Molecular Analysis of Genes Expressed in the Floral Meristem

本研究旨在鉴定、分离和表征花分生组织中特异性表达的基因。利用新型烟草（Nicotiana tabacum）“薄细胞层”（Thin Cell Layer， TCL）组织培养体系生产含花分生组织的外植体。在花培养条件下，根据以下方案，TCL外植体最多可产生15朵完全分化的功能花。第7天：细胞分裂活跃；第13天：形成有组织的分生组织，第20天：可见分化器官。从第13天的花TCL外植体中提取的cDNA文库的差异筛选将用于分离在培养第13天而不是第7天转录表达的基因的克隆。通过这种方法分离的潜在分生组织特异性基因将使用原位杂交来鉴定在花分生组织中表达的基因。通过稳定的植物转化，对感兴趣的基因进行分子和离体突变分析，以确定花形成过程中基因调控和功能的机制。这项工作将极大地提高我们对植物发育中基因表达的理解，为控制发育调节基因表达的因素提供证据，并为改变植物生长策略所需的基因类型提供见解。

This proposal is designed to identify, isolate, and characterized genes specifically expressed in floral meristems. The novel tobacco (Nicotiana tabacum) "Thin Cell Layer" (TCL) tissue culture system will be used to produce explants containing floral meristems. TCL explants in floral culture conditions produce up to 15 fully differentiated and functional flowers according to the following scheme. Day 7:active cell division; Day 13: organized meristems formed, Day 20: differentiated organs visable. Differential screening of a cDNA library made from Day 13 floral TCL explants will be used to isolate clones for genes transcriptionally expressed at Day 13, but not a Day 7, of culture. Potential meristematic specific genes isolated by this approach will be characterized using in situ hybridization to identify those expressed in floral meristems. Genes of interest will be subjected to molecular and in vitro mutational analysis, facilitated by stable plant transformation, to determine the mechanisms of gene regulation and function during floral initiation. This work should greatly improve our understanding of gene expression in plant development by providing evidence of the factors which control developmentally regulated gene expression, and giving insight to the types of genes required to change the strategy of plant growth.