油桃果实采后类胡萝卜素和结合态芳香物质代谢调控机理及其与可溶性糖关联机制研究

类胡萝卜素和芳香物质是评价油桃果实品质的重要指标。油桃萜烯类物质含量丰富，易形成结合态芳香物质，果肉富含类胡萝卜素，两类物质的合成主要经过异戊二烯途径。前期研究发现采后常温和低温贮藏下油桃果实结合态芳香物质的含量变化不同，低温（5ºC）抑制了类胡萝卜素的合成，可溶性糖可以影响类胡萝卜素和结合态芳香物质的合成。但是，其中关联性需进一步研究，特别是采后调控类胡萝卜和结合态芳香物质的机理。因此，本项目拟通过转录组测序，研究不同温度下油桃果实异戊二烯途径基因和转录因子的差异表达，筛选出关键调控基因并克隆其启动子序列，通过酵母单杂交等确定互作的转录因子并研究该转录因子的功能和调控作用。借助果肉圆片温育实验，分析可溶性糖对候选转录因子表达及调控的影响，从而阐明油桃果实采后类胡萝卜素和结合态芳香物质代谢调控机理及其与可溶性糖的关联性，为采后果实风味品质调控提供理论依据。

Carotenoids and aroma compounds are important traits which determine the qualities of nectarines. Nectarine is rich in contents of carotenoids and terpenes, and terpenes can easily form the bounded aromas. Isoprenoid metabolic pathway contributed to the synthesis of carotenoids and terpenes. Our previous study showed that the changes of bounded aromas were different in nectarines stored at room and low temperature, and low temperature (5 ºC) inhibited the synthesis of carotenoids. Besides, sugars affected the synthesis of carotenoids and bound aromas. However, the relationships among sugars, carotenoids and bound aromas require further study, and the mechanism of the synthesis of carotenoid and bound aromas in nectarines during postharvest storage is still unclear. Therefore, the aim is to explore the different expressions of genes and transcript factors in isoprene pathway in nectarines stored at different temperatures using transcriptomics. Further to explore the key regulatory genes and clone their promoter sequences to determine the interacting transcription factors by yeast one-hybrid. Then, to find the function and regulatory role of the target transcription factors in the synthesis of carotenoids and bound aromas. Finally, the effects of soluble sugars on regulation of the above target transcript factors will be analyzed. The results will revealed the metabolic regulation mechanism of carotenoids and bounded aromas in nectarine fruits during postharvest storage and provided the basis for the relationships among sugars, carotenoids and bounded aromas. The research will provide scientific information for better control of fruit flavor during postharvest storage.