Effect Of GABA And Trehalose On The Activity Of Exoenzyme Induced By Heat Stress In Mycelia Of Lentinus Edodes

At present,the cultivation of Letinous edodes in China are always depend on the traditional agriculture sheds,Letinous edodes is often damaged by high temperature stress,the growth of mycelium and the development of the fruiting body are affected,and it can leads to the decline of yield and the decline of quality.Therefore,It is of great academic value and application prospect to improve the stress resistance of mycelium under the high temperature environment,and to explore the biological mechanism of the application of foreign aid materials to alleviate the damage caused by high temperature stress.When the organism is subjected to abiotic stress such as high temperature,salt stress and drought,the endogenous GABA and trehalose are synthesized and accumulated.More and more researchers pay more attention to the important role of GABA and trehalose in response to abiotic stress.However,the studies on the stress resistance of GABA and trehalose were mainly focused on plants and yeasts,there was little research on the stress resistance of edible fungi.Therefore,the_strain of high-temperature XX03 and strain of low-temperature XN68 was acted as materials,it was studied on some effects of exogenous GABA and trehalose on the activity and ariation trend of extracellular enzyme induced by heat stress in mycelia of Letinous edodes.The results were as follows:Under high temperature stress,exogenous GABA and trehalose could significantly increased the content of endogenous GABA and trehalose in mycelium,so as to improve the ability of hyphae to stress under high temperature.The difference is that exogenous GABA had obvious effect on promoting the content of endogenous GABA in mycelium under the normal growth conditions,and the addition of exogenous trehalose had no obvious promoting effect on the content of endogenous trehalose in mycelial.Exogenous GABA have different effects on the activity of extracellular enzymes.Under high temperature stress,the effect of exogenous GABA on the activity of extracellular amylase and laccase of Letinous edodes was significant,which had a certain promoting effect on protease and CMC,but had no effect on the activity of cellulase.High concentration(20mM)of exogenous GABA had a good effect on letinous edodes mycelial extracellular enzyme.Exogenous trehalose have different effects on the activity of different extracellular enzymes.Under high temperature stress,the effect of exogenous trehalose on the activity of extracellular amylase,laccase and CMC of letinous edodes was significant,but had no effect on the activity of protease and cellulase.High concentration(50mM,100mM)of exogenous trehalose on Letinous edodes mycelial extracellular enzyme activity promoting effect was lasting.