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Do silica-based defences drive plant-herbivore dynamics?

基于二氧化硅的防御是否会驱动植物与食草动物之间的动态变化？

基本信息

批准号：
NE/F003137/2
负责人：
Sue Hartley
金额：
$ 14.54万
依托单位：
University of York
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2010
资助国家：
英国
起止时间：
2010 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FF003137%2F2
关键词：
Do silica based defences drive

项目摘要

Understanding the factors that drive changes in the abundance of animal populations is fundamental to ecology. Many herbivore populations show regular oscillations in abundance, known as cycles, and these are usually thought to be due to matched oscillations in the abundance of predators rather than any changes in the herbivore's food plants. Food quality is not thought to respond to herbivory in a way which could lead to cycles, but we have discovered a novel way in which changes in plant quality could cause cycles in herbivore populations. This mechanism has not been considered before but it could apply to wide range of plant-herbivore systems. Our new idea is called the silica induction hypothesis. Periods of sustained heavy grazing lead to an increase in the levels of silica in grasses, so herbivores subsequently experience reduced availability of nutrients. This reduces their growth and reproductive rate and hence slows down the rate of population growth in the following year. Eventually populations fall to a level where there is only low grazing on the grasses, so the levels of silica in the leaves also fall because less well-defended leaves are produced. Herbivores are once again able to access nutrients in the grasses and their growth and reproduction increase again. We believe this mechanism can operate in many plant-herbivore systems, particularly ones based on grasses and other plants that contain high levels of silica. Silicon is the second most abundant mineral on earth and present in significant amounts in all plants, so the mechanism we propose is of wide relevance and significance. We already have some evidence from laboratory experiments and observations in the field that support our idea. In this project we aim to test this potential mechanism for the first time in large-scale field experiments. Firstly, we will determine the silica levels in grasses in areas where vole populations are high and compare them with those in areas where vole populations are low. If our ideas are correct, silica levels should be declining in areas where vole populations are increasing and vice versa. We will then set up an experiment to measure the rate and magnitude of the increase in silica at different levels of grazing and we will also measure how quickly the levels of silica defences decrease. Then we will test our ideas by moving voles into areas where we have induced high silica levels previously and see how feeding in these areas affects their growth and reproduction. These experiments will assess whether changes in plant defences can cause changes in herbivore abundance and help us develop a better understanding of the interactions between grasses and their herbivores. There are many important grassland systems that support a wide range of herbivores, including both rare species and livestock, so this project will be useful to both conservation and sustainable agriculture.

了解驱动动物种群丰度变化的因素是生态学的基础。许多食草动物的种群在丰度上表现出有规律的振荡，称为周期，这些通常被认为是由于捕食者丰度的匹配振荡，而不是食草动物食物植物的任何变化。食物质量不被认为是以一种可能导致周期的方式对食草动物作出反应，但我们发现了一种新的方式，即植物质量的变化可能导致食草动物种群的周期。这种机制以前没有被考虑过，但它可以适用于广泛的植物-草食动物系统。我们的新想法被称为硅诱导假说。持续的大量放牧导致草中二氧化硅水平的增加，因此食草动物随后经历营养物质的可用性降低。这降低了它们的生长和繁殖率，从而减缓了下一年的人口增长率。最终，种群数量下降到只有少量牧草的水平，因此叶片中的二氧化硅水平也下降，因为产生了防御能力较弱的叶片。食草动物再次能够获得草中的营养，它们的生长和繁殖再次增加。我们相信这种机制可以在许多植物-草食动物系统中发挥作用，特别是基于草和其他含有高水平二氧化硅的植物的系统。硅是地球上第二丰富的矿物质，在所有植物中都有大量存在，因此我们提出的机制具有广泛的相关性和意义。我们已经从实验室实验和实地观察中获得了一些证据来支持我们的想法。在这个项目中，我们的目标是在大规模的现场实验中首次测试这种潜在的机制。首先，我们将确定田鼠种群数量高的地区草中的二氧化硅水平，并将其与田鼠种群数量低的地区进行比较。如果我们的想法是正确的，那么在田鼠数量增加的地区，硅含量应该会下降，反之亦然。然后，我们将建立一个实验来测量不同放牧水平下二氧化硅增加的速度和幅度，我们还将测量二氧化硅防御水平下降的速度。然后，我们将测试我们的想法，将田鼠转移到我们以前诱导高二氧化硅水平的地区，看看在这些地区进食如何影响它们的生长和繁殖。这些实验将评估植物防御的变化是否会导致食草动物丰度的变化，并帮助我们更好地了解草与食草动物之间的相互作用。有许多重要的草地系统支持广泛的食草动物，包括稀有物种和牲畜，因此该项目将有助于保护和可持续农业。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Silicon, endophytes and secondary metabolites as grass defenses against mammalian herbivores.

DOI：
10.3389/fpls.2014.00478
发表时间：
2014
期刊：
Frontiers in plant science
影响因子：
5.6
作者：
Huitu O;Forbes KM;Helander M;Julkunen-Tiitto R;Lambin X;Saikkonen K;Stuart P;Sulkama S;Hartley S
通讯作者：
Hartley S

More than herbivory: levels of silica-based defences in grasses vary with plant species, genotype and location

DOI：
10.1111/j.1600-0706.2012.20689.x
发表时间：
2013-01-01
期刊：
OIKOS
影响因子：
3.4
作者：
Soininen, Eeva M.;Brathen, Kari Anne;Hartley, Susan E.
通讯作者：
Hartley, Susan E.

DRI-Grass: A New Experimental Platform for Addressing Grassland Ecosystem Responses to Future Precipitation Scenarios in South-East Australia.

DOI：
10.3389/fpls.2016.01373
发表时间：
2016
期刊：
Frontiers in plant science
影响因子：
5.6
作者：
Power SA;Barnett KL;Ochoa-Hueso R;Facey SL;Gibson-Forty EV;Hartley SE;Nielsen UN;Tissue DT;Johnson SN
通讯作者：
Johnson SN

Defending the leaf surface: intra- and inter-specific differences in silicon deposition in grasses in response to damage and silicon supply.