巨桉HEX基因家族的生物信息学分析

Bioinformatics Analysis of HEX Gene Family in Eucalyptus grandis

己糖激酶(hexokinase,HEX)是催化己糖磷酸化生成6-磷酸己糖的酶,是植物呼吸代谢的过程中的关键酶,在植物糖信号的感受与转导过程中发挥重要作用,亦对植物纤维素生物合成至关重要。为研究桉树HEX基因在纤维素生物合成过程中的生物学功能,本研究从巨桉(Eucalyptus grandis)中筛选出10个HEX基因家族成员(EgrHEX1~EgrHEX10),利用生物信息学方法对其基因特征与表达模式进行综合分析。结果显示,EgrHEX基因分布在5条染色体之上,亚细胞定位均在细胞质膜上。EgrHEX基因家族的各个基因的结构存在明显的差异,外显子数量为7~15个。EgrHEX编码的蛋白质由α-螺旋、延伸链、无规卷曲、β-转角组成。进化分析结果表明,EgrHEX蛋白同与毛果杨HEX蛋白的进化关系接近。10个EgrHEX基因在巨桉未成熟木质部、成熟叶片、韧皮部、茎尖、木质部以及幼叶组织中均检测到了表达,但表达模式存在差异。本研究为进一步深入探索巨桉HEX基因家族的生物学功能提供理论依据。

Hexolinase （HEX） is the key enzyme in the process of plant respiration and metabolism acting on hexose phosphorylating to generate 6-hexosephosphate, which has been found to play an important role in the process of plant sugar signal sense and transduction. It is also essential to plant cellulose synthesis. To reveal the gene characteristics and expression pattem of HEX in Eucalyptus grandis, bioinformatics methods were used to analyze the 10 HEX gene family members of the genome-wide sequence in Eucalyptus grandis （EgrHEX1-EgrHEXIO）. The result indicated that EgrHEX gene was located in 5 chromosomes, and the subcellular localization were located on the cytoplasmic membrane. The structure of each EgrHEX gene was significantly different, and the number of exons varied from 7-15. The proteins which were encoded by the EgrHEX genes were composed by alpha helix, extending chain, random coil and beta corner. Phylogenetic analysis revealed that EgrHEX protein shared close relationship with those in Populus trichocarpa. 10 EgrHEX expression pattern analysis demonstrated that all the HEX expressed differently in the tissues including immature xylem, mature leaf, phloem, shoot tips, xylem and young leaf, and each gene presented different expression patterns. In a word, this study could provide a theory basis for further biological functions of EgrHEX gene family.