XVI International Botanical Congess

The carotenoids are essential pigments for plant viability due to their roles in photosynthesis and photoprotection. A unique class of mutations (chloroplast and carotenoid regulation, ccr) that disrupts specific aspects of chloroplast development and carotenoid accumulation has been identified. In ccr2 chloroplasts, there are fewer light harvesting complex (LHC) trimers and less thylakoid stacking. In ccr2 etioplasts carotenoid precursors accumulate and photomorphogenesis is delayed. ccr1 has similar disruptions in carotenoid accumulation and photomorphogenesis, furthermore, ccr1 exhibits an altered lipid composition,chilling- sensitivity, and partial male sterility. Efforts to identify ccr loci through positional cloning strategies and identification of tagged alleles will also be presented.