Regulation of Compound Leaf Development in Tomato

主要研究人员：Nelima Roy SinhaProposal编号：IOB-0641696 Proposal标题：番茄复叶发育的调节出现在植株顶端分生组织的生长顶端。叶子负责植物中的大部分固定碳，对植物生产力和人类生存至关重要，复杂程度从简单到复杂。复叶可以有羽状或掌状排列的小叶。这项研究的长期目标是确定形成叶片的不确定茎顶端分生组织和确定细胞之间的差异，以及单叶和复叶之间的差异。这项研究将提供关于羽状复叶与掌状复叶形成的步骤的信息，并将使用遗传学以及发育分析。这一分析将扩展到看看在番茄中发现的发育原理是否适用于不同类型的独立进化历史的复叶。这项拟议的研究将采用多管齐下的方法，包括分析一些在其他模式植物物种中具有重要发育调节作用的基因。通过这项工作，应该可以更深入地理解KNOX1基因家族是如何在苗端调节表达的。在这项研究过程中，新的叶片发育调节因子有望被发现。拟议研究的具体目标是：1.对番茄叶片发育进行克隆分析；这将涉及标记幼叶中的细胞并跟踪它们的后代，以跟踪细胞分裂如何产生叶片形状。确定控制番茄叶片发育的遗传位点。将利用定量和基因组扫描的方法来确定新的叶片发育调控因子。利用分子生物学和发育生物学技术分析KNOX1基因表达的调控。阐明HDZIPIII、NAM/CUC、LFY、UFO和JAG基因在叶片发育中的作用，这些基因在模式生物拟南芥中调节植株的形状，但它们在叶片发育中的作用尚不清楚。拟议的研究的智力价值包括提供信息，对于理解植物生物学中的一个基本问题-为什么一些茎的顶端分生组织产生单叶，而另一些形成复叶。叶片在光合作用中起着捕捉光的作用，其形状的变化具有重要的生理和生态后果。在许多物种中，个体的叶片复杂性可以因环境条件而改变(异叶性变异)，并且可以随着发育时间的不同而变化(异叶性变异)。此外，这项研究应该能够理解基因表达是如何在顶端分生组织和发育中的叶片中调节的。这项研究还将确定其他被认为调节营养和生殖发育的基因(基于拟南芥等模式生物)是否在复叶发育中发挥作用。此外，全基因组分析和定量方法的尖端技术将帮助我们识别在叶片形成中发挥作用的未知基因。这项研究活动的更广泛影响包括培养一名博士后研究员、一名研究生和本科生。过去，PI的实验室曾培训过所有这些级别的学生。本科生承担独立的研究项目，几个人有共同撰写的论文，许多本科生来自少数族裔群体。除了科研培训外，博士后研究员和研究生还将接受本科生导师培训。

Principal Investigator: Neelima Roy SinhaProposal Number: IOB-0641696Proposal Title: Regulation of Compound Leaf Development in TomatoLeaves arise at the growing tips of plants on shoot apical meristems. Leaves are responsible for most of the fixed carbon in a plant, are critical to plant productivity and human survival, and can range in complexity from simple to compound. Compound leaves can have leaflets in a pinnate or palmate arrangement. The long-term goal of this research is to determine the differences between the indeterminate shoot apical meristem and determinate cells that give rise to leaves, and between simple and compound leaves. This research will provide information on the steps that give rise to pinnate vs. palmate compound leaves and will use genetics, as well as developmental analyses. This analysis will be extended to see if the developmental principles discovered in tomato are applicable to various types of compound leaves of independent evolutionary history. The proposed research will utilize a multi-pronged approach that includes analysis of a number of genes that are important developmental regulators in other model plant species. A deeper understanding of how the expression of one family of genes, the KNOX1 genes, is regulated at the shoot apex should result from this work. New regulators of leaf development are expected to be identified during the course of this research. The specific aims of the proposed research are to:1. Perform a clonal analysis of tomato leaf development; this will involve marking cells in young leaves and following their progeny to track how cell division gives rise to leaf shapes.2. Identify genetic loci that regulate leaf development in tomato. Quantitative and genome scanning approaches will be utilized to identify new regulators of leaf development.3. Analyze the regulation of KNOX1 gene expression using molecular biology and developmental biology techniques.4. Elucidate the role of HDZIPIII, NAM/CUC, LFY, UFO and JAG genes in leaf development, which are known to regulate plant form in the model organisms Arabidopsis but their role in leaf development is not yet understood.The intellectual merits of the proposed research include providing information crucial to understanding a basic problem in plant biology - why some shoot apical meristems produce simple leaves, while others make compound leaves. Leaves function in photosynthetic light capture and variation in their shape has important physiological and ecological consequences. In many species, leaf complexity in an individual can change due to environmental conditions (heterophyllic variation) and can vary over developmental time (heteroblastic variation). In addition, this research should generate an understanding of how gene expression is regulated both in the apical meristem and in developing leaves. This research will also determine if other genes thought to regulate vegetative and reproductive development (based on model organisms like Arabidopsis) have a role in compound leaf development. In addition cutting edge techniques of whole genome analysis and quantitative approaches will help us to identify as yet unknown genes that have played a role in the formation of leaves. Broader impacts of this research activity include training of a post-doctoral fellow, a graduate student and undergraduate students. The PI's laboratory has trained students at all these levels in the past. Undergraduate students undertake independent research projects, several have co-authored papers and many of the undergraduate students come from minority groups. In addition to research training, the post-doctoral fellows and graduate students will also be trained in undergraduate mentorship.