Exploring Rain as Source of Biological Control Agents for Fire Blight on Apple.

Autor: Mechan Llontop ME; School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA, United States., Hurley K; School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA, United States., Tian L; School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA, United States., Bernal Galeano VA; School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA, United States., Wildschutte HK; Department of Biological Sciences, Bowling Green State University, Bowling Green, OH, United States., Marine SC; Department of Biochemistry, Virginia Tech, Blacksburg, VA, United States., Yoder KS; School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA, United States.; Alson H. Smith Jr. Agricultural Research and Extension Center, Virginia Tech, Winchester, VA, United States., Vinatzer BA; School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA, United States.
Jazyk: angličtina
Zdroj: Frontiers in microbiology [Front Microbiol] 2020 Feb 14; Vol. 11, pp. 199. Date of Electronic Publication: 2020 Feb 14 (Print Publication: 2020).
DOI: 10.3389/fmicb.2020.00199
Abstrakt: Poor survival on plants can limit the efficacy of Biological Control Agents (BCAs) in the field. Yet bacteria survive in the atmosphere, despite their exposure to high solar radiation and extreme temperatures. If conditions in the atmosphere are similar to, or more extreme than, the environmental conditions on the plant surface, then precipitation may serve as a reservoir of robust BCAs. To test this hypothesis, two hundred and fifty-four rain-borne isolates were screened for in vitro inhibition of Erwinia amylovora , the causal agent of fire blight, as well as of other plant pathogenic bacteria, fungi and oomycetes. Two isolates showed strong activity against E. amylovora and other plant pathogenic bacteria, while other isolates showed activity against fungal and oomycete pathogens. Survival assays suggested that the two isolates that inhibited E. amylovora were able to survive on apple blossoms and branches similarly to E. amylovora . Pathogen population size and associated fire blight symptoms were significantly reduced when detached apple blossoms were treated with the two isolates before pathogen inoculation, however, disease reduction on attached blossoms within an orchard was inconsistent. Using whole genome sequencing, the isolates were identified as Pantoea agglomerans and P. ananatis , respectively. A UV-mutagenesis screen pointed to a phenazine antibiotic D-alanylgriseoluteic acid synthesis gene cluster as being at the base of the antimicrobial activity of the P. agglomerans isolate. Our work reveals the potential of precipitation as an under-explored source of BCAs, whole genome sequencing as an effective approach to precisely identify BCAs, and UV-mutagenesis as a technically simple screen to investigate the genetic basis of BCAs. More field trials are needed to determine the efficacy of the identified BCAs in fire blight control.
(Copyright © 2020 Mechan Llontop, Hurley, Tian, Bernal Galeano, Wildschutte, Marine, Yoder and Vinatzer.)
Databáze: MEDLINE