Effects of Heat Stress on Physiological Characteristics of Lentinula edodes Mycelia and Construction of Stress Level
Using Lentinula edode cultivar'Yuxiang 1'as the subject,15 groups of heat stress treatments were set up to resemble temperature variations in summer:H1(30 ℃,12 h),H2(33 ℃,12 h),H3(33 ℃,24 h),H4(33 ℃,48 h),H5(36 ℃,48 h),H6(39 ℃,4 h),H7(39 ℃,8 h),H8(39 ℃,12 h),H9(39℃,48 h)and H10-H15(36 ℃,4ha day for 2,4,6,8,10,and 12 d,respectively).Incubation at 25℃ were set as the control(CK).Mycelia in different treatment groups were measured for mycelial growth,cell morphology,activities of extracellular laccase,protease and cellulase(CMC),contents of hydrogen peroxide(H2O2),o-aminobenzoic acid synthase(TrpE)and 6-phosphate-trehalose synthase(TPS),and reactive oxygen species(ROS)level.Key physiological indices were selected by principal component analysis,and the stress index Z was calculated for different treatments so as to categorize the stress levels.The stress accumulated temperature index ATSI was also used to establish a quantitative relationship between high temperature and duration.The results showed that with the increase of the stress temperature and time,the mycelial growth rate of'Yuxiang 1'decreased,and the contents of TrpE,TPS,H2O2 and ROS increased.Using contents of H2O2,TrpE and TPS,and extracellular laccase activity as the selected key indicators,the heat stress was classified into 4 grades as follows:mild(1.5＜Z≤ 3),moderate(3＜Z ≤ 4.5),severe(4.5＜Z ≤ 6)and extremely severe(6＜Z).The Z values of Hl-H5 and H10-H15 were extremely significantly positively correlated with their ATSI values,and the Z values varied little with the ATSI values.The Z values of H6-H8 were significantly positively correlated with their ATSI values,but the Z values vaired greatly with the ATSI values.The mycelia of H9 completely failed to resume growth after heat stress.These results provided a reference for the regulation and management of L.edodes growth temperature and prevention of high temperature induced losses in yield.
Lentinula edodesheat stress indexaccumulated temperature stress indexstress grade
万方数据
维普
