Genetic dissection of vascular differentiation in arabidopsis and poplar

该项目的主要目标是确定大量参与维管分化和木材形成的基因，并长期利用已确定的基因来改善重要经济物种的纤维和木材性状。与之前的发现资助提案一致，我们已经成功地鉴定了大量在血管分化和功能中具有潜在功能的基因。我们使用了一个基于微阵列的屏幕在正常器官与器官的拟南芥诱导血管肥大的差异基因表达。在这里，我们建议评估的功能的丧失和增益的功能突变体的基因，并通过进行类似的筛选，在树种杨树的基因，也大大扩大我们的材料。最近，一项跨国努力，包括加拿大的一个强有力的组成部分，导致了对P.ducarpa基因组测序的结论。在这个基因组中超过45000个基因的注释现在是可用的，因为是资源，如P.子基因组芯片和微阵列。因此，我们有一个及时的机会，利用这个巨大的投资，并应用我们测试的反向遗传学方法，以确定参与次生维管分化与木材形成相关的基因。该项目包括三个层次：1）通过DNA芯片技术鉴定基因，2）通过整体原位杂交大规模评估潜在的维管表达，3）通过增强转基因白杨和拟南芥植物的内源基因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.