Coexistence of plant and algal energy dissipation mechanisms in the moss Physcomitrella patens
Article first published online: 25 SEP 2012
© 2012 The Authors. New Phytologist © 2012 New Phytologist Trust
Volume 196, Issue 3, pages 763–773, November 2012
How to Cite
Gerotto, C., Alboresi, A., Giacometti, G. M., Bassi, R. and Morosinotto, T. (2012), Coexistence of plant and algal energy dissipation mechanisms in the moss Physcomitrella patens. New Phytologist, 196: 763–773. doi: 10.1111/j.1469-8137.2012.04345.x
- Issue published online: 9 OCT 2012
- Article first published online: 25 SEP 2012
- Manuscript Accepted: 8 AUG 2012
- Manuscript Received: 19 JUN 2012
- Institut Jean-Pierre Bourgin (IJPB)
- Institut National de la Recherche Agronomique (INRA)
- National Institute for Basic Biology. Grant Numbers: CPDA089403, CPDR104834
- LHCSR (Light harvesting complex stress-related);
- nonphotochemical quenching;
- Physcomitrella patens ;
- PSBS (Photosystem II subunit S)
- Although light is the source of energy for photosynthetic organisms, it causes oxidative stress when in excess. Plants and algae prevent reactive oxygen species (ROS) formation by activation of nonphotochemical quenching (NPQ), which dissipates excess excitation energy as heat. Although NPQ is found in both algae and plants, these organisms rely on two different proteins for its activation, Light harvesting complex stress-related (LHCSR) and Photosystem II subunit S (PSBS). In the moss Physcomitrella patens, both proteins are present and active.
- Several P. patens lines depleted in or over-expressing PSBS and/or LHCSR at various levels were generated by exploiting the ability of Physcomitrella to undergo homologous recombination.
- The analysis of the transgenic lines showed that either protein is sufficient, alone, for NPQ activation independently of the other, supporting the idea that they rely on different activation mechanisms. Modulation of PSBS and/or LHCSR contents was found to be correlated with NPQ amplitude, indicating that plants and algae can directly modulate their ability to dissipate energy simply by altering the accumulation level of one or both of these proteins.
- The availability of a large range of P. patens genotypes differing in PSBS and LHCSR content allowed comparison of their activation mechanisms and discussion of implications for the evolution of photoprotection during land colonization.