Key Laboratory of Food Quality and Safety of Jiangsu Province, State Key Laboratory Breeding Base, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Nanjing 210014, China.
Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, 50 Zhongling Street, Nanjing 210014, China.
J Agric Food Chem. 2020 Aug 26;68(34):9180-9187. doi: 10.1021/acs.jafc.0c03523. Epub 2020 Aug 11.
A strain of thiamethoxam-degrading endophyte, named TMX13, was isolated from roots of mulberry ( L.) and was identified as sp. Inoculating Chinese cabbage ( L) with strain TMX13- (-labeled TMX13) could significantly reduce thiamethoxam residues in the aboveground part (edible portion) of the vegetable. The theoretical daily intake (TDI) of thiamethoxam consumption of TMX13- inoculated Chinese cabbage was 0.17 μg/kg body weight per day, far less than the prescribed acceptable daily intake (ADI) for this pesticide. TMX13- colonization could increase the leaf chlorophyll content and plant biomass and promote the development of plant roots. Compared with the uninoculated treatment, the contents of malondialdehyde (MDA) and hydrogen peroxide (HO) and the activity of superoxide dismutase (SOD) in leaves of the TMX13- inoculated plants decreased by 18.4%-60.2%, suggesting that TMX13- colonization could alleviate the oxidative stress induced by thiamethoxam exposure. The total amounts of organic acids and amino acids in root exudates from the TMX13- inoculated Chinese cabbage decreased by 9.2% and 85.2%, respectively. Results of this study lead to the conclusion that the isolated endophyte sp. TMX13 could reduce thiamethoxam residues in edible vegetables, promote plant growth, and alleviate the phytotoxic effects induced by thiamethoxam exposure.
一株噻虫嗪降解内生菌 TMX13 从桑根中分离得到，并鉴定为 sp. 用菌株 TMX13-（TMX13-标记）接种白菜可显著降低蔬菜地上部分（可食用部分）的噻虫嗪残留量。噻虫嗪的理论日摄入量（TDI）为 0.17μg/kg 体重/天，远低于该农药规定的每日允许摄入量（ADI）。TMX13-定殖可增加叶片叶绿素含量和植物生物量，促进根系发育。与未接种处理相比，接种 TMX13-的植株叶片中丙二醛（MDA）和过氧化氢（HO）的含量以及超氧化物歧化酶（SOD）的活性降低了 18.4%-60.2%，表明 TMX13-定殖可以减轻噻虫嗪暴露引起的氧化应激。接种 TMX13-的白菜根分泌物中有机酸和氨基酸的总量分别降低了 9.2%和 85.2%。本研究的结果表明，分离到的内生菌 sp. TMX13 可以降低食用蔬菜中的噻虫嗪残留量，促进植物生长，并减轻噻虫嗪暴露引起的植物毒性作用。
