title: Inhibitory Effect of Camptothecin against Rice Bacterial Brown Stripe Pathogen Acidovorax avenae subsp. avenae RS-2.
abstract: Camptothecin (CPT) has anticancer, antiviral, and antifungal properties. However, there is a dearth of information about antibacterial activity of CPT. Therefore, in this study, we investigated the inhibitory effect of CPT on Acidovorax avenae subsp. avenae strain RS-2, the pathogen of rice bacterial brown stripe, by measuring cell growth, DNA damage, cell membrane integrity, the expression of secretion systems, and topoisomerase-related genes, as well as the secretion of effector protein Hcp. Results indicated that CPT solutions at 0.05, 0.25, and 0.50 mg/mL inhibited the growth of strain RS-2 in vitro, while the inhibitory efficiency increased with an increase in CPT concentration, pH, and incubation time. Furthermore, CPT treatment affected bacterial growth and replication by causing membrane damage, which was evidenced by transmission electron microscopic observation and live/dead cell staining. In addition, quantitative real-time PCR analysis indicated that CPT treatment caused differential expression of eight secretion system-related genes and one topoisomerase-related gene, while the up-regulated expression of hcp could be justified by the increased secretion of Hcp based on the ELISA test. Overall, this study indicated that CPT has the potential to control the bacterial brown stripe pathogen of rice.
authors.affiliation: College of Plant Science &amp; Technology, Huazhong Agricultural University, Wuhan 430070, China. dongqiaol4321@sina.com.
authors.forename: Qiaolin
authors.initials: Q
authors.lastname: Dong
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China. luojuinsect@sohu.com.
authors.forename: Ju
authors.initials: J
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310029, China. wenwen20101010@163.com.
authors.forename: Wen
authors.initials: W
authors.lastname: Qiu
authors.affiliation: College of Plant Science &amp; Technology, Huazhong Agricultural University, Wuhan 430070, China. caili@mail.hzau.edu.cn.
authors.forename: Li
authors.initials: L
authors.lastname: Cai
authors.affiliation: State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310029, China. ishtiaq@kust.edu.pk.|Department of Zoology Kohat University of Science and Technology Kohat, Khyber Pakhtunkhwa 26000, Pakistan. ishtiaq@kust.edu.pk.
authors.forename: Syed Ishtiaq
authors.initials: SI
authors.lastname: Anjum
authors.affiliation: State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310029, China. libin0571@zju.edu.cn.
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.affiliation: College of Plant Science &amp; Technology, Huazhong Agricultural University, Wuhan 430070, China. mingshenghou@mail.hzau.edu.cn.
authors.forename: Mingsheng
authors.initials: M
authors.lastname: Hou
authors.affiliation: State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310029, China. glxie@zju.edu.cn.
authors.forename: Guanlin
authors.initials: G
authors.lastname: Xie
authors.affiliation: State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China. sungc01@sina.com.
authors.forename: Guochang
authors.initials: G
authors.lastname: Sun
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D002166:Camptothecin / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects; D042621:Comamonadaceae / Q000187:drug effects / Q000254:growth & development*; D004305:Dose-Response Relationship, Drug; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D008826:Microbial Sensitivity Tests; D012275:Oryza / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology / Q000517:prevention & control*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002166:Camptothecin
keywords: CPT; Hcp; antibacterial activity; antibacterial mechanism; gene expression