Acclimation of Norway spruce photosynthetic apparatus to the combined effect of high irradiance and temperature

0358656 - ÚVGZ 2012 RIV PT eng J - Journal Article
Štroch, M. - Vrábl, D. - Podolinská, J. - Kalina, J. - Urban, Otmar - Špunda, V.
Acclimation of Norway spruce photosynthetic apparatus to the combined effect of high irradiance and temperature.
Journal of Plant Physiology. Roč. 167, č. 8 (2010), s. 597-605. ISSN 0176-1617. E-ISSN 1618-1328
R&D Projects: GA ČR GA522/07/0759
Institutional research plan: CEZ:AV0Z60870520
Keywords : diurnal courses * picea abies * thermal acclimation * thermal energy dissipation * xanthophyll cycle
Subject RIV: ED - Physiology
Impact factor: 2.677, year: 2010

Diurnal courses of photosynthetic parameters, chlorophyll fluorescence and de-epoxidation state of xanthophyll cycle pigments (DEPS) were measured during the acclimation of spruce seedlings to regimes simulated cold cloudy days (LI treatment), cold sunny days (HI), and hot sunny days (HI-HT). Acclimation to HI and HI-HT led to a strong depression in CO2 assimilation (AN), particularly during noon and afternoon. Insufficient stomatal conductance was the main reason of reduced AN. Negligible changes in maximum photochemical efficiency of photosystem (PS) II support the resistance of spruce against PSII photoinhibition. The HI plants had higher content of xanthophyll cycle pigments (VAZ) and enhanced efficiency of thermal energy dissipation (D) that correlated with DEPS. In contrast, HI-HT plants had significantly lower D and DEPS values than HI plants. These results indicate a minor role of the xanthophyll-mediated thermal dissipation in PSII photoprotection under elevated temperatures.
Permanent Link: http://hdl.handle.net/11104/0196620