An analysis of the response of the plastid division genes to the internal and external environments

在细胞分裂过程中，复制并分配给每个子细胞是细胞功能所必需的。然而，叶绿体分裂对植物发育的影响似乎很小，因为大多数影响叶绿体数量的突变体生长正常。拟南芥的皱叶(CRL)是叶绿体分裂和植物发育严重异常的例外之一。我们的结果表明，拟南芥的叶绿体分裂突变ftsZ1-1增强了CRL的所有异常。我们的结果还表明，由于FtsZ1-1：GFP定位于CRL的叶绿体赤道，因此CRL不是形成FtsZ环所必需的。我们发现，CRL突变体在成熟胚子叶中含有缺乏可检测到的质体的细胞。这种细胞很可能是由于分裂细胞的存在而产生的，在分裂细胞中，质体被分配给CRL胚胎中的一个子细胞。在叶绿体6(Arc6)的积累和复制过程中没有缺乏可检测到的质体的细胞，这表明没有可检测到的质体的细胞的产生是CRL发育异常的原因之一。

It is essential for cell functionality that plastids are replicated and allocated to each daughter cell during cell division. However, plastid division seems to have little effect on plant development because most mutants that affect chloroplast numbers grow normally. The crumpled leaf (crl) of Arabidopsis thaliana is one of the exceptions that display severe abnormalities in plastid division and plant development. Our results indicated that ftsZ1-1, a plastid division mutation of A. thaliana enhanced all of the abnormality in crl. These results suggested that inhibition of plastid division is one of the causes of morphological abnormalities in crl Our results also indicated that CRL is not required for the formation of FtsZ ring because FtsZ1-1: GFP was localized at plastid equator in crl. We showed that crl mutant contains cells lacking detectable plastids in cotyledon of mature embryos. Such cells were probably generated by an uneven partition of plastids to each daughter cell, because of the presence of the dividing cells in which plastids were allocated to one of the daughter cells in crl embryos. The absence of cells lacking detectable plastids in the accumulation and replication of chloroplasts 6 (arc6), another plastid division mutant of A. thaliana having no significant defects in plant morphology, suggests that the generation of cells without detectable plastids is one of the causes of developmental abnormalities in crl.