摘要： 为解析花生荚果响应水分胁迫的分子机制,利用盆栽试验并结合转录组学分析,以正常供水处理为对照,系统探究了花针期阶段性干旱和渍涝胁迫对花生产量、品质及基因表达的影响。结果表明,干旱和渍涝胁迫均显著降低花生荚果产量(降幅分别为26.43%和77.69%)及籽仁粗脂肪含量(降幅分别为9.46, 6.71百分点)。转录组分析进一步表明,干旱胁迫组与对照组、渍涝胁迫组与对照组分别鉴定出1 525,1 382个差异表达基因,且两类差异表达基因均以表达下调为主,其中,干旱胁迫抑制了花生荚果中与脂质和脂肪酸代谢相关的6个关键代谢过程,其中88.38%的基因表达呈下调趋势,揭示了脂质代谢紊乱可能是干旱导致花生产量和品质下降的主要原因。渍涝胁迫则主要通过下调催化活性、跨膜运输、氧化还原及次生代谢物的生物合成等相关基因的表达,干扰荚果的代谢与防御功能。此外,KEGG富集分析结果显示,代谢途径和次生代谢物生物合成通路在2种水分胁迫下均受到显著影响。关键基因qRT-PCR验证结果与RNA-seq数据一致,证实了转录组结果的可靠性。综上,从转录组层面阐明了花生荚果响应水分胁迫的分子基础,明确脂质代谢紊乱是干旱胁迫导致花生产量下降、品质变劣的主要原因,而花生主要通过调控荚果中氧化还原及代谢相关通路基因的表达,以应对渍涝胁迫带来的不利影响。

关键词: 花生荚果, 干旱胁迫, 渍涝胁迫, 转录组, 籽仁品质, 产量

Abstract:

To elucidate the molecular mechanisms underlying peanut pod responses to water stress,this study employed pot experiments combined with transcriptomic analysis.Using well-watered conditions as the control, we systematically investigated the effects of periodic drought and waterlogging stress during the flowering-pegging stage on yield,quality,and gene expression in peanut pods. Results demonstrated that both drought and waterlogging stresses significantly reduced peanut pod yield(by 26.43% and 77.69%,respectively)and crude fat content in kernels (by 9.46, 6.71 percentage points,respectively).Transcriptomic analysis further revealed 1 525 and 1 382 differentially expressed genes(DEGs)in the drought-stress and waterlogging-stress groups compared to the control, respectively, with down-regulated expression being predominant in both sets of DEGs. Specifically, drought stress suppressed six key metabolic processes related to lipid and fatty acid metabolism in peanut pods,with 88.38% of associated genes showing downregulated expression,indicating that lipid metabolic disruption may be the primary cause of yield and quality reduction under drought. Waterlogging stress predominantly interfered with pod metabolism and defense functions by downregulating genes associated with catalytic activity,transmembrane transport,redox reactions,and biosynthesis of secondary metabolites.Moreover, KEGG enrichment analysis indicated that metabolic pathways and biosynthesis of secondary metabolites were significantly affected under both water stress conditions. Key gene validation via qRT-PCR corroborated the RNA-seq data, confirming the reliability of the transcriptomic findings. In summary, this research elucidates the molecular basis of peanut pod response to water stress at the transcriptome level, demonstrating that lipid metabolic disruption is the primary factor underlying yield reduction and quality deterioration under drought stress, whereas peanut pods mitigate the adverse effects of waterlogging mainly by modulating the expression of genes associated with redox homeostasis and metabolic pathways.

Key words: Peanut pod, Drought stress, Waterlogging stress, Transcriptome, Kernel quality, Yield

中图分类号: 

• S565.2