Studies on chloroplast-dependent expression of some nuclear genes

叶绿体的发育依赖于核基因组和叶绿体基因组的协调表达。基于遗传学和生理学的研究，已知一些核基因只有在叶绿体具有功能时才能表达。已经有人提出，功能叶绿体向核发信号。这项研究对阐明这种可能的叶绿体信号是有帮助的。叶绿体依赖核基因的鉴定到目前为止分离到的14个cDNA都以叶绿体依赖的方式表达。此外，通过差异显示分析，还鉴定了另外100个表达依赖于叶绿体的cDNA。其中包括PSAD、PSAF、RBC和CAB 2。一种寻找叶绿体信号的系统从烟草-2细胞(含非光合体)培养的烟草建立了体外转录系统。这支持红细胞的低水平转录，而随着烟叶提取物(含有功能叶绿体)的增加，红细胞的转录水平上升。

Chloroplast development depends on coordinate expression of nuclear and chloroplast genomes. Based on genetic and physiological studies, some of nuclear genes are known to be expressed only when chloroplasts are functional. It has been proposed that functional chloroplasts send a signal to the nuclus. This study has forcused on the elucidation of such a possible chloroplast signal.1. Identification of chloroplast-dependent nuclear genesFourteen cDNAs so far isolated are all expressed in a chloroplast-dependent manner. Furthermore, 100 additional cDNAs whose expression is chloroplast-dependent have been identified by differential display assay. These include psaD,psaF,rbcS and cab.2. A system for searching a chloroplast signalAn in vitro transcription system has been developed from tobacco cultured BY-2 cells (containing non photosynthetic plastids). This supports a low level transcription of rbcS while the level increases with extracts from tobacco leaves (containing functional chloroplasts).