Use of an Arabidopsis Mutant to Study the Induction of Plant Cell Differentiation

本提案的目的是扩大对毛状体分化起始所需的基因的分析。该基因GL1是在之前的批准期间分离并初步鉴定的。结果发现，GL1编码的预测多肽与Myb类转录激活因子同源。有趣的是，该基因似乎在叶基部发育的托叶中表达，但在毛状体发育的叶原基中却没有表达。这一结果表明GL1可能参与了激活毛状体形成的扩散信号的产生。提出了实验来证实或否定托叶衍生的毛状形态假说。PI还研究了在含有35S-GL1基因的植物中发现的毛状体形成减少的机制。其他实验旨在鉴定介导GL1时空调控的序列，并开始鉴定编码与GL1启动子相互作用或直接与GL1蛋白相互作用的蛋白质的基因。此外，实验计划确定GL1是否在其他植物物种中得到适当调节，并开始对拟南芥myb基因家族的其他成员进行表征。

The objective of this proposal is to expand the analysis of a gene that is required for the initiation of trichome differentiation. This gene, GL1, was isolated and initially characterized during the previous granting period. It was found that the predicted polypeptide encoded by GL1 is homologous to the Myb class of transcriptional activators. Interestingly, the gene appears to be expressed in stipules, which develop at the base of the leaves, but not in leaf primordia where trichomes develop. This result suggests that GL1 may be involved in the production of a diffusible signal that activates trichome formation. Experiments are proposed to confirm or negate the stipule-derived, trichome morphogen hypothesis. The PI also examine the mechanism behind the reduction in trichome formation that is found in plants that contain a 35S-GL1 gene. Other experiments are designed to identify the sequences that mediate the temporal and spatial regulation of GL1, to begin to identify genes that encode proteins that interact with GL1 promoter or that directly interact with the GL1 protein. In addition, experiments are planned to determine if GL1 is regulated appropriately in other plant species and to begin the characterization of other members of the Arabidopsis myb gene family.