In this work the role of xanthophyll cycle and its relation to the photosynthetic activity in the dominant species of a semiarid sandy grassland community (Potentillo-Festucetum pseudovinae) were studied during the stressful summer period. The total amount of xanthophyll cycle pigments (violaxanthin, anteraxanthin, zeaxanthin) related to total chlorophyll content (VAZ pool) showed considerable interspecific alterations and it was 2-3 times larger in the summer period than in spring. The changes in the xanthophyll cycle, the potential (Fv/Fm) and actual photochemical efficiency (ΔF/Fm') of PSII, as well as, the results of parallel measurements on their daily dynamics show that zeaxanthin has a major role in the photoinhibition in the photosynthetic apparatus during the summer stress on sandy grassland species. In July, the decreases of Fv/Fm was accompanied with increases of NPQ at the 100-120% extent depending on the species.
|Number of pages||2|
|Journal||Acta Biologica Szegediensis|
|Publication status||Published - jan. 1 2002|
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Agricultural and Biological Sciences(all)