玉米ZmAGA3的生物信息学及基因表达特性分析

Bioinformatics and Gene Expression Analysis of ZmAGA3 in Maize

α-半乳糖苷酶(α-Galactosidase)属于糖苷水解酶家族,是棉子糖(RFO)分解代谢过程中的关键酶。为了探究玉米α-半乳糖苷酶基因ZmAGA3在玉米生长发育及应对非生物逆境过程中的功能,对玉米ZmA⁃GA3(alkaline alpha-galactosidase 3)基因及其编码的蛋白质进行了生物信息学预测分析,并研究了ZmAGA3在不同非生物胁迫处理下的表达模式。结果表明,ZmAGA3编码747个氨基酸,相对分子质量81155.05,理论等电点(PI)6.59,总平均亲水性-0.146。ZmAGA3具有AmyAc_family结构域(淀粉酶催化结构域),主要由α-螺旋(26.77%)和无规则卷曲(42.97%)构成;可能发生磷酸化的位点共有46个,主要集中在丝氨酸上;与高粱、狗尾草的亲缘关系更近,与拟南芥和水稻的亲缘关系较远;在外源PEG、ABA、NaCl、H_(2)O_(2)的处理下,ZmA⁃GA3基因的表达量均发生了上调。因此,ZmAGA3基因可能在响应非生物胁迫过程中发挥着重要作用,这为进一步揭示ZmAGA3基因的功能奠定了基础。

α-galactosidase belongs to the glycoside hydrolase family and is a key enzyme in the catabolism of raffi⁃nose(RFO).In order to explore the function of maizeα-galactosidase gene ZmAGA3 in maize growth and develop⁃ment,further in the response to abiotic stress,the bioinformatics prediction analysis of maize ZmAGA3 and its encod⁃ed protein was carried out.Moreover,the relative gene expression of ZmAGA3 under different abiotic treatments was studied.The results showed that ZmAGA3 encoded 747 amino acids,the relative molecular weight was 81155.05,the theoretical isoelectric point(PI)was 6.59,and the total average hydrophilicity was-0.146.Conserved domain analysis of ZmAGA3 showed it has AmyAc_family domain(amylase catalytic domain).The prediction of the second⁃ary and tertiary structure showed that ZmAGA3 was mainly composed ofα-helix(26.77%)and irregular crimp(42.97%).Analysis of phosphorylation sites showed that there were 46 phosphorylation sites of ZmAGA3,mainly on serine.Phylogenetic tree analysis displayed ZmAGA3 had the closest relationship with Sorghum and Setaria,whlie the relationship with Arabidopsis and rice was more distant.The relative gene expressions of ZmAGA3 were signifi⁃cantly increased under exogenous treatments of PEG,ABA,NaCl and H_(2)O_(2).Therefore,ZmAGA3 may play an impor⁃tant role in response to abiotic stress,which lays a foundation for further revealing the function of ZmAGA3 gene.