Discovery and characterization of low-molecular weight inhibitors of Erwinia tracheiphila

Cláudio M. Vrisman, Loïc Deblais, Yosra A. Helmy, Reed Johnson, Gireesh Rajashekara, Sally A. Miller

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

Plant pathogenic bacteria in the genus Erwinia cause economically important diseases, including bacterial wilt of cucurbits caused by Erwinia tracheiphila. Conventional bactericides are insufficient to control this disease. Using high-throughput screening, 464 small molecules (SMs) with either cidal or static activity at 100 µM against a cucumber strain of E. tracheiphila were identified. Among them, 20 SMs (SM1 to SM20), composed of nine distinct chemical moiety structures, were cidal to multiple E. tracheiphila strains at 100 µM. These lead SMs had low toxicity to human cells and honey bees at 100 µM. No phytotoxicity was observed on melon plants at 100 µM, except when SM12 was either mixed with Silwet L-77 and foliar sprayed or when delivered through the roots. Lead SMs did not inhibit the growth of beneficial Pseudomonas and Enterobacter species but inhibited the growth of Bacillus species. Nineteen SMs were cidal to Xanthomonas cucurbitae and showed >50% growth inhibition against Pseudomonas syringae pv. lachrymans. In addition, 19 SMs were cidal or static against Erwinia amylovora in vitro. Five SMs demonstrated potential to suppress E. tracheiphila when foliar sprayed on melon plants at 2× the minimum bactericidal concentration. Thirteen SMs reduced Et load in melon plants when delivered via roots. Temperature and light did not affect the activity of SMs. In vitro cidal activity was observed after 3 to 10 h of exposure to these five SMs. Here, we report 19 SMs that provide chemical scaffolds for future development of bactericides against plant pathogenic bacterial species.

Original languageEnglish
Pages (from-to)989-998
Number of pages10
JournalPhytopathology
Volume110
Issue number5
DOIs
StatePublished - May 2020

Bibliographical note

Funding Information:
Funding: This research was partially supported by U.S. Department of Agriculture National Institute of Food and Agriculture (USDA NIFA SCRI) grant 2012-51181-20295. This study was partially funded by The Ohio State University Graduate School Alumni Grants for Graduate Research and Scholarship.

Publisher Copyright:
© 2020 The American Phytopathological Society

Keywords

  • Bacteriology
  • Discovery
  • Disease control and pest management
  • Erwinia tracheiphila
  • Small molecule

ASJC Scopus subject areas

  • Agronomy and Crop Science
  • Plant Science

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