The thylakoid protease Deg2 is involved in stress-related degradation of the photosystem II light-harvesting protein Lhcb6 in Arabidopsis thaliana
Article first published online: 13 JUN 2011
© 2011 The Authors. New Phytologist © 2011 New Phytologist Trust
Volume 192, Issue 1, pages 74–86, October 2011
How to Cite
Luciński, R., Misztal, L., Samardakiewicz, S. and Jackowski, G. (2011), The thylakoid protease Deg2 is involved in stress-related degradation of the photosystem II light-harvesting protein Lhcb6 in Arabidopsis thaliana. New Phytologist, 192: 74–86. doi: 10.1111/j.1469-8137.2011.03782.x
- Issue published online: 2 SEP 2011
- Article first published online: 13 JUN 2011
- Received: 3 January 2011, Accepted: 26 April 2011
- Arabidopsis thaliana;
- Deg2 protease;
- photosystem II;
- •The thylakoid protease Deg2 is a serine-type protease peripherally attached to the stromal side of the thylakoid membrane. Given the lack of knowledge concerning its function, two T-DNA insertion lines devoid of Deg2 were prepared to study the functional importance of this protease in Arabidopsis thaliana.
- •The phenotypic appearance of deg2 mutants was studied using a combination of stereo and transmission electron microscopy, and short-stress-mediated degradation of apoproteins of minor light-harvesting antennae of photosystem II (PSII) was analysed by immunoblotting in the mutants in comparison with wild-type plants.
- •Deg2 repression produced a phenotype in which reduced leaf area and modified chloroplast ultrastructure of older leaves were the most prominent features. In contrast to the wild type, the chloroplasts of second-whorl leaves of 4-wk-old deg2 mutants did not display features typical of the early senescence phase, such as undulation of the chloroplast envelope and thylakoids. The ability to degrade the photosystem II light-harvesting protein Lhcb6 apoprotein in response to brief high-salt, wounding, high-temperature and high-irradiance stress was demonstrated to be impaired in deg2 mutants.
- •Our results suggest that Deg2 is required for normal plant development, including the chloroplast life cycle, and has an important function in the degradation of Lhcb6 in response to short-duration stresses.