ARS | Publication request: Aluminum induced proteome changes in tomato cotyledons

Submitted to: Plant Signaling and Behavior
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 4, 2009
Publication Date: August 1, 2009
Citation: Zhou, S., Sauve, R., Thannhauser, T.W. 2009. Aluminum induced proteome changes in tomato cotyledons. Plant Signaling and Behavior. 4(8):769-772.

Interpretive Summary: In acidic soils, toxic levels of aluminum inhibit plant growth, development and ultimately crop yields. The adverse consequences of Al exposure impacts all plant tissues including the cotyledons which develop with reduced chlorophyll levels resulting in limited photosynthetic activities. To understand the molecular mechanisms involved it is important to determine the change in protein expression in the cotyledon in response to Al stress. Using the tomato as a model system we compared the protein expression in the cotyledons as a function of Al exposure using Difference Gel Electrophoresis and mass spectrometry. A set of proteins were found to have altered levels of expression due to this exposure which suggest that three major cellular processes were impacted by Al treatment. Two processes were found to be enhanced: antioxidant/detoxification metabolism and glyoxylate and glycolytic processes. Furthermore the photosynthetic and carbon fixation machinery were suppressed. This knowledge allows for the generation of new hypotheses concerning the molecular mechanisms involved in Al toxicity in photosynthetic tissues and may provide insights to help mitigate its negative effects.

Technical Abstract: Cotyledons of tomato seedlings that germinated in a 20 µM AlK(SO4)2 solution remained chlorotic while those germinated in an aluminum free medium were normal (green) in color. Previously, we have reported the effect of aluminum toxicity on root proteome in tomato seedlings (Zhou et al. J Exp Bot, 2009; 60:1849-57). Two dimensional DIGE protein analysis demonstrated that Al stress affected three major processes in the chlorotic cotyledons: antioxidant and detoxification metabolism (induced), glyoxylate and glycolytic processes (enhanced), and the photosynthetic and carbon fixation machinery (suppressed).