阳生植物和阴生植物的叶黄素循环与非辐射能量耗散X

自然条件下阳生植物和阴生植物的光合速率存在着明显的差距，它们拥有不同的适应强光胁迫的能力，前者明显强于后者。从叶黄素组分来看，阳生植物拥有更大的叶黄素库[紫黄质（V）＋单环环氧玉米黄质（A）＋玉米黄质（Z）]，其中Z和[Z＋A]的含量更明显高于阴生植物；从阳生植物或阴生植物内部来看，不同物种间，Z1[Z＋A]和[V＋A＋Z]含量的差异相对较小，A则基本相同；不论是阳生植物还是阴生植物，非光化学猝灭值与Z、[Z＋A]及[V＋A＋Z]含量均呈现较好的正相关关系，后三者含量越高，非光化学猝灭值越大，而且[V＋A＋Z]库的大小与Z含量基本上是成比例增另的。说明在不同植物种间，[Z＋]（主要是Z）仍然是影响非辐射能量耗能的主要因素。

Xanthophyll Cycle and Non-Radiative Energy Dissipation in Sun and Shade Plants

There were large differences in photosynthetic rates between sun plants and shade plants under natural conditions. They had different capacities to adapt to high light stress. The light saturation rate of the former is higher than that of the later. Comparing with shade plants, sun plants generally possessed the bigger [Violaxanthin (V) Antheraxanthin (A) Zeaxanthin (Z)] pool size, while Z and [Z A] contents all exceeded more than that of shade plants. Within sun plants or shade plants, the differences of Z, [Z A] and [V A Z] contents in different species were relatively smaller under the same situation and the content of A is basically consistent. Whether it was sun plant or shade plant, the contents of Z, [Z A] and [V A Z] all apperently presented a positive correlation with NPQ. The more the xanthophyll content was, the higher the NPQ was.The contents of Z and [Z A] were basically proportional to the [V A Z] pool size in both species. So it showed that the content of [Z A] was still the major factor to affect NRD in different species. As the xanthophyll pool sizes could obviously affect the maximal contents of Z and A, so they were also regarded as important factors to limit the NRD in different species.