title: Antibacterial Activity and Mechanism of Action of Sulfone Derivatives Containing 1,3,4-Oxadiazole Moieties on Rice Bacterial Leaf Blight.
abstract: In this study, sulfone derivatives containing 1,3,4-oxadiazole moieties indicated good antibacterial activities against rice bacterial leaf blight caused by the pathogen Xanthomonas oryzaepv. pv. oryzae (Xoo). In particular, 2-(methylsulfonyl)-5-(4-fluorobenzyl)-1,3,4-oxadiazole revealed the best antibacterial activity against Xoo, with a half-maximal effective concentration (EC50) of 9.89 μg/mL, which was better than those of the commercial agents of bismerthiazole (92.61 μg/mL) and thiodiazole copper (121.82 μg/mL). In vivo antibacterial activity tests under greenhouse conditions and field trials demonstrated that 2-(methylsulfonyl)-5-(4-fluorophenyl)-1,3,4-oxadiazole was effective in reducing rice bacterial leaf blight. Meanwhile, 2-(methylsulfonyl)-5-(4-fluorophenyl)-1,3,4-oxadiazole stimulate the increase in superoxide dismutase (SOD) and peroxidase (POD) activities in rice, causing marked enhancement of plant resistance against rice bacterial leaf blight. It could also improve the chlorophyll content and restrain the increase in the malondialdehyde (MDA) content in rice to considerably reduce the amount of damage caused by Xoo. Moreover, 2-(methylsulfonyl)-5-(4-fluorophenyl)-1,3,4-oxadiazole, at a concentration of 20 μg/mL, could inhibit the production of extracellular polysaccharide (EPS) with an inhibition ratio of 94.52%, and reduce the gene expression levels of gumB, gumG, gumM, and xanA, with inhibition ratios of 94.88%, 68.14%, 86.76%, and 79.21%, respectively.
authors.affiliation: State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China. s2012l@sina.com.
authors.forename: Li
authors.initials: L
authors.lastname: Shi
authors.affiliation: State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China. pl19890627@126.com.
authors.forename: Pei
authors.initials: P
authors.lastname: Li
authors.affiliation: State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China. wangwenli0208@163.com.
authors.forename: Wenli
authors.initials: W
authors.lastname: Wang
authors.affiliation: State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China. gaodunanqi@126.com.
authors.forename: Manni
authors.initials: M
authors.lastname: Gao
authors.affiliation: State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China. wzx3120@163.com.
authors.forename: Zengxue
authors.initials: Z
authors.lastname: Wu
authors.affiliation: State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China. sxp1529@163.com.
authors.forename: Xianpeng
authors.initials: X
authors.lastname: Song
authors.affiliation: State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China. fcc.dyhu@gzu.edu.cn.
authors.forename: Deyu
authors.initials: D
authors.lastname: Hu
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D002734:Chlorophyll / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D012275:Oryza / Q000382:microbiology*; D010069:Oxadiazoles / Q000737:chemistry*; D010544:Peroxidases / Q000378:metabolism; D018515:Plant Leaves / Q000382:microbiology*; D013450:Sulfones / Q000737:chemistry / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000378:metabolism; D014974:Xanthomonas / Q000187:drug effects* / Q000472:pathogenicity
chemical_list: D000900:Anti-Bacterial Agents; D010069:Oxadiazoles; D013450:Sulfones; D002734:Chlorophyll; C583463:1,3,4-oxadiazole; D010544:Peroxidases; D013482:Superoxide Dismutase
keywords: Xanthomonas oryzae pv. oryzae; action mechanism; antibacterial activity; extracellular polysaccharide; sulfone derivative