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.

中文翻译：

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来自Hypsizygus marmoreus的热激蛋白70（HmHsp70）使烟草具有耐热性。

70 kD热激蛋白（Hsp70s）已被证明对于几乎所有生物体中的胁迫耐受性以及蛋白折叠和展开都很重要。但是，Hsp70s在蘑菇中的功能尚不清楚。在本研究中，克隆了来自Hypsizygus marmoreus的hsp70基因hmhsp70，并将其转移到烟草（Nicotiana tabacum）中，以评估其在耐热性中的功能。序列比对和系统发育分析表明，HmHsp70可能位于线粒体区域。qPCR分析表明，高温（42°C）热激处理后，与未处理的菌丝体（25°C）相比，marmoreus菌丝体hmhsp70的转录水平增加。与野生型（WT）植物相比，表达hmhsp70基因的转基因烟草对致死温度的抵抗力增强。在高温（50°C和52°C 4 h）处理后，将近30％的转基因烟草得以存活。但是，几乎所有野生型烟草在50°C处理后都死亡，并且在52°C的热激后没有野生型烟草存活。这项研究首先显示了H. marmoreus的hsp70基因的功能。