TRTech-PGR: PlantTransform: Boosting Agrobacterium-mediated transformation efficiency in the orphan crop tef (Eragrostis tef) for trait improvement

植物遗传转化是理解复杂性状遗传基础的关键。已经为模式植物和一些主要作物(如水稻和玉米)开发了转化方法，这些作物通常缺乏必要的营养。相比之下，由于基因组信息有限以及缺乏科学家和资助机构的关注，对未充分利用或孤立的作物，如Eragrostis tef(Eragrostis Tef)，这种作物没有面筋，含有丰富的营养物质(矿物质、维生素、氨基酸)和有益的植物化学物质，其遗传转化还处于非常幼稚的阶段。这极大地延缓了此类作物的性状改良。因此，有必要为种子大小和颜色、矿物质含量、铁的生物利用率和成熟期天数等理想性状不同的tef基因型开发一种有效的转化方法。此外，印度草地早熟禾(E.Pilosa)是早熟禾(E.tef)的野生祖先，具有适应更广泛的环境条件、早熟和耐倒伏等特点，目前还没有针对它的转化方法，是改良早熟禾的潜在性状来源。本项目的主要目标是开发适用于不同基因类型的E.tef和E.Pilosa的转化工具。该项目还将为北卡罗来纳大学格林斯伯勒分校的少数民族学生、博士后研究员和来自埃塞俄比亚的访问科学家提供培训机会，在埃塞俄比亚，茶叶是最重要的主食作物。此外，该项目还将支持在埃塞俄比亚农业研究所组织的tef遗传转化研讨会。最近，利用玉米胚性调节基因Baby bom(Bbm)和wushel(Wus2)对包括tef在内的顽固性单子叶植物进行农杆菌介导的转化具有很大的前景。不同品种间的转化效率也存在差异。然而，这些方法还有待于优化。本研究的具体目标是：1)建立高效的茶树遗传转化技术；2)建立毛果油桐的遗传转化方法。针对顽固性单子叶植物新近培育出的几种农杆菌菌株，如胸腺嘧啶营养缺陷型和毒力工程菌，不同的tef基因在所需性状和目标组织(叶鞘和胚性愈伤组织)上的差异，以及不同的组织培养条件，将为tef及其野生近缘印度爱草提供一种有效的转化方法。该项目产生的资源将以出版物、协议、研讨会、演示文稿和网站的形式与科学界自由共享。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Plant genetic transformation plays a key role in understanding the genetic basis of complex traits. Transformation methods have been developed for model plants and some major crops such as rice and corn, which are usually poor in essential nutrients. In contrast, genetic transformation for underutilized or orphan crops such as tef (Eragrostis tef), which are gluten-free and rich in nutrients (minerals, vitamins, amino acids) and beneficial phytochemicals, is at a very infant stage due to limited genome information and lack of attention from scientists and funding agencies. This has tremendously delayed trait improvement in such crops. Therefore, there is a need to develop an efficient transformation method for tef genotypes varying in desirable traits including seed size and color, mineral content, iron bioavailability, and days to maturity. Moreover, transformation method has not been developed for the Indian lovegrass (E. pilosa), which is a wild progenitor of E. tef, and has several desirable traits including adaptation to wider environmental conditions, early maturity, and lodging tolerance, and is a potential source of traits for tef improvement. The major goal of this project is to develop transformation tools for diverse genotypes of E. tef and E. pilosa. This project will also offer training opportunities for University of North Carolina–Greensboro minority students, a postdoctoral researcher, and a visiting scientist from Ethiopia where tef is the most important staple crop. Furthermore, this project will support a tef genetic transformation workshop to be organized at the Ethiopian Institute of Agricultural Research.Recently, the use of maize embryogenic regulator genes Baby boom (Bbm) and wushel (Wus2) has shown great promise for Agrobacterium-mediated transformation of recalcitrant monocots including tef. Differences in transformation efficiency have also been observed between some tef varieties. However, the methods remain to be optimized. The specific objectives are: 1) to develop an efficient genetic transformation technique for tef, and 2) to develop transformation method for E. pilosa. Several Agrobacterium strains recently developed for recalcitrant monocots such as the thymine auxotrophic strains and engineered virulent strains, different tef genotypes varying in desirable traits and target tissues (leaf sheath and embryogenic calli), and varying tissue culture conditions will be tested to develop an efficient transformation method for tef and its wild relative Indian love grass. Resources generated from this project will be freely shared with the scientific community in the form of publications, protocols, workshops, presentations and websites.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.