The Function Of MfERF014 Gene In AP2/ERF Family Under Abiotic Stress

Medicago falcata L.,is a perennial herb of Leguminosae,which has strong adaptability,drought resistance,wind and sand resistance and cold resistance,and is an important gene source for alfalfa breeding.In this study,a member of AP2/ERF gene family named MfERF014(Gen Bank No.MW715673)was cloned from Medicago falcata.The gene expression of MfERF014 under low temperature,freezing,high salt,drought and ABA stress was analyzed by q-PCR;The expression vector pBE-35S::MfERF014-GFP for plant subcellular localization analysis was constructed,and the expression of fusion protein was observed under laser confocal microscope;The MfERF014 promoter was cloned by chromosome walking method,and the promoter activity of pMfERF014 was verified by transient expression of tobacco cells.In this paper,three pKGWRR expression vectors of overexpression,control and interference of MfERF014 gene were constructed,and the exogenous gene was transiently expressed in A17 root tissue of truncated alfalfa by hairy root transformation method to study the role of MfERF014 gene in plant response to abiotic stress.The results showed that under low temperature,freezing,high salt,drought and ABA stress,the expression of MfERF014 gene in roots,stems and leaves changed obviously with the stress time,under low temperature(4℃)and ABA stress,the expression changed most obviously and the response was stronger.The results of subcellular localization analysis showed that MfERF014-GFP fusion protein was localized in the nucleus,which preliminarily proved that MfERF014 was a transcription factor and played a role in the nucleus.The A17 root tissue of alfalfa transformed with MfERF014 exogenous gene was subjected to stress treatment at 4℃,-8℃,200 m M NaCl,300 m M mannitol and 100 mba for 2weeks,and the root length and fresh weight of three transformants after stress treatment were measured and counted.q-PCR was used to detect the expression of drought response related gene MtDR2 and key gene MtCAS15 A in the cold signal pathway.The results indicated that MfERF014 participated in the plant response to appeal abiotic stress,and enhanced plant stress resistance,especially enhanced plant resistance to freezing(-8 ℃),and played a positive role in regulating MtDR2 and MtCAS15 A.The research preliminarily proves that MfERF014 gene can enhance the abiotic stress resistance of plants,and provides a new candidate gene for the fine breeding of alfalfa.