Genome-Wide Identification and Expression Analysis of WRKY Transcription Factors under Multiple Stresses in Brassica napus
Genome-Wide Identification and Expression Analysis of WRKY Transcription Factors under Multiple Stresses in Brassica napus
复制标题
多重胁迫下甘蓝型油菜WRKY转录因子的全基因组鉴定及表达分析
DOI：
10.1371/journal.pone.0157558
复制
发表时间：
2016-06-20
期刊：
影响因子：
3.7
通讯作者：
Qian, Wei
中科院分区：
文献类型：
--
作者：
He, Yajun;Mao, Shaoshuai;Qian, Wei
WRKY 转录因子在环境应激刺激的反应中发挥重要作用。通过全基因组域分析，我们在甘蓝型油菜的测序基因组中鉴定出了 287 个 WRKY 基因，其中 343 个 WRKY 域，其中 139 个位于 A 亚基因组中，148 个位于 C 亚基因组中。根据系统发育分析，这些基因被分为八组。在343个WRKY结构域中，共有26个成员在WRKY结构域上表现出分歧，其中21个属于I组。这一发现表明，与其他组中的基因相比，I组中的WRKY基因更加活跃和可变。通过对甘蓝型油菜 WRKY 基因家族的全基因组鉴定和分析，我们观察到基因组重复、染色体/节段重复和串联重复。所有这些重复都促进了 WRKY 基因家族的扩展。检测到的重复片段表明，在两个二倍体祖先白菜和油菜结合形成欧洲油菜之前，基因组重复事件发生在它们中。对甘蓝型油菜公共微阵列数据库和EST数据库的分析表明，74个WRKY基因在胁迫条件下被诱导或优先表达。根据公开的QTL数据，我们在31个QTL区域中鉴定出77个与各种胁迫耐受性相关的WRKY基因。我们进一步通过 qRT-PCR 评估了 26 个 BnaWRKY 基因在多重胁迫下的表达。大多数基因是由低温、盐度和干旱胁迫诱导的，表明WRKYs在甘蓝型油菜逆境响应中发挥重要作用。此外，3个BnaWRKY基因同时对三种多重胁迫有强烈响应，这表明这3个WRKY基因可能在胁迫耐受性方面具有多功能作用，并有可能用于育种新的油菜品种。我们还发现 6 个串联重复对在各种胁迫条件下表现出相似的表达谱，其中 3 对被定位在胁迫相关 QTL 区域，表明在进化过程中对环境刺激的适应性反应中存在串联重复 WRKY。我们的结果为未来研究 WRKY 基因响应甘蓝型油菜胁迫的功能提供了一个框架。
WRKY transcription factors play important roles in responses to environmental stress stimuli. Using a genome-wide domain analysis, we identified 287 WRKY genes with 343 WRKY domains in the sequenced genome of Brassica napus, 139 in the A sub-genome and 148 in the C sub-genome. These genes were classified into eight groups based on phylogenetic analysis. In the 343 WRKY domains, a total of 26 members showed divergence in the WRKY domain, and 21 belonged to group I. This finding suggested that WRKY genes in group I are more active and variable compared with genes in other groups. Using genome-wide identification and analysis of the WRKY gene family in Brassica napus, we observed genome duplication, chromosomal/segmental duplications and tandem duplication. All of these duplications contributed to the expansion of the WRKY gene family. The duplicate segments that were detected indicated that genome duplication events occurred in the two diploid progenitors B. rapa and B. olearecea before they combined to form B. napus. Analysis of the public microarray database and EST database for B. napus indicated that 74 WRKY genes were induced or preferentially expressed under stress conditions. According to the public QTL data, we identified 77 WRKY genes in 31 QTL regions related to various stress tolerance. We further evaluated the expression of 26 BnaWRKY genes under multiple stresses by qRT-PCR. Most of the genes were induced by low temperature, salinity and drought stress, indicating that the WRKYs play important roles in B. napus stress responses. Further, three BnaWRKY genes were strongly responsive to the three multiple stresses simultaneously, which suggests that these 3 WRKY may have multi-functional roles in stress tolerance and can potentially be used in breeding new rapeseed cultivars. We also found six tandem repeat pairs exhibiting similar expression profiles under the various stress conditions, and three pairs were mapped in the stress related QTL regions, indicating tandem duplicate WRKYs in the adaptive responses to environmental stimuli during the evolution process. Our results provide a framework for future studies regarding the function of WRKY genes in response to stress in B. napus.