SGER: Early Steps in the Sensory Transduction of Blue Light in Guard Cells

University Of California-Los Angeles, Los Angeles CA

Investigators

Abstract

The chloroplastic carotenoid, zeaxanthin, has been identified as a blue light photoreceptor in guard cells. This SGER award addresses the early events in the sensory transducing cascade that follows the photoexcitation of zeaxanthin, using a recently discovered blue-green reversibility of stomatal movements as a diagnostic probe. Specific experiments include the characterization of zeaxanthin isomerization in a reconstituted pigment-protein system, using UV/VIS, Raman, and FTIR spectroscopy, and the study of possible conformational changes of zeaxanthin binding protein(s) in the antenna bed of the chloroplast. Other experiments will examine whether chloroplast movements in Arabidopsis leaves are also blue-green reversible. All experiments demand the introduction of new techniques to central aspects of this research program. Success in this research would dramatically enhance our understanding of the early events in the sensory transduction of blue light in guard cells. The intrinsic high risk of the experiments and the high impact that would ensue from success in their implementation, make this appropriate as a SGER.