Expressão do gene ASYMMETRIC LEAVES1 (AS1) em explantes radiculares de Passiflora edulis Sims e organogênese in vitro em Passiflora setacea D.C. (Passifloraceae)

• Ano de defesa: 2011
• Autor(a) principal: Vieira, Lorena Melo
• Orientador(a): Otoni, Wagner Campos
• Banca de defesa: Dias, Leonardo Lucas Carnevalli
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Botânica
• Departamento: Botânica estrutural; Ecologia e Sistemática
• País: BR
• Palavras-chave em Português: Passifloraceae; ASYMMETRIC LEAVES1; Organogênese in vitro; Citometria de fluxo
• Palavras-chave em Inglês: Passifloraceae; ASYMMETRIC LEAVES1; Organogenesis in vitro; Flow cytometry
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BOTANICA
• Link de acesso: http://locus.ufv.br/handle/123456789/2526

This study aimed to characterize the expression of ASYMMETRIC LEAVES1 (PeAS1) gene via in situ hybridization, during in vitro regeneration from root segments of Passiflora edulis Sims, a species typically commercial, and establish a protocol which could be repeated, via organogenesis in vitro in Passiflora setacea, a wild species. Root explants from P. edulis were cultured on MS medium for organogenesis induction in branches, supplemented with 2.35 mM BA. For PeAS1 gene detection by in situ hybridization it was produced an antisense probe, using cDNA fragments that had 900 pb. The visualization of the hybridization signal was obtained using a commercial solution of NBT / BCIP as a substrate for alkaline phosphatase. After 12 days on induction medium, meristems were formed via direct organogenesis. In this group of cells, the immunodetection positive reaction on in situ hybridization showed the presence of gene transcripts PeAS1. In buds that has its sources in meristems, PeAS1 gene was expressed in dome and leaf primordia regions, after 25 days of cultivation. For induction of organogenesis in vitro in P. setacea, leaf, hypocotyl and root explants were cultured on MS medium supplemented with 4.44 mM benzylaminopurine (BA), 2.27 mM thidiazuron (TDZ) or in combination with BA (4.44 mM) + TDZ (2. 27 mM) under two distinct light conditions (16h light and dark). For the control treatment, there was no addition of plant growth regulator. Patterns of direct and indirect regeneration were observed in hypocotyls and root. Leaf explants, regeneration only occurred from callus. In hypocotyls, the media supplemented with BA at light condition or BA + TDZ in both incubation conditions provided a higher average of shoots. In root explants, the highest frequency of regeneration was observed when it was cultured in BA + TDZ at light medium. However, under these conditions, the analysis of flow cytometry showed an increase in the average amount of nuclear DNA, in two of five regenerants analyzed, when compared to material derived from seeds. The same medium composition and incubation conditions did not induce polyploidy in regenerating from hypocotyls. It is concluded that the explant type, composition of culture medium and incubation conditions had influence on in vitro morphogenesis of Passiflora setacea. This paper describes, for the first time, information on the molecular aspects of organogenic process from root explants in P. edulis, as well obtaining organogenesis in vitro and characterization of the genetic stability of regenerants from P. setacea. These advances enable the employment of this wild species in breeding programs.