RESUMEN
Intracellular content of hydrogen peroxide and of the product of lipid peroxidation malonic dialdehyde as well as activity of antioxidant enzymes catalase, ascorbate peroxidase, and superoxide dismutase were studied in cells of morphogenic and derived from them non-morphogenic calluses of tatar buckwheat Fagopyrum tataricum L. Non-morphogenic calluses were characterized by significantly higher content of hydrogen peroxide and malonic dialdehyde, low catalase activity, and high activity of superoxide dismutase compared to morphogenic cultures. The results may indicate that cells of non-morphogenic calluses are in the state of continuous oxidative stress. Nevertheless, proliferative activity of non-morphogenic cultures and the biomass increase significantly exceeded these parameters in morphogenic calluses. An analogy is drawn between animal cancer cells and non-morphogenic plant calluses.
Asunto(s)
Fagopyrum/embriología , Morfogénesis/fisiología , Estrés Oxidativo/fisiología , Especies Reactivas de Oxígeno/metabolismo , Ascorbato Peroxidasas , Biomasa , Catalasa/metabolismo , Proliferación Celular , Células Cultivadas , Cromosomas de las Plantas , Fagopyrum/metabolismo , Peróxido de Hidrógeno/metabolismo , Peróxidos Lipídicos/metabolismo , Malondialdehído/metabolismo , Índice Mitótico , Oxidación-Reducción , Peroxidasas/metabolismo , Proteínas de Plantas/metabolismo , Superóxido Dismutasa/metabolismoRESUMEN
Arabinogalactan proteins (AGPs) are highly glycosylated hydroxyproline-containing variously located proteoglycans dynamically regulated in the course of plant ontogenesis. Special functions of AGPs are still unclear, but their involvement in vegetative growth and reproduction of plants is well established. This review considers data on the structure, biosynthesis, and metabolism of AGPs. Special attention is given to involvement of AGPs in growth and morphogenesis, and possible mechanisms of their regulatory action are considered. AGPs are also compared with animal proteoglycans.
Asunto(s)
Morfogénesis , Mucoproteínas/fisiología , Desarrollo de la Planta , Fenómenos Fisiológicos de las Plantas , Animales , Humanos , Mucoproteínas/química , Células Vegetales , Proteínas de Plantas/química , Proteínas de Plantas/fisiología , Proteoglicanos/química , Proteoglicanos/fisiología , Transducción de Señal , Relación Estructura-ActividadRESUMEN
The effect of salicylic acid on the content of soluble proteins and individual polypeptides in Tatar buckwheat Fagopyrum tataricum calluses differing in ability for morphogenesis was studied. Changes in the protein composition of the calluses cultivated in the dark and in the light indicated the higher sensitivity of the non-morphogenic callus. Different response of callus cultures to salicylic acid and conditions of cultivation (light, darkness) is suggested to be associated with the antioxidant defense system, which is, in particular, characterized by the hydrogen peroxide content in the calluses. Salicylic acid increased the H2O2 content in non-morphogenic calluses more strongly than in morphogenic calluses, and the difference was more significant for the calluses cultivated in the light.
Asunto(s)
Fagopyrum/efectos de los fármacos , Fagopyrum/crecimiento & desarrollo , Morfogénesis/efectos de los fármacos , Proteínas de Plantas/efectos de los fármacos , Ácido Salicílico/farmacología , Oscuridad , Fagopyrum/metabolismo , Peróxido de Hidrógeno/metabolismo , Luz , Proteínas de Plantas/metabolismo , SolubilidadRESUMEN
Buckwheat (Fagopyrum esculentum Moench.) thin cell-layers (TCLs) cultured individually in a liquid medium were used to test the root-inducing activity of pectic polysaccharides with a degree of polymerization (DP) of 20-25, isolated from pea (Pisum sativum L.) stem cell walls. These pectic fragments induced more rapid root formation on the explants in comparison with untreated controls. This pectic fragment treatment also promoted root growth as measured by both fresh and dry weights and about doubled the number of roots formed. This buckwheat TCL system is proposed as a new bioassay for oligosaccharins due to its sensitivity, reproducibility and ease of preparation.