Abstract: Based on co-oxidation secondary reaction functio n of lipoxygenase-3(LOX-3) in rice embryo, a rapid method for detecting the lack of LOX-3 in rice embryos by carotene bleaching for only three hours was developed and optimized. The method is simple, inexpensive and suitable to rapid screening storable rice cultivars compared with monoclonal antibody technique and indide-starch method. It was deduced that LOX-1 and LOX-2 in rice embryos probably displayed less or no co-oxidation activities under normal air condition in comparison with that of LOX-3. The perspective of carotene bleaching method on the usage in breeding for storable rice cultivars and related-cloning research was also discussed.

Key words: rice, embryo, lipoxygenase, null of isoenzyme, scree ning methods

摘要： 根据水稻种胚脂氧合酶的主要同工酶LOX-3的活性缺失可以提高耐贮性的特性，研究了快速测定LOX-3酶活性以筛选耐储藏水稻品种的方法。报道了水稻种胚LOX-3具有共氧化的次生反应特性，并根据该特性建立了快速筛选其缺失体的胡萝卜素漂白法（检测时间为3 h），优化了反应体系。推测在正常氧压下水稻种胚LOX-1和LOX-2不具备或仅具备相对较弱的共氧化次生反应能力。与LOX-3缺失体的单克隆抗体技术和I2-KI比色法相比，胡萝卜漂白法具有方法简单、成本低、快速的优点。还探讨了胡萝卜素漂白法在耐储藏水稻品种改良和相关分子克隆研究中的应用前景。

关键词: 水稻, 种胚, 脂氧合酶, 同工酶缺失体, 筛选方法