镉胁迫对不同品种羊肚菌镉富集规律与抗氧化系统的影响

Effects on accumulation of cadmium and antioxidant system of different Morchella spp.under cadmium stress

羊肚菌(Morchella spp.)作为一种覆土栽培的食用菌,面临土壤环境镉(Cd)暴露和积累的风险。本研究选取常用栽培品种六妹羊肚菌(Morchella sextelata)M25和梯棱羊肚菌(Morchella importuna)I15作为试验材料,对比分析Cd胁迫对菌丝生理和Cd富集规律的影响,具体探究菌丝生长速度、生物量、微观结构、抗氧化酶、抗氧化活性物质和Cd含量的变化差异。结果显示,I15比M25富集Cd的能力强,不同品种羊肚菌过氧化氢酶(CAT)、谷胱甘肽还原酶(GR)、抗坏血酸过氧化物酶(APX)活性和丙二醛(MDA)、抗坏血酸(AsA)含量均随Cd质量浓度的增加呈先增后减趋势,但I15比M25的GR、谷胱甘肽过氧化物酶(GSH-Px)活性和谷胱甘肽(GSH)含量更高。综合两个羊肚菌品种的生理和Cd富集能力等指标发现,相比六妹羊肚菌M25而言,Cd富集能力更强、生长更旺盛、更不易受镉损害的梯棱羊肚菌I15在谷胱甘肽转化体系中起到的解毒效果更强。研究结果不仅为羊肚菌Cd抗性菌株筛选和含Cd土壤栽培模式的创新奠定了基础,也为真菌生物修复提供了新的见解。

Morchella spp.,as a kind of edible fungus cultivated in soil,faces the risk of exposure and accumulation of cadmium(Cd)in the soil environment.In this study,the commonly used cultivars Morchella sextelata M25 and Morchella importuna I15 were selected as test materials to compare and analyze the effects of Cd stress on mycelium physiology and Cd accumulation,specifically including the differences in mycelial growth rate,biomass,microstructure,antioxidant enzymes,antioxidant active substances and Cd content.The results showed that I15 had stronger ability of Cd accumulation than M25.The catalase(CAT),glutathione reductase(GR),ascorbate peroxidase(APX)enzyme activities and malondialdehyde(MDA),ascorbic acid(AsA)contents of the different Morchella spp.showed a trend of first increasing and then decreasing with the increase of Cd concentration,but the GR,glutathione peroxidase(GSH-Px)enzyme activities and glutathione(GSH)contents of I15 were higher than M25.Combining the physiology and Cd accumulation capacity of the different Morchella spp.,it found that I15 had stronger accumulation ability,better grow,less damage under Cd stress than M25,also had stronger defense ability against cell damage in the glutathione transformation system.The results of this study not only laid the foundation for the screening of Morchella spp.Cd-resistant strains and the innovation of Cd-containing soil cultivation models,but also provided new insights for fungal bioremediation.