Elucidating the Gene Networks Controlling Branch Angle and the Directional Growth of Lateral Meristems in Trees

阐明控制树木分枝角度和侧分生组织定向生长的基因网络

• 批准号: 1339211
• 负责人: Kenong Xu
• 金额: $ 155.64万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-12-15 至 2019-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1339211&HistoricalAwards=false
• 关键词: Elucidating; Gene; Networks; Controlling; Branch

This project will uncover genes and gene networks that underpin how apical control influences branch growth in trees. Deciphering this poorly understood yet fundamental aspect of plant biology will shed light on the evolution of tree species and have important implications for forest ecology and growth dynamics. In a practical sense, the work will help transform the orchards and tree plantations of the future through the development of tree varieties suitable for high density planting- achieving productivity improvements analogous to those accomplished for cereal crops over the past half century. Commercial planting of these improved varieties will lead to more efficient land space utilization, reduction of chemical inputs, and increased industry profitability and sustainability. To integrate education and research and broaden participation, the project will provide research training in plant genomics for undergraduate and high school students from underrepresented minority groups. In addition, the project will organize and hold a series of workshops on plant architecture and biotechnology solutions that will educate growers and agricultural industry personnel about specific benefits biotechnology has to offer tree crops. Finally, the project will develop and hold short courses on a novel sequence-based mapping and gene identification method using pooled genomes or pnomes for fellow scientists working on trees and other horticultural crops. All data generated in this project will be accessible to the public through the NCBI (http://www.ncbi.nlm.nih.gov) Short Reads Archive databases and/or the Genome Database for Rosaceae (http://www.rosaceae.org/). Trees can adopt a wide variety of architectural forms. Architectural plasticity plays important roles in forest ecosystems, agriculture, and landscape aesthetics. Tree architecture is a consequence of numerous developmental traits that include branching pattern, branch number, branch length, and branch angle. These traits are largely a function of two key developmental processes: apical dominance and apical control. Apical dominance is a well understood process that inhibits lateral bud outgrowth through signals emanating from the shoot apex. Intensive studies have revealed the signals and the underlying molecular mechanisms that operate in herbaceous plants such as Arabidopsis and pea. In contrast, apical control is the process by which the apex influences the overall tree structure upon successive years of growth and development in woody species. Although some progress has been made from a physiological perspective, the genetic and molecular mechanisms of apical control are largely unknown. The overarching goal of the project is to develop detailed knowledge about how trees adopt specific architectural forms, specifically with regard to apical control of the lateral branch angle and directional growth. Using a combination of genome-scale studies to elucidate key gene networks and molecular pathways coupled with innovative whole tree imaging technologies that will enable non-destructive structural phenotyping, the project will address the following questions: 1) What gene expression networks differentiate the shoot apical meristem from lateral meristems? What changes take place when a lateral shoot meristem transitions to becoming the apical meristem? How are these expression networks altered in branch angle mutants including pillar/columnar tree forms and weeping types? 2) What is the genetic and molecular basis for these mutant tree forms in peach and apple? What are the identities of the mutated genes? 3) With regard to the identified genes, what protein-protein interaction networks are they associated with? Through which pathways do they exert their effects on tree form?

这个项目将揭示基因和基因网络，这些基因和基因网络支持顶端控制如何影响树木的枝条生长。破译这一鲜为人知的植物生物学基本方面将有助于揭示树木物种的进化，并对森林生态和生长动态具有重要影响。在实际意义上，这项工作将通过开发适合高密度种植的树种来帮助改变未来的果园和树木种植园-实现类似于过去半个世纪谷类作物所实现的生产率提高。这些改良品种的商业种植将导致更有效的土地空间利用，减少化学品投入，并提高行业盈利能力和可持续性。为了将教育和研究结合起来，并扩大参与，该项目将为来自少数族裔群体的本科生和高中生提供植物基因组学方面的研究培训。此外，该项目将组织和举办一系列关于植物结构和生物技术解决方案的研讨会，教育种植者和农业行业人员了解生物技术为树木作物提供的具体好处。最后，该项目将为从事树木和其他园艺作物工作的其他科学家开发和举办一种新的基于序列的绘图和基因识别方法的短期课程，该方法使用汇集的基因组或pNOME。本项目产生的所有数据都将通过http://www.ncbi.nlm.nih.gov)短读档案数据库和/或蔷薇科基因组数据库(http://www.rosaceae.org/).)向公众开放树木可以采用各种各样的建筑形式。建筑的可塑性在森林生态系统、农业和景观美学中扮演着重要的角色。树木结构是许多发育特征的结果，这些特征包括分枝模式、分枝数量、分枝长度和分枝角度。这些特征在很大程度上是两个关键发育过程的作用：顶端优势和顶端控制。顶端优势是一个众所周知的过程，它通过从顶端发出的信号来抑制侧芽的生长。深入的研究揭示了在拟南芥和豌豆等草本植物中运行的信号和潜在的分子机制。相反，顶端控制是指顶端在木本植物连续几年的生长和发育过程中影响整个树木结构的过程。虽然从生理学的角度来看已经取得了一些进展，但根尖控制的遗传和分子机制仍然很不清楚。该项目的总体目标是发展关于树木如何采用特定建筑形式的详细知识，特别是关于侧枝角度和定向生长的顶端控制。利用基因组规模的研究来阐明关键的基因网络和分子途径，再加上创新的全树成像技术，使非破坏性结构表型成为可能，该项目将解决以下问题：1)哪些基因表达网络区分了茎顶端分生组织和侧生分生组织？当侧枝分生组织转变为顶端分生组织时，会发生什么变化？这些表达网络在分枝角度突变体中是如何改变的，包括柱状/柱状树型和垂枝型？2)桃树和苹果这些突变体树型的遗传和分子基础是什么？突变基因的身份是什么？3)关于已鉴定的基因，它们与什么蛋白质-蛋白质相互作用网络有关？它们通过哪些途径对树形产生影响？