Genome-wide identification of auxin response factor (ARF) gene family and the miR160-ARF18-mediated response to salt stress in peanut (Arachis hypogaea L.)

Auxin response factors (ARFs) are transcription factors that regulate the transcription of auxin-responsive genes during plant growth and development. In this study, 29 and 30 ARF members were identified from the two wild peanut species, A. duranensis and A. ipaensis, respectively. The ARFs, including their classifications, conserved domains and evolutionary relationships were characterized. RNA-seq analyses revealed that some of the ARF genes were responsive to abiotic stress, particularly high salinity. In addition to abiotic stress, the expression of 2 ARF members was also regulated by biotic stress, specifically Bradyrhizobium infection in A. duranensis. The ARF gene Arahy.7DXUOK was predicted to be a potential target of miR160. Overexpression of miR160 could cause degradation of the Arahy.7DXUOK target gene transcript and increased salt tolerance in miR160OX transgenic plants. Therefore, these molecular characterization and expression profile analyses provide comprehensive information on ARF family members and will help to elucidate their functions to facilitate further research on peanuts.

Automated summary

The study identified 29 and 30 ARF members from two wild peanut species, characterized their classifications, conserved domains, and evolutionary relationships. RNA-seq analyses showed some ARF genes responsive to abiotic stress, particularly high salinity, and two ARF members regulated by biotic stress, such as Bradyrhizobium infection in A. duranensis. Additionally, the ARF gene Arahy.7DXUOK was predicted as a potential target of miR160, with overexpression of miR160 leading to increased salt tolerance in transgenic plants.