Genetic dissection of vascular differentiation in arabidopsis and poplar

该项目的主要目标是识别大量与维管分化和木材形成有关的基因，并着眼于使用已识别的基因来改善经济重要物种的纤维和木材性状。根据之前的发现资助建议，我们成功地鉴定了大量具有潜在功能的血管分化和功能基因。我们使用基于微阵列的筛选方法，在拟南芥的正常器官和药物诱导血管肥大的器官中进行差异基因表达的筛选。在这里，我们建议通过功能突变的丧失和获得来评估已识别基因的功能，并通过对树种毛果杨中的基因进行类似的筛选来大大扩展我们的材料。一项跨国家的努力，包括一个强大的加拿大成分，最近导致了三果青霉基因组测序的完成。这个基因组中的45000多个基因的注释现在是可用的，资源也是可用的，比如三果青霉基因组芯片和微阵列。因此，我们有一个及时的机会从这项巨大的投资中获利，并应用我们经过测试的反向遗传学方法来识别与木材形成相关的次生维管分化相关基因。该项目包括三个层次：1)通过DNA芯片技术进行基因鉴定；2)通过整体原位杂交技术大规模评估潜在的维管组织表达；3)通过提高转基因杨树和拟南芥植株中内源基因的表达来评估基因功能。

The prime objective of the project is to identify a large number of genes that are involved in vascular differentiation and wood formation with the long-term vision of using the identified genes to improve fiber and wood traits in economically important species. In line with the previous discovery grant proposal, we have successfully identified a large number of genes with potential functions in vascular differentiation and function. We used a microarray-based screen for differential gene expression in normal organs versus organs with pharmacologically induced vascular hypertrophy in Arabidopsis. Here, we propose to evaluate the functions of identified genes by loss- and gain-of function mutants and also to expand our material considerably by carrying out a similar screen for genes in the tree species Populus trichocarpa. A trans national effort, including a strong Canadian component, recently led to the conclusion of the sequencing of the P. trichocarpa genome. The annotation of more than 45000 genes in this genome is now available, as are resources such as P. trichocarpa genome chips and microarrays. Thus, we have a timely opportunity to capitalize from this huge investment and apply our tested reverse genetics approach to identify genes involved in secondary vascular differentiation associated with wood formation. The project consists of three levels: 1) gene identification by DNA chip technology, 2) large-scale evaluation of potential vascular expression by whole-mount in situ hybridization, and 3) assessment of gene function by boost of endogenous gene expression in transgenic poplar and Arabidopsis plants.