Improving Camelina seed oil production by modulating mucilage synthesis

由于其对不利生长条件的抵抗力以及用于营养或生物燃料生产的油的质量，山茶正在成为一种替代油料作物。从本质上讲，这是一种古老的作物，进行的选择相对较少，育种和改良潜力巨大。山茶花是十字花科的一员，包括许多重要的经济作物，其农艺特性使其成为生产的极好补充。然而，由于可利用的遗传和基因组资源相对较少，目前茶树的农艺潜力的开发是有限的。拟南芥是茶树的近亲，通过转录因子的突变减少了形成种子粘液的多糖的产生，从而提高了拟南芥的含油量。粘液多糖在种子发育过程中积累在种皮的表皮细胞中，这些亲水性聚合物在吸胀过程中被释放。此外，粘液多糖作为乳化剂和隔离油，从种子中去除它们应该会改善提取能力。在CASOM项目中，我们的目标是通过减少粘液的生产来增加Camelina的石油产量。这将在概念验证研究中进行，方法是对拟南芥中发现的粘液合成所需的两个转录调节因子的基因同源基因进行定点突变。将开发一种新的种子微挤压系统来验证它们对油脂提取的效果。还将进行最近由项目合作伙伴确定的其中一个转录因子的分子遗传特征。同时，转录学和全基因组关联研究将用于识别新的Camelina基因候选，这些候选基因可用于修改粘液生产和改善油脂提取。将获得不同发育阶段种皮表皮细胞的转录组数据，并将数据与其他植物组织的转录组数据进行筛选。对于GWAS，将从来自不同背景的大约200个茶树种质的基因组重测序数据中识别序列多态。这些数据还将有助于我们对茶树属之间的遗传变异进行表征。转录组和基因组序列数据将在用户友好的网络资源中免费提供给其他研究人员，从而有助于改善可用于未来研究的基因组资源。CASOM项目涉及一名法国合作伙伴和一名德国合作伙伴的合作，这些合作伙伴在种子和多糖研究方面具有互补的专业知识和坚实的背景。CASOM的主要目标是(1)验证通过转录调控减少拟南芥和山茶的粘液产量可以增加含油量和可萃取性，以及(2)为调节山茶的粘液生产寻找新的靶点。

Camelina is emerging as an alternative oilseed crop due to its resistance to adverse growth conditions and the quality of its oil for nutrition or biofuel production. Essentially an ancient crop, relatively little selection has been carried out and there is an enormous potential for breeding and improvement. Camelina sativa is a member of the Brassicaceae family, which includes a number of economically important crops, and its agronomic attributes make it an excellent complement to their production. Nevertheless, development of the agronomic potential of Camelina is currently limited as relatively few genetic and genomic resources are available. Increased oil contents have been achieved in Arabidopsis, a close relative of Camelina, by reducing the production of the polysaccharides that form seed mucilage through the mutation of a transcription factor. Mucilage polysaccharides are accumulated in the epidermal cells of the seed coat during seed development and these hydrophilic polymers are released during imbibition. Furthermore, mucilage polysaccharides act as emulsifiers and sequester oil, and their removal from seeds should improve extractability. In the CASOM project we aim to increase oil production in Camelina by reducing the production of mucilage. This will be carried out in proof of concept studies by site-specific mutation of gene homologs for two transcription regulators identified in Arabidopsis as required for mucilage synthesis. A novel seed micropress system will be exploited to validate their effect on oil extraction. The molecular genetic characterization of one of the transcription factors, recently identified by the project partners, will also be carried out. In parallel, transcriptomic and genome wide association studies will be used to identify novel Camelina gene candidates that can be used to modify mucilage production and improve oil extraction. Transcriptome data will be obtained for the seed coat epidermal cells at different developmental stages and data will be filtered against transcriptomes from other plant tissues. For GWAS, sequence polymorphisms will be identified from genome resequencing data for around 200 Camelina accessions from diverse backgrounds. This data will also contribute to our characterisation of the genetic variability between Camelina. The transcriptome and genome sequence data will be made freely available to other researchers in a user friendly web resource and will thus contribute to improving the genomic resources available for future studies.The CASOM project involves the collaboration of one French and one German partner with complementary expertise and a solid background in seed and polysaccharide research. The primary objectives of CASOM are (1) to validate that reducing mucilage production in Arabidopsis and Camelina through transcription regulators can increase oil contents and extractability and (2) to identify novel targets for the modulation of mucilage production in Camelina.