DuBell A. N., Mullet J. E.
Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128.
Plant Physiol. 1995 Sep;109(1):105-112. doi: 10.1104/pp.109.1.105.
Plastid gene expression was analyzed in pea (Pisum sativum L.) plants grown in darkness, continuous far-red light, and white light. Responses induced by continuous far-red light were most likely mediated by PHYA. Plastid transcription activity was low in dark-grown plants. In contrast, plastids of plants grown in white or far-red light showed a 10-fold increase in transcription activity between 4 and 6 d postimbibition (dpi) and a decrease between 6 and 9 dpi. Plastid RNAs accumulated in illuminated plants from 5 to 7 dpi. In far-red-light-illuminated plants, plastid mRNA levels remained elevated until 14 dpi. In white-light-grown plants, most plastid RNAs decreased in abundance after 7 dpi to very low levels by 14 dpi. This indicates that white light induces a general decrease in plastid RNA stability compared to far-red-light-illuminated seedlings. PsbA mRNA accumulated in older, dark-grown, far-red, and white-light-illuminated seedlings, consistent with this RNA having high stability. Transcription of genes encoding the plastid's transcription and translation apparatus increased relative to rbcL and other genes encoding proteins of the photosynthetic apparatus from 4 to 5 dpi and then declined 10-fold from 5 to 9 dpi. These data document dynamic modulation of plastid gene transcription and mRNA stability during light-induced chloroplast development in pea.
对在黑暗、持续远红光和白光条件下生长的豌豆（Pisum sativum L.）植株的质体基因表达进行了分析。持续远红光诱导的反应很可能是由PHYA介导的。在黑暗中生长的植株中，质体转录活性较低。相比之下，在白光或远红光下生长的植株的质体，在吸胀后4至6天（dpi）转录活性增加了10倍，在6至9 dpi之间则下降。质体RNA在光照植株中从5至7 dpi开始积累。在远红光照射的植株中，质体mRNA水平一直升高到14 dpi。在白光下生长的植株中，大多数质体RNA在7 dpi后丰度下降，到14 dpi时降至非常低的水平。这表明与远红光照射的幼苗相比，白光诱导质体RNA稳定性普遍下降。PsbA mRNA在较老的、黑暗生长的、远红光和白光照射的幼苗中积累，这与该RNA具有高稳定性一致。编码质体转录和翻译装置的基因转录相对于rbcL和其他编码光合装置蛋白质的基因，在4至5 dpi时增加，然后在5至9 dpi时下降10倍。这些数据证明了豌豆光诱导叶绿体发育过程中质体基因转录和mRNA稳定性的动态调节。
