短期连续LED光照下水培生菜硝酸盐代谢规律及响应机理研究

High volume of nitrate accumulation in vegetable has great potential harm for human body. Preliminary studies by the applicant found that continuous LED illumination 2-3 days before harvest can significantly reduce the nitrate content. It could be also greatly improve the content of soluble sugar in the hydroponic lettuce, which mechanism is still unclear. In this study, changes of nitrate metabolism in plants under continuous illumination will be tested from absorption, transportation and assimilation perspective proven metastatic patterns of nitrate in different organs ,cell parts and the variation of nitrate assimilation intensity of lettuce under short-term continuous illumination conditions. Combined with the analysis of lettuce in different parts of the Gln, Glu in sucrose and glucose content of the change ,the study on activity changes of key enzymes (NR, PEPCase, SPS)which balance the carbon and nitrogen metabolism of plants will be taken to explore short-term continuous light intensity and balance of plant carbon and nitrogen metabolism variation, and explicit the critical point of time of carbon and nitrogen metabolism balance. Explore the strength of plant carbon and nitrogen metabolism and balance the direction of regulation changes from the point of view that the feedback control of the production and the tends to re-balance mechanism of the balancing mechanism and carbon-nitrogen metabolism of nitrate content in plants under continuous illumination.

蔬菜高量累积硝酸盐对人体健康存在极大的潜在危害。申请人前期的研究发现，采收前2-3天的连续LED光照可以显著降低水培生菜中的硝酸盐含量，并可大大提高可溶性糖含量，其机理尚不清楚。本研究将从吸收、转运以及同化的角度研究连续光照下植物体内硝酸盐代谢的变化，探明短期连续光照条件下硝酸盐在生菜不同器官、不同细胞部位中的转移规律，明确连续光照下生菜中硝酸盐同化强度的变化特征；同时从植物碳氮代谢平衡调节关键酶（NR、PEPCase、SPS）的活性变化，结合生菜不同部位Gln、Glu、蔗糖及葡萄糖含量的变化分析，探究短期连续光照下植物碳氮代谢强度及平衡方向的变化规律，明确碳氮代谢平衡方向变化的时间临界点；从产物累积反馈调控的角度探索连续光照下光对植物碳氮代谢强度及平衡方向调控作用的变化，探索连续光照下植物中硝酸盐含量趋向平衡机制及碳氮代谢重新平衡机理。

蔬菜高量累积硝酸盐对人体健康存在极大的潜在危害。申请人前期的研究发现，采收前2-3天的连续LED光照可以显著降低水培生菜中的硝酸盐含量，并可大大提高可溶性糖含量，其机理尚不清楚。本研究将从吸收、转运以及同化的角度研究连续光照下植物体内硝酸盐代谢的变化，探明短期连续光照条件下硝酸盐在生菜不同器官、不同细胞部位中的转移规律，明确连续光照下生菜中硝酸盐同化强度的变化特征；同时从植物碳氮代谢平衡调节关键酶（NR、PEPCase、SPS）的活性变化，结合生菜不同部位Gln、Glu、蔗糖及葡萄糖含量的变化分析，探究短期连续光照下植物碳氮代谢强度及平衡方向的变化规律，明确碳氮代谢平衡方向变化的时间临界点；从产物累积反馈调控的角度探索连续光照下光对植物碳氮代谢强度及平衡方向调控作用的变化，探索连续光照下植物中硝酸盐含量趋向平衡机制及碳氮代谢重新平衡机理。