Molecular Genetics of Shoot Apical Meristems

在植物中，发育是由被称为分生组织的多能细胞小组的活动持续进行的。植物的整个地上部分是由位于茎尖的分生组织（即茎尖分生组织）中的连续事件发展而来的。由于许多植物寿命长达一个世纪并不罕见，因此茎尖分生组织的持续活动描述了生物学中其他地方无法比拟的过程。本研究将重点研究分生组织中的分子事件如何使植物形成。将研究分生组织富集表达的基因，称为“meri”。特定cdna的表达模式将在组织特定水平上得到确认和定位。更多的梅里克隆将被隔离。大多数特定克隆的转录启动子将被定义，融合到一个报告基因（GUS）并转移到拟南芥植物中。表达嵌合meri- gus基因的转基因植物将进行组织学表达分析，以确认定位研究，并确定meri基因在分生组织动态事件中的表达方式。此外，将通过将“meri- gus”植株与能够热诱导激素改变的转基因品系杂交来检测meri基因对生理线索的反应。这些研究将深入了解茎尖分生组织内的基因如何在发育过程中发挥作用，从而深入了解分生组织如何“制造”植物。

In plants, development takes place continuously from activities of small groups of pluripotent cells known as meristems. The entire above ground portion of a plant develops from continuous events in a meristem found in the shoot apex, the shoot apical meristem. Since it is not uncommon for many plants to live for a century, the continuous activities in shoot apical meristems describes processes unmatched elsewhere in biology. This study will focus on how molecular events in the meristem function to make a plant. Genes with meristematic enriched expression, designated "meri", will be studied. Expression patterns for specific cDNAs in hand will be confirmed and localized on a tissue specific level. Additional meri clones will be isolated. The transcriptional promoter for the most specific clones will be defined, fused to a reporter gene (GUS) and transferred to Arabidopsis plants. Transgenic plants expressing the chimeric meri-GUS gene will be analyzed for histological expression to confirm localization studies and to determine how the meri genes are expressed in the dynamic events in meristems. Furthermore, the response of the meri genes to physiological cues will be examined by crossing the 'meri-GUS' plants to a transgenic line capable of heat inducible hormone alterations. These studies will provide insight into how genes within the shoot apical meristem function in development, and hence insight into how the meristem "makes" a plant.