Ectopic Overexpression of Maize Heat Stress Transcription Factor ZmHsf05 Confers Drought Tolerance in Transgenic Rice.

Weina Si,Li Chen,Haiyang Jiang,Feiyang Song,Qizhi Liang,You Chen

doi:10.3390/genes12101568

Abstract

Drought is a key factor affecting plant growth and development. Heat shock transcription factors (Hsfs) have been reported to respond to diverse abiotic stresses, including drought stress. In the present study, functional characterization of maize heat shock transcription factor 05 (ZmHsf05) gene was conducted. Homologous analysis showed that ZmHsf05 belongs to Class A2 Hsfs. The mRNA expression level of ZmHsf05 can be affected by drought, high temperature, salt, and abscisic acid (ABA) treatment. Ectopic overexpression of ZmHsf05 in rice (Oryza sativa) could significantly enhance the drought tolerance. Faced with drought stress, transgenic rice exhibited better phenotypic performance, higher survival rate, higher proline content, and lower leaf water loss rate, compared with wild-type plant Zhonghua11. Additionally, we assessed the agronomic traits of seven transgenic rice lines overexpressing ZmHsf05 and found that ZmHsf05 altered agronomical traits in the field trials. Moreover, rice overexpressing ZmHsf05 was more sensitive to ABA and had either a lower germination rate or shorter shoot length under ABA treatment. The transcription level of key genes in the ABA synthesis and drought-related pathway were significantly improved in transgenic rice after drought stress. Collectively, our results showed that ZmHsf05 could improve drought tolerance in rice, likely in an ABA-dependent manner.

Highlights

The uneven distribution and overall shortage of water resources, as well as increasingly severe global warming, have made drought stress one of the most serious threats to plant survival
To identify all Heat shock transcription factors (Hsfs) from maize, rice and Arabidopsis, proteome of maize were downloaded from MaizeGDB, and proteomes of rice and Arabidopsis were downloaded from the Phytozome database
Amino acid sequences and position of N-terminated DNA binding domain (DBD), oligomerization domain (OD), nuclear localization signal (NLS), and aromatics hydrophobic and acidic amino acid residues (AHA) and nuclear export signal (NES) of ZmHsf05 were shown in Figure 1B, according to previous annotation of AtHsfA2 and OsHsfA2e (Figure 1B)

Summary

Introduction

The uneven distribution and overall shortage of water resources, as well as increasingly severe global warming, have made drought stress one of the most serious threats to plant survival. Deciphering the genetic mechanism of plant responses to water deficit and exploring drought-responsive genes would be of great value. Plants respond to drought stress through the integration of sophisticated signaling pathways, resulting in external morphological changes, including changes to plant size, leaf morphology [4,5,6], stomatal characteristics [7,8] and root development [9,10]. This eventually leads to the coordination of plant growth and development

Methods

Results

Discussion

Conclusion