title: Inhibition of Grape Crown Gall by Agrobacterium vitis F2/5 Requires Two Nonribosomal Peptide Synthetases and One Polyketide Synthase.
abstract: Agrobacterium vitis nontumorigenic strain F2/5 is able to inhibit crown gall disease on grapevines. The mechanism of grape tumor inhibition (GTI) by F2/5 has not been fully determined. In this study, we demonstrate that two nonribosomal peptide synthetase (NRPS) genes (F-avi3342 and F-avi5730) and one polyketide synthase gene (F-avi4330) are required for GTI. Knockout of any one of them resulted in F/25 losing GTI capacity. We previously reported that F-avi3342 and F-avi4330 but not F-avi5730 are required for induction of grape tissue necrosis and tobacco hypersensitive response. F-avi5730 is predicted to encode a single modular NRPS. It is located in a cluster that is homologous to the siderophore vicibactin biosynthesis locus in Rhizobium species. Individual disruption of F-avi5730 and two immediate downstream genes, F-avi5731 and F-avi5732, all resulted in reduced siderophore production; however, only F-avi5730 was found to be required for GTI. Complemented F-avi5730 mutant (ΔF-avi5730(+)) restored a wild-type level of GTI activity. It was determined that, over time, populations of ΔF-avi4330, ΔF-avi3342, and ΔF-avi5730 at inoculated wound sites on grapevine did not differ from those of ΔF-avi5730(+) indicating that loss of GTI was not due to reduced colonization of wound sites by mutants.
authors.affiliation: Department of Plant Pathology and Plant-Microbe Biology, New York State Agricultural Experimental Station, Cornell University, 630 W. North Street Geneva, NY 14456, U.S.A.
authors.forename: Desen
authors.initials: D
authors.lastname: Zheng
authors.affiliation: Department of Plant Pathology and Plant-Microbe Biology, New York State Agricultural Experimental Station, Cornell University, 630 W. North Street Geneva, NY 14456, U.S.A.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Burr
mesh_terms: D060054:Agrobacterium / Q000145:classification* / Q000502:physiology; D000898:Antibiosis; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D005810:Multigene Family; D010453:Peptide Synthases / Q000235:genetics / Q000378:metabolism*; D010935:Plant Diseases / Q000382:microbiology*; D048630:Polyketide Synthases / Q000235:genetics / Q000378:metabolism*; D017262:Siderophores; D027843:Vitis / Q000382:microbiology*
chemical_list: D001426:Bacterial Proteins; D017262:Siderophores; D048630:Polyketide Synthases; D010453:Peptide Synthases; C104385:non-ribosomal peptide synthase