干旱和NaCl胁迫下木薯GB含量及BADH基因的表达

发布时间：2018-11-13 11:38

【摘要】：甜菜碱醛脱氢酶(betaine aldehyde dehydrogenase,BADH)是甜菜碱(glycine betaine,GB)合成过程中的关键酶。为检测BADH基因在木薯(Manihot esculenta)不同组织中的表达差异,探究干旱与NaCl胁迫下其表达谱变化规律,本研究利用生物信息学方法分析和鉴定木薯BADH基因,定位MeBADHs在染色体上的位置以及确定5'端上游序列顺式作用元件;采用qRT-PCR测定BADH基因在木薯品种SC5根、块根、茎和叶中的表达差异,同时检测在PEG-6000模拟脱水胁迫、NaCl胁迫及自然干旱胁迫下MeBADHs基因的转录水平变化,采用相关试剂盒测定木薯中GB含量的变化。结果显示,MeBADHs两个基因在各组织之中均有表达,在块根中表达量显著高于根(P0.05)。PEG-6000模拟干旱条件下,与0 h相比,1~2 h时MeBADH1和MeBADH2在叶、茎、根以及块根中的表达量变化不大;NaCl处理条件下,叶中MeBADH1在8 h表达量极显著高于0 h(P0.01),而MeBADH2则在不同处理时间下的表达量水平相差不大,在茎和根中,MeBADHs在处理发生1 h时表达量水平极显著高于0 h(P0.01);自然缺水干旱条件下,茎和根中MeBADH1和MeBADH2分别在6和18 d时的表达量极显著高于0 d(P0.01)。PEG-6000处理下,GB含量出现了波动并呈现略增趋势;NaCl处理条件下GB含量在前期表达较稳定,8 h时剧烈响应,即出现下调趋势,24 h时GB含量显著低于0 h(P0.05)。在自然干旱胁迫下,GB含量逐渐呈现上调趋势,并在9和15 d达到高峰,显著高于0 d(P0.05)。研究结果为进一步研究木薯分子抗旱机制及新品种的选育提供了理论依据。
[Abstract]:Betaine aldehyde dehydrogenase (betaine aldehyde dehydrogenase,BADH) is a key enzyme in the synthesis of betaine (glycine betaine,GB). In order to detect the difference of BADH gene expression in different tissues of cassava (Manihot esculenta) and to explore the variation of BADH gene expression profile under drought and NaCl stress, the BADH gene of cassava was analyzed and identified by bioinformatics. Locate the position of MeBADHs on chromosome and determine the cis acting element of 5'terminal upstream sequence; QRT-PCR was used to detect the difference of expression of BADH gene in SC5 roots, tubers, stems and leaves of cassava cultivars. The transcription level of MeBADHs gene was also detected under PEG-6000 simulated dehydration stress, NaCl stress and natural drought stress. The change of GB content in cassava was determined by correlation kit. The results showed that two MeBADHs genes were expressed in all tissues, and the expression level in tuber root was significantly higher than that in root (P0.05). Under PEG-6000 simulated drought, compared with 0 h, MeBADH1 and MeBADH2 were in leaves and stems at 1h and 2 h, respectively. The expression level of root and tuber root showed little change. Under the condition of NaCl treatment, the expression of MeBADH1 in leaves at 8 h was significantly higher than that in 0 h (P0.01), while the expression level of MeBADH2 in stem and root was not different under different treatment time. The expression level of MeBADHs at 1 h was significantly higher than that at 0 h (P0.01). The expression of MeBADH1 and MeBADH2 in stem and root were significantly higher than that in 0 d (P0.01) at 6 d and 18 d, respectively. Under the condition of natural water shortage and drought, the GB content fluctuated and increased slightly. Under the condition of NaCl treatment, the expression of GB was stable in the early stage, and the response was intense at 8 h, which showed a downward trend, and the GB content at 24 h was significantly lower than that at 0 h (P0.05). Under natural drought stress, the content of GB increased gradually, and reached its peak at 9 and 15 days, which was significantly higher than that of 0 days (P0.05). The results provide theoretical basis for further study on molecular drought resistance mechanism of cassava and breeding of new varieties.
【作者单位】：海南大学农学院;中国热带农业科学院热带生物技术研究所/农业部热带作物生物学与遗传资源利用重点实验室;中国环境科学研究院;
【基金】：国家自然科学基金项目(No.31201603) 2016农业部热作技术试验示范项目(No.15162130106232022) 海南省自然科学基金项目(No.312051) 国家高技术研究发展计划(863计划)子课题(No.2012AA101204-2) 海南省重大科技项目子课题(No.ZDZX2013023-1) 海南省研究生创新课题(S03) 环境保护部生物多样性保护专项(No.2096001006)
【分类号】：S533

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