title: Plant regeneration and biochemical accumulation of hydroxybenzoic and hydroxycinnamic acid derivatives in Hypoxis hemerocallidea organ and callus cultures.
abstract: Micropropagation of Hypoxis hemerocallidea Fisch. and C.A. Mey was used as a model system to study the influence of cytokinins (CKs) on plant regeneration and biochemical accumulation of hydroxybenzoic and hydroxycinnamic acid derivatives in organ and callus cultures and their antioxidant activity. Fourteen free phenolic acids were detected using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) while antioxidant activity was evaluated using oxygen radical absorbance capacity (ORAC) and 2,2-diphenyl-1-picryl hydrazyl (DPPH) radical scavenging activity. Cytokinins had a significant effect on the biochemical accumulation of hydroxybenzoic and hydroxycinnamic acid derivatives in H. hemerocallidea organ cultures. In particular, meta-topolin-treated organ cultures produced high concentrations of gallic, protocatechuic, gentisic, p-hydroxybenzoic, m-hydroxybenzoic, salicylic, chlorogenic and trans-cinnamic acids. The isoprenoid CK, N(6)-(2-isopentenyl)-adenine significantly increased the accumulation of hydroxycinnamic acid derivatives, namely, caffeic, p-coumaric, sinapic and ferulic acids. Cytokinin-treated organ cultures exhibited a significant increase in antioxidant activity, particularly in the ORAC model. In callus cultures, CKs decreased the concentrations of hydroxycinnamic acid derivatives and antioxidant activity when compared to the control. Overall, both CK type and concentration had a significant effect on plant regeneration, callus proliferation, biochemical accumulation of free phenolic acids and antioxidant activity of the resultant extracts.
authors.affiliation: Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa.
authors.forename: Mack
authors.initials: M
authors.lastname: Moyo
authors.affiliation: Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa.
authors.forename: Stephen O
authors.initials: SO
authors.lastname: Amoo
authors.affiliation: Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa.
authors.forename: Adeyemi O
authors.initials: AO
authors.lastname: Aremu
authors.affiliation: Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University and Institute of Experimental Botany, Academy of Sciences of Czech Republic Šlechtitelů 11, 783 71 Olomouc-Holice, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Gruz
authors.affiliation: Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University and Institute of Experimental Botany, Academy of Sciences of Czech Republic Šlechtitelů 11, 783 71 Olomouc-Holice, Czech Republic.
authors.forename: Michaela
authors.initials: M
authors.lastname: Subrtová
authors.affiliation: Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University and Institute of Experimental Botany, Academy of Sciences of Czech Republic Šlechtitelů 11, 783 71 Olomouc-Holice, Czech Republic.
authors.forename: Karel
authors.initials: K
authors.lastname: Doležal
authors.affiliation: Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa. Electronic address: rcpgd@ukzn.ac.za.
authors.forename: Johannes
authors.initials: J
authors.lastname: Van Staden
mesh_terms: D000975:Antioxidants / Q000378:metabolism* / Q000494:pharmacology; D001713:Biphenyl Compounds / Q000378:metabolism; D003373:Coumaric Acids / Q000378:metabolism* / Q000494:pharmacology; D003583:Cytokinins / Q000494:pharmacology*; D062385:Hydroxybenzoates / Q000378:metabolism* / Q000494:pharmacology; D027802:Hypoxis / Q000254:growth & development / Q000378:metabolism*; D007541:Isopentenyladenosine / Q000494:pharmacology; D010636:Phenols / Q000378:metabolism* / Q000494:pharmacology; D010851:Picrates / Q000378:metabolism; D010937:Plant Growth Regulators / Q000494:pharmacology*; D058439:Plant Somatic Embryogenesis Techniques; D018514:Plant Structures / Q000254:growth & development / Q000378:metabolism; D012038:Regeneration
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D003373:Coumaric Acids; D003583:Cytokinins; D062385:Hydroxybenzoates; D010636:Phenols; D010851:Picrates; D010937:Plant Growth Regulators; C001478:N(6)-(delta(2)-isopentenyl)adenine; D007541:Isopentenyladenosine; C004931:1,1-diphenyl-2-picrylhydrazyl
keywords: Antioxidants; Hydroxybenzoic acids; Hydroxycinnamic acids; Hypoxidaceae; Organogenesis; Secondary metabolites