Bilateral NSF/BIO-BBSRC: Development of the Grass Leaf

开花植物表现出两种主要的生长策略。一种（称为双茎策略）是植物的生长尖端通过在其下方产生细长的茎而向上攀登。另一种策略（称为单子叶策略）是让生长尖端保持在植物基部的保护，并产生一系列的叶子，这些叶子从植物上方升起，然后在植物周围生长。后一种单子叶策略的优点是在植物生命的大部分时间里保护植物基部的生长尖端。它使草能够在广泛的放牧中生存下来，这是小麦、玉米和水稻等植物所采用的生长策略。尽管对生态和农业有重要意义的植物使用这种单子叶植物，但人们对这种单子叶植物的策略还不是很了解。在这个项目中，美国（加州大学伯克利分校）和英国（约翰英尼斯中心）的研究人员组成的合作团队将使用包括高分辨率成像和计算方法在内的工具组合来测试将开发预测和可测试模型的机制。这些模型将描述单子叶的生长过程和形状变化。由于叶片的位置会影响植物光合作用所获得的光量，因此这项工作可能会对作物产量产生重大影响。通过对组织发育过程的更深入的基本理解，生物技术产业将从这项工作中受益。调查人员将积极参与各级教育，包括K-12和公共教育，通过开发实践培训活动、YouTube视频和传播研究成果的更传统方法。计算模型已经导致了单叶发育的初步假设。一个关键的想法是，生长是由极性场引导的，这类似于磁场可以用来确定导航方向的方式。观察到的单片叶的生长和形状变化可以用极性场的简单变化和它所指向的生长速率模式来解释。这个项目的目的是测试和进一步建立这个模型，并确定极性场和模型预测的生长速度是否正确，使用玉米单子叶系统（它具有发达的遗传和相关技术的优势）。通过观察突出显示假定极性场的标记，并通过确定叶片不同区域的生长速率，可以对模型的预测进行测试。模型还将通过分析突变体来检验，在这些突变体中，关键的发育转变被打乱了。这些研究将通过编写自动提取相关措施的计算机程序来量化。新的计算方法也将被开发并应用于该系统，以便可以在不同的水平上理解这些过程，即从细胞到组织尺度。这个英美合作项目由美国国家科学基金会和英国生物技术和生物科学研究委员会支持。

Flowering plants exhibit two major growth strategies. One (called the dicot strategy) is for the growing tip of the plant to climb upward by producing an elongating stem below it. The alternative strategy (termed the monocot strategy) is for the growing tip to stay protected at the base of the plant and produce a series of leaves that rise above the plant and then grow around it. This latter monocot strategy has the advantage of protecting the growing tip at the base of the plant for much of its life. It enables grasses to survive extensive grazing, and it is the growth strategy that is used by plants like wheat, maize and rice. Despite its use by plants of ecological and agricultural importance, this monocot strategy is not well understood. In this project, a collaborative team of US (University of California, Berkeley) and UK (John Innes Centre) investigators will use a combination of tools including high resolution imaging and computational methods to test mechanisms that will develop predictive and testable models. These models will describe the processes of growth and shape changes in the monocot leaf. Because the position of the leaf blade has an effect on the amount of light a plant can harvest for photosynthesis, this work could significantly impact crop yield. Biotech industries will benefit from the work, through greater fundamental understanding of processes involved in tissue development. The investigators will be actively engaged in education at all levels, including K-12 and public education, through the development of hands on training activities, YouTube videos, and more traditional methods of diffusion of research findings. Computational modeling has led to preliminary hypotheses of monocot leaf development. A key idea is that growth is oriented by a polarity field, which is analogous to the way a magnetic field can be used to orient directions of navigation. The observed growth and shape changes of the monocot leaf can then be explained by simple changes in the polarity field and the pattern of growth rates it orients. The aim of this project is to test and further build upon this model and determine whether the polarity fields and the growth rates the model predicts are correct using the maize monocot system (which has the advantage of well-developed genetics and associated technologies.) By looking at markers that highlight the presumed polarity fields and by determining the growth rates in different regions of the leaf, predictions of the model can be tested. Models will also be tested by analyzing mutants in which key transitions of development are disrupted. These studies will be made quantitative by writing computer programs that automatically extract the relevant measures. New computational methods will also be developed and applied to this system so that the processes can be understood at different levels, i.e. from cellular to tissue scale.This collaborative US/UK project is supported by the US National Science Foundation and the UK Biotechnology and Biological Sciences Research Council.