Identification and characterization of the GhHsp20 gene family in Gossypium hirsutum.

Wei Ma,Bingliang Liu,Yan Hu,Tianzhen Zhang,Lei Fang,Jie Li,Ting Zhao

doi:10.1038/srep32517

Abstract

In higher plants, Heat Shock Protein 20 (Hsp20) plays crucial roles in growth, development and responses to abiotic stresses. In this study, 94 GhHsp20 genes were identified in G. hirsutum, and these genes were phylogenetically clustered into 14 subfamilies. Out of these, 73 paralogous gene pairs remained in conserved positions on segmental duplicated blocks and only 14 genes clustered into seven tandem duplication event regions. Transcriptome analysis showed that 82 GhHsp20 genes were expressed in at least one tested tissues, indicating that the GhHsp20 genes were involved in physiological and developmental processes of cotton. Further, expression profiles under abiotic stress exhibited that two-thirds of the GhHsp20 genes were responsive to heat stress, while 15 genes were induced by multiple stresses. In addition, qRT-PCR confirmed that 16 GhHsp20 genes were hot-induced, and eight genes were up-regulated under multiple abiotic stresses and stress-related phytohormone treatments. Taken together, our results presented here would be helpful in laying the foundation for understanding the complex mechanisms of GhHsp20 mediated developmental processes and abiotic stress signaling transduction pathways in cotton.

Highlights

Increased yield could be best achieved by selecting genes for increased yield under optimal production conditions
A total of 111 genes were identified in the G. hirsutum genome as candidate members of the GhHsp[20] family
The encoded proteins varied from 113 to 268 amino acids in length. These 94 GhHsp[20] genes were subjected to further analysis; detail on the other parameters of the nucleic acid and protein sequences are provided in Supplementary Dataset 1

Summary

Introduction

Increased yield could be best achieved by selecting genes for increased yield under optimal production conditions. Increased Hsp expression strengthen the ability of plants to resist various stress factors, as it acts as a molecular chaperone that has a significant role in stress physiology. According to their molecular weights and amino acid sequence homology, Hsps can be classified as high molecular mass proteins, including Hsp[100], Hsp[90], Hsp70/DnaK and Hsp60/GroE, and low molecular mass proteins, including Hsp[20], a type of small heat shock protein (sHsp)[2]. The Hsp[20] proteins are ATP-independent molecular chaperones that usually spontaneously form large oligomeric complexes ranging in size from 9 to 50 subunits (200–800 kDa) and act by preventing protein denaturation in both eukaryotic and prokaryotic cells[11,12]

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Results

Conclusion