Abstract: In order to explore the important role of WRKY transcription factors in plant resistance to adversity stress. In this study, a WRKY transcription factor gene (SbWRKY71) was cloned from Sorghum BTx623. The transcription factor gene was 1 335 bp in length (Phytozome Graviton No: Sb04g005520), encoded 364 amino acids, and the molecular weight was 38.95 kDa. Through bioinformatics method to predict the transcription factor located in the nucleus, with WRKY transcription factors typical conservative structure domain, and the protein belongs to the group Ⅱ member of WRKY protein family. Phylogenetic tree analysis showed that sorghum SbWRKY71 had the closest affinity with gramineous corn ZmWRKY71, and its affinity was 75%. Quantitative real-time PCR (RT-qPCR) showed that SbWRKY71 gene expression was tissue specific, with the highest expression abundance in the leaves and the lowest in the stems. SbWRKY71 expression decreased first, then increased and then decreased after treatment with the hormone salicylic acid (SA, 1 mmol·L^-1), indole-3-acetic acid (IAA 10 mol·L^-1) and abscisic acid (ABA, 200 mol·L^-1). Under the treatment of drought stress simulated by gamma-aminobutyric acid (GABA) and D-Mannitol (300 mmol·L^-1) as well as salt stress (NaCl, 250 mmol·L^-1), the gene expression of SbWRKY71 presented a pattern of first increase and then decrease. The expression of SbWRKY71 reached its maximum value at 3, 6 and 9 h respectively, after which it was significantly down-regulated. SbWRKY71 expression was inhibited after sorghum was treated with pathogen-related molecular model (PAMPs) flagellin (flg22, 100 nmol·L^-1), translation elongation factor (elf18, 100 nmol·L^-1) and Chitin (8 nmol·L^-1). This study provides a basis for further exploring the role of SbWRKY71 gene in regulating sorghum resistance, hormone response and stress response.

Key words: Sorghum bicolor, SbWRKY71, gene cloning, bioinformatics analysis, expression analysis

摘要： 为了探究WRKY转录因子在植物抵抗逆境胁迫方面的重要作用,本研究通过基因克隆的方法,从高粱BTx623中克隆得到一个WRKY转录因子基因(SbWRKY71),该转录因子基因全长1 335 bp(phytozome登录号:Sb04g005520),编码364个氨基酸,分子量为38.95 kDa;预测该转录因子定位于细胞核,具有WRKY转录因子典型的保守结构域,且该蛋白属于WRKY蛋白家族的第Ⅱ组成员。系统进化树分析表明,高粱SbWRKY71氨基酸序列与禾本科作物玉米ZmWRKY71的亲缘关系最近,为75%;实时荧光定量PCR(RT-qPCR)检测表明,SbWRKY71基因表达具有组织特异性,在叶中表达丰度最高,茎中最低。经激素水杨酸(SA,1 mmol·L^-1)、吲哚-3-乙酸(IAA,10 μmol·L^-1)和脱落酸(ABA,200 μmol·L^-1)处理后,SbWRKY71的表达量呈现先下降后升高再下降的趋势;在γ-氨基丁酸(GABA)和甘露醇(D-Mannitol,300 mmol·L^-1)模拟干旱胁迫以及氯化钠(NaCl,250 mmol·L^-1)盐胁迫处理下,SbWRKY71的表达量均先升后降,分别在3、6和9 h达到最大值;高粱经病原相关分子模式(PAMPs)flg22(100 nmol·L^-1)、翻译延长因子(elf18,100 nmol·L^-1)处理后,SbWRKY71表达均受到抑制,但在几丁质(Chitin,8 nmol·L^-1)处理下,SbWRKY71受到诱导表达。本研究为进一步探索SbWRKY71基因在调节高粱抗性、响应激素以及逆境胁迫应答等过程中的作用机制提供了基础。

关键词: 高粱, SbWRKY71, 基因克隆, 生物信息学分析, 表达分析