title: Glutathione and abscisic acid supplementation influences somatic embryo maturation and hormone endogenous levels during somatic embryogenesis in Podocarpus lambertii Klotzsch ex Endl.
abstract: Here we propose a protocol for embryogenic cultures induction, proliferation and maturation for the Brazilian conifer Podocarpus lambertii, and investigated the effect of abscisic acid (ABA) and glutathione (GSH) supplementation on the maturation phase. ABA, zeatin (Z) and salicylic acid (SA) endogenous levels were quantified. Number of somatic embryos obtained in ABA-supplemented treatment was significant higher than in ABA-free treatment, showing the relevance of ABA supplementation during somatic embryos maturation. Histological analysis showed the stereotyped sequence of developmental stages in conifer somatic embryos, reaching the late torpedo-staged embryo. GSH supplementation in maturation culture medium improved the somatic embryos number and morphological features. GSH 0mM and GSH 0.1mM treatments correlated with a decreased ABA endogenous level during maturation, while GSH 0.5mM treatment showed constant levels. All treatments resulted in decreased Z endogenous levels, supporting the concept that cytokinins are important during the initial cell division but not for the later stages of embryo development. The lowest SA levels found in GSH 0.5mM treatment were coincident with early embryonic development, and this treatment resulted in the highest development of somatic embryos. Thus, a correlation between lower SA levels and improved somatic embryo formation can be hypothesized.
authors.affiliation: Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Centro de Ciências Agrárias, Universidade Federal de Santa Catarina, Florianópolis, SC, 88034-001, Brazil.
authors.forename: Hugo Pacheco de Freitas
authors.initials: HP
authors.lastname: Fraga
authors.affiliation: Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Centro de Ciências Agrárias, Universidade Federal de Santa Catarina, Florianópolis, SC, 88034-001, Brazil.
authors.forename: Leila do Nascimento
authors.initials: LD
authors.lastname: Vieira
authors.affiliation: Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Centro de Ciências Agrárias, Universidade Federal de Santa Catarina, Florianópolis, SC, 88034-001, Brazil.
authors.forename: Catarina Corrêa
authors.initials: CC
authors.lastname: Puttkammer
authors.affiliation: Laboratório de Fisiologia Vegetal, Empresa Brasileira de Pesquisa Agropecuária, Embrapa Uva e Vinho, Bento Gonçalves, RS, 95700-000, Brazil.
authors.forename: Henrique Pessoa
authors.initials: HP
authors.lastname: Dos Santos
authors.affiliation: Laboratório de Fisiologia Vegetal, Empresa Brasileira de Pesquisa Agropecuária, Embrapa Uva e Vinho, Bento Gonçalves, RS, 95700-000, Brazil.
authors.forename: Julio de Andrade
authors.initials: JA
authors.lastname: Garighan
authors.affiliation: Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Centro de Ciências Agrárias, Universidade Federal de Santa Catarina, Florianópolis, SC, 88034-001, Brazil. Electronic address: miguel.guerra@ufsc.br.
authors.forename: Miguel Pedro
authors.initials: MP
authors.lastname: Guerra
mesh_terms: D000040:Abscisic Acid / Q000008:administration & dosage*; D005978:Glutathione / Q000008:administration & dosage*; D058439:Plant Somatic Embryogenesis Techniques / Q000379:methods*; D064028:Tracheophyta / Q000187:drug effects / Q000196:embryology* / Q000378:metabolism
chemical_list: D000040:Abscisic Acid; D005978:Glutathione
keywords: Brazilian conifer; Embryonic development; In vitro culture; Micropropagation; Redox metabolism