caa a22 4500 445841966 CHVBK 20180317145347.0 cr unu---uuuuu 170323e20111101xx s 000 0 eng 10.1007/s10725-011-9614-x doi (NATIONALLICENCE)springer-10.1007/s10725-011-9614-x UV-B radiation induces changes in polyamine metabolism in the red seaweed Porphyra cinnamomea [Elektronische Daten] [K. Schweikert, J. Sutherland, C. Hurd, D. Burritt] Early investigations on the productivity of intertidal seaweeds found that, unlike some seaweeds, members of the genus Porphyra, a Rhodophyte, could tolerate physical stressors such as ultraviolet-B radiation (UV-B) both during immersion and when exposed to air. Increased stress tolerance was thought to be due to an unknown mechanism that operated at the thylakoid level. As recent research has shown that polyamines (PAs), bound to the thylakoid membranes of chloroplasts, play a critical role in protecting the photosynthetic apparatus from high-light and UV damage in both higher plants and in unicellular algae, we investigated PA metabolism in Porphyra cinnamomea exposed to UV-B. Our results show that PA biosynthesis was significantly upregulated in P. cinnamomea in response to UV-B, with the greatest proportional increases being in bound soluble putrescine (PUT), which increased by over 200%, in bound soluble spermidine (SPD) and spermine (SPM) which both increased by more than 150% and in bound insoluble SPM which increased by more than 120%. As PAs can be synthesised from ornithine via ornithine decarboxylase (ODC) or from arginine via arginine decarboxylase (ADC) we investigated the pathway via which polyamines were synthesised in P. cinnamomea. While exposure to UV-B caused increases in the activities of both ADC and ODC, the increase in ADC activity was 10 fold greater than that of ODC, suggesting that the ADC pathway was the principle route by which PA levels increased in response to UV-B. Mechanisms of PA mediated UV-B protection are discussed. Springer Science+Business Media B.V., 2011 Porphyra cinnamomea nationallicence Rhodophyta nationallicence Ultraviolet-B radiation nationallicence Polyamines nationallicence Ornithine decarboxylase nationallicence Arginine decarboxylase nationallicence ADC : Arginine decarboxylase nationallicence Bis : Bound-insoluble nationallicence Bs : Bound-soluble nationallicence ODC : Ornithine decarboxylase nationallicence PAs : Polyamines nationallicence PAR : Photosynthetically active radiation nationallicence PUT : Putrescine nationallicence SPD : Spermidine nationallicence SPM : Spermine nationallicence UV-A : Ultraviolet radiation A (400-315nm) nationallicence UV-B : Ultraviolet radiation B (315-280nm) nationallicence Schweikert K. Department of Botany, University of Otago, PO Box 56, Dunedin, New Zealand aut Sutherland J. School of Biological Sciences, University of Auckland, Auckland Mail Centre, Private Bag 92019, 1142, Auckland, New Zealand aut Hurd C. Department of Botany, University of Otago, PO Box 56, Dunedin, New Zealand aut Burritt D. Department of Botany, University of Otago, PO Box 56, Dunedin, New Zealand aut Plant Growth Regulation Springer Netherlands 65/2(2011-11-01), 389-399 0167-6903 65:2<389 2011 65 10725 https://doi.org/10.1007/s10725-011-9614-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10725-011-9614-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Schweikert K. Department of Botany, University of Otago, PO Box 56, Dunedin, New Zealand aut NATIONALLICENCE 700 1- Sutherland J. School of Biological Sciences, University of Auckland, Auckland Mail Centre, Private Bag 92019, 1142, Auckland, New Zealand aut NATIONALLICENCE 700 1- Hurd C. Department of Botany, University of Otago, PO Box 56, Dunedin, New Zealand aut NATIONALLICENCE 700 1- Burritt D. Department of Botany, University of Otago, PO Box 56, Dunedin, New Zealand aut NATIONALLICENCE 773 0- Plant Growth Regulation Springer Netherlands 65/2(2011-11-01), 389-399 0167-6903 65:2<389 2011 65 10725 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer