Shioi Y, Sasa T
Arch Biochem Biophys. 1983 Jan;220(1):286-92. doi: 10.1016/0003-9861(83)90412-5.
The formation and degradation of protochlorophyllide esters, i.e., protochlorophylls, were studied in etiolated leaves of kidney bean in relation to their aging. By the sensitive analysis of the pigments using high-performance liquid chromatography, the presence of four protochlorophylls esterified with phytol, tetrahydrogeranylgeraniol (THGG), dihydrogeranylgeraniol (DHGG), and geranylgeraniol (GG) was detected in kidney bean grown in the dark. Similar components were also observed in the etiolated seedlings of cucumber, sunflower, and corn. The content of each protochlorophyll species changed with the plant species and age of plants. In the case of kidney bean, the content of protochlorophyll phytol reached a maximal level at 9 days, then decreased rapidly during the subsequent development, in spite of the total protochlorophyll content remaining unchanged. In contrast to the degradation of protochlorophyll phytol, the other three protochlorophylls esterified with THGG, DHGG, and GG accumulated. These results may indicate that (i) protochlorophyll phytol is formed from the first esterified protochlorophyll GG through the next three hydrogenation steps as in the case of chlorophyll a phytol formation; (ii) the esterification reaction stops at 9 days and then reaction proceeds in sequence in the reverse direction, leading to the dehydrogenation of the alcohol moiety of protochlorophyll phytol to protochlorophylls THGG, DHGG, and GG.
研究了菜豆黄化叶片中原叶绿素酯（即原叶绿素）的形成与降解及其与叶片衰老的关系。通过高效液相色谱法对色素进行灵敏分析，在黑暗中生长的菜豆中检测到了四种与叶绿醇、四氢香叶基香叶醇（THGG）、二氢香叶基香叶醇（DHGG）和香叶基香叶醇（GG）酯化的原叶绿素。在黄瓜、向日葵和玉米的黄化幼苗中也观察到了类似的成分。每种原叶绿素的含量随植物种类和植株年龄而变化。就菜豆而言，原叶绿素叶绿醇的含量在第9天达到最高水平，随后在后续发育过程中迅速下降，尽管原叶绿素的总含量保持不变。与原叶绿素叶绿醇的降解相反，其他三种与THGG、DHGG和GG酯化的原叶绿素积累。这些结果可能表明：（i）原叶绿素叶绿醇如叶绿素a叶绿醇的形成一样，是由第一种酯化的原叶绿素GG通过接下来的三个氢化步骤形成的；（ii）酯化反应在第9天停止，然后反应按相反顺序进行，导致原叶绿素叶绿醇的醇部分脱氢生成原叶绿素THGG、DHGG和GG。
