Genome-wide identification and expression analysis of auxin response factors in peanut (Arachis hypogaea L.).

Xingguo Zhang,Qian Ma,Xingli Ma,Fangping Gong,Shuliang Zhu,Dongmei Yin,Chengxin Qu,Peipei Li,Kunkun Zhao,Zhongfeng Li

doi:10.7717/peerj.12319

Abstract

Auxin response factors (ARFs) are transcription factors that regulate the expression of auxin response genes, and have important functions in plant growth and development. In this study, available genome data for peanut (Arachis hypogaea L.) were used to identify AhARF genes. In total, 61 AhARFs and 23 AtARFs were divided into six groups (I–VI). Molecular structural analysis revealed that the protein members of AhARF contain at least two domains, the B3 domain and the Auxin-resp domain, and that some have a C-terminal dimerisation domain. Screening of the transcriptome data of 22 tissues of A. hypogaea cv. Tifrunner in a public database showed high expression levels of AhARF2 and AhARF6. AhARF6 was expressed more highly in the stem and branch than in the root and leaf of the wild species Arachis monticola (A. mon) and cultivated species H103. After treatment with exogenous auxin (NAA), the expression of AhARF6 was inhibited, and this inhibition was greater in A. mon than in H103. The transcriptome map revealed that the expression of AhARF6 was higher in the larger pods of H8107 and ZP06 than in the medium pods of H103 and small pods of A. mon. Moreover, AhARF6-5 was proven to be localised in the nucleus, consistent with the location of AtARF6. These results suggest that AhARF6 may play an important role in pod development in peanut.

Highlights

Auxins play a very important role in the regulation of plant growth and development processes (De Smet & Jurgens, 2007; Jain & Khurana, 2009; Zhao, 2010), such as vascular elongation, embryogenesis, lateral root initiation, flower and fruit development, and apical dominance
Auxins can regulate the activity of auxin response factors (ARFs) (Guilfoyle & Hagen, 2007; Okushima et al, 2005; Yang et al, 2013), which are transcription factors that regulate the expression of auxin response genes
AhARF6/AtARF6, AhARF8/AtARF8, and AhARF19/AtARF19 belong to Group II, and AhARF5/AtARF5 belong to Group IV

Summary

Introduction

Auxins play a very important role in the regulation of plant growth and development processes (De Smet & Jurgens, 2007; Jain & Khurana, 2009; Zhao, 2010), such as vascular elongation, embryogenesis, lateral root initiation, flower and fruit development, and apical dominance. Auxins can regulate the activity of auxin response factors (ARFs) (Guilfoyle & Hagen, 2007; Okushima et al, 2005; Yang et al, 2013), which are transcription factors that regulate the expression of auxin response genes. ARFs were first reported in Arabidopsis thaliana (Ulmasov et al, 1997), and the ARF gene family was subsequently identified in Arabidopsis. Genome-wide identification and expression analysis of auxin response factors in peanut (Arachis hypogaea L.).

Methods

Results

Discussion

Conclusion