Tubulin Gene Expression During Morphogenesis of Arabidopsis

这项拟议研究的长期目标是了解高等植物生长发育的遗传控制。本研究的重点是模式植物拟南芥形态发生的遗传控制。本研究的主要目的是确定微管复合体中单个微管蛋白基因和微管蛋白异构体在控制植物组织和器官形态发生的细胞分裂和细胞伸长过程中的具体作用。拟议研究的具体目的是1)通过Northern印迹和原位杂交实验表征单个微管蛋白基因表达的空间和时间模式，2)在空间和时间上定位，通过蛋白质印迹分析和免疫荧光显微镜对发育中的植物组织和器官中的单个微管蛋白异构体进行分析，3)使用免疫荧光显微镜和异构体特异抗体来确定微管中存在哪些异构体，这些微管包含前相带、有丝分裂纺锤体、成纤维细胞和皮质阵列等结构，4)鉴定控制拟南芥微管蛋白基因组织特异性表达的顺式作用序列和反式作用蛋白及基因；5)利用根癌农杆菌Ti质粒介导的转基因植株中“过表达”的反义基因特异性序列，探索单个微管蛋白基因的功能。微管是丝状聚合物，在高等生物细胞的几个基本过程中发挥核心作用。在植物细胞中，它们参与细胞分裂和细胞扩张，这是植物形态发生的关键过程。这个项目是对植物中微管成分的详细分子研究。

The long-term goal of the proposed research is to understand the genetic control of growth and development of higher plants. The investigation focuses on the genetic control of morphogenesis in the model plant Arabidopsis thaliana. The major objective of the present study is to determine the specific roles of individual tubulin genes and tubulin isoforms in the microtubule complexes centrally involved in the processes of cell division and cell elongation that govern the morphogenesis of plant tissues and organs. The specific aims of the proposed investigations are 1) to characterize the spatial and temporal patterns of expression of individual tubulin genes by northern blot and in situ hybridization experiments, 2) to localize, spatially and temporally, the individual tubulin isoforms in developing plant tissues and organs by western blot analyses and immunofluorescence microscopy carried out with isoform-specific antibodies, 3) to use immunofluorescence microscopy and isoform- specific antibodies to determine which isoforms are present in microtubule containing structures such as preprophase bands, mitotic spindles, phragmoplasts, and the cortical arrays, 4) to identify the cis-acting sequences and trans-acting proteins and genes that control the tissue specific expression of Arabidopsis tubulin genes and 5) to utilize "overexpressed" antisense gene specific sequences in transgenic plants produced by Agrobacterium tumefaciens Ti plasmid mediated transformation to probe the function of individual tubulin genes. %%% Microtubules are filamentous polymers that play central roles in several basic processes of the cells of higher organisms. In plant cells they are involved in cell division and cell expansion, processes key to plant morphogenesis. This project is represents a detailed molecular study of the components of microtubules in plants.