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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。
The trehalose synthase gene was obtained from banana root cDNA library by random cloning and sequencing and named as MaTPS1. The cDNA sequence of MaTPS1 was amplified with a total length of 3 946 bp and an open reading frame of 2 562 bp encoding 853 amino acids. Biological information analysis showed that the MaTPS1 protein is an unstable protein with an isoelectric point of 4.72 and a TPS and TPP domain. Sequence prediction analysis showed that the MaTPS1 protein localized in the cytoplasm and no signal peptide existed, which is a transmembrane hydrophobin. The results of amino acid homology comparison with known TPS amino acids showed that the identity was 74.81%. The amino acid sequence identities with TPS of two wild Malaysian maize, maize, wild tea tree and coffee were 100%, 79.91% , 71.33%, 63.93% and 65.13% respectively. Organ-specific analysis showed that MaTPS1 was expressed in banana roots, bulbs, pseudostems, leaves, flowers and fruits, with higher expression levels in roots, corms, pseudostems and flowers. qRT-PCR analysis showed that the expression of MaTPS1 increased under salt stress after treatment of ABA, ACC, drought, hypothermia, salt stress and Fusarium wilt. The expression of MaTPS1 reached its peak at 24 h and decreased under other stress conditions. The study suggests that MaTPS1 may be involved in the regulation of banana salt stress mechanism, thereby enhancing the salt tolerance of bananas.