Regulatory Hierarchies and Roles of Non-Coding RNAs in Maize Anthers

Pi：Blake C.Meyers(特拉华大学)Copis：弗吉尼亚·沃尔伯特(Stanford University)和格雷格·艾布拉姆斯(Greg Abrams)(德克萨斯先进计算中心/德克萨斯大学奥斯汀分校)该项目产生的信息将为调节玉米和相关牧草的雄性生殖器官花药的发育事件提供新的见解。新的见解和广泛实用的资源最终应该有助于控制农业中的植物肥力，特别是在谷类作物中。该项目建立并改进了个人投资促进机构的各种广泛的宣传和教育部分及其通过科学领导作出的贡献，以继续对地方和科学界以及对下一代科学家产生强有力的积极影响。“虚拟花药”的实施将使项目数据得到广泛的获取，同时帮助学生和公众了解花药是如何发育的。一个以本科生为重点的测序和注释基本草类基因组的项目将为该项目和所有在开花植物中进行系统发育分析的人提供宝贵的数据，同时培训下一代植物生物学家。所有项目成果将通过一个项目网站和诸如GEO和MaizeGDB等长期储存库向研究界开放。所有生物资源，如抗体、克隆和载体，将根据要求提供。种子将通过玉米遗传合作社长期储存和分发。用于“虚拟花药”的软件将被开源，并可通过德克萨斯州先进计算中心网站获得。(https://www.tacc.utexas.edu/tacc-software/).Male不育是自然物种中一种常见的表型，它是促进异交的一种机制。此外，植物育种者控制花粉产生是一项基本技术，继续支撑着许多作物的杂交种子生产。在农业方面，人们也越来越担心气候破坏：高温和寒冷都会导致作物雄性不育。这项研究试图更广泛地了解植物细胞从有丝分裂到减数分裂过程中花药发育和潜在细胞过程的协调，包括染色质重塑。具体目标是：(1)组织单个花药细胞类型中基因表达的层次结构；(2)阐明小RNA的功能，特别是高度富含在草药中的两类不寻常的“阶段性”次生小RNA(PhasiRNAs)。这些phasiRNA是从一组广泛的协调表达的长非编码RNA前体加工成21或24个核苷酸的次级小RNA。利用精确分期的玉米花药和激光显微解剖的细胞类型，该项目将产生丰富的转录和蛋白质组数据，组织转录因子的转录层次结构，在时空背景下产生关于小RNA的广泛数据，并分析phasiRNAs的功能和生物发生。使用现有的和工程的突变进行的遗传分析将用于测试关键的转录和phasiRNA生物发生因子在花药发育中的关键作用。遗传学和“组学”实验将检验有关花药细胞和减数分裂中的phasiRNA功能的新假说。大部分的分析将在玉米上进行，因为它精致的发育规律，花药解剖的大小和容易，以及现有的关于玉米花药的分子和遗传知识。将对水稻的关键见解进行评估，以区分一般和物种特定的点，并与其他草本植物进行额外的比较。为了产生新的假设，所有的数据都将被整合到一个“虚拟花药”可视化系统中。

PI: Blake C. Meyers (University of Delaware)CoPIs: Virginia Walbot (Stanford University) and Greg Abrams (Texas Advanced Computing Center/University of Texas - Austin) Information generated from this project will provide new insights into the regulation of developmental events in the anther, the male reproductive organ, of maize and related grasses - crops that feed much of the world. New insights and resources of broad utility should ultimately contribute to controlling plant fertility in agriculture, particularly in the cereal crops. The project builds and improves on the varied and extensive outreach and education components of the PIs and their contributions via scientific leadership to continue a strong, positive impact on local and scientific communities, and on the next generation of scientists. Implementation of the "Virtual Anther" will make the project data widely accessible while helping students and the public understand how anthers develop. An undergraduate-focused project to sequence and annotate a basal grass genome will provide invaluable data for the project and to all those employing phylogenomics analysis in flowering plants, while training the next generation of plant biologists. All project outcomes will be accessible to the research community through a project website and long-term repositories such as GEO and MaizeGDB. All biological resources such as antibodies, clones and vectors will be available upon request. Seed will be deposited and distributed long-term through the Maize Genetics Cooperative. Software for the "Virtual Anther" will be made open-source and available via the Texas Advanced Computing Center website (https://www.tacc.utexas.edu/tacc-software/).Male sterility is a common phenotype in natural species, functioning as one mechanism to promote outcrossing. Furthermore, control of pollen production by plant breeders is a fundamental technology that continues to underpin hybrid seed production in many crops. In the agricultural context, there is also a growing concern over climate disruption: both heat and cold cause male sterility in crop plants. This study seeks to more broadly understand the coordination of anther development and underlying cellular processes, including chromatin remodeling, as plant cells switch from mitosis to meiosis. The specific goals are to: (1) organize hierarchies of gene expression in individual anther cell types and (2) elucidate functions of small RNAs, particularly two unusual classes of "phased" secondary small RNAs (phasiRNAs) that are highly enriched in grass anthers. These phasiRNAs are processed from an extensive set of coordinately-expressed long non-coding RNA precursors into secondary small RNAs of 21 or 24 nucleotides. Using precisely staged maize anthers and laser microdissected cell types, the project will generate copious transcriptomic and proteomic data, organize transcriptional hierarchies of transcription factors, generate extensive data on small RNAs in a spatiotemporal context, and analyze the function and biogenesis of phasiRNAs. Genetic analysis using existing and engineered mutations will be used to test for essential roles of key transcription and phasiRNA biogenesis factors in anther development. Genetic and "omics" experiments will test new hypotheses about phasiRNA functions in anther cells and in meiosis. Most of the analysis will be conducted in maize because of its exquisite developmental regularity, the large size and ease of anther dissection, and existing molecular and genetic knowledge about maize anthers. Key insights will be evaluated in rice to distinguish general and species-specific points, with additional comparisons to other grasses. To generate new hypotheses, all data will be integrated into a "Virtual Anther" visualization system.