木薯MePP2CAb基因克隆及表达分析OACSCDCSTPCD

Protein phosphatase 2C(PP2C)plays a key role in the ABA signaling pathway.In order to investigate the response process of the PP2C gene to abiotic stress in cassava,MePP2CAb gene was cloned from Arg7 in cassava using the RT-PCR technique.Bioinformatic analysis,autoactivation activity analysis,promoter activity analysis,and expres-sion pattern analysis of the MePP2CAb gene under different stress and hormone treatments were conducted.The results showed that(1)the total length of the MePP2CAb gene was 1296 bp,encoding 431 amino acid residues.The MePP2CAb protein had a relative molecular weight of 47.08 kDa and a theoretical isoelectric point of 5.5.It exhibited structural domain characteristics of the PP2C family.Protein sequence analysis showed that MePP2CAb was most similar to PP2C sequences of Hevea rubber and J atropha j atropha,with consistencies of 82.75%and 74.01%,respec-tively,and a conserved C-terminal.These results indicated that MePP2CAb belongs to the PP2C family.(2)The expres-sion of the MePP2CAb gene was found to be higher in cassava storage roots,stems,and leaves,with the highest expres-sion observed in storage roots.(3)MePP2CAb demonstrated self-activation activity,and its full-length promoter exhib-ited high activity.(4)The MePP2CAb gene belongs to the core ABA pathway,and promoter sequence analysis showed that it contained ABRE(abscisic acid responsiveness)elements,MeJA response elements,and a drought-induced motif.Under different stress and hormone treatments,low temperature and SA treatment significantly repressed the MePP2CAb gene,while mannitol,NaCl,ABA,and MeJA significantly induced its expression.In addition,the interac-tion between MePP2CAb and MePYL1 was also observed.These results suggest that MePP2CAb may be responsive to abiotic stress in cassava,although its role as a positive or negative regulatory factor remains unclear.These results pro-vide a clue for further investigation into the role of the MePP2CAb gene in the ABA signaling pathway and the im-provement of cassava's adaptation to abiotic stress.