谷子LAC基因家族的鉴定及分析

Identification and Analysis of LAC Gene Family in Millet

漆酶(LAC)是植物木质素生物合成中催化木质素单体聚合的关键酶,而木质素对植物生长有着重要的作用。试验采用生物信息学方法筛选了谷子(Setaria italica)漆酶基因家族成员,并对其理化性质、染色体定位、启动子顺式作用元件、基因结构以及表达情况进行了相关分析。结果表明,豫谷1号基因组中包括52个LAC同源基因,可分为5个亚家族,其中GroupⅤ中含有33个SiLAC成员,占整个家族的63.46%;52个基因不均匀地分布在1、3、4、5、7、8、9号染色体上,其中,5号和8号染色体上存在多基因串联重复;52个SiLAC基因的CDS序列长度在813~1953 bp,编码471~650个氨基酸,预测均为分泌型蛋白,这与其促进细胞壁中木质素合成的功能一致。SiLAC启动子序列包含与植物生长发育调控、逆境响应相关的顺式作用元件。基因结构分析显示,52个基因均为断裂基因,且每个基因的基因结构存在一定的差异。SiLAC的外显子数目在2~6个,其中,10个SiLAC基因没有UTR区域,并且聚集在同一分支的SiLAC基因的内含子和外显子结构相似。组织特异性表达模式分析结果显示,SiLAC13、SiLAC25、SiLAC28在根中的表达量最高,谷子LAC基因家族在叶片中几乎不表达。研究结果可为进一步分析谷子LAC基因家族的功能、解析其在谷子生长过程中表达调控机制提供参考。

Laccase(LAC)is a key enzyme that catalyzes the polymerization of lignin monomers in plant lignin biosynthesis,which plays an important role in plant growth.This paper screened the laccase gene family members in Yugu 1,a kind of Setaria italic(SiLAC),by bioinformatics method,and analyzed their physicochemical properties,chromosomal localization,cis-acting elements of promoter,gene structure and expression pattern.The results showed that a total of 52 homologous genes were found in the genome of Yugu 1 and were divided into 5 groups.Significantly,the group V clustered 33 SiLAC gene members,which accounts for 63.46%of the whole family.52 SiLAC genes were unequally distributed into No.1,No.3,No.4,No.5,No.7,No.8,No.9 chromosomes,in which No.5 and No.8 chromosomes had tandem duplication.The CDS length of SiLAC ranged from 813 bp to 1953 bp,encoded 471-650 amino acids.All of proteins were predicted as secretory proteins,which was consistent with their function of promoting lignin synthesis in the cell wall.The structure of SiLAC genes showed that its promoter sequence contained cis-acting elements related to plant developmental regulation and stress response.All SiLAC genes were broken genes and the structure of each gene was different.The number of exons ranged from 2 to 6.There were not UTR regions in 10 SiLAC genes and the intron/exon structures of SiLAC genes clustered in the same branch were similar.The tissue specific expression pattern analysis showed that SiLAC13,SiLAC25,SiLAC28 had significantly high expression in roots and the LAC gene family was almost not expressed in leaves.This study will provide a reference for further analysis of the function of the LAC gene family in foxtail millet and expression regulation mechanism in the growth process of foxtail millet.