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Testing the Role of the N-Terminal Tail of D1 in the Maintenance of Photosystem II in Tobacco Chloroplasts

SYSNO ASEP	0469222
Document Type	J - Journal Article
R&D Document Type	Journal Article
Subsidiary J	Článek ve WOS
Title	Testing the Role of the N-Terminal Tail of D1 in the Maintenance of Photosystem II in Tobacco Chloroplasts
Author(s)	Michoux, F. (GB) Ahmad, N. (PK) Wei, Z-Y. (CN) Belgio, Erica (MBU-M) Ruban, A.V. (GB) Nixon, P. (GB)
Source Title	Frontiers in Plant Science. - : Frontiers Research Foundation - ISSN 1664-462X Roč. 7, 21 June (2016), s. 844
Number of pages	9 s.
Language	eng - English
Country	CH - Switzerland
Keywords	D1 degradation ; PSII repair ; chloroplast transformation
Subject RIV	EF - Botanics
Institutional support	MBU-M - RVO:61388971
UT WOS	000378213100001
EID SCOPUS	84976489816
DOI	10.3389/fpls.2016.00844
Annotation	A key step in the repair of photoinactivated oxygen-evolving photosystem II (PSII) complexes is the selective recognition and degradation of the damaged PSII subunit, usually the D1 reaction center subunit. FtsH proteases play a major role in D1 degradation in both cyanobacteria and chloroplasts. In the case of the cyanobacterium Synechocystis sp. PCC 6803, analysis of an N-terminal truncation mutant of D1 lacking 20 amino-acid residues has provided evidence that FtsH complexes can remove damaged D1 in a processive reaction initiated at the exposed N-terminal tail. To test the importance of the N-terminal D1 tail in higher plants, we have constructed the equivalent truncation mutant in tobacco using chloroplast transformation techniques. The resulting mutant grew poorly and only accumulated about 25% of wild-type levels of PSII in young leaves which declined as the leaves grew so that there was little PSII activity in mature leaves. Truncating D1 led to the loss of PSII supercomplexes and dimeric complexes in the membrane. Extensive and rapid non-photochemical quenching (NPQ) was still induced in the mutant, supporting the conclusion that PSII complexes are not required for NPQ. Analysis of leaves exposed to high light indicated that PSII repair in the truncation mutant was impaired at the level of synthesis and/or assembly of PSII but that D1 could still be degraded. These data support the idea that tobacco plants possess a number of back-up and compensatory pathways for removal of damaged D1 upon severe light stress.
Workplace	Institute of Microbiology
Contact	Eliška Spurná, eliska.spurna@biomed.cas.cz, Tel.: 241 062 231
Year of Publishing	2017

Number of the records: 1