Institute of Crop Science and Zhejiang Key Laboratory of Crop Germplasm, Zhejiang University, Hangzhou, 310058, Zhejiang, China.
Institute of Crop and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China.
Plant Cell Rep. 2018 May;37(5):741-757. doi: 10.1007/s00299-018-2264-y. Epub 2018 Feb 21.
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.
高温（HT）诱导的花药中 ROS 爆发与 CAT 活性降低密切相关，这是 OsCATB 转录本明显受到抑制的结果，从而导致在减数分裂阶段暴露于 HT 的水稻植株严重的育性损伤。水稻植株的生殖阶段对热应激非常敏感。在本文中，使用不同的水稻品种在受控气候条件下研究 HT 诱导的小花不育与水稻花药中活性氧（ROS）解毒之间的关系。结果表明，高温（HT）暴露显著增强了发育中的花药中的 ROS 水平和丙二醛（MDA）含量，HT 暴露下水稻花药中 ROS 量的增加与 HT 诱导的几种抗氧化酶活性下降密切相关。对于各种抗氧化酶，SOD 和 CAT 比 APX 和 POD 更容易受到 HT 暴露诱导的水稻花药中 ROS 爆发的影响，其中 HT 暴露显著降低了发育中的花药中的 SOD 和 CAT 活性，而 APX 活性在不同温度条件下相对稳定。HT 诱导的 CAT 活性降低归因于 OsCATB 转录本的抑制。这种情况是 HT 诱导的 ROS 水平升高和水稻花药氧化损伤的主要原因，最终导致暴露于 HT 的水稻植株在减数分裂期间花粉活力和小花育性显著降低。外源施用 1000µM 水杨酸（SA）可以缓解 HT 诱导的花粉活力和小花育性降低，同时增加 CAT 活性并降低水稻花药中的 ROS 水平。
