An R2R3-type MYB transcription factor, GmMYB29, regulates isoflavone biosynthesis in soybean.
An R2R3-type MYB transcription factor, GmMYB29, regulates isoflavone biosynthesis in soybean.
复制标题
R2R3型MYB转录因子GmMYB29调节大豆异黄酮生物合成
DOI：
10.1371/journal.pgen.1006770
复制
发表时间：
2017-05
期刊：
影响因子：
4.5
通讯作者：
Yu D
中科院分区：
文献类型：
--
作者：
Chu S;Wang J;Zhu Y;Liu S;Zhou X;Zhang H;Wang CE;Yang W;Tian Z;Cheng H;Yu D
异黄酮包含一组几乎仅由豆科植物产生的次级代谢物，包括大豆[Glycine max（L.）Merr.]。它们在植物防御中起着至关重要的作用，对人类健康有许多有益的影响。异黄酮含量是一个由多基因控制的复杂数量性状，其生物合成的遗传机制尚不清楚。通过全基因组关联研究（GWAS），我们确定了28个单核苷酸多态性（SNPs）与大豆中的草甘膦浓度显著相关。这28个SNP中的一个位于R2 R3型MYB转录因子GmMYB 29的5 ′-非翻译区（5 ′-UTR），因此选择该基因作为进一步分析的候选基因。亚细胞定位研究证实GmMYB 29定位于细胞核。瞬时报告基因分析表明，GmMYB 29激活IFS 2（α-淀粉酶2）和CHS 8（查尔酮合成酶8）基因启动子。在大豆毛状根中，GmMYB 29的过表达和RNAi介导的沉默分别导致了大豆毛状根中拟南芥含量的增加和减少。此外，候选基因关联分析显示，11种天然GmMYB 29多态性与异黄酮含量显着相关，GmMYB 29表达的调节可能部分导致观察到的表型变异。总之，这些结果提供了重要的遗传见解的分子机制，大豆中的甜菜碱生物合成。
Isoflavones comprise a group of secondary metabolites produced almost exclusively by plants in the legume family, including soybean [Glycine max(L.) Merr.]. They play vital roles in plant defense and have many beneficial effects on human health. Isoflavone content is a complex quantitative trait controlled by multiple genes, and the genetic mechanisms underlying isoflavone biosynthesis remain largely unknown. Via a genome-wide association study (GWAS), we identified 28 single nucleotide polymorphisms (SNPs) that are significantly associated with isoflavone concentrations in soybean. One of these 28 SNPs was located in the 5’-untranslated region (5’-UTR) of an R2R3-type MYB transcription factor,GmMYB29, and this gene was thus selected as a candidate gene for further analyses. A subcellular localization study confirmed thatGmMYB29was located in the nucleus. Transient reporter gene assays demonstrated that GmMYB29 activated theIFS2(isoflavone synthase 2) andCHS8(chalcone synthase 8) gene promoters. Overexpression and RNAi-mediated silencing ofGmMYB29in soybean hairy roots resulted in increased and decreased isoflavone content, respectively. Moreover, a candidate-gene association analysis revealed that 11 naturalGmMYB29polymorphisms were significantly associated with isoflavone contents, and regulation ofGmMYB29expression could partially contribute to the observed phenotypic variation. Taken together, these results provide important genetic insights into the molecular mechanisms underlying isoflavone biosynthesis in soybean.