摘要 从广东省梅州市丰顺县工厂化生产刺芹侧耳(Pleurotus eryngii)的软腐病样品中分离纯化病原菌,对其进行致病性测定、理化特征分析及分子鉴定,并通过分析病原菌对刺芹侧耳菌丝生长和防御酶活性等的影响,研究软腐病的致病机制。结果表明:分离得到假单胞菌(Pseudomonas sp.)和北京泛菌(Pantoea beijingensis),在实验范围内,病原菌J2和F1在pH为6.0、8.0和6.0、7.0时生长速度较快;温度为24、28℃时J2的生长速度较快,F1在温度为24℃时生长速度较快。J2的生长速度总体上随着NaCl质量浓度的升高而下降;F1的生长速度在NaCl质量浓度低于2.0%时与对照差异不显著,之后生长速度呈下降趋势。两种病原菌均能分泌几丁质酶和纤维素酶,其菌体和代谢物均可抑制刺芹侧耳菌丝生长,导致菌丝形态异常。与正常子实体相比,病原菌侵染的子实体内过氧化氢酶(catalase,CAT)活性在初期(0.5 d)较高;过氧化物酶(peroxidase,POD)活性在前期(1.5 d)较高,后期(2 d和3 d)降低;超氧化物歧化酶(superoxide dismutase,SOD)的活性则在1~2.5 d显著降低(P<0.05),推测这两种病原菌通过破坏细胞壁和影响主要防御酶活性侵染刺芹侧耳。 Two pathogenic strains of bacteria causing soft rot disease in P.eryngii were isolated and purified from samples collected in a factory in Fengshun county,Meizhou city,Guangdong province.These two strains were determined for pathogenicity,analyzed for physicochemical characteristics and identified by characteristic DNA sequences.Pathogenic mechanisms of these two strains were explored through analyzing their effects on mycelial growth and the defense enzyme system of P.eryngii.The results showed that the two isolated bacteria were identified as Pseudomonas sp.(named as J2)and Pantoea beijingensis(named as F1),respectively.J2 grew fast at pH 6.0,pH 8.0 and temperature 24℃and 28℃;and F1 grew fast at pH 6.0,pH 7.0 and 24℃.The growth rate of J2 decreased with the increase of NaCl concentration.There was no significant difference in the growth rate of F1 cultivated at different NaCl concentrations up to 2.0%,and then the growth rate of F1 decreased at NaCl concentrations above 2.0%.Both pathogens secreted chitinase and cellulase,and both their bacterial cells and metabolites inhibited P.eryngii mycelial growth and resulted in abnormal mycelial morphology.Compared with normal P.eryngii fruiting bodies,the diseased fruiting bodies showed higher catalase(CAT)activity at 0.5 d,higher peroxidase(POD)activity at 1.5 d followed with diseased POD activity at 2 d and 3 d,and decreased superoxide dismutase(SOD)activity during 1-2.5 d(P<0.05).These two pathogens may infect P.eryngii by destroying the cell wall and affect activities of major defense enzymes.
机构地区 华南农业大学食品学院 华南农业大学农学院
出处 《食用菌学报》 CSCD 北大核心 2021年第2期89-99,共11页 Acta Edulis Fungi
基金 广东省重点领域研发计划(2018B020206001) 国家自然科学基金(31772020) 广州市科技计划项目(201904010388)。
关键词 刺芹侧耳(杏鲍菇) 软腐病 病原菌 致病机制 假单胞菌 北京泛菌 Pleurotus eryngii soft rot disease pathogen pathogenic mechanism Pseudomonas sp. Pantoea beijingensis
