Genome-Wide Analysis of AP2/ERF Family Genes in Lotus corniculatus Shows LcERF054 and LcERF080 Enhance Salt Tolerance

Abstract

Lotus corniculatus is used in agriculture as a main forage plant. Apetala2/Ethylene response factor (AP2/ERF) family plays an important role in regulating the gene expression in response to many forms of stress. Here, we identified 127 AP2/ERF genes by in silico cloning method. The phylogeny , gene structures, and putative conserved motifs in L. japonicus ERF proteins were analyzed. Expression profile analysis of AP2/ERF genes by quantitative real-time PCR revealed that 19 LcERF genes, including B-2 group LcERF054 and B-4 group LcERF080, were significantly induced by salt stress . Overexpression of LcERF054 or LcERF080 in Arabidopsis enhanced the tolerances to salt stress, showed elevated levels of relative moisture contents, soluble sugars, proline , and lower levels of malondialdehyde under stress conditions compared to wild-type. The expression of hyperosmotic salinity response genes COR15A, P5CS1, and so on were found to be elevated in the LcERF054 or LcERF080 overexpressing Arabidopsis plants compared to wild-type. These results revealed that LcERF genes play important roles in L. corniculatus cv Leo under salt stress and that LcERFs are attractive engineering targets in applied efforts to improve abiotic stress tolerances in L. corniculatus or other crops.