蓖麻RcACA基因家族鉴定及非生物胁迫下表达模式分析

Identification and expression pattern analysis of RcACA gene family in castor under abiotic stresses

摘要:

自抑制Ca²⁺-ATPase酶（auto-inhibited Ca²⁺-ATPase，ACA）作为Ca²⁺-ATPase的亚家族之一，在植物细胞内维持Ca²⁺浓度平衡发挥着重要的作用。为探究蓖麻（Ricinus communis） RcACA基因家族的功能及基因表达模式，文中采用生物信息学手段鉴定蓖麻RcACA基因家族成员，预测分析了其基础的理化性质、亚细胞位置、蛋白的二级和三级结构、保守域、保守基序、基因结构、染色体位置及共线关系、进化特征、启动子顺式作用元件，并通过蓖麻转录组数据中的表达量（fragments per kilobase of exon model per million mapped fragments，FPKM）分析RcACA基因在非生物胁迫下的表达模式。结果表明，在蓖麻中共鉴定到8个RcACA基因家族成员，均是酸性蛋白且定位在细胞质膜；所有蛋白的二级和三级结构中α-螺旋和不规则卷曲较多；RcACA基因被聚为3类，同一类别中基因的结构与保守基序相似；均有典型的4个结构域RcACA3–RcACA8，还有1个Ca²⁺-ATPase N端自抑制结构域（N-terminal autoinhibitory domain）；RcACA基因多位于染色体长臂，拥有2对共线关系。RcACA基因编码区上游拥有较多的光响应作用元件，激素诱导类作用元件较少。种间聚类显示ACA基因在物种间的进化是保守的。组织表达模式分析显示，RcACA基因拥有明显的组织表达特异性，且多数基因在雄花中表达量最高；非生物胁迫表达分析表明，RcACA2–RcACA8在高盐和干旱胁迫下均上调表达，RcACA1在低温胁迫的0–24 h上调表达，表明RcACA基因积极地响应非生物胁迫。上述结果为探究RcACA基因在蓖麻生长发育和逆境胁迫中的作用提供了理论参考。

Abstract:

Auto-inhibited Ca²⁺-ATPase (ACA) is one of the Ca²⁺-ATPase subfamilies that plays an important role in maintaining Ca²⁺ concentration balance in plant cells. To explore the function and gene expression pattern of the RcACA gene family in castor, bioinformatics analysis was used to identify the members of the RcACA gene family in castor. The basic physical and chemical properties, subcellular location, protein secondary and tertiary structure, conserved domain, conserved motif, gene structure, chromosome location and collinear relationship, as well as the evolutionary characteristics and promoter cis-acting elements were predicted and analyzed. The expression pattern of the RcACA gene under abiotic stress was analyzed by expression (fragments per kilobase of exon model per million mapped fragments, FPKM) in castor transcriptome data. The results showed that 8 RcACA gene family members were identified in castor, acidic proteins located in the plasma membrane. In the secondary structure of all proteins, the α-helix and random coil is more; the RcACA genes were clustered into three categories, and the design of the genes in the same category was similar to the conserved motif. Both of them had four typical domains, RcACA3-RcACA8 had a Ca²⁺-ATPase N-terminal autoinhibitory domain. The RcACA gene is mostly located on the long arm of the chromosome and has 2 pairs of collinear relationships. There are more light response elements but fewer hormone-induced elements located upstream of the RcACA coding region. Interspecific clustering showed that the evolution of ACA genes among species was conservative. Tissue expression pattern analysis showed that RcACA genes showed apparent tissue expression specificity, and most of the genes showed the highest expression level in male flowers. Expression analysis under abiotic stress showed that RcACA2-RcACA8 were up-regulated under high salt and drought stress, and RcACA1 was up-regulated at 0-24 h under low-temperature stress, indicating that RcACA genes positively responded to abiotic stresses. The above results provide a theoretical basis for exploring the role of the RcACA gene in castor growth, development and stress response.