Adjustment of photosynthetic activity to drought and fluctuating light in wheat

Michele Grieco, Valentin Roustan, Georgi Dermendjiev, Sanna Rantala, Arpit Jain, Manuela Leonardelli, Kerstin Neumann, Vitus Berger, Doris Engelmeier, Gert Bachmann, Ingo Ebersberger, Eva-Mari Aro, Wolfram Weckwerth, Markus Teige

Drought is a major cause of losses in crop yield. Under field conditions, plants exposed to drought are usually also experiencing rapid changes in light intensity. Accordingly, plants need to acclimate to both, drought and light stress. Two crucial mechanisms in plant acclimation to changes in light conditions comprise thylakoid protein phosphorylation and dissipation of light energy as heat by non-photochemical quenching (NPQ). Here, we analyzed the acclimation efficacy of two different wheat varieties, by applying fluctuating light for analysis of plants, which had been subjected to a slowly developing drought stress as it usually occurs in the field. This novel approach allowed us to distinguish four drought phases, which are critical for grain yield, and to discover acclimatory responses which are independent of photodamage. In short-term, under fluctuating light, the slowdown of NPQ relaxation adjusts the photosynthetic activity to the reduced metabolic capacity. In long-term, the photosynthetic machinery acquires a drought-specific configuration by changing the PSII-LHCII phosphorylation pattern together with protein stoichiometry. Therefore, the fine-tuning of NPQ relaxation and PSII-LHCII phosphorylation pattern represent promising traits for future crop breeding strategies.

Functional and Evolutionary Ecology, Department of Biochemistry and Cell Biology, Research Platform Vienna Metabolomics Center, Large-Instrument Facility for Mass Spectrometry in Life Sciences
External organisation(s)
Leibniz Inst Plant Genet & Crop Plant Res IPK, Leibniz Institut fur Pflanzengenetik und Kulturpflanzenforschung, Dept Genebank, University of Turku, Johann Wolfgang Goethe-Universität Frankfurt am Main, Senckenberg Forschungsinstitut und Naturmuseum, Universität Wien, Max F. Perutz Laboratories GmbH (MFPL)
Plant Cell and Environment
No. of pages
Publication date
Peer reviewed
Austrian Fields of Science 2012
106031 Plant physiology, 106030 Plant ecology, 106002 Biochemistry, 106044 Systems biology
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