisms associated with drought adaptation. Differential expression analyses revealed a conserved core set of drought-responsive genes shared among species, including genes involved in abscisic acid signaling, reactive oxygen species detoxification, solute transport, and plant defense. In parallel, each species exhibited distinct transcriptional and metabolic signatures reflecting alternative adaptive strategies related to osmoregulation, and oxidative stress mitigation. Weighted gene co-expression network analysis (WGCNA) further revealed significant associations between constitutive, non-plastic gene expression and root phenotypic traits. Overall, our findings demonstrate that wild Vitis species rely on both conserved stress-responsive pathways and species-specific constitutive regulation to cope with drought stress. These results highlight the importance of root-associated traits and intrinsic regulatory networks in shaping drought adaptation and provide new targets for the development of drought-resilient grapevine rootstocks.

O_LIPlants continuously adjust photosynthesis to balance growth and photoprotection under changing environmental conditions. Environmental fluctuations frequently impose a mismatch between energy production and CO2 assimilation. How photochemical reactions are regulated to maintain performance under these conditions remains a central question in plant biology. C_LIO_LIWe previously developed transplastomic tobacco (Fd1-OE plants) overexpressing ferredoxin (Fd) displaying enhanced photoprotection and growth penalties with a variegated leaf phenotype under greenhouse conditions. Here, we investigate how these plants respond to different growth irradiances using physiological, ultrastructural, and photosynthetic analyses, including PAM, gas exchange, and P700 absorbance measurements, and dynamic-light assays. C_LIO_LIFd1-OE plants progressively recovered growth, leaf phenotype and photosynthetic performance as growth irradiance increased, reaching near WT performance at 1400 mol m-{superscript 2} s-{superscript 1}. This enhanced adaptation to "high-light" was associated with a larger fraction of open PSII reaction centers and enhanced NPQ. Dynamic-light analyses further revealed faster plastoquinone (PQ) turnover, a more oxidized PQ pool and enhanced electron withdrawal downstream of PSI. C_LIO_LIOur results indicate that Fd overexpression redefines the balance between photochemistry and photoprotection. This adjustment shifts adaptation toward higher irradiance and enhances photosynthetic performance under changing light environments. Electron partitioning downstream of PSI emerges as a promising target to improve photosynthetic resilience. C_LI One sentence summaryOverexpression of Fd1 in tobacco plants adjusts photosynthesis/photoprotection trade off to enhance high-light adaptation

O_LIHeatwaves are increasing in frequency and intensity and may alter competitive interactions between native and non-indigenous plant species. C_LIO_LIWe compared the responses of the native Sporobolus maritimus and the non-indigenous Sporobolus anglicus to a simulated 5-day heatwave using an integrative approach combining morphological, physiological, biochemical, transcriptomic, and metabolomic analyses. C_LIO_LIS. maritimus showed reduced survival, greater physiological damage, and no recovery, indicating high sensitivity to heat stress. Conversely, S. anglicus exhibited a rapid and coordinated response, limited damage to the photosynthetic apparatus, and full recovery after stress. C_LIO_LIThese results highlight the greater resilience of S. anglicus and suggest a potential decline of the native species in the Venetian salt marshes under increasing heat stress. C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=139 SRC="FIGDIR/small/728445v1_ufig1.gif" ALT="Figure 1"> View larger version (49K): org.highwire.dtl.DTLVardef@14818aaorg.highwire.dtl.DTLVardef@4b5d40org.highwire.dtl.DTLVardef@1d7451dorg.highwire.dtl.DTLVardef@1fa8653_HPS_FORMAT_FIGEXP M_FIG C_FIG We investigated the effects of heatwaves on a native and NIS Sporobolus species from the Venice Lagoon using an integrative, multi-level approach during a simulated 5-day heatwave and recovery phase. The native species showed reduced survival, pronounced physiological damage, and no recovery, indicating high sensitivity to heat stress. Conversely, the NIS exhibited a rapid response, limited impairment of the photosynthetic apparatus, and full recovery. These findings indicate greater resilience of the NIS and suggest a potential decline of the native species in the Venice Lagoon under increasing heat stress. Image created with BioRender (www.biorender.com).

Low temperature stress causes significant damage to the strawberry plant. During cold stress, plants undergo morphological and physiological changes often regulated at the genetic and/or epigenetic levels. Some strawberry cultivars are more cold-hardy than others. Using the diploid woodland strawberry as a model, we analyzed the effects of cold acclimation on methylome and transcriptome dynamics in the crowns and leaves of three ecotypes with contrasting cold tolerance. Alta, which was the most cold-tolerant ecotype, exhibited the highest genetic and epigenetic plasticity in response to cold. CHH-context methylation dominated the differentially methylated regions (DMRs) with more hypomethylation in crowns and hypermethylation in leaves. CG methylation was enriched in gene bodies, while non-CG methylation was prevalent in upstream and downstream regions. Our study revealed that less than a quarter of differentially methylated genes (DMGs) showed changes in transcript accumulation levels. This finding indicates that universal cold response in Fragaria vesca, as reflected by gene expression, cannot be mechanistically attributed to DNA methylation. The majority of differentially expressed differentially methylated genes (DEDMGs) were ecotype- and tissue-specific. Enrichment analysis revealed that these genes were involved in pathways related to stress tolerance, such as carbohydrate metabolism, lipid metabolism, ATP hydrolysis, and cellular detoxification. Each ecotype responded to cold through mobilization of its own set of differentially expressed genes (DEGs), DMGs, and DEDMGs, and variation in expression and methylation patterns exhibited by Alta, FDP817, and NCGR1363 suggest that cold signaling processes and survival depend on the tissue, ecotype, and geographical origin of the plants exposed to cold stress. Therefore, this study highlights the potential of both genetic markers and epialleles as molecular markers for the development of cold-tolerant octoploid strawberry cultivars that are better suited for propagation in Nordic climates.

Globally, heat waves (HWs) have become more frequent, intense, and prolonged, with extreme temperatures that reduce quality or result in crop loss in wine grapes. Irrigation prior to or during HWs is one of the most common means of mitigating damage to vines and berries. However, the effect of this practice on flavonoids is not well established. Red wine quality is directly impacted by phenolics, including anthocyanins and proanthocyanidins (PAs). This study was conducted over three vintages (2019-2021) in a commercial vineyard to evaluate the impact of supplemental irrigation - applied before and during HWs - on winegrape chemistry in Cabernet Sauvignon. Results demonstrated that supplemental irrigation significantly reduced anthocyanin loss compared to a control treatment maintained at 60% evapotranspiration (ET), and that pre-HW irrigation can mitigate some of the deleterious effects on classes of flavonoids important to red wine quality. Furthermore, applying excessive water (3x, or 180% ET) had no additional beneficial effects on flavonoids relative to a moderate supplemental application (2x, or 120% ET).