RESEARCH-PGR: SECRETome Project: Systematic Evaluation of CellulaR ExporT from plant cells

在多细胞生物中，一些细胞专门从事分泌功能。分泌细胞的实例包括分泌营养物用于分配的某些维管细胞、输出保护性化合物的表皮细胞、分泌溶质以奖励传粉者的蜜腺、滋养生殖细胞的绒毡层细胞和分泌营养物以填充种子的种皮细胞。病原体显然通过操纵营养分泌系统来利用营养资源。尽管分泌细胞的重要性，这些细胞和生物过程的理解是有限的。该项目旨在确定分泌细胞的基本机制，以提高作物质量和产量，植物与其他生物体的相互作用以及胁迫耐受性。该项目团队结合了单个细胞类型的全基因组分析（Bailey-Serres，Girke，UC滨江），膜转运过程（Frommer，Carnegie，斯坦福大学）和基因组编辑（Yang，爱荷华州州立大学）的专业知识。预计该项目将为农业提供新的工具和有价值的信息。该项目开发的概念和资源将被纳入招收大量服务不足学生的两年制院校的课堂。一个公共网站、博客和论坛将提供关于基因组编辑技术的讨论，专家和当地社区学院将参与其中。该项目旨在确定植物分泌细胞各种功能的特定成分和调控机制。为了能够评估单个细胞和组织内的基因功能，将以综合方式采用成像、核糖体-mRNA复合物捕获、基因编辑和信息学。通过对作物水稻和参考植物拟南芥的分析，将能够实现比较方法。具体目标包括：（1）核糖体相关转录物的分析在两个发育过程和两种生物相互作用的背景下，（2）确定特定分泌细胞的特征基因表达模式和网络，类型，以促进功能研究的候选基因的选择，和（3）分泌细胞特异性启动子和候选基因功能的验证和表征，包括亚细胞定位，生物化学和反向遗传表型。分泌细胞特异性启动子对于其他研究（例如，控制用于增强病原体防御、有益微生物相互作用、生育力或种子质量的细胞特异性过程的基因）。这些结果将为细胞功能、发育和生物相互作用之间的交叉提供广泛的新见解。该项目将在本科生的参与下制作关于基因组编辑的公共资源和讨论论坛。

In multicellular organisms, some cells specialize in secretory functions. Examples of secretory cells include certain vascular cells that secrete nutrients for distribution, epidermal cells that export protective compounds, nectaries that secrete solutes to reward pollinators, tapetal cells that nourish reproductive cells, and seed coat cells that secrete nutrients to fill seeds. Pathogens apparently tap into nutrient resources by manipulating nutrient secretion systems. Despite the importance of secretory cells, the understanding of these cells and biological processes is limited. This project seeks to identify the fundamental mechanisms of secretory cells, to permit the enhancement of crop quality and yield, of the interaction of plants with other organisms, and of stress tolerance. The project team combines expertise in the genome-wide analysis of individual cell types (Bailey-Serres, & Girke, UC Riverside), membrane transport processes (Frommer, Carnegie, Stanford) and genome editing (Yang, Iowa State U). The project is expected to provide new tools and information of value for agriculture. Concepts and resources developed by the project will be integrated into classes at 2-year institutions with substantial enrollments of underserved students. A public website, blog and forum will provide discussion of genome editing technologies, with the participation of experts and local community colleges.The SECRETome project seeks to identify specific components and regulatory mechanisms of the varied functions of plant secretory cells. To enable an evaluation of gene function within individual cells and tissues, imaging, ribosome-mRNA complex capture, gene editing and informatics will be employed in an integrated fashion. A comparative approach will be enabled through the analysis of both the crop rice and the reference plant Arabidopsis. Specific aims include (1) the profiling of ribosome-associated transcripts (translatomes) of key secretory cell types with prominent roles in secretion or nursing of neighboring cells in the two species, in the context of two developmental processes and two biotic interactions, (2) the identification of characteristic gene expression patterns and networks for specific secretory cell-types to facilitate selection of candidate genes for functional studies, and (3) the validation and characterization of secretory cell-specific promoters and candidate gene functions, including subcellular location, biochemistry, and reverse-genetic phenotype. The secretory cell-specific promoters will be valuable for other studies (e.g., to control genes for cell-specific processes that enhance pathogen defense, beneficial microbial interactions, fertility or seed quality). The results will provide broad new insights into the intersection between cell function, development and biotic interactions. The project will produce public resources and discourse forums regarding genomic editing with the engagement of undergraduate students.