All of neoxanthin in chlorophasts is 9'-cis form : pyhlogeny, distribution and function

本文系统地研究了产氧光养生物主要类胡萝卜素新黄质的分布和几何构型（顺式或反式）。在种子植物、蕨类植物、苔藓和绿色藻类的破绿细胞中发现了9 '-顺式新黄质，但没有发现全反式新黄质，这些植物都含有叶绿素a和B。与此相反，新黄质在其他藻类纲，如异鞭毛藻门，红藻门和产氧光合原核生物中没有发现。因此，关于叶绿素发生，新黄质的出现似乎与叶绿素B的出现有关。在非光合器官中，如花瓣和果实，新黄质的存在被分为四种类型：只有9 '-顺式形式的，只有全反式形式的，两种形式的，以及没有任何形式的。因此，只有9 '-顺式新黄素存在于叶绿体中，而全反式新黄素只存在于非光合作用器官中。由于两种形式的吸收光谱几乎相同，它们在光合作用中的作用可能相似。9 '-顺式新黄素不参与叶黄素循环，但它是脱落酸合成的合适底物。几何异构体的差异进行了讨论，脱落酸的合成。

The distribution and geometric form (cis or trans) of neoxanthin, one of the major carotenoids of oxygenic phototrophs, were systematically examined. The 9'-cis form of neoxanthin, but not the all-trans form, was found in chlorophlasts of seed plants, ferns, mosses and green algae, all of which contain chlorophylls a and b. In contrast, neoxanthin was not found in other algal classes, such as Heterokontophyta, Rhodophyta and oxygenic phototrophic prokaryotes. Consequently, with regard to phylogeny, the appearance of neoxanthin appears to be associated with the appearance of chlorophyll b. In non-photosynthetic organs, such as petals and fruits, the presence of neoxanthin was classified into four types ; those having only the 9'-cis form, those with only the all-trans form, those with both forms, and those without either form. Thus only 9'-cis neoxanthin is found in chlorophasts, and the all-trans neoxanthin is found only in non-photosynthetic organs. Bexause the absorption spectra of both forms are almost identical, their functions in photosynthesis might be similar. 9'-Cis neoxanthin is not involved in the xanthophyll-cycle, whereas it is a suitable substrate for abscisic acid synthesis. Differences in geometric isomerism are discussed in relation to abscisic acid synthesis.