Consequences of the reduction of the Photosystem II antenna size on the light acclimation capacity of Arabidopsis thaliana. (5th February 2020)

• Record Type: Journal Article
• Authors: Bielczynski, Ludwik W.; Schansker, Gert; Croce, Roberta
• Is Part Of: Plant, cell and environment. Volume 43:Number 4(2020)
• Page Start: 866
• Page End: 879
• Publication Date: 2020-02-05
• Subjects: antenna size reduction -- dLhcb2 -- light acclimation -- long‐term acclimation -- photoprotection -- photosynthesis -- photosystem II antenna size -- short‐term acclimation; Plant physiology -- Periodicals; Plant cells and tissues -- Periodicals; Plant communities -- Periodicals; 581.105
• DOI: 10.1111/pce.13701
• Languages: English
• ISSNs: 0140-7791

Abstract

Abstract: In several systems, from plant's canopy to algal bioreactors, the decrease of the antenna size has been proposed as a strategy to increase the photosynthetic efficiency. However, still little is known about possible secondary effects of such modifications. This is particularly relevant because the modulation of the antenna size is one of the most important light acclimation responses in photosynthetic organisms. In our study, we used an Arabidopsis thaliana mutant ( dLhcb2 ), which has a 60% decrease of Lhcb1 and Lhcb2, the two main components of the major Photosystem II antenna complex. We show that the mutant maintains the photosynthetic and photoprotective capacity of the Wild Type (WT) and adapts to different light conditions by remodelling its photosynthetic apparatus, but the regulatory mechanism differs from that of the WT. Surprisingly, it does not compensate for the decreased light‐harvesting capacity by increasing other pigment‐protein complexes. Instead, it lowers the ratio of the cytochrome b6 f and ATP synthase to the photosystems, regulating linear electron flow and maintaining the photosynthetic control at the level of these complexes as in the WT. We show that targeting the reduction of two specific antenna proteins, Lhcb1 and Lhcb2, represents a viable solution to obtain plants with a truncated antenna size, which still maintain the capacity to acclimate to different light conditions. Abstract : Plants with reduced light‐harvesting complexes II (LHCII) content adapt to different light conditions using strategies different from WT plants, without modulating the pigment content. The reduction of LHCII can thus be a viable strategy to increase light‐use efficiency in the canopy.