Physiologia plantarum最新文献

Drought events can have long-lasting effects on plant performance and progeny traits. We investigated how an early, severe drought at the seedling stage affected plant fitness and seed traits in Lolium multiflorum, and whether these responses were modulated by symbiosis with the vertically transmitted fungal endophyte Epichloë occultans. Drought caused significant mortality, and the symbiosis with the endophyte improved survival independently of plant biomass. Surviving plants fully recovered aboveground biomass and seed production only in the presence of the endophyte. Isotopic analyses indicated that only non-symbiotic plants showed reduced stomatal conductance during seed set, which likely explains their lower seed production. Seeds from drought-exposed symbiotic plants had higher concentrations of compatible solutes (mannitol and sorbitol) and starch. However, symbiotic seeds from drought-exposed plants showed reduced germination under intermediate water potential. This response was associated with a drought-induced increase in the base water potential (Ψ_b). Alternatively, constant hydrotime was positively associated with starch content. Our results suggest that endophyte symbiosis enables recovery from early drought via osmotic adjustment and photosynthetic maintenance, with intergenerational responses mediated by changes in seed biochemical composition and germination. These findings highlight the role of vertically transmitted endophytes in plant memory of stress and drought resilience across generations.

Polyploid plants often present a variety of agriculturally advantageous traits, such as larger organs. Plant cell expansion is ultimately constrained by the cell wall, yet the impact of polyploidization on the cell wall architecture of orchids remains unexplored. Here, we employed Dendrobium catenatum (syn. D. officinale) as a model to dissect the impacts of polyploidization on phenotypic traits, cell size and cell wall composition. Compared with diploids, tetraploids of D. catenatum have larger organs underpinned by larger cells. The analysis of gene expression revealed that the differentially expressed genes (DEGs) were significantly enriched in the cell wall metabolism and DNA packaging pathways. The cell wall component lignin- and xylan-related transcripts were upregulated, whereas histone-variant genes were repressed. Compositional assays revealed that the contents of many cell wall components, such as lignin, are increased in tetraploids. Despite cell wall reinforcement, tetraploids remained colonized by the symbiotic fungus Serendipita indica, although fungal biomass was moderately reduced. Thus, polyploidization enlarges D. catenatum by reprogramming cell wall construction, while preserving the plant's ability to maintain fungal symbiosis.

Receptor-like kinases (RLKs) detect external and internal signals, triggering responses essential for growth and adaptation. Among internal cues, cell wall integrity (CWI) sensing plays a key role, as changes in cell wall structure activate responses critical for development and defense. While RLKs are well-studied in vascular plants, their diversity and function remain largely unknown in green algae belonging to the Chlorophyta phylum, a group that is relevant for global oxygen production and carbon cycling. Due to their varied cell wall structures, Chlorophyta offer a useful system to study the origins of CWI sensing. In this study, we used advanced bioinformatics and AI-based tools to analyze RLKs in 34 Chlorophyta species, mapping their distribution, structural features, and similarity to plant RLKs. We identified 736 putative RLKs, expanding the known repertoire in green algae. Structural analyses showed a wide range of extracellular domains, including motifs related to plant CWI sensors: domains mediating protein interactions (e.g., Leucine Rich Repeats-LRR, Plasminogen Apple Nematod e-PAN, Armadillo repeat-ARM), cell wall remodeling (e.g., glycosyl hydrolases, lyases), and mechanosensing (e.g., Leucine-Proline-X-Threonine-Glycine motifs-LPXTG, Fibronectin). This diversity suggests that mechanisms for extracellular sensing and CWI monitoring emerged early in evolution. The results provide a basis for future studies on the function of RLKs in algae and their evolutionary links to vascular plant signaling.

Fruit quality in wampee is strongly influenced by the accumulation of key metabolites, including anthocyanins, sugars, and organic acids, yet their metabolic dynamics during fruit development remain poorly understood. In this study, we analyzed metabolite profiles and the expression of metabolism-related genes in the pulps of two wampee cultivars, "Jixin" (JX) and "Zirou" (ZR), across multiple fruit developmental stages. Two anthocyanins, 17 sugars, and 32 organic acids were identified. Total phenolics, flavonoids, starch, and soluble sugars accumulated mainly during early fruit development. "JX" wampee exhibited higher ascorbic acid levels than "ZR" wampee. Sucrose and citric acid were the predominant sugars and organic acids in both cultivars. Transcriptomic analysis revealed 37 anthocyanin-related, 29 sugar-related, and 18 organic acid-related genes. Strong correlations between candidate gene expression and metabolite levels suggest that these genes play key roles in regulating the biosynthesis and accumulation of anthocyanins, sugars, and organic acids in wampee.

Verticillium wilt (VW) is a soil-borne fungal plant disease. Gossypium hirsutum varieties with the widest planting area are highly susceptible to VW pathogens, because their narrow genetic background of germplasm resources causes difficulties in cultivating VW-resistant varieties through intraspecific breeding. Therefore, G. barbadense cultivars, harboring a natural VW resistance, become ideal donor materials to cultivate high-yield and multi-resistance chromosome segment substitution lines (CSSLs) through hybridization and backcrossing with G. hirsutum receptor and recurrent parent. In order to investigate the molecular mechanism of cotton response to VW infection, a BC₅F_3:5 CSSL MBI9626 and its parents, CCRI36 (G. hirsutum) and Hai1 (G. barbadense), were chosen to perform transcriptome and metabolome sequencing on their root samples at 0, 7, and 15 days after inoculation (DAI) of V. dahliae V991. In total, 36,564 differentially expressed genes (DEGs) and 102 differentially accumulated metabolites (DAMs) were separately identified from 12 pairwise comparison groups among the 27 samples. Of those, 125 common DEGs were found to participate in the biological processes of oxylipin metabolism, jasmonic acid (JA) biosynthesis/metabolism, and response to wounding in Gene Ontology (GO) enrichment analyses, while most of the DAMs were significantly enriched in tyrosine, purine, and phenylalanine metabolism pathways in enrichment analyses of Kyoto Encyclopedia of Genes and Genomes (KEGG). Having performed a conjoint KEGG analysis of all the DEGs and DAMs, we found two commonly enriched pathways, namely plant hormone signal transduction and flavonoid biosynthesis, which were consistent with the enrichment annotations of the significant model in weighted gene co-expression network analysis on the 2091 DEGs identified by an intersection of the genes in 40 previous QTLs and the total DEGs of this RNA-seq data. Among the ABA signaling pathway, the gene GH_D12G0236 (GHABF3) was selected to be used to perform virus-induced gene silencing (VIGS) verification in CCRI36 and MBI9626, and GHABF3-silenced plants showed a more serious wilting phenotype, an increased disease index (DI), and higher accumulation of fungal biomass compared to their empty-vector plants. These results provide a high-efficiency strategy for screening vital genes affecting cotton VW resistance, and lay a solid foundation for further cotton molecular breeding.

Mulberry bacterial wilt disease is devastating to the sericulture industry, and understanding its causal agent and pathogenic mechanisms is essential for effective mulberry disease control. In this study, the strain MSG-1, which was isolated from mulberry branches with typical bacterial wilt symptoms, was identified and designated as Ralstonia pseudosolanacearum MSG-1 according to the pathogenic, morphological, physiological, biochemical, and molecular features. Furthermore, R. pseudosolanacearum MSG-1 was classified as race 5, biovar I, phylotype I, and sequevar 12, and was capable of infecting mulberry but infected ginger, banana, and other Solanaceae weakly or not at all. The complete R. pseudosolanacearum MSG-1 genome is 5.8 Mbp (66.85% GC), and a total of 1991 genes of R. pseudosolanacearum MSG-1 were found to be significantly differentially expressed during the infection of mulberry seedlings, with 1324 genes significantly up-regulated and 667 genes significantly down-regulated. Seven pathogenicity-associated candidate genes were identified, and R. pseudosolanacearum MSG-1 pathogenicity on mulberry was significantly reduced after knocking out six of these genes. This study integrates genomic insights with the pathogenicity mechanisms of R. pseudosolanacearum MSG-1, shedding light on the breeding of resistant mulberry varieties and precision-based wilt control in sericulture.

Leaf margin morphology, encompassing entire, serrated, and lobed forms, is a key feature of leaf architecture with profound developmental, ecological, and evolutionary significance. This review synthesizes recent advances in understanding the regulation of leaf margin development, highlighting the integration of genetic, hormonal, and environmental cues. Central gene families such as cup-shaped cotyledon (CUC), Knotted1-like homeobox (KNOX), TCP, WOX, and LMI1/RCO are discussed in the context of their roles in promoting or restricting marginal growth. Hormonal regulators, particularly auxin, cytokinin, and gibberellin, interact through complex spatial feedback loops to fine-tune margin patterning, often mediated by key transporters, transcription factors, and miRNA modules. Age-dependent transitions, primarily regulated by the miR156-SPL pathway, modulate leaf margin complexity in both herbaceous and woody species. In addition to intrinsic genetic programs, extrinsic factors such as light intensity, temperature, nutrient availability, herbivory, and pathogen attack significantly influence margin development, demonstrating the plasticity of leaf morphology in response to environmental conditions. The integration of environmental signals into hormonal and gene regulatory networks enables plants to optimize leaf structure for photosynthesis, thermoregulation, and defense. This review also identifies emerging tools, such as spatial transcriptomics and genome editing, that promise to unravel the dynamic regulation of margin morphogenesis. By unifying developmental and environmental perspectives, we provide a conceptual framework for future studies on leaf form diversification and offer insights for potential applications in plant adaptation and crop improvement.

Kale (Brassica oleracea var. acephala) is a natural product rich in bioactive substances and a good source of functional compounds. This study evaluated the individual and combined effects of exogenous brassinolide (BR, 0.1 mg L^-1) and sucrose (Suc, 34.2 mg L^-1) on photosynthesis, sugar metabolism, the AsA-GSH cycle, nitrite accumulation, phytochemical composition, and nutritional quality of kale sprouts. Compared with the control and single treatments, combined BR and Suc application markedly increased chlorophyll and carotenoid levels, chlorophyll fluorescence parameters (qL, Y(II), F_v/F_m), sugar metabolism components (fructose, INVA, INVN, SSc, SSs), AsA-GSH cycle indicators (GSH, AsA/DHA), antioxidant enzyme activities (SOD, POD), and beneficial phytochemicals and nutrients (PAL, flavonoids, riboflavin, soluble sugars, cellulose, soluble protein, free amino acids). Conversely, it decreased levels of APX, DHAR, SPS, sucrose, glucose, AsA, DHA, and anthocyanins. Correlation analysis further identified key interactions between sugar metabolism and the AsA-GSH cycle, including sucrose with GSH and GSH/GSSG, GSSG with MDHAR, and fructose and INVA with AsA/DHA. These results indicate that BR and Suc co-treatment improves kale sprout growth and quality by elevating photosynthetic performance, antioxidant capacity, and the accumulation of health-promoting compounds. This studyprovides guidance for the combined application evaluation of plant hormones and carbon sources.

Freezing tolerance (FT) is widely assessed in laboratories by measuring electrolyte-leakage (EL) from tissues exposed to sub-zero temperatures. This method employs cooling programs which typically result in extracellular freezing in herbaceous tissues causing cellular desiccation, a major determinant of injury manifested in EL, among other dysfunctions. Conventionally, samples are exposed to given sub-zero temperatures (certain freeze-desiccation) and thawed out after holding them for 0 to ~30 min at the target temperature before measuring EL. The higher the EL, the greater the injury. This protocol mostly ignores the effect of prolonged freezing at a given sub-zero temperature on the severity of injuries as well as the potential for post-thaw recovery. Research from the present author's laboratory and a few others shows that prolonged freezing causes greater injury than relatively shorter freezing times at the same temperature, that is, despite 'fixed' freeze-desiccation, resulting in higher EL and water-soaking, lower quantum efficiency of photosystem II and higher oxidative stress. The readers of this minireview are briefly introduced to the basic understanding of the mechanics of the EL assay, its application to assess reversible versus irreversible injury, the process of freezing (ice-nucleation, cooling rates), equilibrium freezing, and freeze-desiccation, all predominantly in the context of herbaceous and thermally homogenous tissues without barriers to ice progression. Within this framework, a data-driven discussion is shared to highlight the significance of including freezing duration (FD) in FT tests. Ideas presented herein may refine methodologies for evaluating FT that validly predict plants' responses to natural freezes. This may also incentivize the exploration of cellular/molecular mechanisms for differential responses to varying FDs at a fixed temperature.

The high variability of natural environments poses significant challenges to photosynthetic organisms, which must adapt to constant fluctuations. Mechanisms such as acclimation and adaptation are essential for mitigating stress and ensuring survival. Rugulopteryx okamurae, an invasive alien seaweed recently introduced into Mediterranean and Atlantic waters, displays a remarkable ecological success, forming dense monospecific populations throughout diverse environments. This persistence suggests highly efficient acclimation mechanisms, possibly driven by seasonal physiological performance. The aim of this study was to evaluate the seasonal physiological response of R. okamurae to seasonal environmental fluctuations within a Posidonia oceanica meadow in the Alboran Sea, to better understand the photosynthetic acclimation strategies underlying its invasiveness. Photosynthesis-irradiance curves, pigment concentrations and elemental composition were analysed in individuals sampled bimonthly from July 2021 to July 2022 at a -10 m depth. Results showed significant seasonal variation in physiological parameters, highlighting a consistent acclimation capacity and robust photosynthetic performance. Fluctuations in pigment content and photosynthetic variables reflected the species' ability to optimise metabolic activity in response to environmental changes. Light compensation and saturation parameters further indicated strong photoadaptive capacity, enabling the species to thrive under both low and high light conditions. Its tolerance to a broad range of environmental factors, combined with mechanisms that prevent photoinhibition, may explain its persistence across seasons and wide depth ranges in the Alboran Sea. Although further research along depth gradients is needed, these findings underscore the role of physiological plasticity in the ecological success of R. okamurae and highlight the value of field-based studies in understanding invasion processes of marine macrophytes.