The inhibition of nitric oxide biosynthesis alters anti-oxidant capacity in soybean

Abstract

Nitric oxide is a signalling gaseous molecule endogenously synthesized from various enzymatic and non-enzymatic sources in plants. It is known to play a crucial role in the regulation of plant physiological processes such as growth, development and response to abiotic and biotic stresses. In contrast, reactive oxygen species also act as signalling molecules controlling processes such as growth, differentiation and response to abiotic and biotic stresses. Due to the camaraderie between nitric oxide and reactive oxygen species in the regulation of physiological processes, the effect of changes in nitric oxide content on a subset of antioxidant enzyme activities that regulate the levels of reactive oxygen species in soybean were investigated in this study. In chapters 3 and 4, a decrease in nitric oxide content using either a nitric oxide synthase inhibitor or a nitric oxide scavenger, induced changes in the antioxidant activities as well as the isoform expression patterns of superoxide dismutase, ascorbate peroxidase and catalase.