Cloning And Preliminary Functional Identification Of MfERF026 And MfERF086 Genes From ERF Family Of Wild Medicago Falcata

In alfalfa growing areas of China,the loss of forage production due to abiotic stress and the tight supply of livestock feed have caused considerable economic impact every year.In this study,two ERF gene family members cDNA,named MfERF026 and MfERF086,were analyzed and cloned from wild Medicago falcata based on the results of transcriptome sequencing in the early stage of our research group.The expression patterns of MfERF026 and MfERF086 genes in roots,stems and leaves of Medicago falcata were analyzed by q-pcr under abiotic stress such as low temperature,high salt and drought.Plant binary expression vector pKGWRR was used as the basic framework to construct three expression vectors of gene overexpression,control and tasiRNA interference.The above three recombinant plasmids were transferred into Arqua1 of agrobacterium rhizogenes,and the exogenous genes were transferred into Medicago truncatula A17 root tissues for 2weeks by agrobacterium-mediated hair root transformation method,and stress response experiments were conducted respectively.The cDNA of root tissues after stress treatment were used as the template to detect the expression levels of MtRD2 gene,which plays a key role in the drought signaling pathway,and CAS15 A gene,which plays a key role in the cold signaling pathway.Meanwhile,the nodule experiment was conducted to analyze whether MfERF026 and MfERF086 genes were involved in nodule formation of rhizobium.The results showed that MfERF026 gene and MfERF086 gene of Medicago falcata had no obvious response to rhizobia,but both genes responded to various abiotic stresses such as low temperature,high salt and drought.Under the above abiotic stress,the expression level of MfERF026 gene in roots,stems and leaves increased or decreased significantly with time,indicating that MfERF026 gene is involved in the regulation of abiotic stress in plants.MfERF086 gene expression in roots,stems and leaves were suppressed,under the stress of-8 ℃ cold stress and ABA,its almost no expression in the stem tissue,and its amount of expression in the root tissue have a slow upward trend.After overexpression or interference of MfERF026 under the above abiotic stress,the expression level of MtRD2 gene was significantly changed,suggesting that MtRD2 gene is probably the downstream gene of MfERF026 and is negatively regulated by MfERF026.After the expression of MfERF086 gene was disturbed,the expression level of MfCAS15 A gene was significantly increased,indicating that MfERF086 may be involved in the regulation of the expression of MfCAS15 A gene.This study will provide candidate genes for forage breeding.