Toward Unraveling the Morphological Plasticity and Genome Redundancy of Brassica Oleracea

PI: J. Christopher Pires（密苏里大学）合作PI: Christopher D. Town（基因组研究所），Andrew H. Paterson（佐治亚大学）甘蓝代表了人类驯化所带来的植物形态变化的最壮观的例子之一，并且正在以与狗成为哺乳动物驯化的模式大致相同的方式成为植物模式。大多数作物的驯化导致了植物单一部分的增强，以供人类使用，例如谷物的种子，树木的果实或某些蔬菜的根。相比之下，甘蓝有驯化的形式，已经选择了几个植物部分的变化，包括营养分生组织（卷心菜），茎（大头菜，髓茎甘蓝），叶腋和叶（抱子甘蓝，羽衣甘蓝），和花分生组织（西兰花，花椰菜）。在芸苔属近亲中发现了其他变异，例如B. rapa形态型（白菜、白菜和根萝卜）的叶子和根，以及正在开发用于生物燃料的油籽B. rapa和B. napus的高产量。这种非凡的形态多样性，加上它与拟南芥的密切关系，使甘蓝成为一个特别有吸引力的系统，用于阐明基本的生物过程。基因组序列和相关资源的开发将加快对甘蓝形态变异的分子解剖，并为研究甘蓝形态变异与基因组结构和功能之间的关系提供一个框架。为了更好地了解甘蓝的驯化，该项目还将比较芸苔属的古代复制染色体区域与西西姆属的非复制染色体区域。最近发现西茜草与芸苔的亲缘关系比拟南芥要近得多。利用高覆盖基因组文库和从西芹属植物和甘蓝中测序的30-35个相应的基因组区域，构建甘蓝自兼容快速循环模型基因型的物理图谱。这些序列将相互比较，并与B. rapa和拟南芥进行比较，以揭示芸苔科植物遗传变化的模式和速度。这些资源将为世界范围内的研究人员剖析甘蓝特定性状的遗传控制以及检验关于形态变化与基因组过程之间关系的假设奠定基础。项目活动正在与跨国芸芥基因组计划（http://www.brassica.info/）.The)协调，该项目将通过长期使用威斯康星快速循环的芸芥快速植物，将芸芥整合到许多教室中。乔治亚大学的NSF GK-12项目和相应的活动将为研究型教材的实施提供一个试验场。该项目的主要成果将是细菌人工染色体（BAC）和BAC末端序列，这些序列将存入Genbank （http://www.ncbi.nlm.nih.gov/）。该项目的网站可通过http://www.plantgroup.org/cpires.html访问，将包括带注释的序列以及集成的遗传-细胞分子图谱。

PI: J. Christopher Pires (University of Missouri)Co-PIs: Christopher D. Town (The Institute for Genomic Research), Andrew H. Paterson (University of Georgia)Brassica oleracea represents one of the most spectacular examples of plant morphological change brought about by human domestication and is emerging as a plant model in much the same manner that the dog is emerging as a model for mammal domestication. Domestication of most crops has resulted in enhancement of a single plant part for use by humans, such as the seeds of grains, the fruits of trees, or the roots of some vegetables. In contrast, B. oleracea has domesticated forms that have been selected for changes in several plant parts, including vegetative meristems (cabbages), stems (kohlrabi, marrowstem kale), leaf axils and leaves (Brussels sprouts, kales), and floral meristems (broccoli, cauliflower). Additional variation is found in close Brassica relatives, such as the leaves and roots of B. rapa morphotypes (Pak-choi, Chinese cabbage and root turnip) and high seed yields of oilseed B. rapa and B. napus, being developed for biofuels. This extraordinary morphological diversity, together with its close relationship to Arabidopsis, makes B. oleracea an especially attractive system in which to elucidate fundamental biological processes. Genome sequence and associated resources will be developed to expedite molecular dissection of the morphological variation in B. oleracea, and contribute to a framework for investigating the relationship between this morphological variation and the structure and function of its genome. To better understand B. oleracea domestication, the project will also compare the ancient duplicated chromosomal regions of Brassica to the non-duplicated regions in Sisymbrium. Sisymbrium has been recently found to be much more closely related to Brassica than Arabidopsis. A physical map of a self-compatible rapid-cycling model genotype of B. oleracea will be developed using high-coverage genomic library, and 30-35 corresponding genomic regions sequenced from Sisymbrium and B. oleracea. These sequences will be compared to each other and to B. rapa and Arabidopsis to shed new light on the pattern and tempo of genetic change in the Brassicaeae. These resources will lay the foundation for a worldwide community of researchers to dissect the genetic control of specific traits in B. oleracea as well as test hypotheses about the relationship between morphological change and genomic processes. Project activities are being coordinated with the Multinational Brassica Genome Project (http://www.brassica.info/).The project will take advantage of the integration of Brassica into many classrooms through the long-standing use of Wisconsin rapid-cycling Brassica Fast Plants. An NSF GK-12 program and corresponding activities at University of Georgia will provide a testing ground for implementation of research-based educational materials.Access to project outcomes The primary outcome of the project will be Bacterial Artificial Chromosome (BAC) and BAC-end sequences, which will be deposited in Genbank (http://www.ncbi.nlm.nih.gov/). The project web site, which will be accessible via http://www.plantgroup.org/cpires.html, will include annotated sequences as well as integrated genetic-cytomolecular maps.