Influência do etileno e de poliaminas sobre a morfogênese in vitro do maracujá (Passiflora sp.)

• Ano de defesa: 2006
• Autor(a) principal: Dias, Leonardo Lucas Carnevalli
• Orientador(a): Otoni, Wagner Campos
• Banca de defesa: Floh, Eny Iochevet Segal , Barros, Raimundo Santos , Picoli, Edgard Augusto de Toledo , Vieira, Gerival
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Fisiologia Vegetal
• Departamento: Controle da maturação e senescência em órgãos perecíveis; Fisiologia molecular de plantas superiores
• País: BR
• Palavras-chave em Português: Passiflora cincinnata; Poliaminas; Etileno
• Palavras-chave em Inglês: Passiflora cincinnata; Polyamines; Ethylene
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BOTANICA::FISIOLOGIA VEGETAL
• Link de acesso: http://locus.ufv.br/handle/123456789/4293

The present study was conducted to evaluate possible interactions between ethylene and polyamines levels upon in vitro morphogenesis of two passion fruit species (Passiflora cincinnata Masters and P. edulis Sims f. flavicarpa Degener, population FB-100). Hypocotyl-derived segments (average 10 mm length) were cultivated in MS-based medium, with B5 vitamin complex, 30 g.L-1 sucrose, 100 mg.L-1 myo-inositol, 10% (v/v) coconut water, 0,5 mg.L-1 6-benzyladenine (BA) ), and solidified with 2.5 g L-1 Phytagel®. Ethylene and polyamines were assayed at different times in culture (3, 6, 9, 12, and 30 d). Aiming to characterize the shoot-buds differentiation histological analyses were performed with previous fixation of the samples in FAA 50%. The effects of ethylene inhibitor, promoter and scavenger (aminoethoxyvinilglycine AVG, silver tiosulfate STS, 1-aminocyclopropane-1-carboxylic acid ACC, and mercury perchlorate- MP, respectively), polyamines (spermine, spermidine and putrescine) and its inhibitor (methylglyoxal-bis-guanylhydrazone - MGBG) were also analysed. A delayed organogenic response occurred in explants of P. edulis f. flavicarpa as compared to P. cincinnata, though coincident with a delayed detection of ethylene and polyamine in cultures of the former. Similar morphogenic responses were observed in explants cultured onto AVG- or MPsupplemented medium, whereas ACC-treated cultures impaired organogenic responses. Polyamine-supplemented cultures displayed morphogenic responses similar to those from control treatment. However, MGBG similarly to ACC lessened the morphogenic responses. Interestingly, explants at redifferentiation stages displayed high expansion and elongation rates, linked to elevated ethylene and polyamine, suggesting that competition between their biosynthetic pathways is highly regulated and plastic, and that these interactions may play a key role in differentiation process.