Response of Tomato to Aluminum Toxicity

 Like all tomato cultivars in this species, (Solanum lycopersicon cv. Money Maker) is susceptible to aluminum toxicity. The root system (root tips) presents the first barrier for controlling absorption of the toxic ions into the plant system.  Our research is focusing on the identification of genes that are involved in Al toxicity.  Identification of such genes is based on alterations in gene expression at both the transcript and protein levels.  Genes associated with cellular oxidative stress, detoxification, signal transduction, various transporters, cell cycle progression were all affected by Al toxicity.  These included genes such as oxalate oxidase and wali7 homologs, multidrug efflux transporters, adenosyl-L-homocysteine hydrolase lactoylglutathione lyase, multidrug and toxic compound extrusion (MATE) proteins, p34cdc2 protein kinase, cyclin, and histone, putrescine synthesis, ABC transporter, etc.  Some of these findings have been published in the following articles: "Proteome changes under Al toxicity in tomato roots", JXB, 2009 60(6):1849-1857 and in the article "Identification of genes associated with aluminum toxicity in tomato roots using cDNA microarrays", Plant Stress, 2008 2:113-120.  Our on-going research is presently directed to validate the function of selected genes by gene-over expression and RNAi knock-down.