Biochemistry Section, Jealott's Hill Research Station, Bracknell, Berkshire, England.
Plant Physiol. 1979 Feb;63(2):392-8. doi: 10.1104/pp.63.2.392.
The inhibitor SAN 6706 [4-chloro-5-(dimethylamino)-2-(alpha,alpha,alpha,-trifluoro- m-tolyl-3(2H)-pyridazinone] has been used to study the synthesis of carotenes and xanthophylls during the conversion of etioplasts to chloroplasts in developing barley (Hordeum vulgare) shoots. SAN 6706 inhibits carotenoid synthesis and causes an accumulation of phytoene, but it is also a potent inhibitor of chloroplast electron transport. When developing barley is treated with SAN 6706, carotenoid synthesis is inhibited but total photosynthesis is unaffected. The ability of SAN 6706 to inhibit carotenoid synthesis becomes progressively less if etiolated shoots are illuminated for increasing lengths of time before treatment. During the greening of treated barley shoots only light-induced beta-carotene synthesis is immediately inhibited; xanthophyll synthesis is not affected until after about 8 hours. The hypothesis that SAN 6706 cannot enter the chloroplast but inhibits carotenoid synthesis from the cytoplasm is discussed, and the question as to whether there are not two separate groups of enzymes for the synthesis of carotenes and xanthophylls is considered.
抑制剂 SAN 6706[4-氯-5-（二甲基氨基）-2-（α，α，α-三氟-间-甲苯-3（2H）-哒嗪酮]已被用于研究在大麦（Hordeum vulgare）芽发育过程中质体向叶绿体的转化过程中类胡萝卜素和叶黄素的合成。SAN 6706 抑制类胡萝卜素的合成并导致番茄红素的积累，但它也是叶绿体电子传递的有效抑制剂。当用 SAN 6706 处理发育中的大麦时，类胡萝卜素的合成被抑制，但总光合作用不受影响。如果在处理前对黄化芽进行越来越长时间的光照，SAN 6706 抑制类胡萝卜素合成的能力会逐渐降低。在处理后的大麦芽的绿化过程中，只有光诱导的β-胡萝卜素合成会立即受到抑制；叶黄素的合成要到大约 8 小时后才会受到影响。讨论了 SAN 6706 不能进入叶绿体但从细胞质抑制类胡萝卜素合成的假设，并考虑了是否存在两个用于类胡萝卜素和叶黄素合成的独立酶组的问题。
