异补骨脂查尔酮对葡萄灰霉病菌的抑菌作用

Antifungal effects of isobavachalcone on Botrytis cinerea in grape plants

摘要:

背景 灰霉病是由灰葡萄孢菌(Botrytis cinerea)引起的世界性真菌病害，对农作物产量和品质产生巨大危害。异补骨脂查尔酮(isobavachalcone, ISO)是一种植物源黄酮类化合物，具有农用和药用活性，对植物病原菌有良好的生物防治潜力。目的 探讨ISO对灰葡萄孢菌的抑菌效果和作用机制，为葡萄灰霉病防治提供新的绿色高效药剂。方法 采用离体活性测定研究不同浓度ISO对灰葡萄孢菌菌丝生长、孢子萌发、细胞膜通透性，以及过氧化氢(H₂O₂)、超氧阴离子自由基(O₂^-)含量和超氧化物歧化酶(superoxide dismutase, SOD)、过氧化氢酶(catalase, CAT)、过氧化物酶(peroxidase, POD)活性的影响；采用接种侵染法测定ISO对葡萄灰霉病的防治效果。结果 ISO可以显著抑制灰葡萄孢菌的菌丝生长和孢子萌发，同时能降低葡萄灰霉病的发病率和病斑蔓延；当ISO浓度为24 mg/L时，孢子萌发率低至2.5%。用浓度为24 mg/L的ISO处理后，扫描电镜结果显示灰葡萄孢菌菌丝发生畸变，出现明显皱缩、膨大，甚至断裂；并随着处理时间延长，相对电导率和丙二醛(malondialdehyde, MDA)含量升高，显示细胞膜通透性增加；此外，ISO处理会引起胞内活性氧积累，H₂O₂和O₂^-含量显著升高，并且SOD、CAT、POD活性上升。结论 ISO通过改变菌丝形态，增加细胞膜通透性，增加胞内活性氧积累，从而有效抑制灰葡萄孢菌的生长和侵染，在葡萄灰霉病绿色防控上具有良好的应用潜力。

Abstract:

Background Gray mold, caused by Botrytis cinerea, is a globally prevalent fungal disease that poses serious threats to crop yields and quality. Isobavachalcone (ISO), a plant-derived flavonoid, exhibits agricultural and pharmaceutical purposes and plays a promising potential for biocontrol of plant pathogens.Objective To investigate the antifungal effects and mechanisms of ISO against B. cinerea, providing a novel green and efficient fungicide for controlling grape gray mold.Methods In vitro activity assays were conducted to evaluate the effects of ISO on mycelial growth, spore germination, cell membrane permeability, reactive oxygen species (ROS) levels (H₂O₂ and O₂^-), and activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) in B. cinerea. The control effect of ISO on grape gray mold was determined by the inoculation infection method.Results ISO not only significantly suppressed mycelial growth and spore germination of B. cinerea but also reduced the incidence of grape gray mold and the spread of spots. At a concentration of 24 mg/L, the spore germination rate was as low as 2.5%. After treatment with 24 mg/L ISO, scanning electron microscopy (SEM) results revealed that ISO induced the morphological distortions of hyphae, including shrinkage, swelling, and fragmentation. As the treatment time prolonged, the relative conductivity and malondialdehyde (MDA) content significantly increased, indicating the cell membrane permeability enhanced. Moreover, ISO treatment induced the accumulation of intracellular ROS levels by increasing the content of H₂O₂ and O₂^-, and elevated the activities of SOD, CAT, and POD.Conclusion ISO inhibited B. cinerea growth and infection by disrupting hyphal morphology, increasing cell membrane permeability, and inducing ROS accumulation. These findings highlight ISO has the potential as a green and efficient fungicide for gray mold management in vineyards.