Effects of S2O2 and NO on abiotic stress tolerance in rice

Abstract

Previously we reported that S2O2 and NO induce glycinebetaine accumulation in barley. It is anticipated that the oxidants can induce abiotic stress tolerance in higher plants by inducing biosynthesis of compatible solutes, scavenging system of active oxygen species, heat shock proteins, and so on. Therefore, we studied how S2O2 and NO affect abiotic stress tolerance in rice that doesn¿t accumulate glycinebetaine. Oxidative stress is one of abiotic stresses and causes damage to plants. However, in the present study, the activity of photosystem in rice leaves was decreased under heat and salt, whereas it remained at a higher level by the pretreatment of low levels of S2O2 and NO. This result indicate that low levels of S2O2 and NO can increase tolerance to abiotic stress such as heat and salt in rice. We concluded that low levels of S2O2 and NO act as signal molecule to abiotic stresses. We also report the effects of the oxidants on gene expression of P5CS, sucrose phosphate synthase, small heat shock protein, and calcium dependent protein kinase.