摘要：

ACA作为Ca²⁺-ATPase的亚家族成员之一,在维持植物细胞内Ca²⁺浓度平衡以及调节植物生长发育响应非生物胁迫等方面发挥着重要的作用。为进一步了解生菜ACA基因家族功能,运用生物信息学方法对生菜ACA基因家族成员进行鉴定与分析。结果表明:在生菜中共鉴定到17个ACA基因,命名为LsACA1~LsACA17;LsACA基因不均匀地分布在8条染色体上;亚细胞定位预测结果表明,LsACA蛋白全部定位于细胞质膜;LsACA基因家族成员之间的内含子数量差异较大(0~32个),LsACA蛋白共鉴定到15个保守结构域,氨基酸数量为21~50个;二级结构占比情况为:α-螺旋>无规则卷曲>延伸链>β-折叠;根据系统发育分析将LsACA蛋白分为5个亚家族Group Ⅰ~Group Ⅴ;根据共线性分析发现,6对基因存在片段复制,其共线性基因对的Ka/Ks均小于1,说明在进化中以纯化选择为主。通过qRT-PCR方法分析了LsACA基因家族成员在不同钙离子浓度处理下的表达模式,结果表明:与对照相比,低钙处理的钙敏感型品种宝石绿中有12个LsACA基因表达量极显著下调,而钙不敏感型品种耶罗有9个LsACA基因表达量极显著上调,1个LsACA基因表达量显著上调。研究鉴定了生菜ACA基因家族成员,并进行了生物学分析,揭示了LsACA基因家族成员的特征。

关键词: 生菜, 基因家族, LsACA, 钙, 表达分析

Abstract:

As one of the subfamily members of Ca²⁺-ATPase,ACA exerts a vital role in sustaining the intracellular Ca²⁺ concentration equilibrium and modulating plant growth and development in response to abiotic stress.To acquire an in-depth comprehension of the function of the lettuce ACA gene family,bioinformatics methodologies were utilized to identify and dissect the members of the lettuce ACA gene family.The outcomes manifested that 17 ACA genes were identified in lettuce,denominated as LsACA1 to LsACA17;the LsACA genes were unevenly distributed across 8 chromosomes;the subcellular localization prediction results disclosed that all LsACA proteins were localized in the plasma membrane;the number of introns exhibited significant variation(0—32)among the members of the LsACA gene family,a total of 15 conserved domains of LsACA proteins were identified,with amino acids ranging from 21 to 50;the proportion of the secondary structure was alpha helix>random coil>extended strand>beta turn;based on phylogenetic analysis,LsACA proteins were categorized into 5 subfamilies,namely Group Ⅰ to Group Ⅴ;according to collinearity analysis,it was found that there were fragment duplications in 6 pairs of genes,the Ka/Ks of their collinear gene pairs were all less than 1,signifying that purifying selection was the preponderant force in evolution.The expression patterns of LsACA gene family members under different calcium ion concentrations were analyzed by qRT-PCR.The results showed that:compared with the control,the expression levels of 12 LsACA genes in the calcium-sensitive variety Baoshilü under low calcium treatment were extremely significantly downregulated,while the expression levels of 9 LsACA genes in the calcium-insensitive variety Yeluo were extremely significantly upregulated and the expression level of 1 LsACA gene was significantly upregulated.The ACA gene family members of lettuce were identified and analyzed,and the characteristics of the LsACA gene family members were revealed.

Key words: Lettuce, Gene family, LsACA, Calcium, Expression analysis