The mechanisms whereby the green alga Chlorella ohadii, isolated from desert soil crust, exhibits unparalleled photodamage resistance

Bibliographische Detailangaben
Veröffentlicht in:	The New phytologist. - 1979. - 210(2016), 4 vom: 17. Juni, Seite 1229-43
1. Verfasser:	Treves, Haim (VerfasserIn)
Weitere Verfasser:	Raanan, Hagai, Kedem, Isaac, Murik, Omer, Keren, Nir, Zer, Hagit, Berkowicz, Simon M, Giordano, Mario, Norici, Alessandra, Shotland, Yoram, Ohad, Itzhak, Kaplan, Aaron
Format:	Online-Aufsatz
Sprache:	English
Veröffentlicht:	2016
Zugriff auf das übergeordnete Werk:	The New phytologist
Schlagworte:	Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. Algae CO2-concentrating mechanism photoinhibition photosynthesis stress Photosystem II Protein Complex Soil

Beschreibung
Zusammenfassung:	© 2016 The Authors. New Phytologist © 2016 New Phytologist Trust. Excess illumination damages the photosynthetic apparatus with severe implications with regard to plant productivity. Unlike model organisms, the growth of Chlorella ohadii, isolated from desert soil crust, remains unchanged and photosynthetic O2 evolution increases, even when exposed to irradiation twice that of maximal sunlight. Spectroscopic, biochemical and molecular approaches were applied to uncover the mechanisms involved. D1 protein in photosystem II (PSII) is barely degraded, even when exposed to antibiotics that prevent its replenishment. Measurements of various PSII parameters indicate that this complex functions differently from that in model organisms and suggest that C. ohadii activates a nonradiative electron recombination route which minimizes singlet oxygen formation and the resulting photoinhibition. The light-harvesting antenna is very small and carotene composition is hardly affected by excess illumination. Instead of succumbing to photodamage, C. ohadii activates additional means to dissipate excess light energy. It undergoes major structural, compositional and physiological changes, leading to a large rise in photosynthetic rate, lipids and carbohydrate content and inorganic carbon cycling. The ability of C. ohadii to avoid photodamage relies on a modified function of PSII and the dissipation of excess reductants downstream of the photosynthetic reaction centers. The biotechnological potential as a gene source for crop plant improvement is self-evident
Beschreibung:	Date Completed 08.03.2018 Date Revised 18.03.2022 published: Print-Electronic Citation Status MEDLINE
ISSN:	1469-8137
DOI:	10.1111/nph.13870