Recipient Organization
UNIVERSITY OF CALIFORNIA, DAVIS
410 MRAK HALL
DAVIS,CA 95616-8671
Performing Department
Plant Pathology
Non Technical Summary
Wilt-disease causing bacterial pathogens like Ralstonia colonize the water-transporting xylem vessels. Although its known that these bacteria disrupt the water-transporting function of the xylem vessels, the mechanism for this disruptiong is untested. Here we determine whether the bacteria directly clog the xylem, trigger plant host auto-immunity to clog the xylem, or damage vessels and allow air to displace the sap. To do this, we are adapting the medical imaging technology x-ray microCT to created 3D x-ray images of tomato stem from healthy and wilting tomato plants. This will allow us to definitively identify the mechanism of vascular dysfunction.
Animal Health Component
(N/A)
Research Effort Categories
Basic
100%
Applied
(N/A)
Developmental
(N/A)
Goals / Objectives
Using a tomato and Ralstonia pseudosolanacearum GMI1000 model, we will characterize and visualize the spatial dynamics of xylem dysfunction. We will quantify the progressive spatial decline of xylem functionality using Licor 6400XT gas analyzer measurements of we stomatal conductance as a proxy. We will focus on several categories of leaflets for the spatial analysis: wilted leaflets, turgid leaflets co-located on a petiole with wilted leaflets, and turgid leaflets on petioles without wilt.We will follow this analysis by in depth 3D X-ray visualization of stem. We will use X-ray microcomputed tomography (X-ray μCT) to differentiate between mechanisms of xylem dysfunction: blockage by bacteria, blockage by parenchyma cell tyloses, or sap displacement by gas embolisms.
Project Methods
Standard inoculation methods will be used to directly introduce pathogenic bacteria, Ralstonia solanacearum, directly into the xylem of plants. Subsequently, LICOR measurements will be performed according to standard operating procedures. The X-ray microCT data will be reconstructed with an open source tomopy832.py script using appropriate parameters.Efforts: through laboratory instruction, postdoctoral and graduate student trainees will develop scientific proficiency in these methods.