AtSIBP1, a Novel BTB Domain-Containing Protein, Positively Regulates Salt Signaling in Arabidopsis thaliana.

Xia Wan,Yi Yang,Lu Peng,Xiaoyi Li,Jianmei Wang,Xufeng Li,Jie Xiong

doi:10.3390/plants8120573

Abstract

Because they are sessile organisms, plants need rapid and finely tuned signaling pathways to adapt to adverse environments, including salt stress. In this study, we identified a gene named Arabidopsis thaliana stress-induced BTB protein 1 (AtSIBP1), which encodes a nucleus protein with a BTB domain in its C-terminal side and is induced by salt and other stresses. The expression of the β-glucuronidase (GUS) gene driven by the AtSIBP1 promoter was found to be significantly induced in the presence of NaCl. The sibp1 mutant that lost AtSIBP1 function was found to be highly sensitive to salt stress and more vulnerable to salt stress than the wild type WT, while the overexpression of AtSIBP1 transgenic plants exhibited more tolerance to salt stress. According to the DAB staining, the sibp1 mutant accumulated more reactive oxygen species (ROS) than the WT and AtSIBP1 overexpression plants after salt stress. In addition, the expression levels of stress-induced marker genes in AtSIBP1 overexpression plants were markedly higher than those in the WT and sibp1 mutant plants. Therefore, our results demonstrate that AtSIBP1 was a positive regulator in salinity responses in Arabidopsis.

Highlights

In nature, plants must cope with different kinds of abiotic stress, such as high temperatures, cold, salt, drought and osmotic stresses; salt stress is one of the most common and severe stresses [1].High salinity causes retarded plant growth and reduces agricultural productivity on more than 20% of the cultivated land worldwide [2]
The transcripts of At1g55760 were detected by qRT-PCR under different treatments, and the results showed that the expression levels of At1g55760 were significantly induced under NaCl, mannitol, abscisic acid (ABA) and indole-3-acetic acid (IAA) treatment (Figure 1)
We focused on the functions of Arabidopsis thaliana stress-induced BTB protein 1 (AtSIBP1) in response to the salt stress

Summary

Introduction

Plants must cope with different kinds of abiotic stress, such as high temperatures, cold, salt, drought and osmotic stresses; salt stress is one of the most common and severe stresses [1].High salinity causes retarded plant growth (even death) and reduces agricultural productivity on more than 20% of the cultivated land worldwide [2]. Plants must cope with different kinds of abiotic stress, such as high temperatures, cold, salt, drought and osmotic stresses; salt stress is one of the most common and severe stresses [1]. The unfavorable effects of salt on plants are consequences of both water deficits that result in osmotic stress and excess sodium ions on critical biochemical process [3,4]. In order to deal with unfavorable environmental signals, plants show specific changes in gene expression, metabolism, and physiology in response to different environmental stress conditions [5]. The cullin3a/3b ligase has been identified in the genome of all eukaryotes, and it interacts with “Bric-a-brac, Tramtrack and broad (BTB)/complex/pox virus and zinc finger” (POZ) (hereafter called BTB) domain proteins [9].

Methods

Results

Conclusion