Micro-nano ethylene bubbles water promotes anthocyanin accumulation in grapes by regulating endogenous ethylene and synergistic abscisic acid.

Phytochrome-interacting factors (PIFs): Integrating phytohormone signals at the nexus of development and stress adaptation.

ABA and ABA signaling mediate Arabidopsis stomatal response to CO2 via H2O2 and NO production.

Biochemical and molecular regulation of tomato ripening and disease defense: A trade-off between quality and postharvest integrity.

Synergistic mechanisms of ultrasound and slightly acidic electrolyzed water in peanut germination revealed by multi-omics analysis.

Preharvest sorbitol application modulates phytohormone profiles and enhances nutraceutical quality of extra-early nectarine (Prunus persica).

Root hairs at the frontline: Tiny architects of adaptive responses to salinity stress.

Abscisic acid (ABA) is a key phytohormone that orchestrates adaptive responses in plants exposed to abiotic stress. The ABA signaling cascade is triggered by ABA-mediated binding of PYRABACTIN RESISTANCE1-LIKE (PYL) receptors to clade A Type 2 C protein phosphatases (PP2CAs). In Arabidopsis thaliana, several constitutively active variants of ABA receptors have been described, offering valuable tools for improving plant tolerance to environmental stresses. To identify amino acid residues in the rice ABA receptor OsPYL5 that are involved in ABA-independent interactions, we implemented a random mutagenesis strategy followed by yeast two-hybrid (Y2H) screening. We identified residues L-93 and N-102 as key residues that influence the ABA independent interaction of OsPYL5 with OsPP2CA51. Substituting these residues with T or Y significantly enhanced the activity of an ABA-responsive reporter in rice protoplasts, even in the absence of ABA treatment. We therefore engineered a double-point mutant, OsPYL5L93W N102Y, which demonstrated a strong ABA-independent interaction with OsPP2CA51 in Y2H assays, elevated activation of ABA-responsive reporter in rice protoplasts, and suppression of PP2CA phosphatase activity in vitro in the absence of ABA. Transgenic rice lines overexpressing OsPYL5L93W N102Y showed delayed germination and growth retardation in the absence of ABA treatment. They also exhibited increased sensitivity to ABA during germination and in early seedling growth assays compared to an OsPYL5-overexpressing transgenic rice line (OsPYL5-OX). Moreover, compared to OsPYL5-OX, they showed dramatic upregulation of ABA-responsive genes both without ABA and with low concentrations of ABA. These transgenic lines also showed enhanced tolerance to drought and salt stress compared to both the control cultivar and OsPYL5-OX. Taken together, our findings not only identify key residues of OsPYL5 that enable ABA-independent receptor function, but also highlight the feasibility of engineering ABA receptors to improve abiotic stress tolerance.

Heat stress threatens current crop production systems and food security. Identifying and utilizing elite thermotolerance genes and germplasms have emerged as cost-effective strategies to improve the thermotolerance of crops under global warming. This study identified a Tartary buckwheat (Fagopyrum tataricum) high-temperature-induced FtAT-hook transcription factor that undergoes phase separation and negatively controls seed development by increasing the transcript level of the sugar transporter gene FtERDL6 (Early response to dehydration like 6) and key genes for flavonoid synthesis (FtFLS). Additionally, FtASR, an abscisic acid stress-ripening protein, interacted with FtAT-hook to affect the phase separation of FtAT-hook under heat stress. The interaction between FtAT-hook and FtASR was conserved among other species. As a downstream biosynthetic product of FtFLS, kaempferitrin suppresses FtAT-hook phase separation via a negative feedback regulatory mechanism. Notably, the exogenous application of kaempferitrin significantly enhanced the FtASR-FtAT-hook interaction, leading to an increase in seed size under heat stress. These findings provide mechanistic insights into the design of flavonoid compounds to disturb protein phase separation and thereby change its function, and offer strategies to safeguard food security under global warming.

A novel allelic variant of the heat shock protein 101, designated neo-tetraploid rice fertility gene 1 (NTRF1), has been identified and is implicated in regulating fertility in neo-tetraploid rice (NTR); however, its regulatory mechanism remains unclear. In this study, we identified the ntrf1 mutant and demonstrated that its significantly reduced seed-setting rate was due to pollen developmental defects. Mechanistically, NTRF1 deficiency disrupts reactive oxygen species (ROS) homeostasis in anthers, thereby delaying the progression of programmed cell death (PCD) in tapetal cells. RNA-seq analysis of mutant anthers revealed dysregulated expression of abscisic acid (ABA) signaling components (OsPP2C49, OsbZIP23) and ROS-related genes (OsRBOH1, OsRBOH8), along with a significant downregulation of key tapetal developmental regulators (OsGAmyb, CYP703A3). Integrated multi-omics analysis showed that the reduced pollen viability in the ntrf1 mutant is associated with the pyruvate metabolic pathway. Protein interaction assays confirmed that NTRF1 directly binds SAPK2, a core kinase in ABA signaling transduction. This interaction explained how exogenous ABA application partially restored the reduced seed-setting rate in ntrf1 mutants. Collectively, our findings elucidated an NTRF1-centered regulatory network that coordinates ABA signaling with ROS homeostasis to ensure timely tapetal PCD and subsequent pollen maturation. This study provides valuable molecular targets for advancing the genetic improvement of polyploid rice.

Plant nitrogen nutrition: enhancing plant resilience to abiotic stresses.

Multigenerational stress exposure induces stress memory in plants, influencing resource allocation, defence mechanisms, and productivity. Weed competition imposes both resource-based (abiotic) and allelopathic (biotic) stress, engaging overlapping hormonal pathways. This study examined the hormonal and transcriptomic mechanisms underlying multigenerational stress memory in wheat subjected to inter-specific competition with kochia and Italian ryegrass and intra-specific competition with other wheat plants. Phytohormone analysis revealed increased salicylic acid levels, promoting systemic acquired resistance, whereas jasmonic acid levels declined, indicating suppressed jasmonate-mediated defence. Abscisic acid responses varied, reflecting shifts in water-use efficiency. Cytokinins and auxins exhibited generation- and treatment-specific trends, suggesting adaptive resource acquisition but potential hormonal imbalances. These hormonal shifts corresponded with phenotypic responses, where adaptive benefits peaked at Generation 3 before transitioning to maladaptive responses in later generations. Transcriptomic analysis identified dynamic changes in differentially expressed genes (DEGs) and key pathways. Wheat-only competition peaked in stress-responsive DEGs in Generation 3, while wheat-kochia and wheat-ryegrass exhibited early generation transcriptional reprogramming and long-term adaptations. Intra-specific wheat competition showed early generation transcriptomic surges but persistent growth repression in the current study. These findings provide mechanistic insights into multigenerational stress memory mechanisms and reveal how phytohormonal crosstalk and transcriptional reprogramming shape wheat responses to competition stress across generations.

The galactinol synthase (GolS) and raffinose synthase (RS) play crucial roles in the synthesis of raffinose family oligosaccharides, which are involved in stress protection, carbohydrate transport, and fruit development in plants. This study aimed to conduct a genome-wide identification and characterization of GolS and RS genes in hot pepper (Capsicum annuum) and to investigate their responses to environmental and hormonal factors. Six CaGolS and seven CaRS genes were identified in the pepper genome. Structural analysis showed that CaGolS genes have relatively compact exon-intron arrangements, while CaRS genes possess more complex structures. Phylogenetic comparison with related species revealed strong evolutionary conservation within the Solanaceae group. Transcriptome analysis showed that CaGolS1, CaGolS2, CaGolS3, CaRS2, and CaRS7 were highly responsive to abiotic stresses such as cold, heat, salinity, and osmotic stress, as well as to hormonal treatments involving abscisic acid, jasmonic acid, salicylic acid, and ethylene. Several genes also showed differential expression during fruit development and ripening, indicating their contribution to sugar metabolism and stress adaptation during maturation. The results provide new insights into the GolS and RS gene families in hot pepper and identify potential gene targets for developing stress-tolerant and high-quality pepper cultivars.

Gibberellin (GA) biosynthesis and signaling play important roles in seed setting and grain weight; however, how long-distance GA transport contributes to these traits remains poorly understood. Here, we characterized the Nitrate transporter 1/Peptide transporter Family (NPF) protein OsNPF3.5, which mediates GA allocation in rice (Oryza sativa L. var. Nipponbare). OsNPF3.5 was preferentially expressed in the phloem of the leaf blade at the reproductive stage and was responsive to lower temperatures. Ectopic expression of OsNPF3.5 in Xenopus laevis oocytes showed relatively low uptake activity for GA3,4,7 and abscisic acid (ABA), but a significant efflux activity for GA44 across the plasma membrane. Compared to the wild type, pollen fertility, seed setting rate, 1000-grain weight, and grain yield were decreased in osnpf3.5. Moreover, functional disruption of OsNPF3.5 essentially decreased GA44 redistribution from the flag leaf blade and was accompanied by decreased levels of GA3 in anthers and GA1 in caryopses. These results suggest that OsNPF3.5 functions as a GA44 efflux transporter promoting GA44 loading into phloem, thus facilitating GA allocation from flag leaf blade to sink organs including anthers and caryopses, which consequently regulates seed setting, 1000-grain weight and grain yield. This represents a mechanism by which long-distance GA precursor transport gets involved in rice seed setting and grain weight formation under variable environmental conditions.

Low temperature and drought are among the most pervasive abiotic stresses limiting crop productivity worldwide, and their frequent co-occurrence or alternation imposes compounded constraints on agricultural sustainability. Increasing evidence supports cross-tolerance, whereby exposure to one stress enhances resistance to another, as an emergent property of shared signaling networks and integrative regulatory layers. In this review, we summarize recent advances in understanding cold-drought cross-talk, from early stress perception and secondary messengers to hormonal coordination via abscisic acid, transcriptional reprogramming centered on dehydration responsive element binding protein/C repeat binding factor (DREB/CBF) modules, and longer-term regulatory memory mediated by chromatin remodeling and biomolecular condensates. Importantly, we further discuss how these mechanistic insights can be translated into precision breeding strategies, including genome editing, allele mining, and backcross-assisted introgression, to accelerate the development of crop varieties with stable multi-stress tolerance. Finally, we highlight future directions for integrating multi-omics, high-throughput phenotyping, and data-driven approaches to enable efficient molecular design breeding for complex stress environments.

Drought stress severely constrains plant growth and productivity. To mitigate water loss, plants primarily regulate stomatal aperture through the Abscisic acid (ABA) signaling pathway, where the Sucrose Nonfermenting 1-Related Protein Kinase 2 (SnRK2) family kinase Open Stomata 1 (OST1) acts as a central positive regulator. However, the upstream regulators that fine-tune OST1 activity remain incompletely characterized. Aliphatic Suberin Feruloyl Transferase (ASFT), a BAHD acyltransferase essential for suberin aromatic monomer biosynthesis, was previously uncharacterized regarding its function in leaves. Here, we report that ASFT negatively regulates drought tolerance in Arabidopsis thaliana by directly interacting with OST1 and inhibiting its autophosphorylation, thereby restricting stomatal aperture. Consistent with this, the asft mutant exhibited decreased water loss and enhanced survival under drought, whereas ASFT-overexpressing lines showed opposite phenotypes. BiFC, Co-IP and in vitro kinase assays confirmed that ASFT directly interacts with OST1 and suppresses its autophosphorylation, while dehydration-induced OST1 phosphorylation was elevated in the asft mutant. Genetic evidence confirmed that ASFT functions upstream of OST1. This study reveals a moonlighting role for this suberin biosynthetic enzyme in ABA signaling and provides a potential target for breeding drought-resistant crops.

Anaerobic germination tolerance (AGT) is a critical adaptive trait for rice establishment in flood-prone environments and direct-seeded systems. Here, we identified and validated the quantitative trait locus qAG2.1 for AGT and introgressed it into the elite lowland rice variety CR Dhan 801 through marker-assisted backcross breeding. The introgressed lines exhibited significantly improved germination under anaerobic conditions, demonstrating the effectiveness of qAG2.1 in a high-yielding genetic background. While CR Dhan 801 showed a low anaerobic germination percentage (17.6%), the donor ARC10424 exhibited 82.6%, and the best-performing introgressed line (22009-3) achieved 49.2%. Importantly, the improved lines maintained agronomic performance comparable to CR Dhan 801 under non-stress conditions, indicating minimal yield penalty. To gain mechanistic insight, the qAG2.1 interval was dissected in silico to prioritise candidate genes putatively associated with AGT. This analysis highlighted genes linked to ethylene biosynthesis and signalling (e.g., OsACO3, OsERF109), abscisic acid biosynthesis (OsNCED1), gibberellin homeostasis (OsGA2ox9), trehalose metabolism (OsTPS5, OsTPP1), detoxification of anaerobic by-products (OsALDH2A), and water transport (OsPIP1;3). Collectively, these results validate qAG2.1 as a further deployable locus for improving anaerobic germination in elite rice backgrounds and provide a set of putative candidate genes for future functional characterisation.

Mediator is a central transcriptional coactivator that connects sequence-specific transcription factors with RNA polymerase II to control inducible gene expression in plants. MED16 is a Mediator tail module subunit that functions as a context-dependent integrator, helping coordinate developmental programs with environmental adaptation. This review summarizes current evidence for MED16 function from structural and evolutionary perspectives to physiological outputs, with emphasis on how MED16 interacts with transcription factors and other Mediator subunits to shape RNA polymerase II engagement at target loci. In terms of development, MED16 contributes to organ growth and root system architecture, and comparative studies have revealed that it plays conserved roles in lineage-specific wiring. Under abiotic stress, MED16 supports the efficient activation of stress-inducible transcription, including cold acclimation and nutrient stress responses such as phosphate starvation-dependent root remodeling. In immunity, MED16 modulates salicylic acid- and jasmonate/ethylene-associated defence outputs and can be targeted by plant viruses, which is consistent with its role in antiviral transcriptional responses. Mechanistically, MED16 participates in cooperative and competitive interactions within the Mediator complex that tune hormone-responsive outputs, exemplified by MED25-related competition in abscisic acid signalling. We highlight key limitations and future directions, including the need for mechanistic validation beyond Arabidopsis, clearer models of dosage control in crops, improved understanding of context-dependent tail configurations, and high-resolution mapping of MED16 interaction interfaces.

Cherry blossom trees are iconic ornamental plants of the spring known for their vibrant colors and elegant forms. However, their short flowering period limits their ornamental value. Prunus subhirtella 'Autumnalis' is notable for its ability to flower a second time in autumn. Study of the secondary flowering of this variety may offer insights into the development of cherry blossoms. Here, we studied the secondary flowering of Prunus subhirtella 'Autumnalis' by collecting three types of flower buds: the terminal buds of long branches in autumn (LB), the basal buds of short branches in autumn (SB), and flower buds in spring (FB). Transcriptomic and metabolomic analyses were then conducted on autumn flower buds to identify key metabolic pathways associated with secondary flowering. These pathways were primarily involved in nutrient accumulation and plant hormone biosynthesis. We then quantified changes in indole-3-acetic acid (IAA), abscisic acid (ABA), jasmonic acid (JA), and gibberellic acid (GA3), as well as levels of soluble protein, soluble sugar, and starch in flower buds. Correlation analysis indicated that IAA was necessary for flower bud development; ABA was weakly correlated with secondary flowering; and JA was significantly negatively correlated with secondary flowering. The GA3 content was higher in LB than in SB and was significantly positively correlated with secondary flowering. Additionally, nutrient levels were higher in LB than in SB, suggesting that the accumulation of sufficient nutrients supports the second bloom. Correlation analysis revealed that ABA and GA3 levels were positively correlated in flower buds, but GA3 was negatively correlated with JA levels. This study provides a theoretical basis for understanding the molecular and physiological mechanisms underlying the secondary flowering phenomenon in Prunus subhirtella 'Autumnalis' and offers valuable insights for extending the ornamental period of cherry blossom trees.

Studies indicate that elevated CO2 (eCO2) exacerbates brown planthopper (BPH, Nilaparvata lugens) damage to rice compared to ambient CO2 (aCO2), highlighting the need for enhanced pest resistance strategies under climate change. The phenylpropanoid pathway, activated by phytohormones, synthesizes defense compounds in plants. This study investigated exogenous abscisic acid (ABA) and strigolactone analogue (GR24) treatments on rice defense against BPH under aCO2 and eCO2. Results showed that ABA and GR24 suppressed BPH feeding and survival, particularly under eCO2, while activating the phenylpropanoid pathway and increasing furocoumarin accumulation─more pronounced under eCO2 than aCO2. These furocoumarins exhibited antifeeding effects and reduced BPH survival. Additionally, enzyme assays and molecular docking revealed enhanced detoxification activity in BPH feeding on treated rice or furocoumarin-laced diets under eCO2. These findings demonstrate that ABA and GR24 enhance rice resistance to BPH by activating phenylpropanoid metabolism under eCO2, providing a mechanistic basis for climate-resilient pest management strategies.