Analysis of the plastid-derived signal transduction that regulate nuclear gene expression

在高等植物中，人们一直假设存在来自叶绿体的未知信号(“叶绿体信号”)来控制核基因的表达。对该信号转导途径存在缺陷的突变体的分析表明，四吡咯中间体(如镁原卟啉IX、镁原卟啉)参与了信号转导。虽然已经强烈建议参与四吡咯的生物合成，但信号的实体仍然不清楚。为了更好地了解叶绿体信号，我们一直在利用Fox-Hunting(Riken Arabiopsis全长cDNA过表达)系筛选功能获得型GUN突变体。我们鉴定了编码bHLH基因家族的一个成员的基因和一个含有kelch重复的因子。

In higher plants, it has been hypothesised that there are unknown signals (“plastid signals”) derived from plastids to control nuclear gene expression. Analysis of gun mutants that have defects in this signal transduction pathway suggests the involvement of the tetrapyrrole intermediates (e.g. Mg-Protoporphyrin IX, MgProto) as signaling factors. Although the involvement of tetrapyrrole biosynthesis has been strongly suggested, the entity of the signal is still obscure. For better understanding of plastid signaling, we have been screening the gain-of-function type gun mutants using FOX-hunting (Riken Arabidopsis Full Length cDNA overexpressor) lines. We identified genes that encode a member of bHLH gene family and a kelch-repeat containing factor.