The ontogeny of plant defense: general patterns and genetic variation

植物防御的个体发育：一般模式和遗传变异

基本信息

批准号：
NE/E012418/1
负责人：
Kasey Barton
金额：
$ 27.35万
依托单位：
Royal Holloway University of London
依托单位国家：
英国
项目类别：
Fellowship
财政年份：
2008
资助国家：
英国
起止时间：
2008 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FE012418%2F1
关键词：
ontogeny plant defense general patterns

项目摘要

Plants change dramatically as they develop from young seedlings to the mature adult stage, a progression called ontogeny. For traits involved in defense against herbivores, these ontogenetic patterns are key aspects of natural community dynamics, driving interactions between plants and herbivores. Plant defense traits include toxic chemicals and physical barriers, such as thorns, spines, and hairs, that deter herbivores, as well as plant traits that reduce the negative impacts of herbivores, such as the ability to regrow following damage. Concentrations of toxins, densities of thorns and spines, and regrowth rate may all change as plants develop, and these changes have consequences for the levels of herbivore damage plants experience. For example, some species of plants produce few defenses against herbivores during the seedling stage, and consequently, damage by herbivores is the highest during this vulnerable period. In contrast, other species of plants are relatively better defended against herbivores as seedlings than they are as adult plants, leading to higher levels of damage in older plants. Ontogenetic patterns in plant defense traits are common and have been documented in over 60 plant species. Yet, a general pattern has failed to emerge. Variation among species is likely to be biologically significant, caused by differences among plant species in their life history strategies (woody vs. herbaceous plants), primary defense traits (toxins, thorns, regrowth, etc.), and plant ages studied. The proposed research addresses two primary goals: 1) To synthesize the current literature using powerful statistical techniques (meta-analysis and graphical vector analysis) in order to reveal general patterns in the ontogeny of plant defense. These statistical analyses will also reveal what factors contribute to the variation observed among species (woody vs. herbaceous, kind of defense traits, plant ages, etc.). 2) To examine genetic variation in the ontogeny of plant defense by using a large-scale field experiment with silver birch in southwestern Finland. The second goal puts this work into a broader evolutionary context by considering whether the ontogeny of defense can respond to natural selection. If ontogenetic patterns in plant defense are to evolve in response to natural selection, there must be genetic variation in the ontogenetic patterns of traits. This key assumption, however, has rarely been tested. This research will be done in collaboration with Julia Koricheva at the School of Biological Sciences, Royal Holloway University of London. Dr. Koricheva is an internationally recognized expert in the use of meta-analysis for synthesis in ecology and evolution. She has used meta-analysis repeatedly to investigate key hypotheses in her primary field of expertise, plant-herbivore interactions. Furthermore, she developed the analytical tool, graphical vector analysis, that will be used to understand how plant defense traits change during ontogeny. Finally, Dr. Koricheva designed and has led the large-scale field experiment in southwestern Finland that will be used to measure genetic variation in silver birch. This collaboration will thus capitalize on my particular expertise in the ontogeny of plant defense, developed during investigations of plant defense for my Ph.D. dissertation at the University of Colorado (USA), and Dr. Koricheva's expertise in meta-analysis and graphical vector analysis. This research will make a significant contribution to our understanding of the evolution of plant defense by elucidating the role of ontogeny in defense and herbivory.

随着植物从幼苗到成熟的成年阶段的发展，植物发生了巨大变化，这种进展称为个体发育。对于涉及防御食草动物的特征，这些个体发生模式是自然社区动态的关键方面，促进了植物与食草动物之间的相互作用。植物防御性质包括有毒化学物质和物理障碍，例如刺，刺和头发，以阻止食草动物，以及减少食草动物的负面影响的植物特征，例如在损害后再生能力。随着植物的发展，毒素，刺和刺密度以及再生速率的浓度可能都会发生变化，并且这些变化对草食动物损害植物经历的水平产生了影响。例如，在幼苗阶段，一些植物对草食动物产生的防御能力很少，因此，在此脆弱时期，食草动物的损害最高。相比之下，与成年植物相比，其他植物对草食动物的防御能力相对较高，从而导致老植物的损害水平更高。植物防御性状中的个体发育模式很常见，已在60多种植物物种中进行了记录。然而，一般模式未能出现。物种之间的差异可能在生物学上具有重要意义，这是由于植物物种的生命历史策略（木质与草本植物），主要防御性状（毒素，刺，刺，再生等）以及所研究的植物年龄引起的。拟议的研究涉及两个主要目标：1）使用强大的统计技术（荟萃分析和图形矢量分析）合成当前文献，以揭示植物防御本体的一般模式。这些统计分析还将揭示哪些因素导致物种之间观察到的变化（木质与草原，一种防御性状，植物年龄等）。 2）通过使用芬兰西南部银桦树的大规模野外实验来检查植物防御本体的遗传变异。第二个目标将这项工作置于更广泛的进化环境中，即考虑防御的个体发育是否可以对自然选择做出反应。如果植物防御中的个体发生模式应响应自然选择而发展，则特征的个体发生模式必须存在遗传差异。但是，这个关键假设很少被测试。这项研究将与伦敦皇家霍洛威大学生物科学学院的朱莉娅·科里切瓦（Julia Koricheva）合作。 Koricheva博士是国际公认的荟萃分析来综合生态和进化的专家。她曾多次使用荟萃分析来研究其主要知识领域的主要假设，即植物植物学相互作用。此外，她开发了分析工具，图形矢量分析，该工具将用于了解植物防御性质在个体发育过程中如何变化。最后，Koricheva博士设计并领导了芬兰西南部的大规模现场实验，该实验将用于测量银桦树的遗传变异。因此，这项合作将利用我在植物防御的个体基础上的特殊专业知识，这是在对我的博士学位的植物防御调查期间开发的。科罗拉多大学（美国）的论文以及Koricheva博士在荟萃分析和图形矢量分析方面的专业知识。这项研究将通过阐明个体发育在防御和草食性中的作用来对我们对植物防御的发展做出重大贡献。