Functional Characterization of PsnNAC036 under Salinity and High Temperature Stresses.

Xuemei Zhang,Tingbo Jiang,Wenjing Yao,Xueyi Wang,Zihan Cheng,Kai Zhao

doi:10.3390/ijms22052656

Xuemei Zhang, Tingbo Jiang + Show 4 more

Open Access

https://doi.org/10.3390/ijms22052656

Copy DOI

Abstract

Plant growth and development are challenged by biotic and abiotic stresses including salinity and heat stresses. For Populus simonii × P. nigra as an important greening and economic tree species in China, increasing soil salinization and global warming have become major environmental challenges. We aim to unravel the molecular mechanisms underlying tree tolerance to salt stress and high temprerature (HT) stress conditions. Transcriptomics revealed that a PsnNAC036 transcription factor (TF) was significantly induced by salt stress in P. simonii × P. nigra. This study focuses on addressing the biological functions of PsnNAC036. The gene was cloned, and its temporal and spatial expression was analyzed under different stresses. PsnNAC036 was significantly upregulated under 150 mM NaCl and 37 °C for 12 h. The result is consistent with the presence of stress responsive cis-elements in the PsnNAC036 promoter. Subcellular localization analysis showed that PsnNAC036 was targeted to the nucleus. Additionally, PsnNAC036 was highly expressed in the leaves and roots. To investigate the core activation region of PsnNAC036 protein and its potential regulatory factors and targets, we conducted trans-activation analysis and the result indicates that the C-terminal region of 191–343 amino acids of the PsnNAC036 was a potent activation domain. Furthermore, overexpression of PsnNAC036 stimulated plant growth and enhanced salinity and HT tolerance. Moreover, 14 stress-related genes upregulated in the transgenic plants under high salt and HT conditions may be potential targets of the PsnNAC036. All the results demonstrate that PsnNAC036 plays an important role in salt and HT stress tolerance.

Highlights

Various abiotic stresses such assoil salinity, drought, extreme temperature, and heavy metals affect plant growth, development, and productivity [1]
To analyze changes of expression levels of the NAC TFs, the fragment per kilobases per million reads (FPKM) of 289 NAC transcription factor genes from Populus simonii × P. nigra leaves were retrieved from an RNA-seq dataset [18], which has been deposited in NCBI
PsnNAC036 was significantly upregulated after salt stress treatment of the P. simonii × P. nigra seedlings compared to control

Summary

Introduction

Various abiotic stresses such assoil salinity, drought, extreme temperature, and heavy metals affect plant growth, development, and productivity [1]. Many important economic trees are sensitive to these environmental stresses, such as Populus. P. simonii × P. nigra is an endemic plant found in the Yellow River basin and the northern part of mainland in China [2]. It has been used as an urban afforestation tree species in northeast and northwest China. The influence of adverse environmental conditions on the growth of P. simonii × P. nigra has become more and more severe. It is urgent to improve the stress tolerance of this important wood plant through molecular genetics and breeding

Objectives

Methods

Results

Conclusion