香蕉MaTPS1基因序列及其表达特性分析

通过随机克隆测序法,从香蕉根系cDNA文库中获得海藻糖合成酶基因,命名为MaTPS1。MaTPS1扩增获得cDNA序列,全长3 946bp,开放阅读框2 562bp,编码853个氨基酸。生物学信息分析表明,MaTPS1蛋白属于不稳定蛋白,等电点4.72,具有TPS和TPP结构域。序列预测分析表明,MaTPS1蛋白定位于细胞质中,不存在信号肽,为跨膜疏水蛋白。与已知植物TPS氨基酸同源序列比对结果显示,一致性达74.81%,其中与2种马来西亚野生蕉、玉米、野茶树、中果咖啡的TPS编码氨基酸序列一致性分别为100%、79.91%、71.33%、63.93%和65.13%。器官特异性分析表明,MaTPS1在香蕉的根、球茎、假茎、叶、花和果实中都有表达,其中在根、球茎、假茎和花中表达量较高。qRT-PCR分析表明,ABA、ACC、干旱、低温、盐害和枯萎病胁迫处理后,MaTPS1表达量在盐胁下增加,于24h时达到最高,而在其他胁迫下较正常条件下降低。研究认为,MaTPS1可能参与调控香蕉抗盐胁迫机制,从而提高香蕉耐盐性。

Characterization and Expression Analysis of MaTPS1 from Banana

A full length MaTPS1 of 3 946 bp from banana genome A was obtained.It contains a complete open reading frame of 2 562 bp length,encoding 853 amino acids.Biological information analysis showed that MaTPS1 protein belongs to the unstable protein,with an isoelectric point of 4.72 and two domains TPS and TPP.Sequence analysis prediction indicated MaTPS1 is a hydrophobic transmembrane protein without signal peptide and localized in cytoplasm.The amino acid sequence of MaTPS1 protein has 74.81% homology to the amino acid sequence of other known plant TPS ,with 100%,79.91%,71.33%,63.93% and 65.13% to two varieties of Musa acuminata subsp.malaccensis,Zea mays,Camellia sinensis,Coffea canephora.Organ specific analysis suggested that MaTPS1 is expressed in banana roots,corms,false stems,leaves,flowers and fruits,but with higher level in roots,corms and flowers.The banana plantlet was treated with ABA,ACC,drought,cold,salt and banana fusarium oxysporum f.sp stress,qRT PCR analysis showed that the expression of MaTPS1 increased under salt stress,and peaked at 24 h of treatment,while decreased under other biotic and non biotic stress,which suggested MaTPS1 may play a role in regulating salt resistance and enhance salt resistance of banana.