生命科学最新文献

Tartary buckwheat, valued for its nutritious and medicinal quercetin. Following two independent domestication events, distinct quercetin accumulation patterns have emerged between the southwestern (SL) and northern (NL) landrace populations. However, the genetic mechanisms underlying these metabolic divergences remain elusive. Here, we identified the transcription factor FtNAC2 through genome-wide association study (GWAS) of quercetin content in 480 accessions of Tartary buckwheat. Haplotype analysis identified two single nucleotide polymorphisms (SNPs) in the FtNAC2 promoter that defined three major haplotypes, with higher promoter activity and gene expression observed in Hap2. Functional characterization revealed that FtNAC2 promotes quercetin accumulation in Tartary buckwheat hairy roots and potentially serves as a multifunctional regulator influencing both drought tolerance in buckwheat and seed size in Arabidopsis. Transcriptome co-clustering and pull-down mass spectrometry (MS) indicated FtNAC52 as a potential regulatory partner of FtNAC2. DNA affinity purification sequencing (DAP-seq) and quantitative reverse transcription PCR (qRT-PCR) analyses demonstrated that FtNAC2 promoted quercetin biosynthesis by upregulating FtF3'H and FtF3'5'H genes. Collectively, our results elucidated how FtNAC2 influences quercetin content variation in Tartary buckwheat, providing molecular insights into the differential quercetin accumulation between cultivated populations.

Plant domestication involved prolonged artificial selection that progressively adapted plants to human agricultural practices. This process significantly modified both the genetic diversity and the phenotypic and genotypic characteristics of the domesticated plants, resulting in traits that markedly differ from those of their wild ancestors. At the same time, rhizosphere microorganisms, the second largest gene pool of plants, were also inadvertently altered by domestication through changes in root secretions, nutrient uptake or plant defence responses. In this review, we discuss the effects of domestication on plant rhizosphere microbiota and how plants and microbes interact and co-evolve during domestication. The effects of these changes are poorly understood and the subject of active ongoing research. The expected knowledge will help to exploit specific microbial communities for the improvement of plant traits and develop microbial-based management strategies that can be used instead of chemicals to increase plant productivity, reduce environmental pollution and promote the sustainable development of agriculture as a part of the second Green Revolution.

Phosphate (Pi) is an essential macronutrient for plant development that is often limited in soil. Plants have evolved dynamic biochemical, physiological and morphological adaptations to cope with Pi deficiency, known as the Pi starvation response (PSR). While many components of the PSR have been well-characterised, less is known about how metabolic homoeostasis is re-established upon Pi resupply, particularly tissue- and time-specific adaptations. Here, we applied label-free quantitative proteomics to quantify protein-level changes in Arabidopsis thaliana shoots and roots following Pi resupply after prolonged Pi deprivation. Sampling at 1 h and 48 h time-points, we captured immediate signalling and metabolic responses, along with longer-term recovery processes. Early responses prioritised metabolic adjustments restoring Pi pools via enhanced glycolysis and energy production, followed by later shifts toward anabolism. Several key enzymes, including ALTERNATIVE OXIDASE 1 A, FRUCTOSE-BISPHOSPHATE ALDOLASE 5 and subunits of PHOTOSYSTEM I exhibited tissue-specific and time-dependent regulation. Our findings reveal dynamic phases of metabolic reprogramming during recovery from Pi starvation, and identify candidate proteins as potential targets for enhancing Pi uptake- and use-efficiency in crops. While hydroponic liquid culture enabled precise control of Pi availability, soil responses may be further influenced by heterogeneity and other root interactions.

Leaf spot disease, caused by the fungal pathogen Alternaria alternata f. sp. mali, poses a severe threat to apple production. Pathogenesis-related (PR) genes are crucial for plant immunity, yet their regulatory networks remain poorly understood. Here, we report that MdDREB2A, a transcription factor known for its role in abiotic stress, negatively regulates apple resistance to A. alternata by suppressing the expression of MdPR10 genes. We demonstrated that MdDREB2A overexpression plants exhibited increased susceptibility to A. alternata infection, whereas its knockdown conferred enhanced resistance. Based on DAP-seq analysis, we identified three MdPR10 genes as direct targets of MdDREB2A. This direct repression was confirmed by ChIP-qPCR, EMSA, and dual-luciferase assays, which showed that MdDREB2A binds to the promoters of MdPR10s to inhibit their transcription upon pathogen infection. Furthermore, functional studies revealed that MdPR10 proteins possess antifungal activity, and their overexpression enhanced resistance in apple leaves. Consequently, in MdDREB2A overexpression plants, the suppression of MdPR10s leads to diminished antifungal resistance. This study establishes MdDREB2A as a negative regulator of defense against A. alternata in apple, which operates by repressing the expression of three pathogenesis-related genes, thereby proposing a new strategic direction for developing resistant apple cultivars.

Plants produce a wide array of secondary metabolites, also known as natural products (NPs), with diverse chemical properties. These compounds play crucial roles in plant development and defence against environmental stress. DNA methylation has emerged as a key regulator of secondary metabolism by modulating gene expression at the transcriptional level. By providing a new source of variation, DNA methylation holds great potential for enhancing NP accumulation, offering valuable insights for scientists and breeders alike. However, our understanding of current research trends in this area is limited. In this respect, we summarise the most recent findings on the roles of DNA methylation in the biosynthesis of three major classes of important NPs-pigments, flavour compounds and medicinal substances, including methylating and demethylating enzymes, the global methylation dynamics and the dual regulation of DNA methylation in different genomic regions or sequence contexts on gene expression. We also discuss alternative splicing regulated by DNA methylation in plants. Finally, we highlight key unanswered questions and propose potential future research directions to further unravel the regulatory mechanisms of DNA methylation in NP biosynthesis. This knowledge will facilitate the development of innovative strategies for improving plant quality and increasing NP production.

Soil salinity largely impacts plant growth and development worldwide. Uncovering important regulators involved in plant salt tolerance is crucial for helping plants survive in saline land through genetic engineering. Nonetheless, potential key genes directly related to tolerance to soil salinity have not been fully identified. Through a soil-based genetic screen, we obtained the salinity-tolerant mutant tos1 (tolerance of salt 1), which exhibited glossier and greener leaf morphology under salt stress. tos1 mutation localized at the functionally uncharacterized gene BOUNDARY OF ROP DOMAIN3 (BDR3). A defect in BDR3 results in enhanced resistance to salt stress, accompanied by lower Na⁺ accumulation and water deprivation mediated by a decreased transpiration rate, due to the increased accumulation of cuticular wax, especially VLCFAs and alkanes. BDR3 has no lipase activity, but the fatty acid metabolic process was strongly affected, and glycerolipid hydrolysis was enhanced in tos1; more fatty acids were consumed for wax synthesis, strengthening the cuticular wax maintenance. Our results demonstrate that BDR3 is a novel and negative regulator involved in plant salt tolerance, controlling cuticular transpiration and ion balance depending on its biofunctions in wax synthesis through fatty acid metabolic reprogramming. The study could provide a new molecular basis for the improvement of the regulatory network of wax biosynthesis and plant salt tolerance.

Wheat is a staple crop crucial for global food security, but its production is significantly affected by salt stress. Exploring natural genetic diversity in wheat can identify ways to improve salt tolerance. We subjected five wheat genotypes: Mocho de Espiga Branca (enhanced tissue tolerance), Fretes (tissue tolerance), Wyalkatchem and Westonia (salt exclusion) and Westonia Nax1 (enhanced salt exclusion), to 150 mM NaCl for 8 days. We measured changes in biomass, photosynthesis, chlorophyll content, Na⁺/K⁺ ratios and protein abundance. Mocho maintained growth despite high tissue Na⁺, showing physiological tolerance supported by differential regulation of mitochondrial proteins, central carbon metabolism, the GABA shunt and compatible solutes. Mitochondrial complexome profiling revealed salt-induced instability of 2-oxoglutarate dehydrogenase complex (OGDC) and a hydroxyglutarate synthase orthologue (HglS). In vitro assays confirmed subtle but significant OGDC activity and stability differences in Mocho, which also retained higher TCA cycle enzyme levels in vivo. Whole-plant treatment with the OGDC inhibitor succinyl phosphonate reproduced salt-like reductions in chlorophyll and biomass, particularly in Mocho. These findings highlight distinct strategies of tissue tolerance and salt exclusion in wheat, emphasising OGDC's role in Mocho's salt tolerance and pointing to metabolic pathways that could improve tissue tolerance traits and support sustainable agriculture.

Cadmium (Cd) is a toxic metal that accumulates in plants to inhibit growth and enters the food chain to harm human health. Although Cd accumulation and tolerance in plants have been extensively analysed, their regulation is less understood. Here, we identify a stress-responsive receptor-like kinase (OsSRK) involved in rice Cd accumulation and tolerance. Our results show that OsSRK expression was strongly induced by Cd treatment. OsSRK overexpression decreased while its silencing or mutations increased both Cd accumulation and Cd-induced leaf chlorosis in rice. OsSRK is a close homologue of MULTIPLE SPOROCYTE 1 (MSP1), which controls sporogenic development with its TAPETUM DETERMINANT1 (TPD1)-LIKE 1 A (OsTDL1A) ligand. OsSRK interacts with OsTDL1B, an OsTDL1A homologue, in both yeast and plant cells. Like OsSRK, expression of OsTDL1B was induced by Cd treatment, and mutations of OsTDL1B enhanced both Cd accumulation and Cd-induced symptoms in rice. These results strongly support that OsTDL1B acts as a ligand for the OsSRK receptor kinase in Cd stress signalling. Comparative transcriptome and proteome profiling support that OsSRK plays a critical role in rice Cd accumulation and tolerance through the regulation of genes in Cd accumulation and oxidative stress responses.

Photoperiod regulates flowering time and maturity in soybean, thereby determining yield performance and latitudinal adaptation. However, the molecular network through which photoperiod regulates flowering remains incompletely elucidated. Here, we identify two BBX family transcription factors, BBX32a and BBX32b, that act as positively regulators flowering under long-day (LD) conditions in soybean. We demonstrate that BBX32a and BBX32b can form both homologous and heterologous dimers. The bbx32a and bbx32b mutants exhibit significantly delayed flowering compared to wild-type W82. However, the bbx32a bbx32b double mutants flower at a similar time to the single mutants, suggesting that the BBX32a-BBX32b heterodimer plays a central role in regulating soybean flowering. E3 and E4 upregulate the transcription of BBX32a and BBX32b, which repress E1 transcription to promote flowering under LD conditions. Genetic evidence demonstrates that BBX32a and BBX32b regulate flowering time, completely dependent on functional E3, E4 and E1 family genes. Four haplotypes of BBX32a were identified in 1295 soybean accessions; BBX32a^Hap3 exhibits significantly reduced nuclear accumulation relative to BBX32a^Hap1. The BBX32a^Hap1 allele is predominantly fixed in cultivated soybeans, whereas BBX32a^Hap2 and BBX32a^Hap3 alleles remain largely unexploited. Collectively, our findings identify novel genetic targets for developing novel soybean cultivars adapted to high-latitude regions, thereby maximising yield potential.