|Thannhauser, Theodore - Ted|
Submitted to: Journal of Experimental Botany
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/16/2009
Publication Date: 3/30/2009
Citation: Zhou, S., Sauve, R., Thannhauser, T.W. 2009. Proteome changes induced by aluminum stress in tomato roots. Journal of Experimental Botany. 60:1849-1857. Interpretive Summary: In acidic soils, toxic levels of aluminum inhibit plant growth and crop yields. The primary point of control against Al toxicity is the root system as it controls the absorption and transportation of toxic metals to the rest of the plant. To understand the molecular mechanisms involved it is important to determine the change in protein expression in the root tissue in response to Al stress. Using the tomato as a model system we compared the protein expression in the roots of tomatoes as a function of Al exposure using Difference Gel Electrophoresis and MALDI mass spectrometry. A total of 49 proteins were found to have altered levels of expression due to this exposure. Knowledge of the identity of these proteins allows for the generation of new hypotheses concerning the molecular mechanisms involved in Al toxicity and may provide insights to help mitigate its negative effects.
Technical Abstract: Growth inhibition in acid soils due to Al stress affects crop production worldwide. To understand mechanisms in sensitive crops that are affected by Al stress, a proteomic analysis of primary tomato root tissue, grown in Alamended and non-amended liquid cultures, was performed. DIGE-SDS-MALDI-TOF-TOF analysis of these tissues resulted in the identification of 49 proteins that were differentially accumulated. Dehydroascorbate reductase, glutathione reductase, and catalase enzymes associated with antioxidant activities were induced in Al-treated roots. Induced enzyme proteins associated with detoxification were mitochondrial aldehyde dehydrogenase, catechol oxidase, quinone reductase, and lactoylglutathione lyase. The germin-like (oxalate oxidase) proteins, the malate dehydrogenase, wali7 and heavy-metal associated domain-containing proteins were suppressed. VHA-ATP that encodes for the catalytic subunit A of the vacuolar ATP synthase was induced and two ATPase subunit 1 isoforms were suppressed. Several proteins in the active methyl cycle, including SAMS, quercetin 3-O-methyltransferase and AdoHcyase, were induced by Al stress. Other induced proteins were isovaleryl-CoA dehydrogenase and the GDSLmotif lipase hydrolase family protein. NADPH-dependent flavin reductase and b-hydroxyacyl-ACP dehydratase were suppressed.