糜子bZIP基因家族鉴定及幼苗期聚乙二醇6000处理下的表达特征

Genome-wide identification of bZIP gene family in broomcorn millet and analysis of its expression characteristics under polyethylene glycol treatment in seedling stage

采用生物信息学方法结合转录组测序,鉴定分析糜子bZIP家族成员的理化性质、系统进化关系、染色体分布、基因结构、顺式作用元件及幼苗期聚乙二醇6000(PEG-6000)模拟干旱胁迫下的转录谱特征.结果显示:糜子含有129个bZIP基因,不均等分布于18条染色体上,PmbZIP蛋白长度为114-1 204个氨基酸,等电点4.87-11.42,家族成员含有1-13个外显子,亚细胞均定位在细胞核内,基因结构相对复杂多样.系统进化分析发现,糜子129个bZIP基因划分为A、B、C、D、E、G、H、I2、J和S共10个亚家族;PlantCARE数据库顺式作用元件分析表明,在糜子bZIP基因上游2000bp序列中,普遍存在数目不等、种类不同参与了干旱诱导、低温和盐胁迫响应的顺式作用元件.幼苗期不同浓度梯度PEG-6000处理下的转录组及qRT-PCR分析显示,地上器官中,PmbZIP80和PmbZIP10表达量随着处理浓度升高逐渐上调;PmbZIP94表达量则随着处理浓度升高呈明显下调趋势;地下器官中,PmbZIP94、PmbZIP10和PmbZIP40表达量随浓度变化都有明显变化.上述结果说明bZIP基因家族成员参与了糜子干旱胁迫的生物过程,并提供了涉及糜子抗旱的优良候选基因.(图7表2参46)

Bioinformatic methods and transcriptome sequencing were used to analyze the physical and chemical characteristics, phylogenetic relationships, chromosome distribution, gene structure, cis element of the broomcorn millet bZIP family, and its expression characteristics at the seedling stage under PEG-6000 stress. The results showed 129 bZIP genes in broomcorn millet, which were distributed unevenly on 18chromosomes. The length of PmbZIP protein ranged from 114 to 1204 amino acids, and the isoelectric point ranged from 4.87 to 11.42. The family members contained 1–13 exons, which are expressed in the nucleus by subcellular localization, and their physical and chemical properties and gene structures were relatively complex and diverse. Phylogenetic analysis divided 129 bZIP genes into 10 subfamilies A, B, C, D, E, G, H, I2, J, and S.PlantCARE database was used to analyze the cis-acting elements, and the results showed that the number and type of cis-acting elements, such as drought induction, low temperature stress, and salt stress, varied in the 2 000 bp upstream sequence of bZIP gene, indicating that most members of the family were involved in abiotic stress response. The expression profiles of PmbZIP80 and PmbZIP10 in the aboveground organs at different concentration gradients of PEG-6000 showed that the expression levels of PmbZIP80 and PmbZIP10 were gradually upregulated with an increase in treatment concentration. PmbZIP94 showed an obvious decreasing trend with increase in PEG-6000 concentration. In underground organs, the expression levels of PmbZIP94,PmbZIP10, and PmbZIP40 changed with different nucleotide concentrations. These results indicate that the gene family is involved in the biological process of drought stress in broomcorn millet, and provides good gene candidates for future studies of drought resistance in broomcorn millet.