Antioxidant enzyme activity in germination of Dalbergia spruceana seeds under different temperatures

Clenes Cunha Lima,Eduardo Euclydes De Lima E Borges,Ely Simone Cajueiro Gurgel

doi:10.1590/2317-1545v43244385

Abstract

Abstract: Antioxidant enzyme activity can be used to measure heat stress and predict the tolerance of a species to heat stress. This study investigated the effects of temperature on germination and antioxidant enzyme activity in Dalbergia spruceana Benth. seeds. Seeds were incubated at constant temperatures of 20, 25, 30, 35, and 40 °C for ten days; and germination percentage, germination speed index, antioxidant enzyme activity, and electrical conductivity were evaluated. Temperature affected the seed germination process but not antioxidant enzyme activity. Germination percentage and germination speed index were higher at 25 and 35 °C and lower at 20 and 40 °C. Superoxide dismutase activity was not affected by temperature. Catalase and peroxidase activities were too low to be used as indicators of temperature stress. The pattern of increasing electrolyte leakage manifested a trend toward loss of cell membrane semipermeability at higher temperatures.

Highlights

Temperature changes in the environment can be detected by plant cells, and specific pathways of biochemical and molecular responses are triggered due to these temperature changes (Ruelland and Zachowski, 2010)
H2O2 is detoxified into molecular oxygen and water by two different systems: the glutathione peroxidase system, which is the first line of defense against H2O2, or CAT and POX, which act in reduction of hydrogen peroxide (Sharma et al, 2012; Matos et al, 2014)
For the germination speed index (GSI), the temperature of 30 °C led to the highest germination speed, with a mean of 6.7 seeds germinated per day (Figure 1B)

Summary

Introduction

Temperature changes in the environment can be detected by plant cells, and specific pathways of biochemical and molecular responses are triggered due to these temperature changes (Ruelland and Zachowski, 2010). Plants have developed a complex system of enzymatic and non-enzymatic antioxidant protection to neutralize the effects of ROSs in cells: superoxide dismutase (SOD), catalase (CAT), and peroxidase (POX), for example (Sharma et al, 2012; Matos et al, 2014). H2O2 is detoxified into molecular oxygen and water by two different systems: the glutathione peroxidase system, which is the first line of defense against H2O2, or CAT and POX, which act in reduction of hydrogen peroxide (Sharma et al, 2012; Matos et al, 2014)

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