The ERF transcription factor family in cassava: genome-wide characterization and expression analyses against drought stress.

Wei Fan,Yunxie Wei,Weiwei Tie,Haitao Shi,Wei Hu,Zehong Ding,Yunling Guo,Yan Yan,Chunlai Wu,Meirong Hai,Yang Liu,Kaimian Li,Xupo Ding

doi:10.1038/srep37379

Abstract

Cassava (Manihot esculenta) shows strong tolerance to drought stress; however, the mechanisms underlying this tolerance are poorly understood. Ethylene response factor (ERF) family genes play a crucial role in plants responding to abiotic stress. Currently, less information is known regarding the ERF family in cassava. Herein, 147 ERF genes were characterized from cassava based on the complete genome data, which was further supported by phylogenetic relationship, gene structure, and conserved motif analyses. Transcriptome analysis suggested that most of the MeERF genes have similar expression profiles between W14 and Arg7 during organ development. Comparative expression profiles revealed that the function of MeERFs in drought tolerance may be differentiated in roots and leaves of different genotypes. W14 maintained strong tolerance by activating more MeERF genes in roots compared to Arg7 and SC124, whereas Arg7 and SC124 maintained drought tolerance by inducing more MeERF genes in leaves relative to W14. Expression analyses of the selected MeERF genes showed that most of them are significantly upregulated by osmotic and salt stresses, whereas slightly induced by cold stress. Taken together, this study identified candidate MeERF genes for genetic improvement of abiotic stress tolerance and provided new insights into ERF-mediated cassava tolerance to drought stress.

Highlights

Cassava (Manihot esculenta) shows strong tolerance to drought stress; the mechanisms underlying this tolerance are poorly understood
The Ethylene Response Factor (ERF) subfamily genes, which play more diverse functions than the DREB subfamily genes, was reported to induce or repress gene expression with external stimuli of ethylene, cytokinin and abiotic stresses, such as wounding, cold, high salinity, and drought by recognizing the GCC-box[21,22,23,24,25]. These studies demonstrated that ERF family genes play a crucial role in abiotic stress and related signaling response, which can be used as excellent candidates for genetic breeding to enhance crop tolerances to abiotic stress
Phylogenetic analysis indicated that groups I, II, III and IV, groups V, VI, VI-L, VIII and Xb-L, and groups VII, IX and X were clustered, respectively, which was consistent with the classification of ERF family in Arabidopsis

Summary

Introduction

Cassava (Manihot esculenta) shows strong tolerance to drought stress; the mechanisms underlying this tolerance are poorly understood. The ERF subfamily genes, which play more diverse functions than the DREB subfamily genes, was reported to induce or repress gene expression with external stimuli of ethylene, cytokinin and abiotic stresses, such as wounding, cold, high salinity, and drought by recognizing the GCC-box[21,22,23,24,25]. Together, these studies demonstrated that ERF family genes play a crucial role in abiotic stress and related signaling response, which can be used as excellent candidates for genetic breeding to enhance crop tolerances to abiotic stress. Considering the crucial roles of ERF genes in abiotic stress response, we perform systematic analysis of the cassava ERF family

Methods

Results

Conclusion