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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Soybean Genomics & Improvement Laboratory » Research » Publications at this Location » Publication #288693

Title: Proteomic analysis of the Heliotropic Organ Pulvinus in Glycine max

item LEE, HAKME - University Of Maryland
item Garrett, Wesley
item SULLIVAN, JOSEPH - University Of Maryland
item Natarajan, Savithiry - Savi

Submitted to: International Journal of Plant Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/14/2012
Publication Date: 12/18/2012
Citation: Lee, H., Garrett, W.M., Sullivan, J., Natarajan, S.S. 2012. Proteomic analysis of the Heliotropic Organ Pulvinus in Glycine max. International Journal of Plant Biology. 5:4887-4899.

Interpretive Summary: Application of genetic modification (GM) to soybean is important in providing nutritious and high quality soybean products. A suitable method to determine the effects of genetic modification at the genetic level is through protein expression analysis. While soybean seed and leaf tissue have been used in prior investigations, there still exists a need for additional methods to accurately identify and quantify protein composition in GM soybean. Therefore, we standardized and applied proteomic methods for the protein expression analysis of normal soybean, containing no transgenes. We first applied a modified extraction procedure to extract proteins from the soybean pulvinus, a motor organ located at the base of leaves which causes leaf movement in response to environmental factors. These proteins were then isolated and identified through a procedure called mass spectrometry, resulting in 167 identified protein spots. This method can be utilized to determine protein composition and variation in GM soybeans and to create a “protein reference map” of the soybean pulvinus. Our reference map from this investigation provides scientists with a basis for comparison with similar maps derived from the GM soybean studies.

Technical Abstract: BACKGROUND: Certain plant species respond to light, dark, and other environmental factors by leaf movement. Leguminous plants both track and avoid the sun through turgor changes of the pulvinus tissue at the base of leaves. Mechanisms leading to pulvinar turgor flux, particularly knowledge of the proteins involved, are not well-known. RESULTS: In this study we used 2-D gel electrophoresis and LC-MS/MS to separate and identify the proteins located in the soybean pulvinus. A total of 183 protein spots were separated and 167 spots were identified and functionally analyzed. The dominant functions of the proteins expressed in the pulvinus were involved in energy production and the stress response. CONCLUSION: To our knowledge, this is a novel report on the analysis of proteins found in soybean pulvinus. These findings provide a better understanding of the proteins required for turgor change in the pulvinus.