Transcriptome analysis of the tomato-Clavibacter michiganensis subsp. michiganensis compatible interaction

Experiment description: The phytopathogenic bacterium Clavibacter michiganensis subsp. michiganensis (Cmm) is a Gram-positive actinomycete that causes bacterial wilt and canker disease in tomato. To investigate the molecular basis of this compatible interaction and to gain insight into changes associated with the host gene expression during the development of the disease, we have used the Affymetrix tomato genome array followed by real time RT-PCR validation. The tomato cultivar Rio-Grande PtoS was used in our experiments. About four to five-week-old green house grown tomato plants were inoculated with 1*10⁸ cfu/ml (0.2 OD at 600 nm) cells of Cmm in 10 mM MgCl₂ buffer on the stem region flanked by two cotyledons. Control plants were inoculated only with 10mM MgCl₂ buffer and treated as mock. Two time points were chosen, an early time point (4 days after inoculation) at which the bacteria are in active stage of multiplication in the xylem vessels and has induced no wilt symptom and a later time point (8 days after inoculation) at which bacteria reached near saturation levels and induced the typical unilateral wilt symptoms. After 4 and 8 days after inoculation (dai), stem samples from 16 independent plants of both the mock- and Cmm-inoculated plants were harvested, flash freezed in liquid Nitrogen and stored at -80C. Two independent biological replicated samples were included to compare and determine consistency between experiments for the transcript changes induced by Cmm. The goal is to investigate the molecular basis of this compatible interaction and to gain insight into changes associated with the host gene expression during the development of the disease.

Author: Vasudevan Balaji

Contact: Guido Sessa (guidos@post.tau.ac.il), Department of Plant Sciences, Tel Aviv University

PubMed ID: 18245454