COLLABORATIVE RESEARCH: Testing a new hypothesis for global patterns in leaf form using Viburnum (Adoxaceae)

合作研究：使用荚莲属植物（Adoxaceae）测试叶子形式整体模式的新假设

• 批准号: 1757362
• 负责人: Erika Edwards
• 金额: $ 6.56万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1757362&HistoricalAwards=false
• 关键词: COLLABORATIVE; RESEARCH; Testing; new; hypothesis

Scientists have long recognized a global pattern in leaf shape between tropical and temperate climates: tropical leaves have smooth margins while plants living in cold regions have leaves with teeth or lobes, like a birch or a maple. The relationship is so strong that paleobotanists use leaf shapes in fossil floras as a proxy for temperature, allowing for estimates of climate change through time. But there is still no mechanistic understanding of why this relationship exists. The PIs hypothesize that the evolution of complex leaf margins in temperate plants results in part from the way that young, immature leaves are packed into overwintering buds. This is inspired by recent mathematical models of efficient leaf folding within buds, and by observations of within-plant differences in leaf form. Viburnum is a lineage of ~170 species of woody shrubs and trees that have shifted between tropical and temperate forests many times throughout the past 50 million years, and exhibit the expected changes in leaf shape. The PIs will document timing of growth, leaf lifespan, and patterns of leaf-packing within buds, and gather additional data on a suite of relevant morphological and physiological traits on a set of Viburnum species spanning the tropical-temperate gradient. They will also continue long-term phenological monitoring of ~30 Viburnum species in a common garden. This is a highly collaborative and interdisciplinary project, involving biologists from four other nations as well as an applied mathematician. The PIs will also develop educational modules designed for elementary school children aimed to bridge the gap between math and biology, using origami and basic geometric principles to understand common leaf shapes.

长期以来，科学家已经认识到热带气候和温带气候之间的叶片形状的全球模式：热带叶子的边缘光滑，而生活在寒冷地区的植物则带有牙齿或叶的叶子，例如桦木或枫木。这种关系是如此牢固，以至于古植物学家在化石植物群中使用叶形形状作为温度的代理，从而可以随着时间的流逝估计气候变化。但是仍然没有机械理解这种关系的原因。 PI假设温带植物中复杂的叶缘的演变部分是由于年轻，未成熟的叶子被包装成越冬的芽的方式。这是受芽内有效叶片折叠的最新数学模型的启发，并观察到叶片内植物内差异的观察。在过去的5000万年中，繁荣是约170种木本灌木和树木的谱系，在热带和温带森林之间发生了变化，并且在叶形状上显示了预期的叶片变化。 PI将记录芽内生长，叶片寿命和叶片包装模式的时机，并收集有关一组相关的形态和生理特征的数据，这些数据横跨热带温度梯度。他们还将继续在一个公共花园中对〜30种繁殖物种进行长期的物候监测。这是一个高度协作和跨学科的项目，涉及来自其他四个国家以及应用数学家的生物学家。 PI还将开发专为小学生设计的教育模块，旨在使用折纸和基本​​的几何原理弥合数学和生物学之间的差距，以了解常见的叶子形状。