中波紫外光联合盐胁迫调控发芽玉米叶黄素富集机理

摄食富含叶黄素的食品可保护人眼免受氧化及高能光线伤害。黄玉米是叶黄素的良好来源，前期研究发现中波紫外光（UV-B）和盐胁迫可诱导发芽玉米叶黄素的积累，但其调控机理尚不明确。针对这一科学问题，本项目系统研究UV-B联合盐胁迫下发芽玉米子叶、胚芽、胚根和胚轴中叶黄素累积规律；探究茉莉酸(JA)合成抑制剂、Ca2+通道抑制剂与玉米黄质合成抑制剂对发芽玉米中PSY、β-LCY/ε-LCY、β-OHase/ε-OHase活性、基因与蛋白组表达的差异及叶黄素富集的影响；解析内源JA水平与PSY的效应关系、细胞Ca2+流受阻后钙通道蛋白的变化及α-分支途径中ε-LCY/ε-OHase的依赖作用，从分子水平上阐明UV-B联合盐胁迫下发芽玉米定向富集叶黄素JA和Ca2+的信号传导作用途径及α-分支途径对叶黄素合成积累的调控机制。该研究既可为开发谷芽类食品创建新的科学理论，又能为增强其保健功能提供技术支撑。

Eating plant-based foods with rich lutein can protect human eyes from oxidation and high energy lighting damage. Yellow maize is an excellent source of lutein. The previous studies found that UV-B (280–315 nm）and salinity stress could induce lutein accumulation in maize sprouts. However, its mechanism is still unclear to date. The purpose of the proposed project is to fill this gap. It will deeply and systematically investigate influences of UV-B combined with salinity stress on lutein accumulation in cotyledon, plumule, radicle and plumular axis of maize sprouts; identify impacts of jasmonic acid (JA) synthesis inhibitor, Ca2+ channel inhibitor and zeaxanthin synthesis inhibitors on PSY, β-LCY/ε-LCY and β-OHase/ε-OHase activities, as well as protein-gene expression differences, and lutein enrichment in maize sprouts; analyze the effect relationship between endogenous JA level and PSY, the changes of calcium channel protein after Ca2+ flow blockage, and the dependence of ε-LCY/ε-OHase in the α-branch pathway of lutein biosynthesis; reveal bio-regulatory mechanisms of endogenous JA, Ca2+ signaling pathway and α-branch pathway of lutein biosynthesis for its direct accumulation in maize sprouts under UV-B irradiation combined with salinity stress at bio-molecular level; This study will not only create a novel scientific theory of sprout food, but also provide useful technological information for improving its healthy functions.