Genome-wide Identification and Functional Analysis of Gretchen Hagen 3 Genes in Soybean Resistance to Cyst Nematodes

The Gretchen Hagen 3 genes maintain endogenous hormone homeostasis by conjugating excess hormones with amino acids. Herein, we identified the members of the GH3 family in soybeans and analyzed their phylogeny, gene duplication, structure, domains, conserved motifs, cis-elements in promoter regions for stress responses, and functional characteristics. We found that GH3 genes are induced by pathogens in Group-II. Furthermore, eight out of 16 Group-II genes responded to cyst nematode infection. Overexpression of eight GmGH3 genes can enhance soybean resistance to the cyst nematode. In addition, our metabolomic analysis showed that overexpression of them affected the content of salicylic acid, jasmonic acid, indole-3-acetic acid, and gibberellic acid. Overexpression of GmGH3 in soybean affects the expression of genes involved in plant hormone biosynthesis. This provides valuable insights into the complex molecular mechanisms underlying the interaction between soybeans and cyst nematodes.格蕾琴·哈根3（Gretchen Hagen 3，GH3）基因可通过将过量激素与氨基酸缀合，维持植物内源激素稳态。本研究鉴定了大豆中的GH3家族成员，并对其系统发育关系、基因复制事件、基因结构、蛋白质结构域、保守基序、胁迫响应相关启动子区域的顺式作用元件以及功能特征展开了系统分析。研究发现，第II类GH3基因可被病原菌诱导表达；16个第II类GH3基因中有8个可响应胞囊线虫侵染。过表达8个大豆GH3（GmGH3）基因可增强大豆对胞囊线虫的抗性。此外，代谢组学分析显示，过表达这些基因会影响水杨酸、茉莉酸、吲哚-3-乙酸以及赤霉素的含量。大豆中GmGH3基因的过表达会影响植物激素生物合成相关基因的表达。本研究为解析大豆与胞囊线虫互作的复杂分子机制提供了极具价值的参考。