Submitted to: Biennial Conference on Molecular and Cellular Biology of the Soybean
Publication Type: Abstract Only
Publication Acceptance Date: 5/27/2008
Publication Date: 7/20/2008
Citation: Clough, S.J., Zhu, J., Tranel, P., Patzholdt, W.L., Radwan, O., Li, M., Calla, B. 2008. Gene expression responses in photosynthetic tissues to herbicides and pathogens [abstract]. In: Proceedings of the 12th Biennial Conference on Molecular and Cellular Biology of the Soybean. July 20-23, 2008. Indianapolis, Indiana. p. 25.
Technical Abstract: When plants are attacked by pathogens, the photosynthetic tissue is often dramatically affected. The chloroplasts within this tissue can participate in defense by being a source of many plant secondary metabolites that serve as defense signaling compounds, antioxidants, and phytoalexins. The chloroplast electron transfer system can serve as a potential rapid source of reactive oxygen species. Therefore, it would be advantageous for a plant to control these effects as a defensive strategy, and for a pathogen to target the manipulation of chloroplasts during plant-pathogen interactions as a strategy to favor pathogen propagation. Many commercial herbicides also target chloroplast-related functions, as these tend to be vital to plants. For example, atrazine and bentazon both target photosystem II by blocking electron transfer to plastoquinone B; and glyphosate blocks EPSPS, a key enzyme of the chorismate pathway that is the source of essential aromatic amino acids. In an effort to identify responses that are pathogen or herbicide specific, or that are shared, we are comparing gene expression responses in soybean to herbicide-induced interruptions of specific chloroplast operations to the multitude of events triggered by various pathogens. Microarray time-course experiments, focused on the first 24 hours post treatment, have been completed and clustering results will be presented. Herbicides being used in this study are atrazine, bentazon, and glyphosate. Pathogen-soybean interactions being used in this study are: compatible and incompatible to Pseudomonas syringae, susceptible and resistant to Verguliforme solani (aka Fusarium solani) phytotoxin, and susceptible and resistant to Sclerotinia sclerotiorum.