Genome-wide identification of peanut ERFs and functional characterization of AhERF28 in response to salt and drought stresses.

Key message: Genome-wide identified 116 ERF members in cultivated peanut. Comprehensive analysis shows that AhERF28 is the key factor for peanut in its response to salt and drought stresses. Ethylene response factor (ERF) belongs to the AP2/ERF (APETALA2/ERF) superfamily, which is widely involved in plant responses to various abiotic stresses, including drought and salt stresses. Although members of the ERF family have been reported in multiple plant species, the members and functions of the peanut ERF family are largely unknown. In this study, a total of 116 ERFs were identified in peanut (Arachis hypogaea L.) via genome-wide identification. The peanut ERFs were classified into ERF and DREB subfamilies. Through phylogenetic tree analysis, the 116 ERFs were divided into 11 different subgroups, and the genes in the same group had conserved motifs, exon coding sequences, and domains. The ERF family genes demonstrated differential expression across 22 tissues. Further analysis revealed that AhERFs contain a variety of cis-acting elements in their promoters. Among them, there are 6, 11, and 15 elements related to development, hormones, and abiotic/biotic stress, respectively. In addition, by analyzing the transcriptome data under salt and drought treatments and qRT-PCR verification of AhERFs, it was found that the expression level of AhERF28 increased after both salt and drought treatments. Further research indicates that silencing AhERF28 enhanced the tolerance of peanut to salt and drought stress, likely due to an increased capacity of ROS scavenging. This study identified the ERF members in the cultivated peanut and revealed the potential role of AhERF28 in salt and drought stresses, which provides a new perspective for understanding the functions of ERFs in peanut response to abiotic stress processes and a theoretical basis for crop improvement.