陆地棉GST基因家族全基因组分析

Genome-wide analysis of the GST gene family in Gossypium hirsutum L.

谷胱甘肽转移酶(glutathione-S-transferase,GST)是一种普遍存在的具有多功能的超家族蛋白,在植物初次生代谢、逆境胁迫、胞间信号传递等方面具有重要作用;同时,作为配体其在植物激素代谢以及物质转运方面也发挥作用。为了解析陆地棉(Gossypium hirsutum L.)GST基因家族的信息,本研究对该基因家族成员的种类、进化关系、物理定位、基因结构和保守基序以及表达模式进行了分析。结果显示,在陆地棉全基因组中共含有70个GST基因,进化树和基因结构分析将该家族分为U族、F族、T族、Z族、EF1Bγ族和TCHQD族。基因定位分析发现,除了AD/At2、AD/At4、AD/At5、AD/Dt5、AD/Dt10号染色体上没有GST基因外,其他染色体上都有GST基因,并且在AD/At9、AD/Dt7、AD/Dt12、AD/Dt13这4条染色体上出现基因簇。对F族(Phi类)9个GST基因进行荧光定量分析,结果表明,除Gh GSTF1可能为假基因外,Gh GSTF2~9等8个基因在陆地棉根、茎、叶以及各个发育时期的纤维中均有表达;结合生物信息学分析,推测Gh GSTF8可能参与原花青素/花青素的转运和积累;Gh GSTF4、Gh GSTF6和Gh GSTF9可能在调节陆地棉的生长和胁迫反应中起作用,而Gh GSTF2、Gh GSTF3、Gh GSTF5和Gh GSTF7的功能还有待进一步研究。本研究为陆地棉GST基因家族的分子进化及功能研究提供了理论依据。

Glutathione-S-transferase(GST) is a ubiquitous multi-functional protein superfamily that plays important roles in plant primary and secondary metabolism, stress and intercellular signal transduction. Concomitantly, it also functions as a ligand in the metabolism of plant hormones and substance transport. In order to understand the GST gene family in upland cotton(Gossypium hirsutum L.), herein we analyzed the species, evolutionary relationship, physical location, gene structure, conserved motifs and expression patterns. We identified 70 GST genes in the whole genome of upland cotton, and divided them into U, F, T, Z, EF1Bγ and TCHQD groups by phylogenetic tree and gene structure analyses. The gene mapping analysis indicated that the GST genes were on every chromosome except chromosome AD/At2, AD/At4, AD/At5, AD/Dt5 and AD/Dt10. Moreover, the GST gene cluster appeared on four chromosomes(AD/At9, AD/Dt7, AD/Dt12 and AD/Dt13). q RT-PCR assays showed that eight genes(Gh GSTF2-9) were expressed in the root, stem, leave and fiber of different developmental stages while Gh GSTF1 might be a pseudogene. Combining q RT-PCR and bioinformatic analysis, we speculated that Gh GSTF8 might be involved in the transport and accumulation of proanthocyanidins/anthocyanins; Gh GSTF4, 6 and 9 might play roles in regulating the growth and stress response of upland cotton; the function of Gh GSTF2, 3, 5 and 7 remains to be further investigated. Our work provides a theoretical basis for further studies on the molecular evolution and function of the GST gene family in upland cotton.