title: Auxin and cytokinin relationships in 24 microalgal strains(1).
abstract: Endogenous auxins and cytokinins were quantitated in 24 axenic microalgal strains from the Chlorophyceae, Trebouxiophyceae, Ulvophyceae, and Charophyceae. These strains were in an exponential growth phase, being harvested on day 4. Acutodesmus acuminatus Mosonmagyaróvár Algal Culture Collection-41 (MACC) produced the highest biomass and Chlorococcum ellipsoideum MACC-712 the lowest biomass. The auxins, indole-3-acetic acid (IAA) and indole-3-acetamide (IAM) were present in all microalgal strains. No other auxin conjugates were detected. IAA and IAM concentrations varied greatly, ranging from 0.50 to 71.49 nmol IAA · g(-1) DW and 0.18 to 99.83 nmol IAM · g(-1) DW, respectively. In 19 strains, IAA occurred in higher concentrations than IAM. Nineteen cytokinins were identified in the microalgal strains. Total cytokinin concentrations varied, ranging from 0.29 nmol · g(-1) DW in Klebsormidium flaccidum MACC-692 to 21.40 nmol · g(-1) DW in Stigeoclonium nanum MACC-790. The general trend was that cis-zeatin types were the predominant cytokinins; isopentenyladenine-type cytokinins were present in moderate concentrations, while low levels of trans-zeatin-type and very low levels of dihydrozeatin-type cytokinins were detected. Ribotides were generally the main cytokinin conjugate forms present with the cytokinin free bases and ribosides present in similar but moderate levels. The levels of O-glucosides were low. Only one N-glucoside was detected, being present in nine strains in very low concentrations. In 15 strains, the auxin content was 2- to 4-fold higher than the cytokinin content.
authors.affiliation: Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, P/Bag X01, Scottsville, 3209, South Africa.
authors.forename: Wendy A
authors.initials: WA
authors.lastname: Stirk
authors.affiliation: Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, P/Bag X01, Scottsville, 3209, South Africa.|Institute of Plant Biology, Faculty of Agricultural and Food Science, University of West Hungary, Mosonmagyaróvár, H-9200, Hungary.
authors.forename: Vince
authors.initials: V
authors.lastname: Ördög
authors.affiliation: Laboratory of Growth Regulators, Palacký University & Institute of Experimental Botany AS CR, Šlechtitelů 11, Olomouc, CZ-783 71, Czech Republic.
authors.forename: Ondřej
authors.initials: O
authors.lastname: Novák
authors.affiliation: Laboratory of Growth Regulators, Palacký University & Institute of Experimental Botany AS CR, Šlechtitelů 11, Olomouc, CZ-783 71, Czech Republic.
authors.forename: Jakub
authors.initials: J
authors.lastname: Rolčík
authors.affiliation: Laboratory of Growth Regulators, Palacký University & Institute of Experimental Botany AS CR, Šlechtitelů 11, Olomouc, CZ-783 71, Czech Republic.|Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 11, Olomouc, CZ-783 71, Czech Republic.
authors.forename: Miroslav
authors.initials: M
authors.lastname: Strnad
authors.affiliation: Institute of Plant Biology, Faculty of Agricultural and Food Science, University of West Hungary, Mosonmagyaróvár, H-9200, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Bálint
authors.affiliation: Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, P/Bag X01, Scottsville, 3209, South Africa.
authors.forename: Johannes
authors.initials: J
authors.lastname: van Staden
keywords: auxins; cytokinin free bases; cytokinin ribotides; cytokinins; indole-3-acetamide; indole-3-acetic acid