毛竹Dirigent基因家族的全基因组鉴定与分析

Genome-wide identification and analysis of Dirigent gene family in moso bamboo(Phyllostachys edulis)

Dirigent (DIR)是指导维管植物木质素与木脂素生物合成的一类关键基因,在植物抵御非生物胁迫、生物防御应答和次生代谢调控等生长发育过程中起重要作用。本研究通过生物信息学方法,基于全基因组数据对毛竹(Phyllostachys edulis) DIR基因家族成员进行鉴定,并对其基因结构、启动子元件、编码蛋白理化性质、系统进化关系、蛋白三级结构及表达模式等进行了解析。结果表明:毛竹全基因组一共含有43个DIR候选成员,其基因结构、基序和结构域相对保守,所有成员均具有dirigent结构域, 3个成员还含有抗虫相关凝集素基因jacalin结构域。基于系统进化关系将43个毛竹成员聚集分为3个不同的亚家族,各成员理化特性有一定差异,但多数含有信号肽。其同水稻(Oryza sativa)共线性关系远高于拟南芥(Arabidopsis thaliana),染色体水平存在全基因组复制加倍现象。蛋白同源模建显示DIR蛋白质三级结构相对保守,基因上游启动子含有多个同非生物胁迫和激素诱导相关顺式作用元件。结合毛竹转录组测序数据进行DIR基因表达量分析,发现多个成员参与了笋快速生长发育过程,并响应赤霉素和萘乙酸的诱导表达。以上结果为开展毛竹DIR基因功能鉴定、深入了解木质素和木脂素生物合成途径及植物抗逆机制研究提供参考。

Dirigent(DIR) is a key gene that directs the biosynthesis of lignin and lignans in vascular plants, playing a vital role in the growth and development of plant abiotic stress resistance, biodefense response and secondary metabolic regulation. In this study, bioinformatic methods were used to identify members of the DIR gene family in moso bamboo(Phyllostachys edulis) based on genome-wide data, and their gene structures, promoter elements, physicochemical characters of encoded proteins, phylogenetic relationships, protein tertiary structures and expression patterns were analyzed. The results indicate that the whole genome of P. edulis contains 43 DIR candidate genes, and their structures, motifs and domains were relatively conservative. All members have dirigent domains, and three of them also contain the jacalin domain of the insect-resistant lectin gene. According to the evolutionary relationships, 43 members of P. edulis could be divided into three different subfamilies. The physicochemical characteristics of these members were different, but most of them contain signal peptides. The collinearity relationship with rice(Oryza sativa) was much higher than that with Arabidopsis thaliana, and there is a doubling of genome-wide replication at the chromosome level. The homology model of the protein show that the DIR protein tertiary structures were relatively conservative. The upstream promoter of the genes contained multiple cis-acting elements associated with abiotic stress and hormone induction. Combined with the transcriptome sequencing data of P. edulis, the expression of DIR genes were analyzed. It was found that many members participated in the rapid growth and development of bamboo shoots and responded to the induced expression of gibberellin and naphthyl acetic acid. The above results provide an references for the identification of the function of DIR genes in P. edulis, an in-depth understanding of the biosynthesis pathway of lignin and lignans, and the mechanism of plant stress resistance.