Location: Plant, Soil and Nutrition ResearchTitle: Proteomic analysis of differentially expressed proteins in the roots of columbia-0 and landsberg erecta ecotypes of arabidopsis thaliana in response to aluminum toxicity) Author
Submitted to: Canadian Journal of Plant Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/16/2012
Publication Date: 11/1/2012
Publication URL: DOI: 10.4141/CJPS2012-098
Citation: Karuppanapandian, T., Rhee, S., Kim, E., Han, B., Hoekenga, O., Lee, G. 2012. Proteomic analysis of differentially expressed proteins in the roots of columbia-0 and landsberg erecta ecotypes of arabidopsis thaliana in response to aluminum toxicity. Canadian Journal of Plant Science. 92:1267-1282. Interpretive Summary: The collection of proteins found in a given tissue or cell type is often referred to as the proteome. Evaluating the composition of the proteome is a useful but technically challenging way to take a snapshot of cellular activity. These experiments are often more accurate in describing the physiological processes in a given time or place than examining patterns of gene expression. Here we describe the proteome of aluminum-treated Arabidopsis roots, to examine the cellular physiology of stressed plants. This system has already been well described at the genetic, physiological and molecular levels. We integrate our results with those of researchers who have employed gene expression analysis in Arabidopsis or maize. Our results are largely consistent with these other reports, but key differences between the patterns of protein and gene expression reaffirm the importance of performing both kinds of experiments.
Technical Abstract: Aluminum (Al) is phytotoxic when solubilized into Al3+ in acidic soils and represents a major constraint for crop production. The present study describes Al-stress responses in roots of Al-tolerant and Al-sensitive Arabidopsis ecotypes, Columbia-0 (Col-0) and Landsberg erecta (Ler). Comparative proteomic analysis was applied to plants grown in hydroponic culture under acidic pH (4.2) conditions. To investigate time-dependent responses, 6-day-old seedlings were exposed to 50 uM AlCl3 for 24, 48 or 72 hr; total proteins were prepared from roots and separated by two-dimensional gel electrophoresis (2-DE). From 2-DE analysis, where 600 proteins were inspected, 29 proteins were differentially responsive to Al-treatment. The 2-DE patterns were compared and differentially expressed proteins were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Most of the identified proteins are functionally associated with the tricarboxylic acid (TCA) and glycolysis, reactive oxygen quenching and detoxification, and signal transduction pathways in the Arabidopsis ecotypes. The results also showed that proteins involved in plant defense mechanisms were up regulated in response to Al stress, which highlights crosstalk between abiotic and biotic stress responses. We observed that proteins related to energy metabolism and reactive oxygen detoxification were up-regulated more in Al tolerant Col-0 than Al sensitive Ler under Al-stress. The identified acquired protein signature for Al toxicity in Arabidopsis ecotypes will be useful for the isolation of tolerance genes for Al-toxicity and description the physiology for Al tolerance at the cellular level.