Gray mold, caused by Botrytis cinerea, is one of the major fungal diseases in crops. Botanical fungicides are preferred over chemical fungicides to control gray mold since they are less toxic to the environment and could reverse the resistance to chemical fungicides in pathogens. Cembratrien (CBT)-diols are carbocyclic diterpenes found in abundance in Nicotiana, especially in tobacco inflorescence, and possess a wide range of biological activities. In this study, the antifungal activities of two isomers of CBT-diols (α- and β-CBT-diols) against B. cinerea were evaluated in vitro and in vivo. In addition, the antifungal mechanism was studied on cytoderm, membrane system, and oxidative stress. Results showed that CBT-diols could inhibit wild and multi-resistant strains of B. cinerea, and the half-maximal effective concentration was within 9.67–16.38 μg/mL. The effects of α- and β-CBT-diols were similar but non-synergistic. The inhibition rate of CBT-diols (200 μg/mL) against B. cinerea in different fruits was between 71.9 and 84.2 %. The cellular structure of B. cinerea treated with CBT-diols was observed by scanning electron microscopy, transmission electron microscopy, Crystal violet-Congo red staining, and propidium iodide staining. Results showed that there was almost no change in cytoderm integrity; however, a significant damage to the membrane system integrity was observed, which led to disintegration of the organelles. Cembratrien-diols could increase the activity of chitinase, resulting in an accumulation of N-acetyl-d-glucosamine, which is a precursor for chitin biosynthesis. Cembratrien-diols caused significant increase in conductivity and cellular contents in the culture medium by increasing the membrane permeability of B. cinerea. Furthermore, CBT-diols decreased the levels of essential membrane components such as ergosterol and linoleic acid, but increased the malondialdehyde concentration, which indicated that CBT-diols damaged B. cinerea membrane and induced membrane lipid peroxidation. With growing research, it has been found that the damage to B. cinerea membrane system is mainly associated with the oxidative stress reaction induced by CBT-diols, due to the increase in reactive oxygen species levels and activities of catalase and peroxidase, and the decrease in superoxide dismutase activity and hydrogen peroxide content. The results provide a scientific foundation for the application of CBT-diols as an alternative biological agent against B. cinerea, which may ultimately promote organic fruits and vegetable crops production.

由灰葡萄孢引起的灰霉病是农作物的主要真菌病害之一。植物性杀菌剂优于化学杀菌剂，以控制灰霉病，因为它们对环境的毒性较小，并且可以逆转病原体对化学杀菌剂的抵抗力。Cembratrien（CBT）-二醇是在烟草中，尤其是在烟草花序中大量发现的碳环二萜，具有广泛的生物活性。在这项研究中，（CBT-二醇的两种异构体的抗真菌活性α -和β -CBT二醇）对灰葡萄孢的评价在体外和体内。此外，还研究了抗真菌机制对细胞真皮，膜系统和氧化应激的影响。结果表明，CBT-二醇可以抑制野生的和多重耐药的灰葡萄孢菌株，其最大有效浓度的半数在9.67–16.38μg/ mL之间。的影响α -和β -CBT二醇相似的但非协同的。CBT-二醇（200μg/ mL）在不同果实中对灰葡萄孢的抑制率在71.9％和84.2％之间。灰葡萄孢的细胞结构通过扫描电子显微镜，透射电子显微镜，结晶紫-刚果红染色和碘化丙锭染色观察了用CBT-二醇处理的CBT-二醇。结果显示，细胞真皮的完整性几乎没有变化；然而，观察到对膜系统完整性的显着损害，这导致细胞器的分解。Cembratrien二醇可以增加几丁质酶的活性，从而导致的积累Ñ乙酰基d -葡糖胺，它是几丁质生物合成的前体。Cembratrien-diols通过增加灰葡萄孢菌的膜渗透性，导致培养基中的电导率和细胞含量显着增加。此外，CBT-二醇降低了必需膜成分如麦角固醇和亚油酸的水平，但增加了丙二醛浓度，这表明CBT-二醇损害了灰葡萄孢菌膜并引起膜脂质过氧化。随着研究的不断发展，人们发现灰质芽孢杆菌膜系统的损害主要与CBT-二醇引起的氧化应激反应有关，这是由于活性氧水平和过氧化氢酶和过氧化物酶活性的增加以及其降低所致。超氧化物歧化酶活性和过氧化氢含量。研究结果为CBT-二醇作为替代抗灰葡萄孢菌的生物制剂的应用提供了科学依据。，最终可能促进有机水果和蔬菜作物的生产。