RESUMO
This paper purposes suitable conditions for callus induction and co-cultivation with Agrobacterium tumefaciens of J-104 rice cultivar. It was evaluated the effect of different concentrations of 2.4-D and agar, and the inclusion of L-proline and L-glutamine in callus culture medium. The use of 2.5 mg/L 2.4-D and 0.8% agar allowed the highest percentage of embryogenic calli. Callus formation was improved considerably with 500 mg/L of L-proline and L-glutamine in the culture medium. Different factors were studied throughout co-cultivation of calli with A. tumefaciens: inoculation time, co-cultivation temperature, concentration of acetosyringone and co-cultivation period. Transient GUS expression was quantified by fluorometry in all co-cultivated calli. The best results were obtained with the following conditions: 10 min as inoculation time, 100µM acetosyringone in co-cultivation medium, temperature of 20ºC, and 3 days as co-cultivation period.
Se describen las condiciones óptimas para la callogénesis y cocultivo de callos con Agrobacterium tume-faciens de la variedad de arroz J-104. Se determinó el efecto de diferentes concentraciones de 2.4-D, agar y de L-prolina y L-glutamina en el medio de cultivo de callos. El uso de 2,5 mg/L de 2.4-D y 0,8% de agar permitió lograr el porcentaje más alto de callos embriogénicos. La formación de callos fue mejorada considerablemente con la adición de 500 mg/L de L-prolina e igual concentración de L-glutamina en el medio de cultivo. Se estudiaron diferentes factores en el cocultivo de los callos con A. tumefaciens: tiempo de inoculación, concentración de acetosiringona, temperatura y tiempo de cocultivo. Para comparar el efecto de cada factor sobre la expresión GUS se cuantificó la actividad transitoria mediante fluorimetría. Los valores más altos de actividad fluorimétrica fueron obtenidos con las siguientes condiciones: 10 min de inoculación, 100µM de acetosiringona en el medio de cocultivo y 3 días de cocultivo a 20 ºC.
Assuntos
Técnicas de Cocultura/classificação , Técnicas de Cocultura/métodosRESUMO
Digestive endoprotease activities of the rice water weevil, Lissorhoptrus brevirostris Suffrian (Coleoptera: Curculionidae), were characterized based on the ability of gut extracts to hydrolyze specific synthetic substrates, optimal pH, and hydrolysis sensitivity to protease inhibitors. Larvae of this species were found to use a complex proteolytic system that includes cathepsin D-, cathepsin B-, trypsin-, and chymotrypsin-like activities. Trypsin-like activity was evenly distributed among the anterior, middle, and posterior portions of the gut, whereas cathepsin B- and cathepsin D-like activities were mainly located in the anterior and middle sections, and the chymotrypsin-like activity was highest in the middle and posterior sections. Gelatin-containing native-PAGE gels indicated the presence of several aspartyl, cysteine, and serine protease forms and confirmed the spatial organization of the proteolytic digestive process.