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- Produção de metabolitos de stress por culturas de células em suspençaõ de Ononis natrix L. SSP. Ramosíssima e Hyoscyamus albus L.Publication . Miguel, Maria Graça; Barroso, J. G.
- Accumulation of stress metabolites in cell-suspension cultures of hyoscyamus-albusPublication . Miguel, Maria Graça; Barroso, J. G.Cell suspension cultures of Hyoscyamus albus treated with freeze-dried Phytophthora cinnamomi autoclaved mycelium of freeze-dried Candida albicans autoclaved cells accumulated mainly lubimin and 10-epilubimun, along with small amounts of rishitin and solavetivone. Cultures treated with cellulase did not accumulate any of the reported compounds. The pattern and the amount of sesquiterpenoids produced were dependent on cell growth stage, incubation time with the elicitor and elicitor concentration. Higher yields of lubimin and 10-epilubimin occurred in cultures inoculated two days after subculturing and incubated for 48 hr. Some elicitor-treated cultures and old untreated ones accumulated acetophenones: acetovanillone, acetosyringone and hydroxyacetosyringone.
- Cell-suspension cultures of ononis-natrix L subspecies ramosissima Establishment and culture conditionsPublication . Miguel, Maria Graça; Barroso, J. G.Explants from petioles, folioles or hypocotyls of Ononis natrix have been used for calli initiation. Hypocotyls inoculated on MS medium supplemented with 2% sucrose and 0.5 mg.l-1 2,4-D/1 mg.l-1 Kin showed to be the best primary explant. Cell suspension cultures were established in MS basal medium supplemented with 2% sucrose, 0.5 mg.l-1 NAA or 2,4-D and 1 mg.l-1 Kin. Different subculturing periods, inoculum density, hormonal supplementation and sucrose concentration were assayed in order to obtain the best culture growth conditions. The optimal conditions were achieved with cultures initiated with 40 g.l-1 of initial inoculum, growing in MS basal medium supplemented with 4% sucrose, 0.5 mg.l-1 NAA and 1 mg.1-1 Kin subcultured every twelve days. Under these experimental conditions, the cultures showed a doubling time of 36.3 hours.
- Proteolytic and clotting activities of cell suspension cultures of Ficus carica under stress saline conditionsPublication . Miguel, Maria Graça; Lima Costa, Maria EmíliaThe latex of fig trees can be used for cheese making due to the presence of ficin, a proteolytic enzyme. The objective of this work was to establish cell suspension cultures of F. carica to obtain the plant proteases and study the milk clotting proteases from these cultures under saline stress conditions. Cell suspension cultures of F. carica were established from calli maintained in GD (Gresshoff and Doy, 1972) basal medium, supplemented with 30 g/l sucrose, 0.01 mg/l NAA and 1 mg/l BA. Cell suspension cultures maintained in GD basal medium, supplemented with 30 g/l sucrose, 0.01 mg/l NAA and 1 mg/l BA or in Gamborg's B5 medium (Gamborg et al., 1968) supplemented with 20 g/l sucrose, 0.5 mg/l and 0.2 mg/l Kin were characterized by determining several parameters; fresh weight, dry weight, intracellular protein and consumption of nitrate, ammonium, and other nutrients from the medium. At the same time, the proteolytic and coagulant activities were determined on these cultures as well as on the others submitted at different concentrations of sodium chloride. The cultures maintained in GD medium induced a lower production of biomass either in terms of fresh or dry weight than those maintained in Gamborg's B5 medium as well as a slower mobilization of nutrients from the culture medium. The cultures maintained in Gamborg's B5 medium seem to have higher proteolytic activity than those maintained in GD medium, however, the clotting activity on milk seems to be similar. The proteolytic activity was changed by the presence of sodium chloride.