香蕉BADH基因序列及表达特性分析

Sequence Analysis and Expression Characteristics of BADH Gene in Banana

甜菜碱醛脱氢酶(BADH)是植物体内甜菜碱合成过程中的关键酶,对植物抵御逆境具有重要作用。为研究香蕉BADH基因序列及表达特性,本研究利用香蕉基因数据库对香蕉BADH基因序列及蛋白序列进行生物学信息分析,采用qTR-PCR技术对香蕉幼苗中BADH基因进行表达分析。结果表明:MaBADH基因属单克隆基因,含有15个外显子,14个内含子;顺式调控元件预测显示在MaBADH启动子区域存在15种激素和逆境胁迫相关的顺式调控元件;蛋白结构域和功能分析有一个甜菜碱醛脱氢酶结构域具有氧化还原酶活性;亚细胞定位在叶绿体中,多重序列比对发现其具有N-端信号肽和C-端信号肽两种信号肽;系统进化树显示其与水稻、玉米、菠萝亲缘关系最近。基因表达分析发现MaBADH具有组织特异表达特性,在叶片中相对表达量最高,假茎次之,根最低;此外,茉莉酸甲酯能够诱导香蕉幼苗根和叶中MaBADH差异表达,其中对叶片的诱导能力更强。本研究为激素信号调控甜菜碱分子保护机制和利用基因工程提高香蕉抗逆性提供了参考依据。

Betaine aldehyde dehydrogenase (BADH)is a key enzyme in the process ofbetaine synthesis in plants, which plays an important role in stress resistance of plants.To study the sequence and expression characteristics of banana BADH gene,the gene sequence and protein sequence of BADH in banana from banana genome database were analyzed by bioinformatics,and the expression analysis of BADH in banana seedlings was revealed by qTR-PCR technology in this study.The results showed that the MaBA DH gene is a monoclonal gene containing 15 exons and 14 introns.C/s-regulatory element prediction showed that there were 15 species hormone and stress-rela-ted c/s-regulatory elements in MoBADH promoter regions.Protein domain and functional analysis showed that MaBADH has a betaine aldehyde dehydrogenase domain with oxidoreductase activity.This gene may be localized in the chloroplast and has two signal peptides:an N-terminal signal peptide and a C-terminal signal peptide.The phylogenetic tree indicated that BADH of banana was closer to rice,corn and pineapple in the homologous relationship.Expression analysis showed that MaBA DH has tissue specific expression properties,and the relative expession of the middle leaves of most MaBADH was the highest,followed by the pseudostems and the roots.In addition, methyl jasmonate can induce differential expression of MaBADH in roots and leaves of banana seedlings,and the ability to induce leaves is stronger.This study provides a reference for hormone signaling to regulate the molecular protection mechanism ofbetaine and banana resistance improvement by genetic engineering.