Comparative Functional Genomics of Nectaries and Nectar in the Dicots

Pi：Clay J.Carter(明尼苏达大学双子城分校)Copis：Robert W.Thornburg和Basil J.Nikolau(爱荷华州立大学)和Matt W.Hampton(明尼苏达大学德卢斯分校)合作者：Martin Heil(墨西哥CINESTAV)和Patrick von Aderkas(加拿大维多利亚大学)三分之一的作物物种产生花蜜，依赖动物繁殖。此外，棉花、豆类、豌豆、苹果、樱桃、桃子和蓝莓等作物都会产生花外花蜜来吸引互惠互利的捕食性昆虫，从而保护植物免受食草动物的侵害。仅美国授粉者依赖的作物一年的价值就接近250亿美元，花外花蜜是少数几种已证明对植物健康和适合性有稳定影响的防御机制之一。这个项目将利用基因组学技术来研究跨物种和蜜腺类型的花蜜成分合成和分泌所涉及的分子机制。如果成功，该项目将为这些过程以及特定花蜜成分介导的动植物相互作用提供重要的新见解，使有针对性的研究能够提高整体授粉效率，加强对攻击作物的害虫的生物防治，并有可能极大地影响养蜂业。在外展和培训方面，该项目将为学生和博士后助理提供跨学科研究培训。爱荷华州立大学的项目研究生还将担任GK12 SYMBI项目(http://www.gk12.iastate.edu/).)的GK12研究员在NSF的支持下，SYMBI计划是ISU与中学和高中之间的合作伙伴关系，这些学校主要服务于得梅因公立学区代表人数不足的学生。GK12研究员将担任“常驻科学家”，他们将与教师合作，为精选的初中或高中理科学生开展创新的、动手的和参与性的科学活动。最后，该项目还将为康奈尔高中(威斯康星州康奈尔)的高中生提供研究经验。推动该项目的中心假设是，花蜜合成、分泌和功能背后的遗传程序至少在不同物种和蜜腺类型之间部分保守。为了解决这一假设，该项目将应用比较基因组学方法来表征花蜜成分的(I)合成、(Ii)分泌和(Iii)生物功能，这些成分涉及不同的核心甘蓝，包括甘蓝、棉花、烟草、南瓜、利马豆和相思。具体的目标和方法包括：1.蜜腺分泌过程中的比较表达谱。花蜜和花外蜜腺的转录和蛋白质组都将在整个分泌过程中的几个时间点进行检测；2.蜜汁的比较代谢组学。通过无偏的GC-GC/MS-MS和LC/MS-MS方法对花蜜代谢物进行全面的表征；3.花蜜蛋白的比较和功能分析。据报道，在几种蜜汁中存在特定的蛋白质阵列，这既具有保护作用，又具有吸引人的特性。因此，花蜜和花外蜜汁的蛋白质组将在不同物种之间进行定义和功能描述。以及，4.信息学、数据库建设和机制研究的启动。从活跃分泌和不活跃蜜腺中挖掘全球表达数据，将允许识别跨物种活跃分泌蜜汁的基本途径的核心基因和细胞过程。代谢组数据将与从表达数据中确定的活动联系起来，以评估它们对花蜜产量和组成的影响。所有经过验证的数据随后将被整合到一个现有的公共在线数据库(www.nectarygenomics.org)中，数据的子集也将在国家生物技术信息中心(http://www.ncbi.nlm.nih.gov/)和iPLANT合作中心(www.iPLANT Collaborative.org)向公众提供。

PI: Clay J. Carter (University of Minnesota-Twin Cities)CoPIs: Robert W. Thornburg and Basil J. Nikolau (Iowa State University) and Marshall W. Hampton (University of Minnesota-Duluth)Collaborators: Martin Heil (CINESTAV, Irapuato, Mexico) and Patrick von Aderkas (University of Victoria, Canada)One-third of all crop species produce floral nectar and are dependent on animals for reproduction. Moreover, crops such as cotton, bean, pea, apple, cherry, peach, and blueberry, all produce extrafloral nectar to attract mutualistic predatory insects, which protect plants from herbivores. U.S. pollinator-dependent crops alone have an annual value of nearly $25 billion, and extrafloral nectar represents one of the few defense mechanisms for which stable effects on plant health and fitness have been demonstrated. This project will employ genomics technologies to study the molecular mechanisms involved in the synthesis and secretion of nectar components across species and nectary types. If successful, this project will provide significant new insight into these processes and the plant-animal interactions mediated by specific nectar components that will allow targeted studies to improve overall pollination efficiency, enhance biological control of pests that attack crops, and have the potential to greatly impact apiculture. With regard to outreach and training, the project will provide interdisciplinary research training for students and postdoctoral associates. Project graduate students at Iowa State University will also serve as GK12 Fellows in GK12 Symbi program (http://www.gk12.iastate.edu/). Supported by NSF, the Symbi program is a partnership between ISU and middle schools and high schools that serve primarily under-represented students in the Des Moines Public School District. GK12 Fellows will serve as "resident scientists" who will work with teachers to develop innovative, hands-on and engaging science activities for select middle school or high school science students. Finally, the project will also provide research experiences for high school students from Cornell High School (Cornell, Wisconsin). The central hypothesis driving the project is that the genetic programs underlying nectar synthesis, secretion and function are at least partially conserved between diverse species and nectary types. To address this hypothesis, the project will apply comparative genomics approaches to the characterization of the (i) synthesis, (ii) secretion and (iii) biological function of nectar components across a diverse set of core eudicots, including Brassica sp., cotton, tobacco, squash, Lima bean, and acacia. The specific objectives and approaches include:1. Comparative expression profiling of nectaries throughout the secretory process. Both the floral and extrafloral nectary transcriptomes and proteomes of the respective species will be examined at several time points throughout the secretory process;2. Comparative metabolomics of nectars. Nectar metabolites will be comprehensively characterized through a non-biased GC-GC/MS-MS and LC/MS-MS approach;3. Comparative and functional analysis of nectar proteins. Specific arrays of proteins have been reported in several nectars, which confer both protective and attractive properties. Thus, the proteomes of both floral and extrafloral nectars will be defined and functionally characterized across species.; and, 4. Informatics, database building & initiation of mechanistic studies. Mining of global expression data from actively secreting vs. inactive nectaries will allow the identification of genes and cellular processes central to the basal pathways for active nectar secretion across species. Metabolomic data will be linked to activities identified from expression data to assess their impacts on nectar production and composition. All validated data will subsequently be integrated into an existing public online database (www.nectarygenomics.org), with subsets of data also being made available to the public at the National Center for Biotechnology Information (http://www.ncbi.nlm.nih.gov/) and the iPlant Collaborative (www.iplantcollaborative.org).