Multi-level exploration of biological nitrification inhibition in rice for improved sustainability of crop production

水稻生物硝化抑制的多层次探索，提高作物生产的可持续性

• 批准号: BB/Y00633X/1
• 负责人: Gareth Norton
• 金额: $ 180.66万
• 依托单位: University of Aberdeen
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FY00633X%2F1
• 关键词: Multi; level; exploration; biological; nitrification

Context of the researchAgricultural output is currently dependent on the use of synthetic nitrogen fertilisers. However, while the use of nitrogen fertilisers is essential to meet food security targets, the current efficiency of nitrogen fertilisers can be low, with up to 50% of applied nitrogen lost to the environment. Most of this loss happens through microbial-based nitrification and nitrate leaching. Reducing these processes is essential to improving agricultural sustainability.Soil nitrification can be inhibited through both chemical (synthetic) and biological (plant-based) processes, and the latter being termed Biological Nitrification Inhibition (BNI). A range of crops and grasses perform allelopathic BNI through secretion of specific root exudate compounds, which inhibit ammonia oxidising archaea and ammonia oxidising bacteria nitrifiers by blocking either the ammonia monooxygenase or hydroxylamine oxidoreductase, or through other pathways. Plant BNI efficiency was first demonstrated in some tropical pasture grasses. Since then, it has been shown in a wide range of plants, including heavily cultivated crops such as rice.While a small number of rice root BNI compounds have been identified, these are from a limited number of genotypes, and while genotypic variation for BNI efficiency has been determined in rice, the genetic basis of this variation is unknown. Additionally, the potential impact of breeding for high BNI efficient genotypes has not been explored.Research aimsThe overall aim of this multi-disciplinary proposal is to investigate biological nitrification inhibition (BNI) efficiency in rice, by understanding the nature of natural variation in BNI efficiency of both domesticated and wild rice. This will be conducted through genetic mapping and functional genomics (to identify key genes involved in increasing BNI efficiency), characterising BNI compounds produced by rice, evaluating the impact of variation in BNI on soil microbial communities and processes and the use of modelling to evaluate the impact of increasing BNI efficiency in rice on nitrous oxide emissions from soil. Research Objectives1) Characterise how BNI efficiency changes during the growing season and how cultivation water management decisions impact rice BNI efficiency. 2) Identify genomic loci and genes for natural variation for BNI efficiency in domesticated rice (Oryza sativa). 3) Evaluate BNI efficiency of wild rice accessions to identify if BNI efficiency is greater in wild rice relatives, identify accessions with BNI traits to be used in breeding, and to conduct GWA mapping with the O. rufipogon species.4) Identify BNI compounds and their influence on microbial communities.5) Scale up the observed impacts to model the impact of BNI efficiency on N2O emissions at the country level Potential applications and benefitsGenotypes with high BNI efficiency have the potential to slow down the nitrification of ammonium (NH4+) to nitrate (NO3-). As plants can utilise both NH4+ and NO3- as a nitrogen source, reducing the nitrification will not reduce nitrogen availability for plants. However, NO3- can easily leach into groundwater as it is much more mobile in the soil environment than NH4+. Additionally aerobic nitrification generates N2O through various processes, and under the right conditions nitrifiers can also convert NO3- into N2O via the denitrification process, with N2O being a potent greenhouse gas. Therefore, if plants could be bred with increased BNI efficiency there is the potential to decrease NO3- leaching, reduce N2O emissions from soil, and reduce the amount of nitrogen fertiliser used (as it will be available in the soils longer for the plants). The use of systems modelling to evaluate the impact of high BNI efficient genotypes on greenhouse gas emissions, will promote for the prioritisation of breeding for high BNI efficiency targeting specific climatic, edaphic and management scenarios.

农业产出目前依赖于合成氮肥的使用。然而，虽然氮肥的使用对于实现粮食安全目标至关重要，但目前氮肥的效率可能很低，高达50%的氮肥流失到环境中。这种损失大部分通过微生物硝化和硝酸盐淋溶发生。减少这些过程对提高农业可持续性至关重要。土壤硝化可以通过化学（合成）和生物（植物）过程来抑制，后者被称为生物硝化抑制（BNI）。一系列作物和草通过分泌特定的根分泌物化合物来执行化感BNI，所述根分泌物化合物通过阻断氨单加氧酶或羟胺氧化还原酶或通过其他途径来抑制氨氧化古菌和氨氧化细菌硝化菌。植物BNI效率首先在一些热带牧草中得到证实。从那时起，它已被证明在广泛的植物，包括大量种植的作物，如水稻。虽然已经确定了少量的水稻根BNI化合物，这些都是从有限的基因型，而BNI效率的基因型变异已被确定在水稻中，这种变异的遗传基础是未知的。此外，潜在的影响育种高BNI高效基因型尚未explored.Research aimsThe多学科的建议的总体目标是调查生物硝化抑制（BNI）效率在水稻中，通过了解自然变异的性质，在BNI效率的驯化和野生稻。这将通过遗传图谱和功能基因组学（以确定参与提高BNI效率的关键基因）进行，描述水稻产生的BNI化合物，评估BNI变化对土壤微生物群落和过程的影响，并使用建模来评估提高水稻BNI效率对土壤氧化亚氮排放的影响。 研究目的1）研究水稻生长季BNI效率的变化规律以及栽培用水管理决策对水稻BNI效率的影响。2)确定基因组位点和基因的自然变异的BNI效率在驯化水稻（水稻）。3)评价野生稻种质的BNI效率，以确定野生稻近缘种的BNI效率是否更高，鉴定具有BNI性状的种质用于育种，并利用O. 4）确定BNI化合物及其对微生物群落的影响。5）按比例放大观察到的影响，以模拟BNI效率对国家一级N2 O排放的影响。潜在的应用和益处具有高BNI效率的基因型有可能减缓铵（NH 4+）到硝酸盐（NO3-）的硝化作用。由于植物可以利用NH 4+和NO3-作为氮源，因此减少硝化作用不会减少植物的氮可用性。然而，由于NO3-在土壤环境中比NH 4+具有更大的移动的性，因此NO3-很容易渗入地下水。此外，好氧硝化通过各种过程产生N2 O，在适当的条件下，硝化菌还可以通过反硝化过程将NO3-转化为N2 O，N2 O是一种有效的温室气体。因此，如果植物能够以增加的BNI效率进行繁殖，则有可能减少NO3-淋溶，减少土壤中的N2 O排放，并减少氮肥的使用量（因为它将在土壤中更长时间用于植物）。使用系统建模来评估高BNI效率基因型对温室气体排放的影响，将促进针对特定气候，土壤和管理情景的高BNI效率育种的优先顺序。