• 研究报告 •

### 大豆根系中应答镉胁迫的R2R3-MYB基因分析

1. 1中国科学院沈阳应用生态研究所污染生态与环境工程重点实验室， 沈阳 110016；2中国科学院大学， 北京 100049）
• 出版日期:2018-07-10 发布日期:2018-07-10

### Analysis of the R2R3-MYB genes in soybean roots in response to Cd stress.

DING Jie1,2, ZHANG Xiao-na1,2, PIAO Chun-lan1, CUI Min-long1, GAO Zhen-ri1*

1. (1Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; 2University of Chinese Academy of Sciences, Beijing 100049, China).
• Online:2018-07-10 Published:2018-07-10

Abstract: Low concentrations of the non-essential heavy metal cadmium (Cd) generate an extremely high level of toxicity, which affects the growth and development of plants. The MYB  family is one of the largest families of transcription factors in plants. Related studies in recent years have highlighted its role in a wide range of biological processes. In this study, to gain a better understanding of the role of MYB genes in Cd stress responses in soybean roots, 7-day-old soybean seedlings were treated with a culture medium containing 75 μmol·L-1 of Cd for 0, 4, 8, 12, and 48 h, respectively. Transcriptome sequencing and analysis of the soybean roots were subsequently performed using the Illumina HiSeq high-throughput sequencing system. We identified 16 R2R3-MYB genes closely linked to Cd stress responses. An amino acid sequence analysis showed that all 16 MYB transcription factors composed of four conserved elements and contained the conserved R2 and R3 domains. A phylogenetic analysis was conducted using the subgroup classification of R2R3-MYBgenes in Arabidopsis thaliana as reference; the genes belonged to seven subgroups, namely S1, S2, S8, S15, S17, S20, and S22. Under Cd stress, changes in expression levels of at least twofold occurred in all the 16 R2R3-MYB genes. In particular, expression was downregulated in six genes, with the highest degree of downregulation being 17-fold, and upregulated in the other 10 genes, with the highest degree of upregulation being 11 old. Further analysis revealed that MYB genes in soybean roots primarily alleviated Cd toxicity through regulating Cd absorption, transport, and detoxification. Our results will provide both genetic resources and a theoretical basis for the breeding of Cdresistant soybeans.