The role of carotenoid isomerase in maintenance of photosynthetic oxygen evolution in rice plant

• Published in: Acta biochimica et biophysica Sinica Vol. 42; no. 7; pp. 457 - 463
• Main Authors: Wei, Jiali, Xu, Min, Zhang, Dabing, Mi, Hualing
• Format: Journal Article
• Language: English
• Published: China Oxford University Press 01.07.2010
• Subjects: Blotting, Northern; Carotenoids - metabolism; Chlorophyll - chemistry; Chlorophyll - metabolism; cis-trans-Isomerases - genetics; cis-trans-Isomerases - metabolism; Cloning, Molecular; CP43; Fluorescence; Gene Expression Regulation, Plant; Genetic Complementation Test; Immunoblotting; Lutein - metabolism; Mutation; Northern; Oryza - genetics; Oryza - metabolism; Oxygen - metabolism; Phenotype; Photosynthesis; Photosystem II Protein Complex - genetics; Photosystem II Protein Complex - metabolism; Plant Proteins - genetics; Plant Proteins - metabolism; Reverse Transcriptase Polymerase Chain Reaction; Thylakoids - metabolism; 光保护机制; 光合放氧; 异构酶; 氧化还原状态; 类胡萝卜素; PS II supercomplexes; carotenoid isomerase; oxygen evolution; lutein
• ISSN: 1672-9145; 1745-7270
• DOI: 10.1093/abbs/gmq044

Carotenoid isomerase （CRTISO） has been suggested to protect photosystem II （PS II） from photodamage, probably through its product lutein. However, the mechanism of the photoprotection still remains to be further elucidated. In this work, we cloned a point mutated gene reported to encode a CRTISO which is responsible for the accumulation of iutein in rice mutant zell by a mapbased cloning approach. The mutant phenotype was rescued by transformation with the corresponding gene of the wild type （WT）. The activity of photosynthetic oxygen evolution was evidently suppressed in zell. The amount of the core protein of PS II CP47 was much lower in all the PS II complexes especially in the LHCII- PS II supercomplexes and CP43-free PS II of zell than that of WT. On the other hand, the amount of another core protein of PS II CP43 of zell was decreased in the higher supereomplexes, whereas it was increased in the lower ones and PS II monomer. The immunodetection displayed that CP43, CP47, and the oxygen-evolving extrinsic proteins PsbO and PsbP were reduced, but the amount of reaction center protein D1 did not show significant change in zell. Northern blot analysis showed that the transcriptional level of CP43 was down-regu- lated hut not that of CP47 or D1 in zell. In addition, the plastoquinone （PQ） QA was in a reduced state in zell. On the basis of the results, we suggest that CRTISO might function in regulating the transcription of CP43 and the translation of CP47 by affeeting the redox state of the PQ to stabilize the extrinsic proteins of oxygen evolution complexes in the rice plant.