LOX3调控稻谷耐储性作用机制研究

Aging metamorphism and producing rancidity in the process of storage are the main causes of the decrease of rice quality. So enhancing rice seed longevity is a major focus around the world. Lipoxygenase 3 (LOX3) is the key enzyme responsible for the generation of volatile substances by catalyzing the peroxidation of lipids in rice grains. In this study, we will use an antisense technique to down-regulate the expression of rice (Oryza sativa L.) endosperm LOX3 gene, and aim to retard the catalytic rate of lipid peroxidation of LOX3 and increase seed longevity. The technology of iTRAQ markers combined with liquid chromatography and mass spectrometry will be used to construct the expression profile of differential proteins between anti-sense LOX3 transgenic rice seed and control seed before and after artificial aging. We will screen the differential proteins involved in the LOX3 pathway and other major metabolic pathways, also screen the interacting proteins of LOX3 using GST pull-down technology and yeast two-hybrid system, characterize their function and reveal the regulation mechanism of LOX3 pathway in rice seed. The artificial and natural aging analysis of transgenic LOX3 rice seed will be conducted for evaluating the function of LOX3 in rice seed longevity. This study will lay the foundation for creating new storable rice materials.

稻谷储藏过程中的陈化变质以及陈臭味的产生等问题，是引起大米质量下降的主要原因，因此，提高稻谷耐储性是全世界关注的一大热点，而脂肪氧化酶3（LOX3）则是催化水稻种子脂类过氧化反应并产生挥发性物质的关键酶。本研究利用反义技术抑制水稻胚乳LOX3基因的表达，以期实现延缓其催化脂质过氧化速率，从而增加种子的生命力与耐储性的目的。应用iTRAQ标记结合液相色谱串联质谱技术构建反义LOX3转基因水稻与对照种子人工老化处理前后的差异蛋白表达谱，从中筛选参与LOX3代谢途径及其它主要代谢通路中表达差异显著的蛋白质进行功能验证，并利用GST pull-down技术和酵母双杂交系统筛选LOX3的互作蛋白，进而明确水稻种胚LOX3代谢途径。结合转基因种子的人工老化与自然老化分析，研究LOX3调控稻谷耐储性的分子机制，为创制耐储藏水稻新材料奠定基础。

稻谷储藏过程中的陈化变质以及陈臭味的产生等问题，是引起大米质量下降的主要原因，因此，提高稻谷耐储性是全世界关注的一大热点，而脂肪氧化酶3（LOX3）则是催化水稻种子脂类过氧化反应并产生挥发性物质的关键酶。本研究利用反义技术抑制水稻胚乳LOX3基因的表达，延缓了种胚脂质过氧化速率，提高了种子的生命力与耐储性。应用iTRAQ标记结合液相色谱串联质谱技术构建反义LOX3转基因水稻与对照种子人工老化处理前后的差异蛋白表达谱，从中筛选了3个参与LOX3代谢途径及其它主要代谢通路中表达差异显著的蛋白质进行功能验证，并利用酵母双杂交系统筛选到2个LOX3的互作蛋白，结合转基因种子的人工老化与自然老化分析，研究LOX3调控稻谷耐储性的分子机制，同时，利用耐储藏亲本进行组合配制，为创制耐储藏水稻新材料奠定基础。