An efficient method for protoplast-mediated production of transformed castor bean (Ricinus communis) lines.

OBJECTIVE: The purpose of this study was to develop a method for the isolation, culture, and PEG-mediated protoplast transfection from leaves of in vitro-grown plants of Ricinus communis. RESULTS: Factors such as the enzymatic composition and the incubation time were evaluated. The enzymatic solution, containing 1.6% Cellulase-R10 and 0.8% Macerozyme-R10, with 16 h of incubation, was the best condition to achieve a high protoplast yield (481.16 × 104 protoplasts/g FW) with a high percentage of viability (95%). The combination and concentration of enzymes have been shown to affect the protoplast isolation efficiency significantly. Furthermore, we found that a higher number of protoplasts (8.5 × 105 protoplast/g FW) was obtained at a longer incubation time, but their viability decreased. We obtained a simple and efficient protocol to isolate protoplast from Ricinus communis leaves and culture. A PEG-mediated protoplast transfection protocol was also established to introduce plasmid DNA into Ricinus communis genotypes cultivated in Colombia. Thus, strengthening advances in the genetic improvement processes for this crop are presented.

Efficient direct shoot organogenesis and genetic stability in micropropagated sacha inchi (Plukenetia volubilis L.).

OBJECTIVE: It is necessary to improve biotech platforms based on in vitro cell tissue culture to support sacha inchi (Plukenetia volubilis L.) research programs and draw on the nutritional value of the high polyunsaturated fatty acid content of its oilseed. Here, we developed a rapid and efficient method for induction and direct in vitro shoot development for this species. RESULTS: Shoots were generated from hypocotyl explants. The highest organogenic response was obtained in woody plant medium supplemented with 1 mg/L thidiazuron and 0.5 mg/L zeatin supplemented with L-glutamine, adenine hemisulfate, and L-arginine. Shoots obtained using this medium were transferred and subcultivated with different concentrations of indole-3-butyric acid and 1-naphthylacetic acid for rooting. For the first time, a histological analysis was performed supporting direct organogenic development in this species. The plantlets obtained were transferred ex vitro with a survival percentage of 80%. The genetic stability of the plants recovered was confirmed by randomly amplified polymorphic DNA analysis. All results indicate that it would be possible to stimulate direct shoot formation from hypocotyls to support the sustainable use of this species.

Direct in vitro regeneration of castor bean plants (Ricinus communis) using epicotyls / Regeneração direta in-vitro de plantas de mamona ( Ricinus communis ) usando epicótilos

A regeneration protocol for castor bean plant (Ricinus communis) was successfully developed using epicotyl sections obtained from in vitro seedlings. The maximum number of induced shoots (4.3 shoots/explant) and highest shoots frequency (75,56%) was obtained in WPM medium supplemented with TDZ (1 mg/L) and zeatin (0.5 mg/L), whereas the minimum number (0.8 shoots/explant) and lowest shoots frequency (37,78%) was obtained in medium containing TDZ (1 mg/L) and BAP (0.5 mg/L). The highest percentage of rooting (93.3%) was obtained in a medium containing IBA (1 mg/L). These plants were transplanted in a mesh house and achieved a high adaptability to acclimatization, reaching 77% survival. On the other hand, the maximum elongation (height) during this stage was 7.9 cm in plants supplemented with WPM nutrients, whereas it was only 4.38 cm in control plants

Foi desenvolvido com sucesso um protocolo de regeneração para a planta de Mamona (Ricinus communis) utilizando seções de epicótilos, obtidas a partir de mudas in vitro. O número máximo de brotações induzidas (4.3 brotos/explante), assim como a maior frequência de brotações (75,56%), foi obtido em meio WPM suplementado com TDZ (1 mg/L) e zeatina (0,5 mg/L). Enquanto que o número mínimo (0,8 brotos/explante), como a menor freqüência de rebentos (37,78%), foi obtido em meio contendo TDZ (1 mg/L) e BAP (0,5 mg/L). Adicionalmente, a maior percentagem de enraizamento (93,3%) foi obtida em um meio contendo IBA (1 mg/L). Depois da regeneração, as plantas foram transplantadas em casa de vegetação e conseguiram uma alta adaptabilidade e aclimatização, atingindo 77% de sobrevivência. Por outro lado, oalongamento máximo (altura) durante este estágio foi de 7,9 cm em plantas suplementadas com nutrientes de WPM, enquanto as plantas de controle presentaram apenas 4,38 cm