Shakeel, Samina , Etheridge, Naomi , Schaller, G. Eric .
Proteomic and genomic analyses reveal a substantial degree of post-transcriptional regulation in ethylene responses of Arabidopsis seedlings.
The plant hormone ethylene is a key regulator of plant growth and development. Although microarrays have been used to examine the role of ethylene in transcriptional regulation, the effect of ethylene upon protein levels has yet to be thoroughly assessed. We therefore examined proteomic changes in Arabidopsis that result from the plant response to ethylene. For this purpose we used dark-grown seedlings treated with 10 uL/L ethylene, the ethylene insensitive mutant etr1-1, and the constitutive ethylene response mutant ctr1-1. We reproducibly visualized 500-600 proteins by two-dimensional electrophoresis. 20 protein spots were induced greater than 2-fold in ethylene-treated wild-type gel compared to air and 14 protein spots were repressed greater than 2-fold. Similarly, 33 protein spots were induced greater than 2-fold in the ctr1-1 gel compared to the etr1-1 gel; 37 protein spots were repressed greater than 2-fold. MALDI-TOF mass spectrometry was used to identify proteins that were ethylene-regulated. To determine how changes in protein level correlated with changes in transcript level, we conducted a gene expression study of 24 selected candidate genes by Real-Time PCR. Our analysis indicated that some genes, such as those involved in ethylene biosynthesis, showed a positive correlation at protein and RNA levels. However, evidence for significant post-transcriptional regulation of proteins was found based on (1) multiple spots for the same protein suggestive of protein modification and (2) a lack of correlation between protein and transcript levels in many cases. This work was supported by the DOE and NSF.
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Eric shaller lab
1 - Dartmouth College, Biology Department, Gilman 314, Hanover, NH, 03755, USA
2 - Dartmouth College, Biology Department
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM