Using seed-free plants to link diversity in stomatal function with ecological strategy

植物通过叶片上的气孔从大气中获取二氧化碳。 当气孔打开以获得二氧化碳时，水通过蒸发而损失到大气中。 由于用于植物生长的碳增益和可能导致脱水的水分损失之间的权衡，有许多来自环境和植物的信号触发气孔打开和关闭。 该奖项旨在调查蕨类植物物种之间是否存在气孔对环境条件的反应差异，以及这种差异是否与生态策略和栖息地偏好有关。 该项目将重点关注蕨类植物和石松植物，这些古老的植物群体具有相对简单的气孔行为，其中气孔功能的变化可能对植物的生长和存活产生很大的影响。 这些结果将增加对气孔对环境的反应如何演变以及如何在农业物种中操纵它们以提高植物水分利用和生产力的理解。 该项目还将向公众和学生介绍植物的动态本质，帮助提高人们对景观中这些静态特征的反应能力和活力的认识，并为本科生提供研究培训。本项目将调查三个关键假设，使用比较研究来表征无籽植物气孔功能的自然多样性。第一个假说提出，通过水生生长习性或植物干燥耐受性的进化，消除了水分限制对生存的威胁，推动了新的气孔功能的进化，特别是在气孔关闭的调节方面。 第二个建议，独特的叶片水力特性的演变有利于新的气孔调节的演变。 最后，本项目将测试是否有协调进化的气孔调节，叶片水力特性和生态策略在整个生态多样性蕨类植物家庭。 该项目将利用大量不同的蕨类植物和石松植物物种的活体收集和实地实验来解决这些假设，主要是通过气孔和植物水力生理学的比较研究密切相关但生态上不同的物种之间。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Plants obtain carbon dioxide from the atmosphere through microscopic pores on the leaves called stomata. When stomata open to obtain carbon dioxide, water is lost to the atmosphere by evaporation. Due to the tradeoff between carbon gain used for plant growth and water loss that might lead to dehydration, there are many signals from the environment and plant that trigger stomatal opening and closing. This award aims to investigate whether there is variation across fern species in the responses of stomata to environmental conditions, and whether this variation can be linked to ecological strategies and habitat preference. This project will focus on ferns and lycophytes, ancient groups of plants that have comparatively simple stomatal behavior, in which variation in stomatal function is likely to have a large impact on plant growth and survival. The results will increase understanding of how stomatal responses to the environment evolved and how they could be manipulated in agricultural species to improve plant water use and productivity. This project will also inform the public and students on the dynamic nature of plants, to help raise awareness of how responsive and alive these otherwise static features of the landscape are, as well as provide research training to undergraduate students. This project will investigate three key hypotheses using comparative studies to characterize the natural diversity of stomatal function found in seed-free plants. The first hypothesis proposes that eliminating the threat of water limitation on survival through the evolution of an aquatic growth habit or vegetative desiccation-tolerance, drives the evolution of novel stomatal function, particularly in the regulation of stomatal closure. The second proposes that the evolution of unique leaf hydraulic properties facilitates the evolution of novel stomatal regulation. Finally, this project will test whether there is coordinated evolution in stomatal regulation, leaf hydraulic traits and ecological strategy across an ecological diverse fern family. This project will draw upon a large living collection of diverse fern and lycophyte species and field experiments to address these hypotheses, primarily through comparative studies of stomatal and plant hydraulic physiology between closely related yet ecologically dissimilar species.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.