Agricultural College, Guangxi University, Nanning, 530005, China.
College of Ecology and Garden Architecture, Dezhou University, Dezhou, 253023, China.
BMC Plant Biol. 2020 Jan 29;20(1):46. doi: 10.1186/s12870-020-2242-8.
Cassava is highly tolerant to stressful conditions, especially drought stress conditions; however, the mechanisms underlying this tolerance are poorly understood. The GRAS gene family is a large family of transcription factors that are involved in regulating the growth, development, and stress responses of plants. Currently, GRAS transcription factors have not been systematically studied in cassava, which is the sixth most important crop in the world.
Seventy-seven MeGRAS genes were identified from the cassava genome database. Phylogenetic analysis revealed that the MeGRAS proteins could be divided into 14 subfamilies. The gene structure and motif compositions of the proteins were considerably conserved within the same subfamily. Duplication events, particularly segmental duplication, were identified as the main driving force for GRAS gene expansion in cassava. Global expression analysis revealed that MeGRAS genes exhibited similar or distinct expression profiles within different tissues among different varieties. Moreover, qRT-PCR analysis revealed the expression patterns of MeGRAS genes in response to abiotic stress (drought, salt, cold, and HO), and the results suggest that these genes may have multiple functions.
This study is the first to provide comprehensive information on GRAS gene family members in cassava. The data will increase our understanding of both the molecular basis and the effects of GRAS genes. In addition, the results will contribute further to identifying the responses to various environmental conditions and provide insights into the potential functions of GRAS genes.
木薯高度耐受胁迫条件，特别是干旱胁迫条件；然而，这种耐受性的机制还不清楚。GRAS 基因家族是一类参与调控植物生长、发育和应激反应的转录因子，是一个庞大的家族。目前，GRAS 转录因子在世界第六大重要作物木薯中尚未得到系统研究。
从木薯基因组数据库中鉴定出 77 个 MeGRAS 基因。系统发育分析表明，MeGRAS 蛋白可分为 14 个亚家族。同一亚家族内的基因结构和基序组成具有很大的保守性。复制事件，特别是片段复制，被认为是木薯 GRAS 基因扩张的主要驱动力。全局表达分析显示，MeGRAS 基因在不同品种的不同组织中表现出相似或不同的表达谱。此外，qRT-PCR 分析揭示了 MeGRAS 基因对非生物胁迫（干旱、盐、冷和 HO）的表达模式，结果表明这些基因可能具有多种功能。
本研究首次提供了木薯 GRAS 基因家族成员的全面信息。这些数据将增加我们对 GRAS 基因的分子基础和作用的理解。此外，研究结果将有助于进一步了解木薯对各种环境条件的响应，并为 GRAS 基因的潜在功能提供见解。
