| Abstract Detail
Hormone Biology Thornton, Leeann E. [1], Neff, Michael M. [2]. Characterization of two brassinosteroid-regulating cytochrome P450 enzymes from rice, CYP734A2 and CYP734A5. Cytochrome P450 monooxygenases (P450s) represent a diverse family of proteins that have specialized roles in secondary metabolism as well as for normal cell growth and development. Brassinosteroids are a family of plant growth-promoting hormones that regulate development in seedlings and adults. It appears that brassinosteroid biosynthesis and perception is similar in monocots and dicots, but little is known about brassinosteroid inactivation in rice (Oryza sativa). One P450, CYP734A1 (BAS1), has been identified as a brassinosteroid-inactivating enzyme important for steroid-mediated signal transduction in Arabidopsis. Genetic analysis has demonstrated that the activity of this P450 modulates hypocotyl elongation and cotyledon expansion in seedlings exposed to light, as well as leaf size, floral induction, and fruit size in adult plants. There are five potential genes encoding CYP734A family members in rice. Two of these, encoding CYP734A2 and CYP734A5, appear to be regulated in a brassinosteroid-dependent manner. We have cloned the genes for CYP734A2 and CYP734A5 for expression in Arabidopsis to determine if these rice proteins have the same brassinosteroid-inactivating activity as CYP734A1. These rice proteins are important targets for optimizing plant growth and crop yield through subtle changes in endogenous brassinosteroid levels. This work was supported by USDA and NSF. Log in to add this item to your schedule
1 - Washington University, Biology, Campus Box 1137, 1 Brookings Dr., St. Louis, MO, 63130, USA 2 - Washington University, Biology
Keywords: Arabidopsis rice brassinosteroid cytochrome P450.
Presentation Type: Plant Biology Abstract Session: P Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton Date: Sunday, July 8th, 2007 Time: 8:00 AM Number: P35008 Abstract ID:222 |