在高等植物的光系统II中，外周捕光天线除了具有捕获光能的功能外还具有光保护的功能。研究发现，当强光照射时，捕光复合物中结合的紫黄质（Vio）通过叶黄素循环可以转变成玉米黄素（Zea），从而发挥非光化学淬灭（NPQ）的功能。Zea如何参与NPQ目前还没有定论，有研究认为Zea结合到捕光天线后，诱导其构象变化，改变色素分子之间的距离和朝向，从而发生淬灭。目前解析结构的高等植物捕光复合物都是结合Vio分子的，而结合Zea的捕光复合物的结构尚未解析。为了研究结合不同色素分子的捕光复合物的结构变化，我们拟从拟南芥突变株NPQ2（敲除了Zea环氧化酶基因）叶片中提取含有Zea的捕光天线Zea-LHCII以及Zea-CP29等复合物样品，并通过X-射线晶体学研究手段，解析结合Zea捕光复合物的三维结构，为进一步理解高等植物光保护的机制提供结构基础。

In higher plants photosystem II, besides light harvesting, peripheral light-harvesting complex also can carry out light protection function. The previous study found that, under high-light condition, Violaxanthin(Vio) can be converted into Zeaxanthin(Zea) by lutein cycle in the light harvesting antenna, then play the function of Non-Photochemical Quenching (NPQ), how Zea to participate in the NPQ haven’t final conclusion at present. Some studies thought that when Zea binded, will induce the antenna conformational change, thereby the distance between the pigment and its molecules towards will changed, then quenching occurred .At present, the resolved structure of higher plant harvesting antenna are all binding Vio molecules，the Zea-binding antenna haven’t resolved. In order to study the conformational changes of antenna binding different figments, we plan to plant arabidopsis thaliana mutant strains NPQ2(knock out zeaxanthin epoxidase gene),extract Zea-LHCII and Zea-CP29 from its leaves, through the method of crystallography, expect to obtain the structure of Zea-binding light-harvesting antenna, and provide basis for further understanding the light protection mechanisms of higher plants.