Does physiological innovation change the fundamental relationships between growth and survival?

生理创新是否改变了生长与生存之间的基本关系？

• 批准号: NE/N003152/1
• 负责人: Colin Osborne
• 金额: $ 76.37万
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FN003152%2F1
• 关键词: Does; physiological; innovation; change; fundamental

"Live fast, die young" famously describes the wild excesses of rock stars and Hollywood actors, but also encapsulates an important biological principle. Animals and plants that grow and reproduce quickly are more likely to be killed by natural enemies or environmental extremes. We usually explain this biological trade-off in terms of energy: more energy spent on growth means less energy invested in defence against enemies, the capture of essential resources, or into stores for surviving adverse conditions. A logical extension of this explanation is that, if the same growth could be achieved using less energy, more would be available for defence, resource capture and storage, thereby increasing survival. However, this prediction remains untested, despite its central importance for biology.The evolution of C4 photosynthesis in more than seventy plant lineages has increased the efficiency of photosynthetic energy conversion at high light and hot temperatures, in comparison with the ancestral C3 type of photosynthesis. To understand how this increase in photosynthetic efficiency influences growth, we have developed an experimental approach capable of comparing growth among hundreds of plant species in the same environmental conditions. We have discovered that, as well as a direct physiological effect of C4 photosynthesis in promoting faster growth, C4 leaves are unexpectedly less dense than C3 ones, further increasing growth efficiency. This allows C4 plants to be larger, with more growth invested in roots, which leads us to hypothesize that they may be able to accumulate greater storage, and have better access to water during drought than their C3 counterparts. Together, these hypothesized effects are expected to increase plant survival following repeated defoliation and drought events. If supported by experimental evidence, these ecological differences between C3 and C4 plants would have important global scale implications for the responses of plant communities to environmental change and land management.We propose to test these hypothesis using three large comparative experiments, capitalizing on our recent advances in developing high-throughput experimental screening methods. We are able to measure growth, allocation to roots verses shoots, storage and survival on thousands of plants in the same experimental set-up, and have developed novel statistical methods to analyze the large resultant datasets. We are also the first group to successfully apply metabolomic methods to identify and quantify storage compounds across multiple wild plant species. Our strategy for the proposed work will be to combine these approaches, investigating survival of experimentally imposed drought or repeated defoliation in seventy ecologically important grass species, representing seven independent evolutionary origins of C4 photosynthesis and their C3 sister taxa. Alternative hypothesized survival mechanisms will be tested by using plants of different ages to manipulate size. Since C4 photosynthesis also has a direct physiological effect on plant water use, by reducing stomatal aperture, we will make detailed measurements of plant hydraulics during the drought experiment. Findings from the three experiments will allow us to test the relative importance to survival of greater storage, deeper rooting, lower plant water use, and greater plant size in C4 then C4 species, and to gain a holistic understanding of the system. The work will enhance our mechanistic understanding of how a major physiological innovation changed growth-survival relationships and enabled plants to explore new phenotypic space. Throughout the project, we will work with mathematical modelers to ensure that the experiments will generate data that are useful for developing improved models of how global vegetation stores carbon and influences climate.

“快速，年轻的生活”著名地描述了摇滚明星和好莱坞演员的狂野过剩，但也封装了重要的生物学原理。迅速生长和繁殖的动物和植物更有可能被天然敌人或极端环境杀死。我们通常在能源方面解释了这种生物学权衡：在增长上花费的更多能源意味着对敌人的防御，捕获基本资源或用于存活的不利条件的商店的能量减少。这种解释的逻辑扩展是，如果使用更少的能量可以实现相同的增长，则更多可用于防御，资源捕获和存储，从而增加生存。然而，尽管该预测对生物学的重要性仍然没有测试。与祖先C3的光合作用类型相比，C4光合作用在70种植物谱系中的演变提高了光合作用转化率的效率。为了了解这种光合效率的增加如何影响生长，我们开发了一种实验方法，能够比较在相同环境条件下数百种植物物种的生长。我们已经发现，以及C4光合作用在促进更快的生长方面的直接生理效应，C4叶子意外地比C3叶片更少，从而进一步提高了生长效率。这使C4植物可以更大，其根源投入了更多的增长，这使我们假设它们可能能够积累更大的存储空间，并且在干旱期间比C3同行在干旱过程中获得了更好的水。总之，这些假设的影响有望在反复的脱叶和干旱事件后增加植物生存。如果在实验证据的支持下，C3和C4植物之间的这些生态差异将对植物群落对环境变化和土地管理的反应具有重要的全球规模影响。我们建议使用三个大型比较实验来检验这些假设，利用我们最近在开发高促进实验筛选方法方面的进步。我们能够测量在同一实验设置中成千上万植物上对数千个植物的生长，对根部经文的分配，并开发了新颖的统​​计方法来分析大型结果数据集。我们还是第一个成功应用代谢组方法来识别和量化多种野生植物物种的储存化合物的组。我们提出的工作的策略将是结合这些方法，调查实验强加的干旱或重复脱叶的生存，或者在七十个具有生态重要的草种中，代表了C4光合作用的七个独立进化起源和C3姊妹分类群。替代假设的生存机制将通过使用不同年龄的植物来操纵大小来测试。由于C4光合作用也对植物用水具有直接的生理作用，因此通过减少气孔孔，我们将在干旱实验期间对植物液压药进行详细的测量。这三个实验的发现将使我们能够测试对更大的存储，更深的生根，较低的植物用水和C4含量更大的植物大小的相对重要性，并获得对系统的整体了解。这项工作将增强我们对主要生理创新如何改变生长生存关系的机械理解，并使植物能够探索新的表型空间。在整个项目中，我们将与数学建模者合作，以确保实验将生成对开发全球植被如何存储碳和影响气候的改进模型有用的数据。

项目成果

Large seeds provide an intrinsic growth advantage that depends on leaf traits and root allocation

大种子提供了内在的生长优势，这取决于叶子性状和根部分配

• DOI: 10.1111/1365-2435.13871
• 发表时间: 2021
• 期刊: Functional Ecology
• 影响因子: 5.2
• 作者: Simpson K

The morphogenesis of fast growth in plants.

• DOI: 10.1111/nph.16892
• 发表时间: 2020-08
• 期刊: The New phytologist
• 作者: R. Wade;Patrick Seed;Eleanor McLaren;Ellie Wood;P. Christin;K. Thompson;M. Rees;C. Osborne