Biological control agent Agrobacterium vitis strain ARK-1 suppresses expression of the virD2 and virE2 genes in tumorigenic A. vitis
- 233 Downloads
A nonpathogenic strain of Agrobacterium (=Rhizobium) vitis, ARK-1, limits the development of crown gall of grapevine (Vitis vinifera L.). Co-inoculation of grapevine shoots with ARK-1 and the tumorigenic (Ti) strain VAT03-9 at a 1:1 cell ratio resulted in significantly lower expression of the virulence genes virD2 and virE2 of VAT03-9 1 day after inoculation (dai) compared with expression levels when shoots were inoculated only with VAT03-9. In contrast, nonpathogenic A. vitis strain VAR06-30, which does not limit the development of crown gall of grapevine, co-inoculated with VAT03-9 did not affect expression levels of virD2 and virE2 under the same conditions. ARK-1 began to suppress the VAT03-9 population by seven dai, but no such effect was observed with VAR06-30 during the nine dai study period. Thus, the biological control activity of ARK-1 is likely based on the suppression of essential virulence genes.
KeywordsAgrobacterium vitis Grapevine crown gall Biological control RT-qPCR Gene expression
This work was supported by a Japan Society for the Promotion of Science KAKENHI Grant (Number 2550038). I thank Associate Prof. Y. Noutoshi (Okayama University Okayama, Japan) for providing useful advice on experimental design.
- Burr, T. J., & Reid, C. L. (1994). Biological control of grape crown gall with nontumorigenic Agrobacterium vitis F2/5. American Journal of Enology Viticulture, 45, 213–219.Google Scholar
- Kawaguchi, A. (2011). Genetic diversity of Rhizobium vitis strains in Japan based on multilocus sequence analysis using the sequences of pyrG, recA and rpoD. Journal of General Plant Pathology, 77, 299–303.Google Scholar
- Kerr, A. (1980). Biological control of crown gall through production of agrocin 84. Plant Disease, 64, 25–30.Google Scholar
- Vandesompele, J., De Preter, K., Pattyn, F., Poppe, B., Van Roy, N., De Paepe, A., & Speleman, F. (2002). Accurate normalization of real-time quantitative RT-PCR data by geometric averaging of multiple internal control genes. Genome Biology, 3, research0034.Google Scholar