Stimulatory effect of auxins and cytokinins on carotenes, with differential effects on xanthophylls in the green alga Chlorella pyrenoidosa Chick.

Abstract

Research concerning the influence of auxins and cytokinins on the content of carotenoids in <em>Chlorella pyrenoidosa</em> (<em>Chlorophyceae</em>) has been conducted. The strongest stimulating effect on carotenoids content in <em>Ch. pyrenoidosa</em> biomass was exerted by cytokinins (N-6-benzylaminopurine and N-6-furfurylaminopurine) and allantoin, weaker by auxins and their chemical analogues, and the weakest by tryptamine and 2,4-dichlorophenoxyacetic acid compared to the control. Under the influence of cytokinins the content of α- and β-carotene have been stimulated several times stronger than by auxins, and especially 2,4- dichlorophenoxyacetic acid and tryptamine. However, oxygen-rich xanthophylls content was most strongly reduced by cytokinins (60-70% in relation to the control) in the 20 day lasting of <em>Ch. pyrenoidosa</em> cultivation, similarly to auxins: 1-naphthaleneacetic acid, indole-3-butyric acid, 2,4- dichlorophenoxyacetic acid.