Heat shock protein 70 (HmHsp70) from Hypsizygus marmoreus confers thermotolerance to tobacco

Lili Xu,Lizhong Guo,Hao Yu,Jie Gao

doi:10.1186/s13568-020-0947-6

Abstract

The 70-kD heat shock proteins (Hsp70s) have been proved to be important for stress tolerance and protein folding and unfolding in almost all organisms. However, the functions of Hsp70s in mushroom are not well understood. In the present study, a hsp70 gene from Hypsizygus marmoreus, hmhsp70, was cloned and transferred to tobacco (Nicotiana tabacum) to evaluate its function in thermotolerance. Sequence alignments and phylogenetic analysis revealed that HmHsp70 may be located in the mitochondria region. qPCR analysis revealed that the transcription level of hmhsp70 in H. marmoreus mycelia increased after heat shock treatment in high temperature (42 °C) compared with untreated mycelia (at 25 °C). Transgenic tobaccos expressing hmhsp70 gene showed enhanced resistance to lethal temperature compared with the wild type (WT) plants. Nearly 30% of the transgenic tobaccos survived after treated at a high temperature (50 °C and 52 °C for 4 h); however, almost all the WT tobaccos died after treated at 50 °C and no WT tobacco survived after heat shock at 52 °C. This study firstly showed the function of a hsp70 gene from H. marmoreus.

Highlights

Hypsizygus marmoreus is one of the most popular edible mushrooms in East Asia (Wu et al 2019; Mleczek et al 2018)
Clone and sequence analysis of HmHsp70 from H. marmoreus Partial sequence of hsp70 gene was amplified from cDNA library of heat treated H. marmoreus using degenerate primers
The cDNA ends of hsp70 gene were confirmed by 3′ RACE and 5′ RACE methods

Summary

Introduction

Hypsizygus marmoreus (white var.) is one of the most popular edible mushrooms in East Asia (Wu et al 2019; Mleczek et al 2018). Previous studies suggest that HSPs proteins play a pivotal role in heat shock response (Kregel 2002; Richter et al 2010). Transgenic Arabidopsis expressing the hsp70 gene from T. harzianum T34 exhibited enhanced tolerance to heat, oxidative, osmotic and salt stresses (Montero-Barrientos et al 2010). In this study, we cloned the Hsp70 protein coding gene, hmhsp70, from H. marmoreus and transformed tobacco with hmhsp70 gene to determine the role of HmHsp70 in heat-shock response of plants.

Results

Conclusion