Repositorium
Deletion of the chloroplast LTD protein impedes LHCI import and PSI-LHCI assembly in Chlamydomonas reinhardtii
430
Journal Article / 2018
Jeong, Jooyeon; Baek, Kwangryul; Yu, Jihyeon; Kirst, Henning; Betterle, Nico; Shin, Woongghi; Bae, Sangsu; Melis, Anastasios; Jin, EonSeon
Nuclear-encoded light-harvesting chlorophyll- and carotenoid-binding proteins (LHCPs) are imported into the chloroplast and transported across the stroma to thylakoid membrane assembly sites by the chloroplast signal recognition particle (CpSRP) pathway. The LHCP translocation defect (LTD) protein is essential for the delivery of imported LHCPs to the CpSRP pathway in Arabidopsis. However, the function of the LTD protein in Chlamydomonas reinhardtii has not been investigated. Here, we generated a C. reinhardtii ltd (Crltd) knockout mutant by using CRISPR-Cas9, a new target-specific knockout technology. The Crltd1 mutant showed a low chlorophyll content per cell with an unusual increase in appressed thylakoid membranes and enlarged cytosolic vacuoles. Profiling of thylakoid membrane proteins in the Crltd1 mutant showed a more severe reduction in the levels of photosystem I (PSI) core proteins and absence of functional LHCI compared with those of photosystem II, resulting in a much smaller PSI pool size and diminished chlorophyll antenna size. The lack of CrLTD did not prevent photoautotrophic growth of the cells. These results are substantially different from those for Arabidopsis ltd null mutant, indicating LTD function in LHCP delivery and PSI assembly may not be as stringent in C. reinhardtii as it is in higher plants.
Techniques
ID | Corresponding Author Country |
Plant Species | GE Technique Sequence Identifier |
Trait Type of Alteration |
Progress in Research Key Topic |
---|---|---|---|---|---|
989 |
Bae, Sangsu; Melis, Anastasions; Jin, EonSeon South Korea; USA |
Chlamydomonas reinhardtii |
CRISPR/Cas9 LTD |
lower chlorophyll content leading to a reduction in the levels of photosystem I SDN1 |
Basic research Basic research |