Genome-Wide Characterization of HSP90 Gene Family in Malus sieversii and Their Potential Roles in Response to Valsa mali Infection

Yakupjan Haxim,Yu Ding,Xiaoshuang Li,Xiaojie Liu,Gulnaz Kahar,Yu Si,Daoyuan Zhang,Xuejing Wen

doi:10.3390/f12091232

Abstract

Heat shock protein 90 (HSP90) is highly conservative molecular chaperon produced by plants in response to adverse environmental stresses including fungal infection. In China, canker disease, caused by Valsa mali, is the main threat for Malus sieversii, an ancestor of the cultivated apple. In this study, a total of eight HSP90 genes were identified from the M. sieversii genome and randomly distributed on eight chromosomes. According to gene structure and phylogenetic analysis, the MsHSP90s can be divided into five categories. The transcriptome analysis of M. sieversii under V. mali infection showed that the plant pathogen interaction pathway was identified as significantly enriched. RNA-seq data and qRT-PCR analysis demonstrated that the MsHSP90-6a gene was significantly repressed by V. mali infection. We further predicted cis-regulatory elements on the promotor region of MsHSP90 genes and identified canonical SHE motifs. Our results improve our understanding of the HSP90 gene family and provide a foundation for further studies of disease prevention in M. sieversii.

Highlights

Heat shock proteins (HSPs) are highly conserved protein families among the fungi, animals, and plants that respond to a wide variety of stress
To understand how M. sieversii responds to the V. mali infection at a transcriptional level, we previously sequenced transcriptome of M. sieversii in response to V. mali infection by PacBio approach [27]
Heat shock protein 90 (HSP90) is a type of chaperone that is highly conserved throughout biology kingdoms, and widely involved in various biological processes

Summary

Introduction

Heat shock proteins (HSPs) are highly conserved protein families among the fungi, animals, and plants that respond to a wide variety of stress. HSP90s are key molecular chaperons that regulate proteostasis under both physiological and stress conditions in eukaryotic cells [1]. Studies on the biological functions of HSP90s in plants are relatively late than in fungi and mammalian model systems. A large number of HSP90 genes have been identified in various plant species, including Arabidopsis thaliana (L.) Heynh. [2], Oryza sativa L. The number of HSP90 genes in the plant genome varies from plant to plant. Seven, nine, and fifteen HSP90 genes were identified in Arabidopsis [2], rice [3], and soybean [4], respectively

Methods

Results

Conclusion