海岛棉GbGSTU7的克隆及其对枯萎病菌侵染的应答

Cloning of Glutathione Transferase Gene GbGSTU7 and Its Response to Fusarium wilt Infection

该研究基于前期转录组测序数据分析,采用RT-PCR方法从海岛棉06-146中克隆得到参与海岛棉抗枯萎病调控的候选基因谷胱甘肽转移酶基因(GbGSTU7),对其序列进行生物信息学分析,并对GbGSTU7基因在病菌侵染下不同组织的表达特性进行分析,以探讨GbGSTU7基因与棉花抗枯萎病的关系。结果显示:(1)GbGSTU7基因CDS全长711 bp,编码236个氨基酸,属于GST家族tau类,二级结构由5个β折叠和9个α螺旋构成,三级结构呈球状。(2)枯萎病菌侵染后,GbGSTU7基因表达量在抗枯萎病品种06-146的根中呈下降趋势,48 h达到最低,茎和叶中呈先升高再降低的趋势,在茎中12 h达到最高,在叶中24 h达到最高;在感枯萎病品种‘新海14’的根中呈先下降再上升趋势,且在8 h达到最低,在茎和叶中的趋势无明显规律,但在茎中8 h达到最高,在叶中4 h达到最高;且两个材料中均表现为GbGSTU7基因在根中的表达量最低时,茎的表达量升到最高。研究表明,GbGSTU7基因在海岛棉抗、感病材料的各组织中均可响应枯萎病菌的诱导表达,且均具有明显的组织特异性;推测GbGSTU7基因可能与棉花抗枯萎病有着密切的关系,可能在棉花抵御病菌侵染的过程中发挥重要的调控作用。

In this study,based on the analysis of transcriptome sequencing data,we cloned a candidate gene,glutathione transferase gene(GbGSTU7),which is involved in the regulation of Fusarium wilt resistance in Island cotton,from Island cotton 06-146 by RT-PCR method,and analyzed its sequence with bioinformatics.The expression characteristics of GbGSTU7 gene in different tissues were analyzed to explore the relationship between GbGSTU7 gene and Fusarium wilt resistance of cotton.The results showed that:(1)the total length of GbGSTU7 gene CDS was 711 bp,encoded 236 amino acids,belonged to the Tau class of GST family.The secondary structure was composed of 5-folds and 9-helices,and the tertiary structure was spherical.(2)After Fusarium wilt infection,GbGSTU7 gene expression showed a decreasing trend in roots of Fusarium wilt resistant cultivar 06-146,and reached the lowest at 48 h,and then increased in stems and leaves,and reached the highest at 12 h in stems and 24 h in leaves.The root of Fusarium wilt cultivar‘Xinhai 14’showed a trend of decreasing first and then increasing,and reached the lowest at 8 h.The trend of decreasing was not obvious in stem and leaf,but it reached the highest at 8 h in stem and 4 h in leaf.In both materials,the expression of GbGSTU7 gene in the root was the lowest,and the expression in the stem was the highest.The results showed that GbGSTU7 gene could respond to the induced expression of Fusarium oxysporum in the tissues of Island cotton resistant and susceptible materials,and both of them had obvious tissue specificity.It is speculated that GbGSTU7 gene may be closely related to cotton resistance to Fusarium wilt,and may play an important regulatory role in the process of cotton resistance to bacterial infection.