Biologisches Institut II der Universität, Schänzlestrasse 1, D-7800, Freiburg, Federal Republic of Germany.
Planta. 1983 Dec;159(6):518-28. doi: 10.1007/BF00409141.
Mustard (Sinapis alba L.) seedlings were grown in the presence of herbicides (Difunon, Norflurazon) which inhibit carotenoid synthesis without affecting development, in darkness or in continuous far-red light. In strong white light (12,000 lx) the cotyledons of the herbicide-treated seedlings did not contain normal chloroplasts, but only small chlorophyll-free rudiments whose internal structure had almost disappeared. The plastid marker enzyme NADP-dependent glyceraldehyde-3-phosphate dehydrogenase was almost lacking. Plastid ribosomes and ribosomal RNAs were no longer detectable nor could synthesis of mature plastidal ribosomal RNAs be detected. Cytosolic ribosomes and rRNAs were not affected. Plastid DNA was apparently still intact as shown by restriction analysis. The appearance of marker enzymes of glyoxisomes, mitochondria and cytosol was not impaired while the level of marker enzymes of peroxisomes was drastically lowered. Accumulation of anthocyanin in mustard cotyledons was normal after a short, transient delay. Levels of representative enzymes of flavonoid biogenesis (phenylalanine ammonia-lyase, chalcone synthase) were somewhat increased rather than inhibited in the cotyledons of herbicide-treated, white-light-grown seedlings. The growth rate of hypocotyl and cotyledons was inhibited to the same extent in the herbicide-treated, white-light-grown seedling, although light inhibits growth of hypocotyls and promotes growth of cotyledons. Analysis of the data shows that photomorphogenesis of a herbicide-treated, white-light-grown seedling is normal, and is thus independent of plastid gene expression However, a 'factor' which coacts multiplicatively with phytochrome in determining the growth rate of the organs seems to originate from the plastids. Biogenesis of anthocyanin and synthesis of major enzymes of the flavonoid pathway are not affected adversely by a photooxidative elimination of plastid gene expression.
芥菜（Sinapis alba L.）幼苗在存在除草剂（Difunon、Norflurazon）的情况下生长，这些除草剂抑制类胡萝卜素合成而不影响发育，可以在黑暗或连续远红光下进行。在强白光（12000 lx）下，经除草剂处理的幼苗子叶不含正常的叶绿体，而只有小的无叶绿素的原始体，其内部结构几乎消失。质体标记酶 NADP-依赖的甘油醛-3-磷酸脱氢酶几乎不存在。质体核糖体和核糖体 RNA 不再可检测到，也无法检测到成熟质体核糖体 RNA 的合成。细胞质核糖体和 rRNA 不受影响。质体 DNA 显然仍然完整，如限制分析所示。尽管过氧化物酶体的标记酶水平急剧降低，但糖异生体、线粒体和细胞质的标记酶的出现并未受损。芥菜子叶中花色素苷的积累在短暂的瞬时延迟后正常。在经除草剂处理的、在白光下生长的幼苗子叶中，类黄酮生物合成的代表性酶（苯丙氨酸解氨酶、查尔酮合酶）的水平略有增加而不是受到抑制。尽管光抑制下胚轴的生长并促进子叶的生长，但在经除草剂处理的、在白光下生长的幼苗中，下胚轴和子叶的生长速度受到相同程度的抑制。数据分析表明，经除草剂处理的、在白光下生长的幼苗的光形态建成正常，因此独立于质体基因表达。然而，一种与光敏色素协同作用并决定器官生长速度的“因子”似乎来自质体。质体基因表达的光氧化消除不会对花色素苷的生物合成和类黄酮途径的主要酶的合成产生不利影响。
