Bencomia exstipulata is a broad-leaved evergreen shrub endemic to the high-altitude harsh landscapes of the Canary Islands. Whether the extremely reduced distribution of its wild specimens (at around 2000 m a.s.l. in the National Parks of 'El Teide' and 'Caldera de Taburiente') responds to specific microclimatic needs remains undetermined. None of its ecophysiological aspects has been evaluated to date. To fill this gap of knowledge, we have (1) characterised its leaf phenology and physiology, (2) evaluated its tolerance to drought at leaf and xylem levels, and (3) investigated its response to freezing stress at biophysical and photochemical levels. Our results revealed that B. exstipulata has a fast leaf turnover with high rates of photosynthesis and stomatal conductance and high xanthophylls per chlorophyll ratios. Leaves had thin cuticle, high minimum leaf conductance, and encrypted and abaxial stomata. Adult leaves lost 50% of their rehydration capacity at around 45% relative water content, and stem xylem was relatively vulnerable to embolism (with -3 MPa of water potential at 50% loss of conductivity), but no native embolism was found. Under freezing temperatures, leaves showed a supercooling strategy (ice nucleation at -14°C) and low photoprotective responsiveness. We conclude that B. exstipulata lacks clear adaptations to drought, has high constitutive photoprotection, low photoprotective responsivity, and a supercooling strategy to face freezing. In its native montane ecosystem, with a Mediterranean-type climate, severe drought could induce significant xylem-embolism, while severe freezing could lead to irreparable leaf damage, being both risks potentially lethal in the mid- to long term.
Leaf growth is a major determinant of plant architecture and productivity. TWISTED DWARF1 (TWD1/FKBP42) is a conserved immunophilin involved in plant growth and development, but its function in tomato remains unclear. Here, we identified and characterized SlTWD1, the tomato homolog of TWD1. SlTWD1 is highly conserved among land plants and functionally complemented the developmental defects of an Arabidopsis thaliana cr-twd1 mutant. SlTWD1 was broadly expressed in vegetative and reproductive tissues. CRISPR/Cas9-mediated disruption of SlTWD1 caused severe dwarfism and reduced leaf and fruit size, whereas overexpression of SlTWD1 or a C-terminally truncated variant moderately promoted leaf growth. Cellular analyses showed that loss of SlTWD1 markedly reduced epidermal cell size, while overexpression increased cell size, indicating that SlTWD1 promotes leaf growth primarily through cell expansion. Expression changes in auxin- and cell cycle-related genes were also associated with SlTWD1 perturbation. These findings indicate that SlTWD1 functions as an evolutionarily conserved regulator of plant growth that contributes to leaf and fruit size control in tomato.
The photorespiratory metabolism safeguards photosynthesis against abiotic and biotic stress. Nitric oxide (NO) and reactive oxygen species (ROS) levels rise in plants during abiotic stress. Low concentrations of NO or ROS are beneficial as signalling molecules, but they can be toxic to plant cells at high concentrations. ROS are known to modulate photorespiration; however, it is unclear whether NO affects photorespiratory enzymes and photochemical components simultaneously. We therefore used sodium nitroprusside (SNP) under dark, moderate light (ML), or high light (HL) conditions to simultaneously investigate its impact on photorespiratory enzymes and photochemical components. The NO levels were increased upon SNP exposure in Pisum sativum leaves, particularly under HL conditions. The NO release in leaves was confirmed when the NO scavenger cPTIO (2-(4-Carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt) was present, since it decreased the majority of elevated NO. The nitrosative/oxidative stress in Pisum sativum leaves was confirmed by the increase in nitrosothiols and tyrosine-nitrated proteins, as well as reduced aconitase activity after SNP exposure at HL. The protein levels, mRNA levels, and the enzyme activities of the following four photorespiratory enzymes: glycolate oxidase (GO), hydroxypyruvate reductase (HPR), glycerate kinase (GK), and phosphoglycolate phosphatase (PGLP) were markedly increased under elevated NO conditions. Catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD) also showed increased activity, elevated protein and transcript levels upon exposure to SNP. Parallel studies on chlorophyll a fluorescence confirmed that NO restricted electron transport at both PSII and PSI, inhibited photosynthesis and respiration, and damaged photosynthetic pigments. We concluded from this study that NO at high concentrations upregulated photorespiratory enzymes while inhibiting photochemical components such as photosystem II and I (PSII/PSI) simultaneously.
Cold stress severely impairs the growth and metabolic composition of tea shoots, thereby limiting tea production. The application of exogenous regulatory substances offers a potential strategy to mitigate cold-induced damage in tea plants. Therefore, identifying endogenous metabolites that could increase cold tolerance and exploring their working mechanisms would be of interest. Here, we identified 292 differentially accumulated metabolites in young shoots of two different tea cultivars through UPLC-MS/MS assays, among which amino acid metabolism was found to be markedly altered. Further analysis revealed that leucine was dramatically induced in all 10 tested accessions. Phenotype, relative electrolyte leakage (REL), and maximum quantum yield of photosystem II (Fv/Fm) analyses revealed that pre-treatment with 20 mM leucine significantly increased the cold tolerance of young shoots in 4 different cultivars. Transcriptome analysis revealed that 48.06% of differentially expressed genes (DEGs), including calcium (Ca2+) signaling, sugar conversion, and reactive oxygen species (ROS) scavenging pathways, were similarly induced by leucine pretreatment in both tolerant and sensitive cultivars. However, 51.94% DEGs involved in phenylpropanoid biosynthesis, glutathione metabolism, and tyrosine metabolism were differentially expressed. Moreover, free amino acid detection also revealed great differences among tolerant and sensitive cultivars. Taken together, our results demonstrate that exogenous application of 20 mM leucine, a cold-inducible endogenous metabolite, effectively mitigates cold-induced damage in both tolerant and sensitive cultivars through common and cultivar-specific mechanisms. These findings supported the development of leucine as a promising cold resistance agent for mitigating the effects of cold spells on young shoots in fields.
Management of fertilizer application is essential for maintaining adequate food production while preventing the environmental impact caused by excessive fertilizer application. Therefore, it is crucial to understand how crops respond to early nitrogen deficiency. In the present study, we analyzed the responses to early nitrogen deficiency in komatsuna (Brassica rapa var. perviridis) plants, a popular leafy green vegetable in Japan. Komatsuna plants were grown in pot cultures under seven nitrogen levels (0, 30, 60, 90, 150, 210, and 270 mg N per pot), with nitrogen as ammonium nitrate. Shoots were harvested every 5 days from 14 to 39 days after sowing to measure dry weight, total nitrogen, and nitrate concentrations. The dry weight of komatsuna shoots increased significantly even after soil inorganic nitrogen was nearly exhausted. Under the 30 mg N treatment, nitrogen accumulation at 24 days accounted for 81% of the final accumulation at 39 days, whereas dry weight accounted for only 35% of the final value. This indicates about 65% of the final dry weight accumulated after nitrogen accumulation plateaued. To elucidate the molecular mechanisms enabling growth sustained by internal nitrogen, gene expression profiles in leaves were analyzed using RNA-seq in plants grown under marginal or ample nitrogen supply. The results indicated that transcriptional regulation of purine metabolism plays an important role in adaptation to early nitrogen deficiency. These findings contribute to the optimization of nitrogen fertilization by providing a foundation for developing markers to assess the need of top-dressing and for breeding crop varieties with high nitrogen-use efficiency.
The increasing frequency and intensity of extreme thermal events in Maritime Antarctica pose new challenges for terrestrial cryptogamic vegetation, in which bryophytes are major components. We analyzed acute heat-shock responses in two Antarctic mosses with contrasting canopy organization and habitat associations: the dense bank-forming Chorisodontium aciphyllum and the more open lawn-forming Polytrichastrum alpinum under fully hydrated conditions. Both species showed substantial short-term tissue-level heat resistance when LT50 was defined from electrolyte leakage (LT50 > 55°C), whereas Fv/Fm declined over a lower and nearly identical thermal range centered near 43°C. Heat shock induced strong antioxidant enzyme responses and coordinated transcriptional changes in heat-stress- and proteostasis-associated genes, including HSF, HSP70 isoforms, and ubiquitin-related markers. Untargeted metabolomics revealed relative metabolic reorganization in both species, including a shared LT50-associated signature characterized by relative enrichment of carbohydrate- and aromatic/phenolic-associated features and relative depletion of lipid- and terpenoid-related features. Species-related differences were most evident as differences in response amplitude and relative LC-MS feature-family weighting, without evidence of divergent pathway-level activation. Together, these results indicate that Antarctic mosses share core heat-stress modules but orchestrate them divergently through species-dependent redox regulation, membrane-associated stress responses and proteostasis-related regulation, with non-identical enzymatic and metabolomic trajectories under severe thermal challenge.
OJIP chlorophyll a fluorescence is widely used for the rapid assessment of photosynthetic performance, but field workflows may alter the physiological state of the plants probed before the saturating pulse. We compared eight dark-acclimation and sample-handling workflows in field-grown Sida hermaphrodita and Miscanthus × giganteus: daytime clip acclimation, evening and night measurements with or without clip acclimation, flashlight-assisted night measurements, and detached-shoot measurements after laboratory green-light exposure. The same marked leaves were measured sequentially, and the analysis focused on primary OJIP fluorescence levels, phase-specific O-J, J-I and I-P kinetics, area above the transient, FV/FM and FK/FJ. Workflow choice altered OJIP trajectories in both species. Evening and night workflows generally increased the area above the transient relative to the Day-clip method, indicating that short daytime clip acclimation and prolonged natural darkness did not produce equivalent reference states. Night-flashlight and Detached-green workflows introduced further deviations, including altered FO, changed? O-J behavior and I-P rise kinetics. The magnitude and direction of workflow effects were species-specific. These results show that dark-acclimation timing, pre-measurement light exposure and detached-shoot handling are not interchangeable technical details in field OJIP measurements. Workflows should therefore be selected according to the biological question, kept constant within comparisons, and reported with timing, dark-acclimation duration, light exposure and handling conditions.
Strigolactones (SLs) modulate multiple aspects of plant development and stress physiology. This study investigated their role in maize response to abiotic stress by comparing an SL-biosynthesis mutant (zmccd8) with wild-type (WT) seedlings grown for 4 weeks in vermiculite under nutrient and water limitation. Plant growth, time-course pigment accumulation, targeted gene expression, and root transcriptomic profiles were analyzed. Our results showed that zmccd8 plants were largely unable to induce leaf senescence and efficient nutrient remobilization toward younger tissues under nitrogen (N) deficiency, a response previously associated with maize adaptation to low N availability. In parallel, the mutant developed a smaller root system, mainly due to limited adventitious root formation, particularly under N shortage. Root transcriptomic profiling revealed that N deficiency strongly affected WT plants, inducing extensive regulation of pathways involved in nitrogen metabolism and transport, secondary metabolism, ethylene and MAPK signaling, oxidative stress responses, and major transcription factor families. These responses were largely absent in the zmccd8 mutant, suggesting reduced transcriptional plasticity and compromised capacity to cope with stress-associated oxidative imbalance. Conversely, despite inducing substantial physiological and molecular responses, water stress elicited only modest SL-dependent regulation, with limited and heterogeneous changes between genotypes. Overall, our findings demonstrate that in maize, SLs act in a stress-specific manner, playing a predominant role in acclimatisation to nitrogen deficiency through coordinated regulation of senescence, nutrient remobilization, root architecture, and gene expression, while contributing more marginally to water-stress acclimatisation. These results provide new insights into SLs' role in shaping maize physiological plasticity under abiotic stress conditions.
The heterogeneity of cells constitutes the foundation of development, adaptation and evolution, therefore understanding the expression and spatial distribution patterns of genes in different plant tissues has extremely high research value. Traditional transcriptome sequencing can only perform mixed-sequencing analysis on multicellular tissues and fails to detect intercellular heterogeneity. However, the groundbreaking development and integration of single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics (ST) are leading forest tree biology into a new era. This review systematically illustrates the developmental history, technical workflows, and integration of these two technologies and elaborates in detail on their cutting-edge applications in woody plants, such as vascular cambium differentiation, abiotic stress response analysis, and the identification and characterization of rare cell types. In addition, we discuss the challenges encountered in applying these technologies to forest tree research and point out the key directions for future research that should be focused on solving the difficulties in upcoming woody plant studies. This paper reveals the enormous potential of scRNA-seq and ST in research on woody plants, providing a new perspective for further research and applications in related fields.
Drought is a major environmental constraint on crop growth, development, and yield. Xyloglucan endotransglucosylase/hydrolases (XTHs) have been reported to play important roles in plant drought tolerance. We previously identified the cold-responsive tomato gene SlXTH23 as a positive regulator of cold tolerance; however, its function and underlying mechanism in drought tolerance remain unclear. Here, drought stress suppressed SlXTH23 expression. Drought tolerance was reduced in SlXTH23-overexpression lines but enhanced in SlXTH23-knockout lines. Under drought stress, stomatal aperture increased in the overexpression lines. Protein-DNA interaction assays demonstrated that the transcription factors SlNAC48 and SlNAC89 bind directly to the SlXTH23 promoter and repress its transcription. Silencing SlNAC48 or SlNAC89 reduced SlNCED3 expression and abscisic acid (ABA) content but increased stomatal aperture under drought stress. Moreover, ABA deficiency reduced tomato drought tolerance and increased both stomatal aperture and SlXTH23 expression. Collectively, drought stress induces SlNAC48 and SlNAC89, which repress SlXTH23 transcription and thereby restrict stomatal aperture. The SlNAC48/SlNAC89-SlXTH23 module also interacts with ABA signalling, and ABA may act synergistically with this module to enhance drought tolerance in tomato seedlings.
The use of saline water for irrigation is an increasingly important strategy to reduce freshwater consumption in ornamental horticulture; however, the tolerance and physiological responses of many species remain poorly understood. This study provides the first comprehensive assessment of the response of Cestrum nocturnum to saline irrigation under nursery conditions, integrating physiological, nutritional, and ornamental quality parameters. Plants were subjected to three salinity levels (2.1, 4.7, and 7.2 dS m-1) over a 10-week period. The results reveal that C. nocturnum activates early adaptive mechanisms, including stomatal regulation and changes in leaf hydraulic function, in response to salinity. A key finding is the identification of a threshold response: moderate salinity (4.7 dS m-1) caused only minor reductions in biomass with limited impact on plant quality, whereas high salinity (7.2 dS m-1) led to severe photochemical stress, ion toxicity (Na and Cl accumulation), chlorosis, necrosis, and a strong decline in growth and ornamental value. By linking physiological processes with commercial quality traits, this study fills a critical knowledge gap and establishes practical salinity limits for this species. These results support the use of moderately saline water in C. nocturnum production while defining the thresholds beyond which plant performance is compromised.
Carbohydrates are crucial for plant growth and serve as fundamental energy sources, regulated by multiple factors. In tomato, development is closely linked to hormone-mediated sugar metabolism. Although jasmonic acid (JA) is known to function in signaling and growth regulation, its specific role in sugar metabolism remains unclear. This study demonstrated that JA signaling negatively regulates tomato seedling growth. Exogenous application of the JA activator MeJA suppressed growth, whereas the JA inhibitor DIECA and the JA synthesis mutant spr2 promoted it. Further analysis revealed that JA impaired growth by inhibiting photosynthesis-reducing photosynthetic pigment content and efficiency. MeJA treatment increased fructose and glucose levels but decreased sucrose and starch. These changes resulted from downregulated sucrose synthase (SlSS, SlSPS) activity and expression, alongside upregulated acid invertase (SlAI, SlNI) activity and SlTIV1 expression. Thus, JA restricted tomato seedling growth by suppressing photosynthesis and promoting soluble sugar accumulation. Transcriptome analysis identified SlEXPA8, a JA-responsive expansin gene. JA signaling downregulated SlEXPA8 expression; silencing SlEXPA8 impaired photosynthesis, reduced activities of sucrose-metabolizing enzymes, and lowered sucrose and starch levels, inhibiting seedling growth. Overexpression of SlEXPA8, however, enhanced growth. EMSA, ChIP, GUS, and LUC assays confirmed that SlMYC2 directly bound the SlEXPA8 promoter and regulated its transcription. These findings uncovered a mechanism by which JA signaling modulated sugar metabolism via expansin proteins, offering insights for targeted genetic improvement of tomato seedling vigor.
Climate change affects plant acclimation and adaptation, particularly in long-lived perennial crops like apple (Malus domestica Borkh.). Stomata play an essential role in regulating these plant environmental responses. This study examined variation in stomatal density (SD) and stomatal function of apple trees in 2022-2023 across four European locations (Spain, ESP; France, FRA; Italy, ITA; and Switzerland, CHE, the only non-irrigated orchard). A total of 20 preselected apple accessions with extreme SD phenotypes (HSD and LSD) and five commercial varieties (MSD-Comm) were compared. Across locations, SD was consistent for each SD group, but partial plasticity emerged under heat stress in ESP and FRA. In ESP, SD increased under high temperatures and irrigation, but the increase was only significant for MSD-Comm (p < 0.05). In FRA, HSD decreased under high temperatures and limited irrigation in 2022, but these changes reversed under wetter conditions in 2023 (p < 0.05), reinforcing SD stability and the capacity for local acclimation. Net carbon assimilation (Anet) showed no significant differences across SD groups and locations. Stomatal conductance (gs) adjusted to local climate and produced variations in intrinsic water-use efficiency (iWUE). Conditions in FRA, ITA, and CHE also led to a significant correlation between integrated WUE (δ13C) and Total Fruit Weight (p < 0.01, R2 = 0.20). In contrast, high temperatures and irrigation in ESP maintained no correlation between δ13C and Total Fruit Weight. These results highlight the role of SD in short-term acclimation and, given its stability across environments, great potential for breeding climate-adapted apples.
Phosphorus (P) deficiency constrains cereal production, yet improving low-P performance remains challenging because P efficiency depends on rhizosphere mobilisation and internal utilisation. Wild relatives may provide insights into traits weakened during domestication. Here, we compared cultivated barley (Hordeum vulgare; CB) and wild barley (H. spontaneum; WB) to identify traits underpinning low-P tolerance. Twenty barley genotypes (10 CB and 10 WB) were grown under low (P5) and moderate (P20) P supply, and twelve low-P response physiological traits were integrated into a composite tolerance index (D-value) to assess the multidimensional basis of low-P tolerance. Under both P5 and P20, WB showed consistently higher physiological P-use efficiency (PPUE) than CB, while root morphological traits were broadly similar between CB and WB. This decoupling of biomass production from tissue P status indicates more efficient internal utilisation of absorbed P in WB. Under P5, the amount of rhizosheath citrate per plant was strongly stimulated and showed a pronounced species effect with WB exhibiting significantly higher rhizosheath citrate than CB. By contrast, increasing P supply shifted carboxylate composition towards malate dominance (85% at P20). The D value showed strong and consistent associations with key growth, PPUE, root morphology and rhizosphere functional traits in both CB and WB, validating its effectiveness as an integrative metric of low-P tolerance. Overall, WB's superior low-P performance is primarily driven by higher PPUE and elevated citrate exudation under acute P limitation, highlighting the value of targeting internal P utilisation and rhizosphere mobilisation efficiency to improve P-use efficiency in barley.
Cold stress limits plant growth and development, delays transplanting and fruit marketing, and reduces economic returns. Exogenous trehalose (Tre) induces indole-3-acetic acid (IAA) synthesis and upregulates the IAA-responsive small auxin up RNA gene CmSAUR1, and thereby enhances cold tolerance in melon seedlings. Its role in growth regulation, however, remains unclear. In this study, exogenous Tre, IAA, and gibberellin (GA) significantly promoted stem internode cell expansion and elongation and increased plant biomass in melon seedlings. Inhibition of IAA signaling by N-1-naphthylphthalamic acid (NPA), an inhibitor of polar auxin transport, attenuated the effect of Tre but did not affect the effect of GA. In contrast, inhibition of GA biosynthesis by uniconazole, a GA biosynthesis inhibitor, abolished the effect of Tre and significantly weakened the effect of IAA. CmSAUR1, induced by IAA, negatively regulated melon seedling growth, whereas GA3 treatment suppressed CmSAUR1 expression. These findings indicate that Tre promotes melon seedling growth under normal temperature conditions and after recovery from low-temperature stress by mediating IAA and GA signaling. Crosstalk occurs between the IAA and GA pathways, and GA may act downstream of IAA as a central component of Tre function. CmSAUR1 may integrate the interaction between GA and IAA signaling and participate in Tre-mediated growth regulation. The results of this study provide a theoretical reference for the application of Tre in melon cultivation and for further in-depth research on the interaction between IAA and GA signaling in regulating plant growth.
African rice faces flooding, leading to hypoxia, which triggers the accumulation of reactive oxygen species and oxidative stress. Stress priming involves subjecting a plant to mild stress to enhance its tolerance to abiotic stress. This study examined the physiological, biochemical, and anatomical responses of two rice species, Oryza glaberrima (CG 14) and Oryza sativa (FARO 44), under various flooding conditions. The treatments included plants exposed to flooding stress once (FS1) and plants subjected to flood-priming (FP) treatments. Phenotypically, CG 14 and FARO 44 respond to flooding through stem elongation and reduced root formation. Flood priming induced superoxide dismutase, peroxidase, glutathione, and flavonoids in both rice species. FARO 44 differentially increased phenylalanine ammonia-lyase activity, which activates the production of secondary metabolites. Carbohydrate-active enzymes (CAZymes), with primed FARO 44 displaying increased glycoside hydrolase and polysaccharide lyase activities, support cell wall loosening and membrane remodeling, facilitating the formation of wider aerenchyma. Thickened root endodermis and exodermis observed in primed FARO 44 suggest barrier formation, whereas CG 14 showed accumulation of reduced ascorbate with limited anatomical adaptation. Adenosine triphosphatase (ATPase) activity decreased in CG 14 and increased in FARO 44, suggesting superior energy management in FARO 44 to support enzymatic and structural adjustments. Together, enhanced antioxidant defenses, CAZyme-mediated cell wall remodeling, PAL-ATPase integration, and anatomical plasticity underpin the superior flooding tolerance of FARO 44 and demonstrate the metabolic reprogramming benefits of flood priming in rice.
Ocimum americanum L. (American basil or lime basil), an aromatic annual herb of the Lamiaceae family, is widely recognized for its medicinal properties. Traditionally, it has been used in treating cough, respiratory disorders, rheumatism, and renal complications. In the context of global climate change and stratospheric ozone depletion, the increase in ultraviolet B (UV-B) radiation poses a significant threat to plant health and productivity. Understanding how medicinal plants respond to elevated UV-B (eUV-B) is therefore crucial. This study examines the physiological and biochemical responses of O. americanum L. to eUV-B (ambient+7.2 kJ m-2 d-1) at 30, 60, and 90 days after transplantation. Results showed significant reductions in growth, photosynthetic pigments, and overall physiological performance under eUV-B. In contrast, the total phenolic content remarkably increased, indicating activation of secondary metabolism as a protective strategy. eUV-B induced the accumulation of reactive oxygen species (ROS), including superoxide radicals and hydrogen peroxide, resulting in membrane damage and increased electrolyte leakage. Histochemical staining confirmed the localization of ROS in eUV-B-treated leaves. In response to eUV-B, antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) showed significantly enhanced activity across all the developmental stages, suggesting an active defense mechanism. GC-MS analysis further revealed increased levels of bioactive compounds, such as β-Caryophyllene and β-Ocimene, key terpenoids with therapeutic and ecological properties. Overall, O. americanum L. demonstrates adaptive resilience to UV-B stress by strengthening antioxidant defense and enhancing the production of protective specialized metabolites, despite reductions in growth and physiological efficiency.
Soil salinization severely restricts the growth and productivity of ginger (Zingiber officinale Rosc.). The PYL gene family encodes core components of the abscisic acid (ABA) signaling pathway, which plays a pivotal role in plant responses to abiotic stresses. However, the PYL gene family in ginger has not been systematically characterized to date. In this study, 11 ZoPYL genes were identified from the ginger genome and phylogenetically clustered into four subfamilies. Promoter sequence analysis revealed the presence of multiple stress-responsive cis-elements, and transcriptional regulatory network prediction suggested that ZoPYL proteins are potentially regulated by MYB, bZIP, and other transcription factor families. Expression profiling indicated that most ZoPYL genes were upregulated in response to ABA treatment, while salt stress induced tissue-specific expression patterns of ZoPYLs, with ZoPYL11 being significantly upregulated in both leaves and roots. Silencing of ZoPYL11 enhanced ginger sensitivity to salt stress, accompanied by reduced activities of antioxidant enzymes and increased accumulation of reactive oxygen species (ROS). Concomitantly, the expression levels of ZoPP2C and ZoSnRK2 genes were dysregulated in ZoPYL11-silenced plants, indicating disrupted ABA signaling. This study provides a comprehensive characterization of the PYL gene family in ginger and demonstrates that ZoPYL11 plays a crucial role in enhancing salt tolerance by mediating ABA signaling and antioxidant defense.
Like heterochromatin protein 1 (LHP1) is a conserved HP1-like chromatin protein in land plants and a major Polycomb-associated factor that recognizes H3K27me3 enriched euchromatic domains. Recent biochemical, genomic, and structural studies show that LHP1 acts as a modular chromatin scaffold whose regulatory output depends on local histone modifications, RNA interactions, transcriptional factors, and PRC1/PRC2-associated partners. In this review, we outline emerging roles of LHP1 in Polycomb-mediated repression, chromatin-state maintenance, transcriptional responsiveness, hormone signaling, stress responses, and TE-proximal gene regulation. We also examine the structural features and evolutionary diversification of LHP1 homologs across land plants and assess how duplicated LHP1 copies may contribute to species-specific developmental and stress-adaptive traits. Rather than presenting LHP1 as a universal master regulator, we emphasize its context-dependent functions and distinguish experimentally supported mechanisms from correlative or still unresolved models. Finally, we highlight future directions involving genome editing, epigenomic profiling, chromatin conformation analysis, and targeted epigenome engineering to clarify how LHP1 associated modules may be exploited for crop improvement and postharvest quality management.