How boundaries regulate plant architecture

农业是加拿大经济的重要组成部分。提高生产力是育种计划的主要目标。植物构型是决定作物产量的主要因素。我的研究计划的长期目标是了解基因如何控制植物的形状和形式。这些信息在基因组辅助育种中是有价值的，基因组辅助育种试图利用基因和基因组的知识来定制作物植物的农艺性状。 植物的形状和形式依赖于称为分生组织的干细胞自我永存的活动。分生组织在整个生命周期中提供持续的子细胞供应，用于并入新叶、花和芽中。我们的工作集中在位于分生组织外围的器官边界的作用。边界是生长受限的狭窄区域，在新器官形成时将分生组织与新器官分开。这些结构域对于分生组织的维持和器官的生长是必不可少的。这些结构域也是腋生分生组织的来源，腋生分生组织在花序上产生分枝和花，并且是控制果实、叶和花的分离的分离区的位点。尽管边界对植物结构的农学重要性，但对控制其功能的遗传网络知之甚少。 我们的工作已经确定叶片上叶柄（BOP）转录因子及其下游目标的主要决定因素的植物结构功能的器官边界。该模块调节生殖分生组织的发育、花序分枝和分生区的规范。下游靶基因的表达模式和转录组分析表明，该模块在果实发育、器官分离和植物防御中具有更广泛的作用。在接下来的五年里，我们将在模式植物拟南芥（Arabidopsis thaliana）中研究这些联系。我们的研究主要集中在四个方面：（1）BOP模块在果实发育中的作用，（2）模块在果实发育中的功能，（3）TGA转录因子在边界作为BOP辅助因子，（4）BOP在植物防御中的作用。这项工作为3位博士提供了重要的培训机会。学生，3名硕士生，和3-4名本科生HQP每年谁将采取积极的作用，在知识发现。 重要性：BOP已被鉴定为调节与作物产量相关的多种重要农艺性状，包括大麦中的分蘖、番茄中的叶复杂性和花序结构以及豆类中的开花。了解这些基因如何控制边界发育，使我们更接近于农业植物的定制。

Agriculture is a key sector of the Canadian economy. Increased productivity is a major goal of breeding programs. Plant architecture is a major determinant of crop yield. The long-term objective of my research program is to understand how genes control plant shape and form. This information is valuable in genomics-assisted breeding which seeks to use knowledge of genes and genomes to customize agronomic traits in crop plants. Plant shape and form relies on the activity of self-perpetuating groups of stem cells called meristems. Meristems provide a continuous supply of daughter cells for incorporation into new leaves, flowers, and shoots throughout the life cycle. Our work focuses on the role of organ boundaries located at the meristem periphery. Boundaries are narrow domains of restricted growth that separate the meristem from new organs as they form. These domains are essential for meristem maintenance and organ outgrowth. These domains are also the source of axillary meristems that give rise to branches and flowers on the inflorescence and the site of abscission zones that control the detachment of fruits, leaves, and flowers. Despite the agronomic importance of boundaries to plant architecture, little is known about the genetic networks that control their function. Our work has identified BLADE-ON-PETIOLE (BOP) transcription factors and their downstream targets as major determinants of plant architecture functioning at organ boundaries. This module regulates reproductive meristem development, inflorescence branching, and specification of abscission zones. A much broader role for this module in fruit development, organ detachment, and plant defense is suggested by expression patterns and transcriptome analysis of downstream target genes. Over the next five years, we will investigate these links in the model plant species, Arabidopsis thaliana (Arabidopsis). Our proposed research focuses on four areas: (1) Role of the BOP module in fruit development, (2) Module function in abscission, (3) TGA transcription factors acting as BOP co-factors at boundaries, and (4) Role of BOPs in plant defense. This work provides important training opportunities for 3 Ph.D. students, 3 M.Sc. students, and 3-4 undergraduate HQP per year who will take an active role in knowledge discovery. Significance: BOPs have been identified as regulating a variety of important agronomic traits linked to crop yield including tillering in barley, leaf complexity and inflorescence architecture in tomato, and abscission in legumes. An understanding of how these genes control development at boundaries brings us one step closer to customization of plants for agriculture.