Plant Molecular Biology最新文献

Glutathione transferases (GSTs, EC 2.5.1.18) are a diverse enzyme family involved in various cellular processes, regulated by several stimuli, including plant hormones (phytohormones). Additionally, GSTs can also influence hormone levels, as certain GSTs, particularly members of the Phi class GSTs (GSTFs) have been reported to directly bind small phytohormones (auxin, cytokinin, and salicylic acid). However, the structural aspects of these interactions remained unresolved. It has been documented that an Arabidopsis thaliana GSTF, AtGSTF2, possesses unique non-catalytic ligand-binding sites (L sites). This study focuses on the orthologous tomato (Solanum lycopersicum) GSTFs (SlGSTFs) and explores the connection between this non-catalytic ligand-binding function and phytohormones. Using modern in silico techniques, such as protein modelling by AlphaFold, molecular docking, and molecular dynamics (MD) simulations, we provide the first insights into the possible phytohormone-binding ability of SlGSTFs. In particular, SlGSTF5 shows significant potential for a novel phytohormone binding function, thereby broadening the potential roles of plant GSTs. Our work also includes a simple protocol for modelling and analysing protein-ligand interactions, offering valuable insights into the role of individual plant GSTs.

Durio zibethinus, commonly known as the "king of the fruits," is widely cultivated in Southeast Asia, contributing significantly to the region's economy. In addition to commercial cultivars, numerous local edible durian species are also found in these countries. With the rapid advancement of omics technologies, extensive studies have been conducted on durians using various omics approaches. To date, omics studies have primarily focused on commercial durians (D. zibethinus), with relatively less emphasis on endemic, minimally commercialized local durians (Durio sp.). As such, this review summarizes all omics studies performed on both commercial cultivars and local durians of different species. In addition, it explores their applications in evolutionary studies, understanding the fruit ripening mechanism, identifying genetic markers for breeding, and uncovering their pharmaceutical and industry potential, as well as post-harvest processing. Furthermore, the current limitations of durian omics studies and future research prospects are discussed.

OsNF-YC5, a member of the nuclear factor Y (NF-Y) transcription factor family, plays a key role in rice grain development. Expression analysis showed that OsNF-YC5 is highly expressed in young panicles and grains during the grain-filling stage. Knockout of OsNF-YC5 resulted in longer but narrower and thinner grains, with increased length-to-width and length-to-thickness ratios, yet a 15.1% decrease in thousand-grain weight. Scanning electron microscopy revealed that the lemma epidermal cells in the osnf-yc5 mutant underwent longitudinal expansion and transverse contraction, with reduced cell number along the width, likely contributing to the altered grain morphology. Moreover, osnf-yc5 mutant exhibited impaired grain filling, with the chalky grain rate increasing dramatically from 5.5% in the wild type to 81.1%. Composition analysis showed significant content changes in major storage substances, including total starch, amylose, prolamin, glutelin, and total lipid content, which decreased by 14.3%. In contrast, overexpression of OsNF-YC5 resulted in smaller seeds, with reduced grain length, width, thickness, and weight as well as elevated chalky grain rates. Transcriptome profiling identified 1,046 differentially expressed genes (DEGs) in osnf-yc5 mutants, these DEGs were enriched in functions and pathways including regulation of transcription, nutrient reservoir activity, endoplasmic reticulum protein processing, starch and sucrose metabolism, suggesting that OsNF-YC5 is involved in grain filling and storage substance accumulation. These findings underscore the importance of OsNF-YC5 in controlling grain size and quality, highlighting its potential to improve rice production.

The regulation of flowering is crucial for optimizing palm oil yield and ensuring adaptation to environmental conditions. This study investigates two FLOWERING LOCUS T (FT) homologs in oil palm (Elaeis guineensis), EgHd3a-1 and EgHd3a-2, to elucidate their roles in flowering induction and developmental processes. Quantitative PCR and GUS reporter assays in Arabidopsis thaliana revealed that EgHd3a-1 is predominantly expressed in reproductive tissues and vascular structures, functioning analogously to FT as a floral inducer. In contrast, EgHd3a-2 displayed broader expressions across both vegetative and reproductive tissues, particularly during early growth stages, suggesting a role in organ development rather than direct floral induction. Overexpression of EgHd3a-1 and EgHd3a-2 in A. thaliana resulted in distinct flowering phenotypes, with EgHd3a-1 mutants exhibiting accelerated flowering under long-day conditions. Promoter analysis of pEgHd3a-1 and pEgHd3a-2 identified unique cis-acting regulatory elements associated with tissue specificity and environmental responsiveness, reinforcing their complementary functions. These findings provide a molecular basis for targeted genetic modification of flowering time in oil palm, offering significant potential for accelerating breeding cycles, improving yields optimization, and enhancing resilience to environmental changes.

While the role of succinic semialdehyde (SSA) dehydrogenase (SSADH; also known as gabD) is well-reported from model plants, the lack of functionality and structure of SSADH from citrus represents a significant knowledge gap. Herein, genome-wide analyses identified 17 high-confidence SSADH-like proteins from Citrus sinensis, among which three putative SSADHs have potential GABA dehydrogenase function. Sequence alignment, phylogenetic analyses, and domain architecture demonstrated high conservation among CsSSADHs (aka CsgabD) and their homologs across diverse plant taxa. Notably, CsSSADH-2 lacked a conserved QGIVC motif found in CsSSADH-1/-3. Secondary structure analyses indicated conserved aldehyde dehydrogenase domains. Homology-based 3D modeling predicted CsSSADH-1 and 2 as homo-tetramers; however, AlphaFold2-based modeling suggested their full-length monomer structures. PPI networks revealed CsSSADH-1 interacts with 10 proteins, primarily involved in GABA/succinate metabolism and the TCA cycle. Docking studies indicated that CsSSADH-1 displayed acceptable affinity and binding modes with GABA, SSA, and succinate. GABA supplementation enhances CsSSADH expression, GABA, and succinate content in a dose-dependent manner in both healthy and infected citrus plants under greenhouse conditions. CsSSADH was involved in citrus responses to 'Candidatus Liberibacter asiaticus' and/or its vector, Diaphorina citri. Nevertheless, GABA accumulation under biotic stress leads to condition-specific rerouting of GABA metabolism. Chemical inhibition of CsSSADH resulted in increased GABA accumulation but reduced succinate levels in both healthy and infected plants. This study offers the first comprehensive characterization of C. sinensis SSADH isoforms, providing insights into their evolutionary divergence, structural features, and potential functions, and enhancing our understanding of their possible roles in GABA metabolism and citrus defense responses.

Caffeoyl-CoA O-methyltransferase (CCoAOMT) is a key enzyme in the phenylpropanoid pathway that plays a crucial role in lignin biosynthesis; however, its functional role in Medicago sativa remains poorly understood. In this study, we identified 44 MsCCoAOMT family members and analyzed their expression profiles across eight tissues and under polyethylene glycol (PEG)-induced osmotic stress. Among them, MsCCoAOMTh3 displayed preferential expression in roots and flowers, and was significantly upregulated in roots and stems following PEG treatment, suggesting a potential role in both plant development and stress responses. Functional validation through heterologous expression in Arabidopsis thaliana revealed that MsCCoAOMTh3 overexpression markedly increased lignin accumulation and promoted xylem development in roots. Furthermore, transgenic lines displayed enhanced drought tolerance, characterized by elevated antioxidant enzyme activity and reduced malondialdehyde (MDA) levels. Collectively, these findings suggest that MsCCoAOMTh3 acts as a positive regulator of root lignification and enhances drought tolerance by modulating both stress-responsive and lignin biosynthesis-related genes.