In vitro conditions affect photosynthetic performance and crassulacean acid metabolism in Mammillaria gracilis Pfeiff. tissues |
| |
Authors: | Biljana Balen Mirta Tkalec Petra Peharec ?tefani? ?eljka Vidakovi?-Cifrek Marijana Krsnik-Rasol |
| |
Institution: | 1. Division of Biology, Department of Molecular Biology, Faculty of Science, University of Zagreb, Horvatovac 102a, HR-10000, Zagreb, Croatia 2. Division of Biology, Department of Botany, Faculty of Science, University of Zagreb, Rooseveltov trg 6, HR-10000, Zagreb, Croatia
|
| |
Abstract: | Mammillaria gracilis Pfeiff. plants cultivated in the pot (pot plants, PP), as well as in vitro-grown normal shoots (NS), habituated callus (HC), hyperhydric shoots (HS), and tumour tissue (TT) were investigated in order to reveal the influence of in vitro culture on functionality of the photosynthetic apparatus and CAM photosynthesis in cactus M. gracilis Pfeiff. Photosynthetic pigments content as well as maximum (F v/F m) and effective (??PSII) quantum yield of photosystem II (PSII) decreased in all in vitro-grown tissues in comparison to PP. The decrease observed in hyperhydric HC, HS and TT correlated with a low expression of Rubisco large subunit (RbcL) and ?? subunit of ATP synthase (?? ATP synt) and almost undetectable levels of protein D1, light-harvesting chlorophyll a/b-binding protein (LHCII) and cytochrome f protein of thylakoid Cyt b 6 /f-complex (Cyt f) found in these tissues. As for crassulacean acid metabolism (CAM) pattern, PP and NS expressed diurnal acid fluctuation, while HC, HS and TT failed to show it. Nevertheless, all M. gracilis tissues exhibited diurnal changes of phosphoenolpyruvate carboxylase (PEPC) activity indicating the typical CAM physiology. In conclusion, the photosynthesis was down-regulated in all in vitro-grown tissues. NS maintained typical CAM photosynthesis, while HC, HS and TT withheld PEPC activity, but not acid accumulation specific for CAM. Minor changes observed in NS in comparison to PP could be attributed to the sugar supplementation while the more prominent deviations found in HC, HS and TT could be correlated with hyperhydricity and the loss of characteristic tissue organisation pattern. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|