J. Exp. Bot. [JOURNAL]
Sun
200 papers
Evolution of cellulose synthesis complexes in plants: Cellulose synthase-like D rosettes in the charophyte green alga Coleochaete.
Roberts EM, Whelan KA, Gobell M … +2 more , Haigler CH, Roberts AW
J Exp Bot · 2026 Apr · PMID 42029181 · Publisher ↗
The cellulose microfibrils of land plants are synthesized by two families of enzymes, Cellulose Synthase (CESA) and CESA-Like-D (CSLD). Both form rosette Cellulose Synthesis Complexes (CSCs), which appear as hexagonal gr...
The cellulose microfibrils of land plants are synthesized by two families of enzymes, Cellulose Synthase (CESA) and CESA-Like-D (CSLD). Both form rosette Cellulose Synthesis Complexes (CSCs), which appear as hexagonal groups of six particles with freeze fracture transmission electron microscopy. Throughout the green plant lineage, CSC morphology is correlated with cellulose microfibril structure and properties. Charophyte green algae (CGA) have CESAs, CSLDs, and/or CESA/CSLD-like enzymes from which the other two families likely evolved, and most have rosette CSCs. The apparent exception is Coleochaete, previously reported to have unique octagonal CSCs. Using a specimen preparation method that promotes periclinal fractures, we show that Coleochaete has typical six-particle rosette CSCs consistent with expression of CSLD genes, thus resolving a long-standing anomaly. Coleochaetophyceae also express CESA/CSLD-like genes, but no CESAs were detected in 27 Coleochaete and Chaetosphaeridium transcriptomes. The phylogenetic distribution and exon-intron structure of CESAs, CSLDs, and their CESA/CSLD-like common ancestors are consistent with an evolutionary history that included losses and gains of genes and introns, with implications for the divergence and functional specialization of the CESA and CSLD families. Together, these findings help clarify the structural basis of cellulose microfibril synthesis in CGA and the evolution of cellulose synthases in plants.
Golden Promise-rapid, a fast-cycling and transformable barley genotype.
Buchmann G, Haraldsson EB, Schüller R … +4 more , Rütjes T, Walla AA, von Korff Schmising M, Liu S
J Exp Bot · 2026 Apr · PMID 42025324 · Publisher ↗
The spring barley cultivar Golden Promise (GP) is the major reference genotype for transformation due to its high transformability and availability of a reference genome. However, GP is characterized by a long generation...
The spring barley cultivar Golden Promise (GP) is the major reference genotype for transformation due to its high transformability and availability of a reference genome. However, GP is characterized by a long generation cycle and stress susceptibility under non-optimal growth conditions because it carries a mutation at the floral inducer Photoperiod-H1 (Ppd-H1). Previously, we showed that a GP introgression line, Golden Promise-fast (GP-fast), generated by introducing the wild-type Ppd-H1 allele from the winter barley cultivar Igri, exhibits early flowering and improved stress resilience. In this study, we generated a fast-cycling genotype, Golden Promise-rapid (GP-rapid), isogenic to GP with good regeneration capacity and transformability. We conducted two backcrosses of GP-fast to reduce the residual Igri genome. The resulting genotype contains only a single introgression of approximately 0.6 Mbp at the Ppd-H1 locus on chromosome 2H. Under speed breeding conditions, its generation time was reduced to 63 days (25% shorter than GP's 84 days). Parallel transformation of GP, GP-fast, and GP-rapid using CRISPR/Cas9-mediated genome editing of Ppd-H1 revealed that GP-rapid remains amenable to Agrobacterium-mediated transformation. Overall, we report on the development of a fast-cycling GP isogenic line as a research tool for efficient generation of transgenic and gene-edited barley plants.
Chimeras of GROWTH-REGULATING FACTOR and GRF-INTERACTING FACTOR (GRF-GIF) enhance leaf-based regeneration and transformation efficiency in tomato.
Lee S, Choi AH, Jung M … +5 more , Nie H, Ko SR, Kim N, Kwon SY, Shin AY
J Exp Bot · 2026 Apr · PMID 42017305 · Publisher ↗
Efficient regeneration remains a major constraint for tomato (Solanum lycopersicum) transformation, particularly from leaf explants. Here, we evaluated chimeric GROWTH-REGULATING FACTOR (GRF)-GRF-INTERACTING FACTOR (GIF)...
Efficient regeneration remains a major constraint for tomato (Solanum lycopersicum) transformation, particularly from leaf explants. Here, we evaluated chimeric GROWTH-REGULATING FACTOR (GRF)-GRF-INTERACTING FACTOR (GIF) proteins as regeneration enhancers and examined regulatory features underlying their activity. Fusion constructs based on Arabidopsis thaliana GRF5-GIF1 and their tomato homologs SlGRF4 and SlGIF1b markedly increased shoot regeneration from leaf explants, with similar enhancement observed in cotyledon-derived tissues, across three tomato cultivars. Regenerated shoots were able to form roots, indicating that GRF-GIF-mediated regeneration produced developmentally competent plantlets. Temporal expression profiling indicated that GRF-GIF transcript levels increased during regeneration and coincided with the induction of cytokinin- and auxin-associated regulators linked to meristem initiation. RNA-seq analyses revealed a shared early transcriptional program enriched for transcription factor activity and protein homeostasis, accompanied by broad repression of metabolism-related pathways. Despite strong phenotypic effects, GRF-GIF fusion proteins accumulated poorly in stable transformants. Transient expression assays suggested that their abundance is influenced by ubiquitin-proteasome system, and mutational analyses identified lysine residues affecting protein stability, although stabilization did not further enhance regeneration. Together, these findings support the use of GRF-GIF chimeras as effective enhancers of tomato regeneration from leaf explants and highlight the contribution of coordinated regulation at the transcript and protein levels to their functional window during cellular reprogramming.
Bridging Metabolic Pathways: Coordinated Regulation of Isoprenoid and Phenylpropanoid Metabolism in Plants.
Di X, Hu R, Gao Y … +5 more , Schaller H, Madhujith T, Hao G, Hemmerlin A, Liao P
J Exp Bot · 2026 Apr · PMID 42017303 · Publisher ↗
Plants face the core challenge of balancing growth and defense through fine-tuned metabolic regulation, which hinges on the coordinated biosynthesis of specialized metabolites such as isoprenoids and phenylpropanoids. Th...
Plants face the core challenge of balancing growth and defense through fine-tuned metabolic regulation, which hinges on the coordinated biosynthesis of specialized metabolites such as isoprenoids and phenylpropanoids. This review integrates current insights into the dynamic interplay between these pathways, highlighting their role as a unified adaptive response to abiotic stresses, including drought, light, salinity, heavy metals, nutrient deficiency, altitude, temperature extremes, and combined stressors. Their interaction establishes a context-dependent regulatory network, characterized by both synergistic and antagonistic effects, potentially driven by competition for the shared precursor phosphoenolpyruvate. This metabolic node demands dynamic resource allocation, inherently generating trade-offs that shape its complex regulatory relationship. Hierarchical transcriptional networks, involving specific of transcription factors families, further refine this cross-pathway communication. By integrating environmental and developmental cues, these networks fine-tune metabolic output to achieve coordinated physiological responses. The crosstalk between isoprenoid and phenylpropanoid pathways is a key regulatory node for metabolic plasticity, enabling plants to deploy robust, multi-layered defenses. Deciphering the systemic signals and regulatory hubs governing these pathways is critical for the rational engineering of resilient crops and the optimization of phytochemical production. Adopting a holistic view of plant metabolic networks is equally vital for addressing global challenges from climate adaptation to sustainable agriculture.
Metabolic trade-offs in sugar beet under drought and beet leaf miner infestation: implications for herbivore success.
Rahman S, Surovy MZ, Vosteen I … +1 more , Rostás M
J Exp Bot · 2026 Apr · PMID 42015420 · Publisher ↗
Increasing frequency of drought under climate change threatens crop production and intensifies pest pressures, yet the interactive effects of drought and herbivory on plant metabolism and ecological outcomes remain incom...
Increasing frequency of drought under climate change threatens crop production and intensifies pest pressures, yet the interactive effects of drought and herbivory on plant metabolism and ecological outcomes remain incompletely understood. We subjected sugar beet (Beta vulgaris) plants to moderate and high drought, alone or with infestation by the beet leaf miner (Pegomya cunicularia), and analyzed plant physiology, central metabolites, and volatile organic compound (VOC) emissions. Drought alone reduced growth and photosynthetic efficiency, while combined stress led to accentuated metabolic reprogramming, including increased amino acids and organic acids, and a concurrent suppression and alteration of VOC emissions, especially in plants affected by high drought and leaf mining. The resulting changes in VOC blends reduced plant attractiveness to ovipositing females, leading to fewer eggs laid on severely stressed plants. Contrastingly, moderate drought generated a nutrient-rich environment: larvae feeding on these plants exhibited the highest growth rates, larger pupae and adults, and increased feeding damage. High drought strongly limited both plant water content and larval development. These findings reveal a stress-dependent tradeoff between enhanced leaf nutritional quality and reduced host detectability, underscoring the importance of integrating multi-stress plant biology for future pest management and crop resilience.
A maize GT14 family glycosyltransferase affects cell wall composition and carbohydrate export from source leaves.
McCubbin TJ, Mertz RA, Baker RF … +13 more , Leach KA, Barron B, Bhimidine S, Rueda S, Basu A, Chomet P, Wagner R, Grote K, Peevers J, McCann MC, Carpita NC, Slewinski TL, Braun DM
J Exp Bot · 2026 Apr · PMID 42015412 · Publisher ↗
Sucrose translocation from photosynthetic leaves to distant parts of the plant, such as seeds and roots, is a critical aspect of plant growth and development and a major determinant of crop yield. To identify genes contr...
Sucrose translocation from photosynthetic leaves to distant parts of the plant, such as seeds and roots, is a critical aspect of plant growth and development and a major determinant of crop yield. To identify genes contributing to this process in maize (Zea mays), we isolated four allelic mutants, carbohydrate partitioning defective7, 48, 49 (cpd7, cpd48, cpd49) and a UniformMu insertion (mu1049954), all of which exhibited reduced growth and fertility and hyperaccumulation of starch and soluble sugars in mature leaves. Consistent with carbohydrate accumulation, cpd7 mutants exhibited reduced sucrose export from mature leaves. Cpd7 encodes a Golgi-resident glucuronosyl transferase belonging to the Glycosyltransferase14 (GT14) family, which is involved in decoration of type II arabinogalactan proteins. No previously described GT14 mutants exhibit reduced sucrose transport or carbohydrate partitioning defects. Additionally, we show that mature leaves of cpd7 mutants have reduced cellulose content and an altered cell wall composition. Further, cpd7 mutants exhibit ectopic phloem lignification likely as a compensatory mechanism for reduced cell wall integrity. Collectively, our data suggest that Cpd7 functions to facilitate cell wall development in the phloem, which is required for efficient sucrose export from mature maize leaves.
Non-coding RNAs in plant development: the puzzle pieces that wire an intricate regulatory network.
Chen X, Chen Z, Watts R … +2 more , Liu M, Luo H
J Exp Bot · 2026 Apr · PMID 42011903 · Publisher ↗
Noncoding RNAs (ncRNAs) play dominant roles in plant growth traits, involved in architecture shaping, reproductive timing and seed development. Increasing evidence shows that ncRNAs are versatile regulators that connect...
Noncoding RNAs (ncRNAs) play dominant roles in plant growth traits, involved in architecture shaping, reproductive timing and seed development. Increasing evidence shows that ncRNAs are versatile regulators that connect chromatin, transcriptional control, and post-transcriptional gene regulation to these developmental programs. This review synthesizes current understanding of ncRNA functions in plant growth and development across five modules: leaf and shoot development, root development, floral development, fleshy fruit development, and seed development. We integrate detailed mechanisms spanning microRNAs, small interfering RNAs, long noncoding RNAs, circular RNAs, and tRNA-derived fragments, with emphasis on how these ncRNAs influence developmental traits and their regulatory crosstalk. We also discuss opportunities for rational crop engineering by tuning endogenous ncRNA pathways and by introducing synthetic regulatory circuits. Collectively, the continued advances across multi-omic platforms and computational frameworks will refine our understanding of ncRNA regulatory landscapes, providing opportunities to enhance the design of agriculturally versatile crops.
Natural phenolic autofluorescence reveals cell wall-specific distribution of hydroxycinnamates in Brachypodium distachyon.
Vimenet L, Devaux MF, Alvarado C … +9 more , Le Bot L, Leroy A, Brionne L, Pilate G, Barron C, Chauvet H, Jamme F, Guillon F, Sibout R
J Exp Bot · 2026 Apr · PMID 42008503 · Publisher ↗
p-Coumaroyl-CoA:monolignol transferase has been demonstrated to be involved in the coumaroylation of lignins in Brachypodium distachyon. However, the specific localization of acylation remains poorly documented at the ti...
p-Coumaroyl-CoA:monolignol transferase has been demonstrated to be involved in the coumaroylation of lignins in Brachypodium distachyon. However, the specific localization of acylation remains poorly documented at the tissue and cell wall levels in this species. Detecting molecules that are sometimes present at levels <1% in the cell wall remains a challenge, especially when suitable antibodies are not always available. In this work, we applied fluorescence microscopy methods, including large-beam excitation scanning at the SOLEIL synchrotron, to detect variations induced by hydroxycinnamic acids within B. distachyon stems. Using principal component analysis (PCA), fluorescence microscopy imaging effectively distinguished genotypes differing subtly in phenolic composition. The results were supported by immunolabeling, which confirmed that p-coumarate co-localizes with S-unit lignin in lignified tissues, while ferulate is broadly distributed. Strong autofluorescence in the mestome sheath and metaxylem pit area indicated a potential functional role for p-coumaric acid in these tissues. Finally, autofluorescence-based imaging and PCA proved to be a robust, non-destructive tool for visualizing lignin and phenolic compounds, offering valuable insights into cell wall specialization and phenolic function.
Aerenchyma in sugarcane roots: a toolbox for tailoring biomass for bioenergy.
Navarro BV, Pagliuso D, Oliveira MM … +8 more , Grandis A, Ferreira MJP, de Oliveira LP, Romim GH, Araujo AJB, Tavares EQP, Piovezani AR, Buckeridge MS
J Exp Bot · 2026 Apr · PMID 42001464 · Publisher ↗
Sugarcane is a major feedstock for first-generation (1G) ethanol production, but the efficient conversion of its lignocellulosic residues into second-generation (2G) biofuels remains limited by the resilience of its cell...
Sugarcane is a major feedstock for first-generation (1G) ethanol production, but the efficient conversion of its lignocellulosic residues into second-generation (2G) biofuels remains limited by the resilience of its cell wall. Here, we suggest sugarcane root aerenchyma as a relevant biological model to study in vivo mechanisms of cell wall breakdown. By performing spatial transcriptomic profiling across four root segments representing different stages of aerenchyma development, we identified over 32,000 differentially expressed transcripts (DETs), including many genes that encode cell wall-modifying proteins. Co-expression network analysis and functional annotation revealed stage-specific expression of glycoside hydrolases, glycosyltransferases, and expansins, aligning with the gradual degradation of wall components. Among these, an α-L-arabinofuranosidase (ScASD1) was chosen for biotechnological validation due to its strong transcriptional induction. Heterologous expression in Pichia pastoris and saccharification assays with sugarcane bagasse showed that ScASD1 significantly improves reducing sugar release when used with a commercial enzyme cocktail. Our results support using sugarcane aerenchyma as a platform to discover plant-derived enzymes, and establish ScASD1 as a promising candidate for enhancing hydrolytic efficiency in 2G ethanol production. This approach aligns with sustainable bioenergy goals and offers a scalable method to lower costs and promote circularity in sugarcane-based biorefineries.
Precision in Motion: How Plants Route and Control the Mobility of Small RNAs.
Herrmann A, Timmermans MCP
J Exp Bot · 2026 Apr · PMID 41999188 · Publisher ↗
Intercellular movement of small RNAs (sRNAs) is fundamental to the growth and survival of plants. Mobile sRNAs function as short- and long-range signals that coordinate developmental patterning, integrate physiological a...
Intercellular movement of small RNAs (sRNAs) is fundamental to the growth and survival of plants. Mobile sRNAs function as short- and long-range signals that coordinate developmental patterning, integrate physiological and stress responses, and safeguard reproductive success and genome integrity. Recent advances show that sRNA mobility is not governed simply by plasmodesmata (PD) permeability. Instead, multiple regulatory layers govern which sRNAs become mobile, which cell-cell interfaces they can travers, and where they act. Specialized nuclear export pathways and cytoskeleton-dependent mechanisms enable mobile sRNAs to escape sequestration into cell-autonomous ARGONAUTE proteins. In parallel, gatekeeping factors, potentially localized at PDs, generate selective and directional mobility-particularly in stem-cell niches and the central vasculature-to ensure that mobile sRNAs deliver precise positional information. In this review, we summarize contributions from mobile sRNAs to development and synthesize recent advances in understanding how the mobile sRNA pool is generated, how sRNAs traverse plasmodesmata, and how developmental context shapes mobility. We highlight unresolved questions and emerging concepts that explain how plants impose precision on these central organizers of development and environmental adaptability.
Diel carbon buffering by floridoside enables source-sink resilience in the intertidal red alga Pyropia haitanensis.
Mao J, Zhu Z, Li S … +1 more , Chen H
J Exp Bot · 2026 Apr · PMID 41999048 · Publisher ↗
Diel source-sink regulation is conventionally framed by the sucrose-starch buffering system of land plants, raising the question of whether similar organizational logic operates in early-diverging photosynthetic lineages...
Diel source-sink regulation is conventionally framed by the sucrose-starch buffering system of land plants, raising the question of whether similar organizational logic operates in early-diverging photosynthetic lineages. Red algae, which rely on low-molecular-weight carbohydrates ((iso)floridoside) and cytosolic floridean starch rather than sucrose and amylopectin, provide an opportunity to test this framework. Here, we combined a 12-h 13C-NaHCO3 pulse with a 36-h chase, isotopologue-resolved LC-MS of sugar phosphates, UDP-sugars, glycerol-3-phosphate and galactosylglycerols, quantitative floridean starch assays, and time-series transcriptomics in Pyropia haitanensis. Newly assimilated carbon rapidly entered central nodes (glycerol-3-phosphate, hexose-P and UDP-sugars) and subsequently accumulated more slowly in (iso)floridoside and floridean starch. Despite higher basal isofloridoside, 13C was preferentially incorporated into floridoside. During the chase, labelled carbon was diluted and turned over with limited redistribution. These fluxes corresponded with diel transcriptional programs: light-phase up-regulation of carbonic anhydrase, Rubisco and genes directing carbon into galactosylglycerols and starch, and dark-phase induction of α-galactosidase and starch-remodelling enzymes. Together, these results show that LMWCs function as metabolic gatekeepers that relay photosynthate into transient and polymeric sinks, establishing a red-algal analogue of the sucrose-starch buffer and providing a comparative framework for source-sink biology across photosynthetic lineages.
A metabolic complex of acyltransferase enzymes involved in tomato acylsugar biosynthesis.
Dwivedi V, Okertchiri E, Yokom A … +1 more , Schenck CA
J Exp Bot · 2026 Apr · PMID 41995721 · Publisher ↗
Specialized metabolites mediate diverse plant-environment interactions. Recent work has begun to enzymatically characterize entire plant specialized metabolic pathways; however, little is known about how different pathwa...
Specialized metabolites mediate diverse plant-environment interactions. Recent work has begun to enzymatically characterize entire plant specialized metabolic pathways; however, little is known about how different pathway components organize and interact within the cell. Here we use acylsugars - a class of specialized metabolites - to explore metabolic complex formation. In Solanum lycopersicum (tomato) four trichome-localized acylsugar acyltransferases (SlASAT1-4) sequentially add acyl chains to a sucrose core leading to accumulation of tri and tetraacylated sucroses. Confocal microscopy demonstrates that tomato ASATs localize to distinct subcellular locations, including the mitochondria, cytosol, and endoplasmic reticulum. To explore pairwise protein-protein interactions in acylsugar biosynthesis, we used various techniques relying on different interaction principles, including co-immunoprecipitation, split luciferase assays, and bimolecular fluorescence complementation all demonstrating pairwise SlASAT interactions. Following transient expression of SlASAT1-4 in Nicotiana benthamiana, we were able to pull down a complex consisting of SlASAT1-4, which was confirmed through proteomics. Size exclusion chromatography of the SlASAT pulldown suggests a heteromultimeric complex of around 300 kDa. This study sheds light on the metabolic coordination of acylsugar biosynthesis through formation of a metabolic complex enabling production of chemical defenses.
Sulfur as a Central Integrator of Plant-Microbe Interactions: From Nutrient Cycling to Immune Signalling and Microbiome Assembly.
Elkatmis B, Türksoy GM, Rodríguez E … +3 more , Rahmoune B, Koprivova A, Kopriva S
J Exp Bot · 2026 Apr · PMID 41995611 · Publisher ↗
Sulfur (S) is an essential macronutrient that underpins plant growth, stress resilience, and immunity. Beyond its role in primary metabolism, sulfur is incorporated into a diverse array of secondary metabolites that medi...
Sulfur (S) is an essential macronutrient that underpins plant growth, stress resilience, and immunity. Beyond its role in primary metabolism, sulfur is incorporated into a diverse array of secondary metabolites that mediate plant-microbe interactions. In this review, we summarize current knowledge on how microbial sulfur metabolism contributes to plant sulfur nutrition and how plant-derived sulfur-containing compounds shape microbial community assembly and disease outcomes. Microorganisms mobilize organic sulfur in soils through sulfatase activity, volatile sulfur production, and sulfoquinovose degradation, thereby enhancing plant sulfur availability, particularly under limiting conditions. Conversely, plants deploy sulfur-rich metabolites, including volatile organic compounds, glucosinolates, and the phytoalexin camalexin, to restrict pathogens, modulate beneficial associations, and structure rhizosphere communities. These compounds act not only as antimicrobial agents but also as ecological filters that balance defense with microbiome homeostasis. Emerging evidence indicates that sulfur availability and metabolic flux influence the composition and function of plant-associated microbiota, linking primary nutrient assimilation to immune regulation. By integrating insights from sulfur biochemistry, microbial ecology, and plant immunity, we highlight sulfur metabolism as a central node in plant-microbe interactions. Understanding the dynamic exchange of sulfur between plants and their microbiota will be essential for improving crop resilience and sustainable nutrient management in sulfur-limited agricultural systems.
Improving wheat tolerance to post-flowering heat using matched development stages and field-based reaction norms.
Yahya M, Ullah N, Christopher J … +5 more , Cozzolino D, Mellor V, Fox G, Kuhn E, Chenu K
J Exp Bot · 2026 Apr · PMID 41995606 · Publisher ↗
Post-flowering heatwaves impact individual grain weight (IGW) and grain quality of wheat. Here, the effect of post-flowering heatwaves on IGW, yield and grain protein content (GPC) were examined in 25 wheat genotypes gro...
Post-flowering heatwaves impact individual grain weight (IGW) and grain quality of wheat. Here, the effect of post-flowering heatwaves on IGW, yield and grain protein content (GPC) were examined in 25 wheat genotypes grown in irrigated field trials across locations, seasons and sowing dates. The photoperiod-extension method (PEM) was employed with measurements on individual spikes to synchronize flowering among genotypes, ensuring heat impacts were assessed at similar developmental stages. Adjacent to most PEM trials, genotypes were cultivated in machine-harvested field plots to evaluate crop performance using a more conventional screening method. Heat stress significantly reduced IGW and increased GPC in PEM trials, with impacts not as clearly discernible in conventional plots. Across genotypes and traits, heat responses (slope of the reaction norms) were negatively correlated with trait values observed in non-stressed conditions (intercept). The level of heat stress each genotype could endure before reaching critical IGW (30 mg), yield (250 g m-2) or GPC (15%) thresholds revealed high genotypic variability and highly tolerant genotypes. The findings provide insights for improving heat responses in crop models and enhancing genotype selection for climate-resilient breeding.
Apoplastic pH modulates gene expression, proteome, and ABA content in Vicia faba guard cells, accompanied by reduced stomatal aperture under salt stress.
Meyer P, Carpentier S, Mithöfer A … +6 more , Vélez-Bermúdez IC, Lin WD, Herrera HS, Schmidt W, Schmitz-Linneweber C, Geilfus CM
J Exp Bot · 2026 Apr · PMID 41992558 · Publisher ↗
Although the regulatory role of apoplastic pH (pHapo) changes in response to environmental conditions is well documented in root signalling, the contribution of pHapo to guard cell (GC) regulation and NaCl stress respons...
Although the regulatory role of apoplastic pH (pHapo) changes in response to environmental conditions is well documented in root signalling, the contribution of pHapo to guard cell (GC) regulation and NaCl stress response remains poorly understood. To determine whether alterations in leaf pHapo modulate physiological responses in GC under NaCl-stress, hydroponically grown Vicia faba plants were subjected to root-applied NaCl-stress or alkaline-buffered infiltration of the leaf apoplast. In vivo pHapo monitoring was coupled to transcriptomic, proteomic and phytohormone profiling of GC-enriched samples. Leaf apoplastic alkalinisation triggered distinct transcriptomic and proteomic responses in GC. Among over 57,000 transcripts, 1,562 were associated with pHapo, including 577 previously uncharacterised reading frames ('NOVEL regions'). 18 genes and 2 proteins responded consistently in both treatments (e.g. HSC70, SOAR1, OMT1, EDGP), highlighting their responsiveness to shifts in leaf pHapo. These molecular changes accompanied NaCl-induced stomata closure and rising GC-intrinsic ABA. Apoplastic alkalinisation in response to NaCl is closely linked to increased ABA levels, along with transcriptomic and proteomic shifts in GC. This temporal pattern suggests that the rise in pHapo functions as an initiating signal that triggers downstream molecular changes, which unfolds before becoming physiologically visible as stomata closure.
Regulation of Tocopherol (Vitamin E) biosynthesis in Arabidopsis.
Shirvani S, Dörmann P
J Exp Bot · 2026 Apr · PMID 41992549 · Publisher ↗
Tocochromanols, including tocopherols and tocotrienols, encompass a group of lipid antioxidants that are synthesized in chloroplasts of photosynthetic organisms. Tocochromanols are essential for mammals, because they pro...
Tocochromanols, including tocopherols and tocotrienols, encompass a group of lipid antioxidants that are synthesized in chloroplasts of photosynthetic organisms. Tocochromanols are essential for mammals, because they provide vitamin E activity. In plants, tocochromanols can scavenge reactive oxygen species derived from photosynthesis. While most dicot plants including Arabidopsis thaliana produce tocopherols with a saturated side chain, tocotrienols carrying an unsaturated side chain are found in many monocot plants. Here, we present an overview on the current knowledge about the biosynthesis of tocopherols, with a focus on the origin of the head group and side chain precursors, and the regulation of tocopherol synthesis by abiotic stress and phytohormones. The chromanol headgroup is derived from tyrosine which is synthesized via the shikimate pathway, while the phytyl side chain originates from chlorophyll turnover. Tocopherol synthesis is regulated during different abiotic stress conditions, including high light, drought, heat, cold and salt stress. Furthermore, different phytohormones like jasmonate, abscisic acid, gibberellins, brassinosteroids and salicylate are involved in the regulation of tocopherol synthesis. The control of stress- and phytohormone-dependent tocopherol synthesis is mostly based on the regulation on the transcriptional level of key genes of tocopherol synthesis.
Low wind, high impact: sustained low airflow alters water use efficiency and shapes plant acclimation.
Dupont K, Frati R, Vialet-Chabrand SRM
J Exp Bot · 2026 Apr · PMID 41991162 · Publisher ↗
Minor differences in airflow are often assumed to have negligible physiological effects, yet they directly modify heat- and gas exchange by altering the leaf boundary layer. We investigated how sustained low airflow impa...
Minor differences in airflow are often assumed to have negligible physiological effects, yet they directly modify heat- and gas exchange by altering the leaf boundary layer. We investigated how sustained low airflow impacts mechanisms regulating leaf-microclimate exchange, and how these responses shape acclimation in Lactuca sativa and Solanum lycopersicum. Lettuce was grown under two low-velocity airflow regimes (0.22 and 0.65 m s-1), and changes in the leaf surface microclimate, plant transpiration, stomatal regulation, leaf photosynthesis, and growth were quantified. Increased airflow elevated transpirational demand, to which stomata responded dynamically by closing, increasing intrinsic water-use efficiency. This closure did not fully offset enhanced water loss and was constrained by the need to maintain CO2 assimilation, which revealed that airflow alters a functional trade-off between carbon gain and water loss. This trade-off varied spatially, as photosynthetic limitation emerged specifically on the adaxial leaf side, indicating humidity-driven, side-specific diffusion limitations. At the whole-plant scale, increased airflow reduced fresh weight and leaf length by ca. 13%, associated with hydraulic constraints and thermal regulation. We propose a unifying theory in which physiological regulation to airflow constrains structural and leaf-level acclimation, setting limits for plant growth. This framework provides a mechanistic understanding on how airflow affects short-term feedback and acclimation, with important consequences for experimental interpretation and reproducibility.
Conserved mechanisms of plant lipidome remodeling under heat and cold stresses revealed through a systematic review and meta-analysis.
Sathasivam M, Allen DK, Shankar V … +2 more , Saha R, Narayanan S
J Exp Bot · 2026 Jun · PMID 41991157 · Full text
Increasing temperature fluctuations threaten crop productivity worldwide, emphasizing the need for a deeper understanding of plant adaptation to such extremes. Lipids are fundamental biological molecules that furnish str...
Increasing temperature fluctuations threaten crop productivity worldwide, emphasizing the need for a deeper understanding of plant adaptation to such extremes. Lipids are fundamental biological molecules that furnish structural, metabolic, and regulatory roles in plant growth and development, and responses to environmental stresses. The potential of lipids as key targets for crop improvement under changing climates is emerging. This systematic review and meta-analysis presents comprehensive syntheses of current knowledge on plant lipidome responses to heat and cold stresses. The analysis reveals conserved lipidomic responses to heat and cold stresses across plant species, tissue types, and growth stages. The decreased levels of lipids with relatively smaller head groups [e.g. monogalactosyldiacylglycerol (MGDG) and phosphatidylethanolamine (PE)] that promote membrane bilayer structure, a decrease in unsaturation index in membrane lipids, and sequestration of polyunsaturated acyl chains into neutral lipids (e.g. triacylglycerols) emerged as conserved strategies for heat adaptation. Also, very-long-chain fatty acids were identified as important in heat stress adaptation, as their presence is likely to counteract excessive membrane fluidity caused by high temperature and to maintain membrane stability under heat stress. Under cold stress, the levels of membrane lipids containing polyunsaturated acyl chains were elevated, probably as an adaptive shift favoring more fluid, flexible membranes. Further, the levels of bilayer-forming lipids [e.g. digalactosyldiacylglycerol (DGDG)] increased and those of non-bilayer-forming lipids (e.g. MGDG) decreased. Overall, this article synthesizes knowledge of lipidome remodeling in plants and its role in resilience to temperature stress, identifying priority areas for future research to support climate-resilient agriculture.
Completing the acylation landscape in plants: GDSL enzymes join the BAHD and SCPL acyltransferase families.
Mallavergne A, Hilbert JL, Gagneul D
J Exp Bot · 2026 Apr · PMID 41988947 · Publisher ↗
Specialized metabolites are essential for plant adaptation to its environment. Their biosynthesis requires multiple chemical modifications of core structures, among which acylation is one of the most frequent. In plants,...
Specialized metabolites are essential for plant adaptation to its environment. Their biosynthesis requires multiple chemical modifications of core structures, among which acylation is one of the most frequent. In plants, two families of acyltransferases are typically described. The BAHD superfamily, a family with many characterized members, uses mostly CoA-esters as acyl donor, while the serine carboxypeptidase-like (SCPL) family uses mainly 1-O-β-D-glucose esters. Although these enzyme families catalyze most acyltransfer reactions in plants, enzymes from the Gly-Asp-Ser-Leu (GDSL) esterase/lipase family have recently been identified as acyltransferases in the biosynthesis of several specialized metabolites. These enzymes use various energy-rich donors, including CoA esters, chlorogenic acid, glycerol esters, and triacylglycerides, to acetylate a wide range of molecules. Interestingly, acyltransferases exhibit distinct subcellular localization: BAHD, SCPL, and GDSL are usually localized in the cytoplasm, vacuole, and apoplast, respectively. Together, these enzymes form a complex network of acyltransferases that modify specialized metabolites throughout plant cells. In this review, we aim to summarize the current knowledge on plant acyltransferases and their applications, particularly aiming to add GDSL transferases to the BAHD and SCPL, which are usually considered for these types of reactions.
An Arabidopsis receptor-like kinase mediates competitive plant-plant interactions.
Libourel C, Invernizzi M, Roux F … +2 more , Hanemian M, Roby D
J Exp Bot · 2026 Apr · PMID 41988938 · Publisher ↗
While competition among plant species is recognized as a major factor affecting crop yield and plant community dynamics, the genetic and molecular mechanisms underlying natural variation of such biotic interactions remai...
While competition among plant species is recognized as a major factor affecting crop yield and plant community dynamics, the genetic and molecular mechanisms underlying natural variation of such biotic interactions remain poorly characterized. Here, we report the cloning of a Quantitative Trait Locus previously detected in a Genome-Wide Association Study investigating the competitive response of Arabidopsis thaliana to the presence of the annual bluegrass weed species Poa annua. Using mutant and complementation strategies, we identified ESCAPE 1 (ESC1) as the gene responsible for the natural variation of an escape strategy of A. thaliana in response to the presence of P. annua. ESC1 encodes a proline-rich, extensin-like receptor kinase, also known as PERK13. An RNA-seq experiment revealed that PERK13 functions through different pathways in leaves and roots involving genes associated with responses to biotic and abiotic stresses. Using these RNA-seq together with yeast two-hybrid (Y2H) data, protein-protein interaction network reconstruction revealed two distinct decentralized protein networks in leaves and roots. These findings support the notion of an active response mechanism involved in neighbor detection. The functional validation of ESC1 underlying natural variation in response to competition opens new avenues for a better understanding of the molecular dialogue involved in plant-plant interactions.
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