Plant Physiology and Biochemistry最新文献

Programmed cell death (PCD) is a major cause of reduced cell viability following cryopreservation, yet the underlying mechanism remains unclear. In this study, pollen from Paeonia lactiflora was used as the experimental material to investigate the role of the microtubule cytoskeleton in PCD during pollen cryopreservation, which exhibits significant viability decline after cryopreservation. The results showed that post-cryopreservation addition of the microtubule-depolymerizing agent oryzalin significantly decreased pollen viability. This effect was accompanied by the activation of caspase-like proteases, reduced mitochondrial membrane potential, elevated intracellular cytochrome C levels, accumulation of PCD signaling molecules, and ultimately increased apoptosis rates. In contrast, treatment with the microtubule-stabilizing agent paclitaxel exerted the opposite effect. At the transcriptional level, paclitaxel treatment induced 754 differentially expressed genes (DEGs); oryzalin treatment resulted in 575 DEGs, a total of 63 DEGs were shared between the two treatments. At the protein level, paclitaxel treatment yielded 262 differentially expressed proteins (DEPs), while oryzalin treatment led to 270 DEPs, with 100 DEPs overlapping between the two groups. Integrated transcriptomic and proteomic analyses revealed that these DEGs and DEPs were significantly enriched in two key pathways: cysteine and methionine metabolism, and protein processing in the endoplasmic reticulum. Notably, heat shock proteins were prominently expressed at both the transcriptional and protein levels in the endoplasmic reticulum protein processing pathway, while malate dehydrogenase played an extremely critical role in cysteine and methionine metabolism pathway. Collectively, these findings indicate that the microtubule cytoskeleton is involved in regulating PCD during pollen cryopreservation, with cysteine and methionine metabolism and endoplasmic reticulum protein processing serving as the core pathways.

RNA editing is a crucial post-transcriptional mechanism that enables plants to adapt to environmental stress. However, its specific role in remodeling photosynthetic complexes under drought conditions remains unclear. In this study, RNA editing in Solanum lycopersicum (tomato) was investigated during drought stress, focusing on its impact on the cytochrome b₆f (Cyt b₆f) complex a key component of the photosynthetic electron transport chain. Findings revealed that editing sites in petA (Cyt f) and petB (Cyt b₆) transcripts were dynamically regulated by drought, leading to nucleotide substitutions and subsequent amino acid alterations. Notably, an RNA editing event at position A430 in petA introduced a premature stop codon, resulting in both truncated (15 kDa) and full-length (35 kDa) Cyt f isoforms. According to 3D protein calculation, these isoforms exhibited that the smaller size isoform may exhibit altered transmembrane protein stability, heme coordination, and electron transport efficiency. Structural modeling suggested that the truncated Cyt f had impaired redox activity. The reversion of specific petB edits (L150M, A154V) upon rehydration, alongside drought-triggered changes in electron transport linked to conserved editing patterns, establishes RNA editing as a dynamic, stress-responsive regulatory mechanism. Taken together, these findings reveal that RNA editing contributes to the functional plasticity of the Cyt b₆f complex under drought by integrating protein isoform production, reversible amino acid changes, and metal homeostasis, ultimately supporting enhanced photosynthetic adaptation and drought tolerance in plants.

Soda saline-alkali soils severely limit rice productivity. While arbuscular mycorrhizal fungi (AMF) and selenium (Se) are known to alleviate abiotic stresses, their synergistic interaction during critical growth stages remains underexplored. In this study, a pot experiment was conducted using natural soda saline-alkali soil to explore the interactive impacts of Funneliformis mosseae inoculation and selenite application at different growth stages. The results showed that selenite application at the booting stage combined with F. mosseae treatment (F_Se4) significantly enhanced the saline-alkali tolerance of rice (P < 0.05), with a 20% increase in yield compared to the control treatment (CK). Mechanisms enhancing rice's saline-alkali tolerance included: (i) optimizing photosynthetic efficiency, with increases in C_i-D, T_r-D, and P_n-D of 30.7%, 70.1%, and 70.3%, respectively, and a 130% increase in G_s-D compared to CK; (ii) regulating ion homeostasis, with significant increases in K⁺, Ca²⁺, and Mg²⁺ contents in leaves and roots, and decreased Na⁺ content, maintaining higher K⁺/Na⁺, Ca²⁺/Na⁺, and Mg²⁺/Na⁺ ratios; (iii) activities of antioxidant enzymes (SOD, POD, CAT, APX, LAP, GSH, and GSH-Px) showed significant increases relative to CK, with the largest response observed for GSH-Px (P < 0.05); and (iv) enhancing membrane lipid protection, with Pro content in leaves reaching 97.8 μg/g, and MDA accumulation reduced by 45.5%. This study identifies booting stage as the critical window for selenite-F. mosseae synergy, where GSH-Px/GSH system activation and photosynthetic-ionic homeostasis coordination form a dual protective mechanism against soda saline-alkali stress. These findings provide an innovative theoretical framework and practical strategy for rice cultivation in saline-alkali soils.

This study investigated the mitochondrial response mechanisms of Syntrichia caninervis Mitt., a desiccation-tolerant moss from the Chinese Gurbantunggut Desert, to dehydration-rehydration stress at the subcellular level under three dehydration intensities: rapid drying (RD), slow drying (SD), and air drying (AD). The results showed that the moss maintained the structural integrity of mitochondrial membranes across treatments, demonstrating remarkable phenotypic plasticity. Rapid dehydration caused a pronounced decline in mitochondrial membrane potential (ΔΨm) and distortion of cristae, relying primarily on emergency antioxidant responses involving superoxide dismutase (SOD) and ascorbate peroxidase (APX) to scavenge reactive oxygen species (ROS). In contrast, slow dehydration activated a "pre-adaptive" antioxidant strategy characterized by sustained peroxidase (POD) activation, accumulation of reduced glutathione (GSH), and upregulation of alternative oxidase (AOX) activity. Principal component analysis confirmed that APX, SOD, and AOX were key contributors to drought adaptation. This study is the first to reveal dual-track adaptive mechanisms in desiccation-tolerant plants mediated through mitochondrial ultrastructure, membrane potential dynamics, and redox homeostasis regulation, and provides new targets for improving drought resistance in crops.

Understanding crop responses to simultaneous environmental stressors is critical for safeguarding agricultural productivity. Yet, how microplastics (MPs) contamination interacts with water deficit to affect crop physiology, and which functional traits mediate such responses, remains poorly understood. We quantified crop growth parameters and 22 functional traits in two wheat varieties differing in drought sensitivity-drought-sensitive ('SL') and drought-tolerant ('SN')-under four treatments: control, single MPs, single mild water deficit, and combined stress. We characterized associations among leaf economic traits, water-relations traits, and eco-physiological performance. Combined stress reduced shoot dry weight by 28.32% in 'SN' and 41.25% in 'SL'. Under combined stress, 'SN' exhibited more acquisitive trait strategies than 'SL', thereby alleviating growth suppression. The leaf economics spectrum (PC1) showed positive correlations with root activity and water-use efficiency, whereas transpiration rate, stomatal conductance, and leaf water potential were negatively associated with root activity. Our results reveal that wheat resistance to combined MPs and water deficit is enhanced through acquisitive strategies that promote drought avoidance mechanisms, contrasting with the drought tolerance conventionally linked to conservative strategies. The tight coupling between leaf economics and water-relations traits underpins adaptive strategies, emphasizing the importance of trait-based optimization for improving crop performance under emerging multi-stressor environments.

Research on passion fruit traits primarily focuses on abiotic stress due to its detrimental impact on the industry. Transcription factors (TFs) mitigate abiotic stress by participating in various biological processes, among which heat shock factors (HSFs) play a pivotal role in responding to both biotic and abiotic stresses and conferring stress tolerance. This study identified 15 PeHSF family members with complete sequences using a high-quality genome of passion fruit. A systematic analysis of PeHSFs across the genome was conducted through bioinformatics and transcriptome sequencing. Transcriptomic data revealed higher expression levels of most PeHSFs in fruit pulp at stages T1 and T2 compared with T3, demonstrating the family's responsiveness to diverse abiotic stresses. Subsequent subcellular localization confirmed nuclear localization of the selected gene PeHSF-2. Heterologous expression of PeHSF-2 in the INVSc1 yeast strain and Arabidopsis thaliana significantly enhanced tolerance to drought, salt, cold, and heat stresses. Furthermore, PeHSF-2 over-expression up-regulated stress-responsive genes (P5CS1, SOS1, HSP70, and CBF2), and interacted with PeSIP2-2. This study lays the groundwork for further investigation into the regulatory mechanisms of PeHSFs under abiotic stress conditions.

Recently, an Agrobacterium-mediated CRISPR/Cas9 editing system was successfully applied in a gene function analysis, highlighting its great value for improving strawberry genetics. However, the resulting low transformation rates and long regeneration cycles have limited its extensive application. Based on the biological characteristics of crown branching, an Agrobacterium tumefaciens-mediated CRISPR/Cas9 gene editing system was developed to increase the transformation rate and decrease the regeneration time of cultivated strawberry. Two single guide (sg)RNAs were designed for the strawberry anthracnose-related transcription factor, WRKY (FxaC_17g55530), and its alleles. These sgRNAs were inserted into pKSE401G using pCBC-DT1T2; sgRNAs for subtilisin-like protease (FxaC_22g21540) were designed and cloned in a similar manner. After 10 days of co-cultivating plantlets (without media supply of carbon) and GV3101, 65 (61.9%) and 72 (68.6%) GFP-positive calluses for the two genes were respectively obtained from the crown of 105 plantlets. The positive calluses were removed from the crown and placed on Murashige and Skoog media containing 3 mg/L thidiazuron and 0.2 mg/L indole-3-butyric acid. After 50-80 days, 3-5 positive shoots were obtained from different positive calluses for each gene. The three T0 lines for FxaC_17g55530 and FxaC_22g21540 were found to be successfully edited at the target sites of both sgRNA1 and sgRNA2 or either sgRNA1 or sgRNA2. Overall, a quick and effective CRISPR-Cas 9 gene editing system was developed for cultivated strawberry, highlighting the applicability of gene editing in breeding and gene function analysis.

By 2050, the global population is projected to reach 9 billion, necessitating innovative approaches beyond traditional agricultural methods to ensure adequate food security. Several biological control agents have been used throughout the world to control plant diseases by re-programming natural prey-predator interactions. Trichoderma's biocontrol capabilities and plant growth-promoting effects have been extensively studied and documented, paving the way for its widespread adoption in agricultural practices. Here we performed a comprehensive pan-genome analysis of 25 industrially and agriculturally important Trichoderma strains, revealing an open pan-genome indicative of continuous genetic innovation. A combined total of 4960 core genes were shared between both industrial and biocontrol strains, which encode for fundamental functions with accessory and unique genes being enriched in adaptive functions. Industrial strains like T. reesei QM6a with 322 unique genes had enrichment of features for secretion of cellulase and lignocellulose degradation, validating their commercial dominance in industries producing enzymes and biofuels, while biocontrol-associated strains like T. harzianum CBS226.95 and T. virens Gv29-8 showed expanded accessory gene repertoires enriched in defense-related functions and secondary metabolism. Comparative biosynthetic gene cluster analysis across 25 genomes further demonstrated pronounced strain-level variation. Core-genome phylogeny revealed conserved ancestral relationships, whereas pan-genome phylogeny highlighted accessory gene-driven divergence among closely related strains. Remarkably, many strains had dual promise, being both industrial producers of enzymes and agriculturally desirable, highlighting their interdisciplinary applications. These results demonstrate the genomic malleability of Trichoderma and the adaptability of its evolution, facilitating agriculture and biotechnology, and provide a template for strain selection with precision and rational bioformulation design for promoting sustainable agriculture, environmental robustness, and green industry.

Perilla frutescens (L.) Britt., an important medicinal and aromatic plant, is widely utilized in traditional Chinese medicine and health food products. GRAS transcription factors vitally drive plants' growth, development, and environmental stress responses. Nevertheless, the functional role of GRAS transcription factors in P. frutescens remains unexplored. This study identified 83 PfGRAS genes in total from the P. frutescens genome and divided them into nine subfamilies by phylogenetic analysis. According to conserved motif analysis, genes within the same subfamily demonstrated comparable conserved motifs. Most PfGRAS genes lacked introns and their promoters contained multiple cis-acting elements that regulate plant hormone and stress responses. PfGRAS70 was localized to the nucleus and plasma membrane and possessed transcriptional activation function. Overexpression of PfGRAS70 in P. frutescens hairy roots increased rosmarinic acid content, suggesting that PfGRAS70 may positively regulate rosmarinic acid biosynthesis. qRT-PCR and yeast one-hybrid assays indicated that PfGRAS70 may promote PfC4H4 expression by binding to the TTTCATGT motif, accordingly benefiting the rosmarinic acid biosynthesis. Collectively, these findings highlight the potential value of PfGRAS70 in molecular breeding and provide a basis for further functional exploration.