Influência do etileno e de poliaminas sobre a morfogênese in vitro do maracujá (Passiflora sp.) / Morphogenesis in vitro of passion fruit (Passiflora sp.) as affected by ethylene and polyamines

AUTOR(ES)

Leonardo Lucas Carnevalli Dias

DATA DE PUBLICAÇÃO

2006

RESUMO

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.

ASSUNTO(S)

passiflora cincinnata etileno fisiologia vegetal passiflora cincinnata polyamines poliaminas ethylene

Documentos Relacionados

• Advances in passion fruit (Passiflora spp.) propagation
• Efeito do maracujá (Passiflora incarnata) sobre a morfometria de hepatócitos da tilápia do Nilo (Oreochromis niloticus)
• Genetic diversity in passion fruit (Passiflora spp.) evaluated by RAPD markers
• Estudo analítico dos flavonoides dos frutos do maracujá (Passiflora edulis Sims f. flavicarpa Degener)
• Respostas fisiológicas do maracujazeiro (Passiflora edulis SIMS) ao alagamento