温度对梯棱羊肚菌抗氧化酶活及其基因表达的影响

大田栽培条件下,环境温度无法精确调控,温度胁迫是影响羊肚菌生长发育的重要因素。抗氧化酶和抗氧化活性物质是羊肚菌抵御逆境胁迫的重要因子。温度胁迫下,羊肚菌菌丝会通过增加相应酶活性来减少活性氧的积累,降低对细胞的损伤。作者研究了不同温度对梯棱羊肚菌菌丝生长、抗氧化酶（超氧化物歧化酶SOD、过氧化氢酶CAT、谷胱甘肽还原酶GR、谷胱甘肽过氧化物酶GPX）活性及其基因表达和抗氧化活性物质的影响,结果显示：在5-25℃的温度区间内,随着温度的增加,菌丝生长速度加快,菌丝的老化速度也加快;对抗氧化酶活性研究发现,SOD、GPX和GR在低温下活性更高,CAT在高温下活性更高;抗氧化活性物质含量会随温度升高而增加,如还原型抗坏血酸（AsA）和还原型谷胱甘肽（GSH）;温度越高,羊肚菌菌丝中H₂O₂、O^2-和丙二醛含量也随之增加。因此,在温度胁迫下,羊肚菌通过启动不同的抗氧化酶和抗氧化活性物质来减少活性氧含量,缓解菌丝损伤,本研究为探讨温度对羊肚菌种质质量的影响和栽培条件优化提供了基础数据支撑。

Effects of temperature on antioxidant enzyme activities and gene expression in Morchella importuna

In filed cultivation, the ambient temperature cannot be precisely regulated, then temperature stress is an important factor affecting the growth and development of Morchella importuna. Antioxidant enzymes and antioxidant active substances are important factors for M. importuna to resist stress. Under temperature stress, mycelia are able to increase corresponding enzyme activity to reduce the accumulation of reactive oxygen species and to reduce the damage to cells. The effects of different temperatures on the growth of mycelium, antioxidant enzyme activity (sueroxide dismutase, catalase, glutathione reductase, and glutathione peroxidase), gene expression and antioxidant active substances are studied. As a result, in the temperature range of 5-25°C, with the increase of temperature, the growth rate of mycelia is accelerated, and the aging rate of mycelia is accelerated. It was found that SOD, GPX and GR had higher activity at low temperature, and CAT had higher activity at high temperature. The content of antioxidant active substances, such as reduced ascorbic acid (AsA) and reduced glutathione (GSH), increased with the increase of temperature. The content of H₂O₂, O^2- and MDA in M. importuna hyphae increased with the increase of temperature. Therefore, under temperature stress, M. importuna activate different antioxidant enzymes and antioxidant active substances to reduce the content of reactive oxygen species and alleviate mycelial damage. Our study provides basic data support for regulation of temperature effecting quality of spawn and the optimization of cultivation conditions of M. importuna.