Young leaves of tropical trees frequently appear red in color, with the redness disappearing as the leaves mature. During leaf expansion, plants may employ photoprotective mechanisms to cope with high light intensities; however, the variations in anthocyanin contents, nonphotochemical quenching (NPQ), and photorespiration during leaf expansion are poorly understood. Here, we investigated pigment contents, gas exchange, and chlorophyll (Chl) fluorescence in Woodfordia fruticosa leaves during their expansion. Young red leaves had significantly lower Chl content than that of expanding or mature leaves, but they accumulated significantly higher anthocyanins and dissipated more excited light energy through NPQ. As the leaves matured, net photosynthetic rate, total electron flow through PSII, and electron flow for
ribulose-1,5-bisphosphate oxygenation gradually increased. Our results provided evidence that photorespiration is of fundamental importance in regulating the photosynthetic electron flow and CO2 assimilation during leaf expansion., S.-B. Zhang, J.-L. Zhang., and Obsahuje seznam literatury
Modern tomato (Solanum lycopersicum L.) breeding has mainly focused on increasing productivity under unlimited watering. In contrast, some Mediterranean accessions have been traditionally cultivated under water shortage and selected on the basis of their water-use efficiency (WUE). Ramellet and Penjar landraces were planted with other traditional, old and modern inbreeds, under full irrigation. In order to found differences between the tomato accessions, gas-exchange and leaf morphology measurements were performed. Despite high variability, Ramellet and Penjar presented clear differences compared to modern cultivars, mostly related to leaf morphology and photosynthetic traits, while no differences were found in WUE. Results highlighted that better leaf CO2 conductance might be a main factor determining the improvement of net CO2 assimilation and WUE., M. Fullana-Pericàs, M. À. Conesa, S. Soler, M. Ribas-Carbó, A. Granell, J. Galmés., and Obsahuje bibliografii
During the last 12 years, 23 mollusc species were recorded in the Czech Republic for the first time. With the exception of several introduced and invasive species, some of these molluscs are native, rare and even endangered, including Pagodulina pagodula. This rare woodland snail of Alpine origin was found in spring 2012 in the Mutenská obora Nature Reserve, which includes the forested slopes above the Moravská Dyje River in South Moravia. This is another occurrence of the species outside its Alpine range, in addition to one site in Poland, two in Slovakia, and a few sites in Hungary and the Balkan Peninsula. The species was also recorded in the Czech Republic in several interglacial sediments of the Pleistocene and also in one profile of Holocene origin (Atlantic period), not far away from the recent site. and Adam Lacina, Michal Horsák.
Tuto otázku si kladou lidé již od počátku lidstva. Pro členy Laboratoře biochemie a molekulární biologie zárodečných buněk v Ústavu živočišné fyziologie a genetiky AV ČR v Liběchově je odpověď jasná, jelikož na počátek vzniku nového jedince nahlíží prostřednictvím molekulární biologie. První bylo vajíčko. and Denisa Jansová.
Již posedmé se sešla odborná porota složená z fotografů a zároveň vědců, aby zhodnotila příspěvky zaslané do soutěže Věda je krásná. Do ročníku 2015 bylo zasláno celkem 269 příspěvků. Z celkového počtu 7 kategorií patřilo pět výhradně zaměstnancům a studentům Univerzity Karlovy. Objevitelskou kategorii a kategorii Instagram, otevřenou široké veřejnosti, hodnotila porota složená z pracovníků Přírodovědecké fakulty UK v Praze. Diváci pak rozhodli o vítězi ve vlastním hlasování. Věda je krásná ale není jen soutěží mikrofotografií, velký prostor zůstává vymezen klasickým fotografiím a ilustracím, od r. 2014 také snímkům pořízeným ve výše zmíněné mobilní aplikaci., This competition run by the Faculty of Science at Charles University in Prague and its supportive web www.prirodovedci.cz aims to show the beauty and aesthetics revealed by scientific research, either via photography, illustrations or computerized visualizations of natural phenomena., and Michal Andrle.