欧亚国际

转录组和共表达网络分析提供了普通野豌豆（Vicia sativa L.）种子发育过程中氰化氢合成的分子机制

摘要

普通野豌豆（Vicia sativa L.）种子是一种理想的植物蛋白质食品，但其食用价值主要受到氰甙的限制，氰甙可水解产生有毒氰化氢（HCN），而普通野豌豆中调节HCN合成的基因尚不清楚。在本研究中，从开花后5、10、15、20、25、30和35天的普通野豌豆种子中取样，并根据形态学和转录组分析将七个阶段进一步划分为五个发育阶段，即S1、S2、S3、S4和S5。在五个发育阶段共鉴定出16403个差异表达基因。采用碱性滴定法测定了这五个阶段的种子中HCN的含量，并用加权基因共表达网络分析解释了紫云英种子中HCN合成的分子调控机制。确定了18个HCN合成的关键调控基因，包括VsGT2、VsGT17和CYP71A基因，以及VsGT1基因家族。VsGT1、VsGT2、VsGT17和CYP71A在开花后5至25天共同促进HCN的合成，其中VsGT1-1、VsGT1-4、VsGT1-11和VsGT1-14起主要作用。开花后25～35天，VsGT1主要调控HCN的合成。随着VsGT1表达水平的降低，HCN含量不再增加。对种子HCN合成的深入研究，为培育低HCN含量的野豌豆奠定了基础。

关键词：野豌豆；种子发育；HCN；转录组

Transcriptome and Coexpression Network Analyses Provide In-Sights into the Molecular Mechanisms of Hydrogen Cyanide Synthesis during Seed Development in Common Vetch (Vicia sativa L.)

Abstract

The common vetch (Vicia sativa L.) seed is an ideal plant-based protein food for humans, but its edible value is mainly limited by the presence of cyanogenic glycosides that hydrolyze to produce toxic hydrogen cyanide (HCN), and the genes that regulate HCN synthesis in common vetch are unknown. In this study, seeds from common vetch at 5, 10, 15, 20, 25, 30, and 35 days after anthesis were sampled, and the seven stages were further divided into five developmental stages, S1, S2, S3, S4, and S5, based on morphological and transcriptome analyses. A total of 16,403 differentially expressed genes were identified in the five developmental stages. The HCN contents of seeds in these five stages were determined by alkaline titration, and weighted gene coexpression network analysis was used to explain the molecular regulatory mechanism of HCN synthesis in common vetch seeds. Eighteen key regulatory genes for HCN synthesis were identified, including the VsGT2, VsGT17 and CYP71A genes, as well as the VsGT1 gene family. VsGT1, VsGT2, VsGT17 and CYP71A jointly promoted HCN synthesis, from 5 to 25 days after anthesis, with VsGT1-1, VsGT1-4, VsGT1-11 and VsGT1-14 playing major roles. The HCN synthesis was mainly regulated by VsGT1, from 25 to 35 days after anthesis. As the expression level of VsGT1 decreased, the HCN content no longer increased. In-depth elucidation of seed HCN synthesis lays the foundations for breeding common vetch with low HCN content. 

Keywords: common vetch; seed development; HCN; transcriptome