木薯泛素结合酶的生物信息学分析

Bioinformatic Analysis of the Ubiquitin Conjugating Enzyme Gene Family in Cassava

泛素结合酶(ubiquitin conjugating enzyme,E2)在植物蛋白质的泛素化降解系统中处于中心地位,广泛参与调控植物的生长发育以及对逆境胁迫的响应信号途径。木薯(Manihot esculenta Crantz)是许多热带国家主要的粮食作物。随着木薯全基因组序列的公布,木薯功能基因的研究进入了快车道,但有关木薯E2基因的研究尚未有报道。本研究从Phytozome木薯数据库中获得了62个木薯E2基因,并对其进行了生物信息学分析。结果表明,62个木薯E2基因散布在18条染色体上,并且chr2上定位的E2基因最多。进化树分析结果表明,这62个木薯E2基因分成16个亚家族,包括两个UEV亚家族。基因结构分析结果也支持这一结果。利用半定量PCR的方法,检测了部分E2基因在木薯不同组织器官中的表达模式,以及应答模拟盐和干旱胁迫条件下的表达模式,结果表明,3个E2基因(MeUBC14,MeUBC33和MeUBC56)表现出组织特异性表达,而所选的其他E2基因呈现组成性表达模式。在模拟盐和干旱胁迫条件下,分别有10个和11个木薯E2基因表达上调,其中有8个基因同时受到模拟盐和干旱的诱导上调表达。在这两种胁迫条件下,MeUBC8基因的表达不受影响。这些结果表明木薯E2基因可能广泛参与木薯生长发育及抗逆胁迫途径。

Ubiquitin binding enzymes(E2)play a central role in the ubiquitination and degradation system of plant proteins and are widely involved in regulating the growth and development of plants and signaling pathways in response to stress.Cassava is a staple food crop and the main income source in many tropical countries.With cassava whole genome sequencing,functional gene research in cassava entered in fast lane.However,the study about cassava E2 genes has not been reported yet.In this study,62 MeE2 s were obtained from the the publicly available database Phytozome and performed bioinformatic analysis.The results showed that 62 MeE2 s were widely but unevenly distributed on 18 chromosomes and chr2 contains the largest number of MeE2 s with a total of six genes.The phylogenetic analysis revealed that MeE2 s can be divided into 16 groups with two UEV subfamily.The analysis of MeE2 gene structure indicated that MeE2 members in the same subfamilies shared a similar exon/intron structure.Using semi RT-PCR technic,the expression pattern of some MeE2 s in different cassava tissues or in responsive to salt/drought stress was detected.The results showed that three E2 genes(MeUBC14,MeUBC33 and MeUBC56)had tissue specific expression pattern,while the other genes had constitutive expression pattern.Under salt and drought stress conditions,10 and 11 MeE2 expression were upregulated,respectively,and 8 MeE2 s were induced by two stress conditions at the same time.However,the expression of MeUBC8 was not altered under the two stress conditions.The results indicated that MeE2 gene family is widely involved in cassava growth and abiotic tolerance.