玉米SQD3基因的克隆、生物信息学及表达模式分析

Clone Identification,Bioinformatics and Expression Pattern Analysis of Maize SQD3 Gene

SQD基因是膜脂中合成硫脂(SQDG)的关键基因,在植物生长发育和光合作用中发挥重要作用。ZmSQD3基因克隆、生物信息学及表达模式分析表明,ZmSQD3基因编码区域中CDS长度为1314 bp,编码437个氨基酸,与ZmSQD3基因亲缘关系最近的是高粱的SQD基因,相似度为92.62%,ZmSQD3基因编码蛋白理论分子量为49.2 kda,等电点为6.85,属不稳定亲水碱性磷酸蛋白,ZmSQD3蛋白被丝氨酸、苏氨酸和酪氨酸激酶磷酸化激活从而控制基因的表达,蛋白质二级结构显示Zm SQD3基因编码蛋白中46.00%为α螺旋,14.19%被无规则卷曲占据,β折叠占6.18%,β转角占33.64%。基因表达分析表明,低磷(5μM KH2PO4)胁迫下,无论是根系还是叶片,均呈现出1 d时表达量最低,7 d表达量最高。

SQD gene is a key gene for the synthesis of sulfur lipids(SQDG)in membrane lipids,and plays an important role in plant growth and development and photosynthesis.ZmSQD3 gene cloning,bioinformatics and expression pattern analysis showed that the CDS length in the coding region of ZmSQD3 gene was 1314 bp and encoded 437 amino acids.The theoretical molecular weight of the encoded protein was 49.2 kda,and the isoelectric point was 6.85,which was an unstable hydrophilic alkaline phosphate protein.The ZmSQD3 protein was activated by phosphorylation of serine,threonine and tyrosine kinases to control gene expression.Protein secondary structure showed that 46.00%of the protein encoded by ZmSQD3 gene wasα-helix,14.19%was occupied by random coil,6.18%wasβ-sheet,and 33.64%wasβ-turn.Gene expression analysis showed that under low phosphorus(5μM KH2PO4)stress,both roots and leaves showed the lowest expression at 1 d and the highest expression at 7 d.