Genetic dissection of vascular differentiation in arabidopsis and poplar

该项目的主要目标是鉴定大量参与维管分化和木材形成的基因，并长期利用鉴定的基因改善经济上重要物种的纤维和木材性状。根据之前的发现资助提案，我们已经成功地鉴定了大量在血管分化和功能方面具有潜在功能的基因。我们使用微阵列筛选拟南芥正常器官与药物诱导血管肥大器官的差异基因表达。在这里，我们建议通过功能缺失和功能获得突变来评估已鉴定基因的功能，并通过在毛杨树种中进行类似的基因筛选来大大扩展我们的材料。一项跨国合作，包括一个强大的加拿大组成部分，最近得出了糙皮虫基因组测序的结论。该基因组中超过45000个基因的注释现在是可用的，以及诸如毛藻基因组芯片和微阵列等资源。因此，我们有及时的机会利用这一巨大的投资，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的基因。该项目包括三个层面：1)利用DNA芯片技术鉴定基因；2)利用全挂原位杂交技术大规模评估潜在维管表达；3)通过提高转基因杨树和拟南芥植物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.