Caracterização isozimática e atividade de peroxidase em folhas de plantas hiperídrica, intermediária e normal de Bidens pilosa L. mantidas in vitro

Abstract

RESUMOForam caracterizadas as plantas: hiperídrica, intermediária e normal de um clone de Bidens pilosa mantido em cultivo in vitro por meio de isozimas e da atividade de peroxidase. Empregando-se a eletroforese em géis de amido a 12%, testou-se seis isozimas, sendo detectado polimorfismo em peroxidase e fosfatase ácida, permitindo caracterizar cada tipo de planta. Não houve polimorfismo em fosfogluco isomerase, fosfoglucomutase, glutamato oxaloacetato transaminase e malato desidrogenase. A atividade da peroxidase foi maior nas plantas hiperídricas e intermediárias. Conclui-se que a variabilidade enzimática tem potencial como marcador de hiperidricidade em plantas mantidas in vitro.Termos para indexação: Isozima, hiperidricidade, vitrificação. ABSTRACTActivity of peroxidase (EC 1.11.1.7) and isozymes analysis of a Bidens pilosa clone maintained in vitro culture were characterized in hyperhydric, intermediary and normal plants. Electrophorese in starch gels (12%) of six isozymes systems was tested, polymorphisms in peroxidase and acid phosphatase (EC 3.1.3.2) were detected. There was absence of polymorphism in phosphoglucoisomerase (EC 5.3.1.9), phosphoglucomutase (EC 5.4.2.2), glutamate oxaloacetate transaminase (EC 2.6.1.1) and malate dehydrogenase (EC 1.1.1.37). Comparing the activity of peroxidase enzyme, it was higher in hyperhydric and intermediary plants in relation to normal ones. Enzymatic variability is a potential tool as hyperhydricity marker in plants grown in vitro.

Gas Exchanges and Antioxidant Activity in <i>Copaifera langsdorffii</i> Desf. Seedlings after Flooding

“…Regarding the activity of the superoxide dismutase in the foliar and root tissues of the C. langsdorffii seedlings (Figure 6(a) and Figure 6(b)), it can be observed that, although they presented similar results, particularly in those seedlings flooded for 42 and 84 days throughout the experiment, the differences were more expressive in the leaves than in the roots, which allows to infer that this enzyme assumes different functions in different organs or cell compartments of the plants with different routes to the best adaptation to the environment [31] [32]. In the seedlings flooded for 42 days, it was observed that the enzymatic activity was more intense soon after the removal of the flooding condition suggesting a protective adaptation to this type of stress, which is confirmed, over time, The chlorophyll values of seedlings flooded for 63 and 84 days also decreased during the whole recovery period (Figure 7(c)), a direct expression of the damages caused by flooding, since conditions of water stress can favor the reduction of the contents of the photosynthetic pigments due to the oxidative damages they cause [36].…”

Gas exchange and antioxidant activity in seedlings of C opaifera langsdorffii Desf. under different water conditions

“…It is known, however, that adaptation to water stress might be related to the ability of plants to maintain high levels of antioxidants in their tissues, such as the enzymes superoxide dismutase, peroxidase, and catalase, thus, activity of such enzymes constitutes an important parameter for quantifying plant responses to environmental stresses (Shao et al 2007, Oliveira et al 2008, Pompelli et al 2010, Taiz and Zeiger 2013.…”

Castor bean (Ricinus communis L.) as a potential environmental bioindicator

“…Peroxidase activity, an indicator of oxidative stress, was analyzed with the methodology described by Oliveira et al (2008), with adaptations. Absorbance was read using a microplate reader for 96 wells (Microplate) at 492 nm; each reading was taken twice with a 2-min gap between readings.…”

“…NS = variation, but not only for peroxidase activity. The change in value obtained allowed for the verification of peroxidase activity, which is determined by changes from 0.01 to 0.02 u.a./min (Oliveira et al, 2008). …”