Isoflavonoid synthesis: regulatory mechanism of GmMYB176-bZIP complex

异黄酮是一组几乎完全由豆类合成的植物天然化合物，在大豆种子中含量丰富。它们在植物-微生物相互作用中发挥重要作用，例如在感染时抑制病原体生长和诱导在大豆根部形成固氮根瘤的固氮细菌中nod基因表达。异黄酮还有助于与人类和动物食用大豆相关的积极健康影响。真核生物的基因表达受转录因子的调控，MYB转录因子GmMYB 176调控大豆CHS 8基因的表达和拟南芥的合成。最近我们发现GmMYB 176与两个bZIP转录因子相互作用。bZIPs和GmMYB 176都与CHS 8启动子结合。该提案的主要目的是促进我们对大豆中谷胱甘肽合成和积累的理解。此外，利用转录组学和代谢组学的研究相结合，我将确定GmMYB 176-bZIP复合物调控的所有生物和代谢过程。包括蛋白质-蛋白质相互作用，功能基因组学，分子遗传学和代谢生物化学的方法将用于解决这些目标。拟议的研究应提高我们的理解，调节的生物合成，并可能导致生物技术策略，以操纵代谢物水平，无论是提高营养价值或保护植物疾病或固氮在非豆科植物。

Isoflavonoids are a group of plant natural compounds synthesized almost exclusively by legumes and are abundant in soybean seeds. They play important roles in plant-microbial interactions such as inhibition of pathogen growth upon infection and the induction of nod gene expression in nitrogen fixing bacteria that form nitrogen fixing nodules on soybean roots. Isoflavonoids also contribute to the positive health effects associated with soybean consumption by humans and animals. Eukaryotic gene expression is regulated by a group of proteins called transcription factors that recognizes a specific sequence in the promoter region of genes and binds with it. A MYB transcription factor GmMYB176 regulates the expression of CHS8 gene and isoflavonoid synthesis in soybean. Recently we discovered that GmMYB176 interacts with two bZIP transcription factors. Both the bZIPs and GmMYB176 bind with CHS8 promoter. The main objective of this proposal is to advance our understanding of isoflavonoid synthesis and accumulation in soybean. Furthermore, using the combination of transcriptomics and metabolomics studies, I will determine all the biological and metabolic processes regulated by GmMYB176-bZIP complex. Approaches including protein-protein interactions, functional genomics, molecular genetics, and metabolic biochemistry will be used to address these goals. The proposed research should improve our understanding of the regulation of isoflavonoid biosynthesis, and may lead to biotechnological strategies to manipulate the metabolite levels either for the enhancement of nutritional value or for protection against plant diseases or for nitrogen fixation in non-legume plants.