Involvement of CAT in the detoxification of HT-induced ROS burst in rice anther and its relation to pollen fertility

Abstract

HT-induced ROS burst in developing anther is closely related to the lowered CAT activity as the result of the markedly suppressed OsCATB transcript, thereby causing severe fertility injury for rice plants exposed to HT at meiosis stage. The reproductive stage of rice plants is highly sensitive to heat stress. In this paper, different rice cultivars were used to investigate the relationship of HT-induced floret sterility with reactive oxygen species (ROS) detoxification in rice anthers under well-controlled climatic conditions. Results showed that high temperature (HT) exposure significantly enhanced the ROS level and malondialdehyde (MDA) content in developing anther, and the increase in ROS amount in rice anther under HT exposure was closely associated with HT-induced decline in the activities of several antioxidant enzymes. For various antioxidant enzymes, SOD and CAT were more susceptible to the ROS burst in rice anther induced by HT exposure than APX and POD, in which SOD and CAT activity in developing anther decreased significantly by HT exposure, whereas APX activity was relatively stable among different temperature regimes. HT-induced decrease in CAT activity was attributable to the suppressed transcript of OsCATB. This occurrence was strongly responsible for HT-induced increase in ROS level and oxidative-damage in rice anther, thereby it finally caused significant reduction in pollen viability and floret fertility for the rice plants exposed to HT during meiosis. Exogenous application of 1000 µM salicylic acid (SA) may alleviate HT-induced reduction in pollen viability and floret fertility, concomitantly with the increased CAT activity and reduced ROS level in rice anther.

Exogenous application of NaBiF4 nanoparticle affects wheat root development

“…These results demonstrated that nanoparticles were accumulated in root tip. These results were similar with in rice, as the previous reported (Du et al, 2018).…”

DEGENERATED PANICLE AND PARTIAL STERILITY 1 (DPS1) encodes a cystathionine β‐synthase domain containing protein required for anther cuticle and panicle development in rice

“…Trxs usually work in a complex with several other proteins involved in ROS scavenging (Yoshida et al ., ; Zhang et al ., ). In addition to Trxs, antioxidant enzymes, predominantly superoxide dismutase (SOD) and catalase (CAT), also help to reduce cellular ROS levels in rice, particularly under high temperature stress, thus avoiding male sterility (Zhao et al ., ,). Several mutants defective in ROS homeostasis displayed developmental defects and sterility mainly due to ROS accumulation (Hu et al ., ; Heng et al ., ).…”

Agronomic, physiological and molecular characterization of rice mutants revealed key role of ROS and catalase in high temperature stress tolerance

“…This suggested its role as a negative regulator of heat stress tolerance in rice and seems that its role as a negative regulator of abiotic stresses is conserved. Rice SOD and CAT are key stress responsive genes which regulate the level of SOD and CAT enzymes in rice (Zhao et al . 2018a; Zhao et al .…”

“…2018b). Higher expression of these genes is linked with improved heat tolerance in rice (Zhao et al . 2018a; Zhao et al .…”

“…This is consistent with the CAT activity under heat stress, suggesting a key role of CATB in heat tolerance in rice. CATB has also been reported for its potential role in heat tolerance in rice at reproductive stage (Zhao et al . 2018a).…”