Capturing microbial co-symbiosis to sustain plant productivity

随着世界环境的变化，我们必须生产适应这些变化的作物。在土壤中，细菌和真菌的种类与根和根-土壤界面（所谓的作物根际）处的共生关系有关。这种关系使每个合作伙伴都能从资源的相互交易中受益，如关键的生长限制营养素。这一点很重要，因为植物必须从周围环境中获得氮和磷等元素营养素，而这些营养素的可用性往往是植物生长的主要限制。除了带来营养增强之外，互利相互作用还带来了提高植物生产力的额外益处，例如增强植物对不利环境条件或病原体攻击的抗性。然而，我们不能通过简单地向土壤中添加许多“友好”微生物来获得所有这些好处，因为对一种微生物的需求可能会抵消另一种微生物对植物的积极影响。许多根际微生物是如何竞争和联合收割机影响植物的是一个复杂的问题，需要详细研究。我们发现，一种重要的互惠互利的真菌，有助于保护植物免受疾病和供应植物磷，也可以增加苜蓿，一种植物物种，是豌豆和豆类的近亲。结瘤是固氮细菌与植物根系的相互作用，使植物能够获得否则无法使用的氮。我们将研究这种增强的土壤形成是如何发生的，并确定它是否仍然发生在不同土壤类型中生长的植物。为此，我们将使用一系列最先进的植物，土壤和微生物分析技术来评估微生物，植物和土壤类型如何对根际（微生物群落和根附近的土壤）做出贡献，以及这如何影响一系列土壤类型中的作物生产力。鉴定土壤微生物的新技术意味着我们现在可以研究环境对根际多边相互作用的影响-地球上最复杂的生态系统之一。这些结果将有助于解释我们发现的增强互利效应，也将有助于我们确定根际特定因素对农业的重要性，以及如何增强这些因素以提高新环境中的作物产量。

As the world's environment changes it is essential that we produce crop plants adapted to these changes. Within soil, species of bacteria and fungi are involved in symbiotic relationships with the root and at the root-soil interface (so called rhizosphere of crops). The relationship allows each partner to benefit from mutual trading of resources such as critical growth-limiting nutrients. This is important since plants must acquire elemental nutrients such as nitrogen and phosphorus from their surrounding environment and the availability of these nutrients is often a major limitation to plant growth. As well as bringing nutritional enhancement, mutualistic interactions bring additional benefits to improve plant productivity, such as enhanced plant resistance to adverse environmental conditions or pathogen attack. However we cannot gain all of these benefits by simply adding many 'friendly' microbes to soil since the need of one microbe might cancel out the positive effect of another microbe on the plant. How the many rhizosphere microbes compete and combine to affect the plant is a complex question that needs to be studied at a detailed level.We have discovered that an important mutualistic fungus that helps protect plants against disease and supplies plants with phosphorus can also increase 'nodulation' in Medicago, a plant species that is a close relative of peas and beans. Nodulation is an interaction of nitrogen-fixing bacteria with plant roots that enables plants to gain otherwise unusable nitrogen. We will investigate how this enhancement of nodulation occurs, and determine if it still occurs for plants grown in different soil types. To do this we will use a range of state-of-the-art plant, soil and microbe analytical technologies to assess how microbes, plants and the soil type each contribute to the rhizosphere (microbial communities and soil adjacent to the root), and how this affects crop productivity in a range of soil types. New technologies for the identification of soil microbes mean that we are now at a point where we can study the effects of environments on multilateral interactions at the root rhizosphere - one of the most complex ecosystems on Earth. Together the results will help explain the enhanced-mutualistic effects that we have found. It will also help us to determine the importance of specific factors in the rhizosphere for agriculture, and how they could be enhanced to improve crop productivity in new environments.