Location: Crops Pathology and Genetics ResearchTitle: Water stress exacerbates the severity of Botryosphaeria dieback in grapevines infected by Neofusicoccum parvum Author
|Lawrence, Daniel - University Of California|
|Galarneau, Erin - University Of California|
|Travadon, Renaud - University Of California|
Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 6/12/2016
Publication Date: 6/25/2016
Citation: Lawrence, D., Galarneau, E., Travadon, R., Baumgartner, K. 2016. Water stress exacerbates the severity of Botryosphaeria dieback in grapevines infected by Neofusicoccum parvum. American Phytopathological Society Meeting Abstracts. 12-O.
Technical Abstract: Botryosphaeria dieback (causal fungus Neofusicoccum parvum) is a detrimental grapevine trunk disease, causing internal wood degradation, killing shoots, and reducing yields. We examined the interactive effects of drought and N. parvum infection, common vineyard stresses, on wood-lesion development. Woody stems of potted Vitis vinifera ‘Cabernet Sauvignon’ were inoculated after wounding (IW). Control plants were either non-inoculated-wounded (NIW) or non-inoculated-non-wounded (NINW). At 2 weeks post-inoculation (WPI), water stress was imposed on half of the plants. Water use was estimated weekly for non-stressed plants to provide 20% of this volume to stressed plants. Leaf water potential was maintained, through weekly monitoring, at > -8 bars for non-stressed and < -13 bars for stressed plants. To test the specificity of host-based markers of infection, developed previously for N. parvum in non-stressed plants, asymptomatic leaves were collected for RNA extraction at 2 WPI (before water stress), and at 8 and 12 WPI (6 and 10 weeks post-stress, respectively). IW-stressed plants had the most severe levels of wood lesions. At 2 WPI, none of the markers were differentially expressed among treatments. By 12 WPI, seven markers showed higher expression, but only in stressed plants, regardless of inoculation treatment. Two markers showed consistent overexpression at 8 WPI in IW plants that were stressed and non-stressed, suggesting their specificity to N. parvum infection.