Mode of Action of the Antibacterial Compound Ar26 Produced by Agrobacterium vitis Strain E26 with Activity against A. tumefaciens, A. rhizogenes and A. vitis

作者：Li Jin Yun^*; Wang Jian Hui; Wang Hui Min

来源：Journal of Phytopathology, 2009, 157(3): 159-165.

DOI：10.1111/j.1439-0434.2008.01470.x

• Agrobacterium vitis
• grapevine crown gall
• biological control
• agrocin
• mode of action

The biological control bacterium Agrobacterium vitis strain E26 was previously shown to produce an antibacterial compound, Ar26. This compound was involved in the biocontrol process and inhibited grapevine crown gall-causing A. vitis strains in vitro by an unknown mechanism. This work was undertaken to determine the antibacterial properties and mode of action of Ar26. In a well agar plate diffusion assay against 29 tumorigenic isolates of Agrobacterium spp., Ar26 displayed broad inhibitory activity against 27. All of the 10 A. vitis, 8 of 9 A. tumefaciens and 9 of 10 A. rhizogenes strains were sensitive to this compound. Agrobacterium vitis strains were more sensitive to Ar26 than A. tumefaciens or A. rhizogenes strains, with larger inhibition zones and lower minimal inhibitory concentration (MIC). Ar26 exhibited a bactericidal effect against A. vitis. This compound did not cause bacterial cell lysis, as determined by morphological observation with an electronic microscope. Also, no leakage of cytoplasmic materials from cells of A. vitis occurred after treatment with Ar26 at concentrations equivalent to the MIC. However, an inhibition of the incorporation of radiolabelled precursors into DNA, RNA and protein was observed after treatment with Ar26. Results obtained suggest that Ar26 inhibited DNA, RNA and protein syntheses in tumorigenic A. vitis.

• 出版日期2009-3
• 单位中国农业大学