Analyse von Arabidopsis thaliana Mutanten mit Defekten im plastidären Protein-Transport
FacultiesFakultät für Naturwissenschaften
LicenseStandard (Fassung vom 01.10.2008)
In chloroplasts members of the Alb3/YidC/Oxa1p protein family are necessary for assembly of photosynthetic complexes in the thylakoid membranes. For Alb3p in Arabidopsis thaliana an important function in LHCII-integration into thylakoid membranes has been shown. In Synechocystis the Alb3 homolog SynOxa1p is responsible for the insertion of D1 into the thylakoid membrane and the assembly into photosystem (PS) II. The albino3 mutation of Alb3p has pleiotropic defects. Under autotrophic growth conditions albino3 is seedling-lethal. Plants shifted to autotrophic growth grow slowly, are sterile and show a yellowish phenotype. This complex phenotype suggests additive functions for Alb3p beyond dysfunction in LHCII integration and PSII assembly. To analyse this potential additional Alb3 function, different Arabidopsis thaliana mutants with defects in thylakoid membrane protein transport and on mutant with knock-out of carotenoid biosynthesis were characterised at different light conditions and compared to the albino3 mutation. These mutants were knock-out mutations of Hcf106, part of the receptor complex in delta pH/cpTat transport, CpFtsY and CpSRP54 which are together with Alb3p part of the cpSRP transport pathway for post-translational LHCII integration and co-translational D1 assembly and PSY as central enzyme of the carotenoid biosynthesis pathway. Comparison of the different phenotypes shows that Alb3p maybe important for carotenoid assembly into photosynthetic complexes while cpSRP protein insertion into the thylakoid membrane.
Subject HeadingsAckerschmalwand [GND]
Arabidopsis thaliana [LCSH]