Carotenoids and Photoprotection in Crassulacean Acid Metabolism (CAM) Plants

拟议调查的目的是描述 景天科酸代谢（CAM）植物对高浓度的响应 轻，特别强调对就业的一本小说 涉及几种叶类胡萝卜素的光感受过程。 这一过程与玉米黄质的形成有关 从它的前体在叶黄素循环，有利于安全 在光合作用器官中吸收的多余的光的去除。 叶黄素循环的昼夜运作将是 以几种不同类型的植物为特征 CAM，包括Platyopuntias，形成莲座状的丝兰， 具有肉质叶的物种，球兰和蕨类植物 石韦 类胡萝卜素的驯化 组成，特别是叶黄素循环， 光环境将通过比较叶片进行检查 在深阴影中发展的， 此外，这个问题将是 通过检查类胡萝卜素的适应来解决 组合物的梯度在光环境中发生， 在叶子或叶状枝中。 叶黄素的作用 循环将进一步响应于 高光照和低温的结合。 的 光感受能中叶黄素循环的利用 在这些CAM物种中发现的耗散， 然后将经历高光的光与发生的光进行比较， C3物种。

The purpose of the proposed investigations is to characterize the response of crassulacean acid metabolism (CAM) plants to high light, with a particular emphasis on the employment of a novel photoreceptive process that involves several leaf carotenoids. This process, which is associated with the formation of zeaxanthin from its precursors in the xanthophyll cycle, facilitates the safe removal of an excess of absorbed light in photosynthetic organs. The diurnal operation of the xanthophyll cycle will be characterized in several different types of plants that process CAM, including platyopuntias, rosette-forming yuccas, and two species which possess succulent leaves, Hoya australis and the fern Pyrrossia confluens. The acclimation of the carotenoid composition, and particularly the xanthophyll cycle, to different light environments will be examined through a comparison of leaves which have developed in deep shade versus those which have developed in full sunlight, In addition, this question will be addressed by examining the acclimation of the carotenoid composition to the gradient in the light environment that occurs within the leaves or cladodes. The operation of the xanthophyll cycle will furthermore be characterized in response to a combination of high light and chilling temperatures. The utilization of the xanthophyll cycle in photoreceptive energy dissipation in these CAM species which are found in habitats that experience high light will then be compared with that which occurs in C3 species.