Physiologia plantarum最新文献

Phosphorus (P) scarcity severely limits crop productivity; yet, mechanisms balancing P allocation between vegetative and reproductive organs remain unclear. Here, we identify OsPH-2 as a phosphate-responsive regulator in rice (Oryza sativa L.). Under low-P (LP) conditions, OsPHI-2 is transcriptionally repressed by the KNOX family factor OSH1 (KNOX family class 1 homeobox gene of rice), which directly binds its promoter. CRISPR-edited OsPHI-2 knockout lines exhibited enhanced biomass and adaptive root-shoot resource allocation under LP, whereas overexpression lines showed impaired panicle development and reduced grain yield. This repression fine-tunes P partitioning by modulating expression of transporters (OsPT2, OsPHO1;2) and vacuolar effluxes (OsVPE1), prioritizing reproductive over vegetative sinks. Haplotype analysis indicated that subspecies-specific P remobilization strategies may be associated with OsPHI-2. Under P deficiency, Indica rice rapidly suppresses OsPHI-2 expression to preferentially remobilize P to panicles, thereby enhancing adaptation to low-P environments. Our study uncovers an OSH1-OsPHI-2 module that coordinates P allocation, providing a genetic target for improving P-use efficiency in rice.

Balancing growth and immunity pose a fundamental challenge for plants, as investment in defence mechanisms often comes at the cost of growth and development, and vice versa. Ecological theories, particularly those based on principles of economic optimality, propose that plants strategically allocate resources between these competing processes to optimize fitness. Recent advances in multi-omics technologies have provided deep insights into the complex molecular architecture governing growth-defence trade-offs, identifying transcriptional cascades as key regulators of resource allocation. Within this regulatory landscape, non-coding RNAs (ncRNAs) have emerged as critical modulators, fine-tuning the expression of genes involved in both developmental and immune pathways. This review synthesizes current understanding of how ncRNAs mediate the growth-defence balance in plants. We discuss specific ncRNAs that act as regulatory hubs within feedback circuits, their interactions with phytohormonal signalling networks, and the potential of harnessing these mechanisms for precision crop improvement. Ultimately, decoding the functional framework of ncRNA-driven regulation presents new opportunities to develop high-yielding, stress-resilient crop varieties that can bypass the constraints of conventional growth-defence trade-offs, thereby supporting sustainable agricultural productivity amid growing environmental pressures.

In the Pooideae subfamily, resistance to insect herbivores often depends on a defensive mutualism with Epichloë fungal endophytes, which produce anti-invertebrate alkaloids such as lolines and peramine. Herbivory can induce alkaloid accumulation and enhance endophyte-conferred resistance, a response interpreted as analogous to classical herbivore-induced resistance in plants. Yet, abiotic stressors, particularly drought, also stimulate alkaloid production and resistance, suggesting a more general response linked to oxidative stress. Despite these insights, no quantitative synthesis exists, and the regulation of alkaloid induction under stress remains poorly understood. Using a meta-analysis, we synthesized published data to test whether herbivory or drought enhance Epichloë-mediated resistance and increase the in planta concentrations of lolines and peramine. Both stressors significantly elevated resistance, associated with higher alkaloid concentrations, particularly lolines. Peramine increased under drought but not consistently with herbivory. Published molecular and biochemical studies implicate oxidative stress, particularly changes in reactive oxygen species (ROS) levels, in regulating alkaloid production through precursor accumulation and fungal signaling pathways involving NADPH oxidases and stress-activated MAP kinases. Given that Epichloë enhances plant tolerance to stress and that ROS play a key role in the plant-endophyte communication, we propose that alkaloid induction and herbivore resistance are beneficial by-products of endophyte-mediated stress responses, rather than solely adaptive outcomes of coevolution with herbivores. This perspective highlights how herbivory and drought converge on oxidative stress pathways to modulate plant-endophyte associations, with implications for plant defense under climate-driven stress scenarios.

Closed forests are usually characterized by a complex canopy structure that results in dramatic vertical variation in micro-environmental conditions within the tree crown. There is still limited understanding of how plants adjust to vertical gradients in biophysical variables within tree crowns to regulate leaf non-structural carbohydrate (NSC) dynamics and leaf elemental stoichiometry. To enhance the understanding of leaf adaptive strategies across different crown positions, we measured leaf NSC concentrations, elemental composition (C, N, P, K, and Ca), and key morphological features like leaf thickness, leaf area, specific leaf area, leaf water content, and equivalent water thickness at the upper and lower crowns of 13 mature temperate tree species. We found that vertical variation in microclimate, particularly the differences in light availability and air temperature, significantly influenced leaf NSC concentrations, with leaves in the lower crown exhibiting consistently higher NSC levels. Leaf nutrient traits also varied with crown position and were closely associated with changes in leaf morphological characteristics, indicating coordinated adjustments in resource acquisition strategies along the vertical canopy gradient. In contrast, while NSC-to-nutrient ratios declined with increasing crown position, the C:N:P stoichiometric ratios remained largely stable across crown positions. Together, these results suggest that trees maintain relatively stable elemental stoichiometry while allowing flexible NSC allocation and trait coordination to cope with strong vertical microclimatic heterogeneity in closed-canopy forests.

As droughts become more common due to climate change, plant survival may rely not only on its immediate response but also on what it has learned from past challenges. However, we still know little about how plants integrate different types of experiences, such as recurrent drought and hormonal cues, from previous generations. In this study, we examined whether clonal offspring of a grass species, Festuca rubra, previously exposed to drought, stress hormone methyl jasmonate (MeJA), or their combination inherited biological memories that help them tolerate new drought stress. We combined untargeted LC-MS metabolomics with morpho-physiological measurements to evaluate these memory effects. We found that each type of memory changed plant metabolism and physiology, but the most notable changes occurred when both memories were present, and plants faced recurrent drought conditions again. This interaction between drought memory, MeJA memory, and current stress did not just add effects; it created entirely new metabolic responses, not seen in any single treatment. These combined memories fine-tuned water conservation, photosynthesis, and extensive metabolomic reshuffling, revealing a deeper level of drought resilience. Our results uncover a layered memory system in plants where past stresses do not act in isolation but interact to reshape future responses. This offers new insight into how plants prepare for stress and suggests practical strategies for priming drought tolerance across plant generations.

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.