Arabidopsis thaliana three hours after infection with Agrobacterium tumefaciens

This study focuses on responses of the host plant to infection with Agrobacterium tumefaciens. Genome wide changes in gene expression were integrated with the alterations in metabolite levels three hours after inoculation of agrobacteria. Plants were infected with the virulent strain C58, harboring a T-DNA, or with strain GV3101, containing a disarmed Ti-plasmid. This allows discrimination between signals which derive from the bacterial pathogen and the T-DNA encoded genes. The bases of Arabidopsis thaliana (WS-2) inflorescence stalks were wounded and immediately infected with Agrobacterium tumefaciens or mock-infected for three hours. Stalks of intact plants were inoculated with the oncogenic strain C58 (C58 3 hpi 1 to 6) or the non-virulent strain GV3101 (GV3101 3 hpi 1 to 3) to provide conditions close to nature. The gene expression data of three independent experiments of infected material were compared with six non-infected samples (reference 3 hpi 1 to 6). Differential gene expression was determined by applying the LIMMA package (Linear Models for Microarray Data; Smyth, G.K. (2004) Applic. Genet. Mol. Biol. 3, Article 3; http://www.bepress.com/sagmb/vol3/iss1/art3/).