title: Reduction in pathogen populations at grapevine wound sites is associated with the mechanism underlying the biological control of crown gall by rhizobium vitis strain ARK-1.
abstract: A nonpathogenic strain of Rhizobium (=Agrobacterium) vitis, ARK-1, limited the development of grapevine crown gall. A co-inoculation with ARK-1 and the tumorigenic strain VAT07-1 at a 1:1 cell ratio resulted in a higher population of ARK-1 than VAT07-1 in shoots without tumors, but a significantly lower population of ARK-1 than VAT07-1 in grapevine shoots with tumors. ARK-1 began to significantly suppress the VAT07-1 population 2 d after the inoculation. This result indicated that ARK-1 reduced the pathogen population at the wound site through biological control. Although ARK-1 produced a zone of inhibition against other tumorigenic Rhizobium spp. in in vitro assays, antibiosis depended on the culture medium. ARK-1 did not inhibit the growth of tumorigenic R. radiobacter strain AtC1 in the antibiosis assay, but suppressed the AtC1-induced formation of tumors on grapevine shoots, suggesting that antibiosis by ARK-1 may not be the main mechanism responsible for biological control.
authors: Research Institute for Agriculture, Okayama Prefectural Technology Center for Agriculture, Forestry and Fisheries.
authors: Akira
authors: A
authors: Kawaguchi
mesh_terms: D000898:Antibiosis; D010935:Plant Diseases / Q000382:microbiology / Q000517:prevention & control*; D010941:Plant Tumors / Q000382:microbiology*; D012231:Rhizobium / Q000472:pathogenicity / Q000502:physiology*; D014774:Virulence; D027843:Vitis / Q000382:microbiology*