title: Chemical Basis of the Fungicidal Activity of Tobacco Extracts against Valsa mali.
abstract: Under pressure from social criticism and an unclear future, tobacco researchers have begun to seek alternative uses for the product. Here, we present our study on isolating tobacco compounds with fungicidal activity, which could be used as plant-derived pesticides. UsingValsa malias the target fungus, agar plate tests were conducted to evaluate the fungicidal activity of various tobacco extracts, including tobacco leaves extracts prepared with different solvents, extracts of different tobacco cultivars, and samples from different tobacco organs. Fungal growth morphology was used as the criterion to evaluate the fungicidal activity of tobacco extracts. Correlation analyses between the fungicidal activities and the chemical components of tobacco extracts indicated the major chemical constituents with fungicidal activity. Then, the active compounds were isolated and their effects on the ultra-microstructures ofV. maliwas analyzed using scanning- and transmission-electron microscopy. The results suggested that tobacco extracts prepared with solvents of weaker polarity had higher fungicidal activity, and the inhibitory activity of tobacco extracts againstV. maliwas also cultivar dependent. Furthermore, the fungicidal effects of tobacco flower extracts were higher than those of the leaf extracts. Chemical analysis indicated that cembranoids were the main fungicidal substances, which act by destroying the endometrial structure of the fungus. Tobacco cembranoids at 80 μg/mL could completely inhibit the growth ofV.mali, with an EC50value of 13.18 μg/mL. Our study therefore suggests that tobacco leaves and inflorescences are excellent plant resources for the biological control ofV. mali.
authors.affiliation: Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China. duansuzhen2008@126.com.|Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China. duansuzhen2008@126.com.
authors.forename: Chemical Basis Of The Fungicidal Activity Of Tobacco Extracts Against Valsa Mali Suzhen
authors.initials: CB
authors.lastname: Duan
authors.affiliation: Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China. duyongmei@caas.cn.
authors.forename: Yongmei
authors.initials: Y
authors.lastname: Du
authors.affiliation: Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China. houxiaodong@caas.cn.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Hou
authors.affiliation: Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China. yanning@caas.cn.
authors.forename: Ning
authors.initials: N
authors.lastname: Yan
authors.affiliation: Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China. hidwjnhm@163.com.|Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China. hidwjnhm@163.com.
authors.forename: Weijie
authors.initials: W
authors.lastname: Dong
authors.affiliation: Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China. mxxcaas@163.com.|Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China. mxxcaas@163.com.
authors.forename: Xinxin
authors.initials: X
authors.lastname: Mao
authors.affiliation: Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China. zhangzhongfeng@caas.cn.
authors.forename: Zhongfeng
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D001203:Ascomycota / Q000187:drug effects* / Q000648:ultrastructure; D002851:Chromatography, High Pressure Liquid; D005659:Fungicides, Industrial / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D008826:Microbial Sensitivity Tests; D046529:Microscopy, Electron, Transmission; D010936:Plant Extracts / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry; D013729:Terpenes / Q000737:chemistry; D014026:Nicotiana / Q000737:chemistry*
chemical_list: D005659:Fungicides, Industrial; D010936:Plant Extracts; D013729:Terpenes
keywords: Valsa mali; chemical components; fungicide activity; tobacco extracts