Changes in cytokinin and auxin concentrations in seaweed concentrates when stored at an elevated temperature

0109756 - UEB-Q 20043098 RIV US eng J - Journal Article
Stirk, W. A. - Arthur, G. D. - Lourens, A. F. - Novák, Ondřej - Strnad, Miroslav - van Staden, J.
Changes in cytokinin and auxin concentrations in seaweed concentrates when stored at an elevated temperature.
[Changes in cytokinin and auxin concentrations in seaweed concentrates when stored at an elevated temperature.]
Journal of Phycology. Roč. 16, č. 1 (2004), s. 31-39. ISSN 0022-3646. E-ISSN 1529-8817
R&D Projects: GA ČR GA522/03/0323
Institutional research plan: CEZ:AV0Z5038910
Keywords : accelerated storage * auxins * cytokinins
Subject RIV: EF - Botanics
Impact factor: 2.490, year: 2004

Two seaweed concentrates were made from the kelps Ecklonia maxima and Macrocystis pyrifera using a cell burst method. Cytokinin- and auxin-like activities were measured using the soybean callus and mungbean bioassays, respectively. Cytokinin-like activity was detected in both seaweed concentrates, being equivalent to approximately 50 μg L-1 kinetin. Auxin-like activity was also detected in both concentrates with the E. maxima derived concentrate having higher biological activity, equivalent to 10-5ů10-4 M indole-butyric acid. Two replicates of each concentrate were stored at 54 °C for 14 days to accelerate the effects of storage. Both fresh and stored samples of the two seaweed concentrates were analysed for their endogenous cytokinin and auxin content. The samples were purified using a combined DEAE-Sephadex octadecylsilica column and immunoaffinity chromatography based on wide-range cytokinin and IAA specific monoclonal antibodies. These extracts were analysed by HPLC linked to a Micromass single quadrupole mass spectrophotometer. Eighteen and nineteen different cytokinins were detected, respectively, in the two concentrates, with trans-zeatin-O-glucoside being the main cytokinin present. Accelerated storage of the concentrates caused an increase in the total cytokinin concentration with a large increase in the aromatic meta-topolin. Indole-3-acetic acid was the main auxin in both seaweed concentrates. Indole conjugates, including amino acid conjugates, were also quantified. The total auxin concentration decreased with accelerated storage for both concentrates.

Changes in cytokinin and auxin concentrations in seaweed concentrates when stored at an elevated temperature.
Permanent Link: http://hdl.handle.net/11104/0016864