ARF family identification in Tamarix chinensis reveals the salt responsive expression of TcARF6 targeted by miR167.

Youju Ye,Li-An Xu,Jianwen Wang,Wei Wang

doi:10.7717/peerj.8829

Youju Ye, Li-An Xu + Show 2 more

Open Access

https://doi.org/10.7717/peerj.8829

Copy DOI

Abstract

Auxin response factors (ARFs) are important transcription factors (TFs) that are differentially expressed in response to various abiotic stresses. The important roles of ARFs and small RNA-ARF pathways in mediating plant growth and stress responses have emerged in several recent studies. However, no studies on the involvement of ARFs in tamarisk trees, which are resistant to salinity, have been conducted. In this study, systematic analysis revealed 12 TcARF genes belonging to five different groups in Tamarix chinensis. The microRNA response elements of miR160, which belongs to group I and miR167, which belongs to group III, were conserved in terms of their location and sequence. Moreover, digital gene expression profiles suggested that a potential miR167 target gene, TcARF6, was rapidly expressed in response to salt stress. Cloning of TcARF6 revealed that TcARF6 could be an activation TF with a glutamine-rich region and expression pattern analysis revealed that the expression of TcARF6 was significantly downregulated specifically in the roots. A significant negative correlation in the expression pattern of tch-miR167/TcARF6 indicated that this module may play a key role in the response to salt stress. Overall, these results provide basic information on the posttranscriptional regulation of TcARF6 for future investigations of the T. chinensis salt-stress response.

Highlights

Tamarisk plants exist as shrubs or small trees that are naturally distributed in saline soils of Eurasia, the Mediterranean basin and northern and southwestern Africa (Marlin et al, 2017; Sanz Elorza et al, 2010)
Prediction and identification of Auxin response factors (ARFs) To explore the role of the ARF genes in T. chinensis, the members of the TcARF gene family were predicted from the RNA sequencing (RNA-seq) data (Wang et al, 2017b)
12 TcARF genes were identified via analyses of phylogenetic relationships, conserved domains/motifs and expression profiles in plants under salt stress

Summary

Introduction

Tamarisk plants exist as shrubs or small trees that are naturally distributed in saline soils of Eurasia, the Mediterranean basin and northern and southwestern Africa (Marlin et al, 2017; Sanz Elorza et al, 2010). Tamarix chinensis Lour is one of the most highly salt-tolerant tree species that is well suited for investigating salt-stress-response genes (Liu et al, 2014). The high salt tolerance of tamarisk trees was shown by tolerance limit studies and on 340 mM (2% (m/v)) NaCl treatment for 1 week caused no physiological damage to T. chinensis (Wang et al, 2018a). This result indicated that the salt tolerance limit of T. chinensis could be greater than the 2.1% carbonate limit reported by Song et al (2006), the 300 mM NaCl limit of Tamarix aphylla and the 250 mM NaCl limit of.

Objectives

Methods

Results

Discussion

Conclusion