Naslov
Morpho-physiological reactions to phosphate limitation and resulting implications for diatom life strategies

Autori
Kužat, Nataša ; Smodlaka Tanković, Mirta ; Baričević, Ana ; Ivančić, Ingrid ; Pustijanac, Emina ; Kušpilić, Grozdan ; Novak, Tihana ; Gašparović, Blaženka ; Medić, Nikola ; Marić Pfannkuchen, Daniela ; Pfannkuchen, Martin

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Abstracts of the 25th International Diatom Symposium / Kusber, W.-H. ; Abarca, N. ; Van, A. L. ; Jahn, R. - Berlin : BGBM Press Botanic Garden and Botanical Museum Berlin Freie Universität Berlin, 2018, 95-95

ISBN
978-3-946292-27-2

Skup
25th International Diatom Symposium

Mjesto i datum
Berlin, Njemačka, 25.06.2018. - 30.06.2018

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
fitoplankton ; Jadransko more ; dijatomeje ; Cheatoceros ; Leptocylindrus ; APA ; limitacija fosforom
(phytoplankton ; Adriatic Sea ; diatoms ; Chaetoceros ; Leptocylindrus ; APA ; P limitation)

Sažetak
The northern Adriatic is characterized by a multitude of steep and quickly-changing gradients (e.g. nutrients), both temporal and spatial. The current systems and the major freshwater input (River Po), in particular, generate strong gradients in nutrient concentrations with an expressed N/P imbalance and sustained phosphate limitation. This results in a highly structured planktonic ecosystem that allows us to investigate the performance of planktonic species along those gradients and in contrasting conditions. We analyzed several diatom species with respect to their metabolic reaction towards phosphate limitation. Here we report data on species specific growth rates under different nutrient regimes, phosphate uptake rates, alkaline phosphatase activity, localization and activation patterns and characteristics of alkaline phosphatase activity as well as on morphological reactions to phosphate stress. The Leptocylindrus danicus Cleve species complex and Chaetoceros peruvianus Brightw. are two common taxa/species in the northern Adriatic. We compared their performance in situ as well as performed phosphate limitation experiments ex situ. Physiological changes observed include changes in generation time, expression of alkaline phosphatase as well as morphological reactions to phosphate limitation. L. danicus species complex showed cell and chain elongation in phosphate limitation, while C. peruvianus showed elongation of setae and apical axis. We could demonstrate that both morphological changes are increasing volumes and surface areas, where alkaline phosphatase activity is localized and thus increase the species’ capability to make use of organic phosphate resources. In the case of C. peruvianus, the morphological changes resemble the transition between two described variabilities, (C. peruvianus var. peruvianus and C. peruvianus var. gracilis Schröd.). Our results show that careful morphological analysis of in situ samples can be a good indicator for the detection of specific and complex ecological circumstances like e.g. phosphate limitation. We furthermore combine the results of our physiological experiments and in situ performance analyses into a model for the life strategies of L. danicus species complex and C. peruvianus.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Biologija, Interdisciplinarne prirodne znanosti

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