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UV-B radiation induces changes in polyamine metabolism in the red seaweed Porphyra cinnamomea

journal contribution
posted on 2023-05-18, 00:50 authored by Schweikert, K, Sutherland, J, Catriona HurdCatriona Hurd, Burritt, D
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. MechMechanisms of PA mediated UV-B protection are discussed.

History

Publication title

Plant Growth Regulation: An International Journal on Plant Growth and Development

Volume

65

Pagination

389-399

ISSN

0167-6903

Department/School

Institute for Marine and Antarctic Studies

Publisher

Kluwer Academic Publ

Place of publication

Van Godewijckstraat 30, Dordrecht, Netherlands, 3311 Gz

Rights statement

Copyright 2011 Springer Science+Business Media

Repository Status

  • Restricted

Socio-economic Objectives

Ecosystem adaptation to climate change

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    University Of Tasmania

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