木薯MePP2CAa基因克隆、表达及蛋白互作分析

为探究2C型蛋白磷酸酶（protein phosphatase 2C， PP2C）在木薯响应非生物胁迫过程中的作用，利用木薯Arg7叶片cDNA扩增MePP2CAa基因，分析该基因序列、启动子活性、不同逆境和激素处理下的表达模式以及与ABA受体PYLs之间的互作关系。序列分析结果显示，MePP2CAa基因全长1 311 bp，编码436个氨基酸，具有PP2C家族的结构域特征，与橡胶树和麻风树的PP2C序列同源性最高，分别为78.95%和74.09%，在C端保守；qRT-PCR分析结果显示，MePP2CAa基因在木薯储藏根中的表达显著高于茎、叶中的表达量；不同逆境和激素处理结果显示，甘露醇、NaCl、ABA、MeJA、低温和SA处理可以显著诱导MePP2CAa基因的表达；MePP2CAa基因启动子序列分析显示，启动子包含ABA应答元件（abscisic acid responsive element，ABRE）、MeJA响应元件、干旱诱导元件等；酵母双杂交结果显示MePP2CAa能够与MePYL1互作。以上结果表明，MePP2CAa基因可能响应木薯的非生物胁迫。

Cloning，expression，and protein interaction analysis of cassava MePP2CAa gene

The cDNA from cassava Arg7 leaves was used to amplify MePP2CAa gene with RT-PCR to study the role of the protein phosphatase 2C （PP2C） gene in the response of cassava to abiotic stress.The sequence，self-activation activity，and the activity of promoter of the MePP2CAa gene were analyzed bioinformatically.The expression patterns of MePP2CAa gene under different stress and hormone treatments，and its interaction with ABA receptor PYLs were studied.The results showed that the total length of MePP2CAa gene was 1 311 bp，encoding 436 amino acids with the structural domain characteristics of the PP2C family.The protein sequence of MePP2CAa had the highest homology with that of PP2C in Hevea rubber and Jatropha curcas，with 78.95% and 74.09%，respectively，and conserved at the C-terminus.The results of real time fluorescence quantitative PCR showed that the expression level of MePP2CAa gene in cassava storage roots was significantly higher than that in stems and leaves.Mannitol，NaCl，ABA，MeJA，low temperature and SA treatment significantly induced the expression of MePP2CAa gene.The results of analyzing the cis-acting elements of promoters showed that the promoter of MePP2CAa gene included ABRE responsive element，MeJA responsive element，and drought induced element，etc.The results of yeast two hybridization showed that MePP2CAa interacted with MePYL1.It is indicated that the MePP2CAa gene may respond to the abiotic stress in cassava.