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.

目前，研究古文化产量的背景取决于合成氮肥的使用。但是，尽管使用氮肥对于满足粮食安全靶标至关重要，但氮肥的当前效率可能很低，最多50％的施用氮丢失在环境中。这种损失的大部分是通过基于微生物的硝化和硝酸盐浸出发生的。减少这些过程对于改善农业可持续性至关重要。可以通过化学（合成）和生物（基于植物的）过程来抑制硝化作用，后者被称为生物硝化抑制（BNI）。一系列的农作物和草通过分泌特定的根渗出酸盐化合物来执行特ellopathicBNI，从而抑制氧化古细菌和氨氧化细菌硝化剂，通过阻断氨基氧酶或羟基胺氧化剂，或通过其他途径，或通过其他途径。植物BNI效率首先在一些热带草场中得到证明。从那时起，已经在广泛的植物中显示了它，包括大米等种植的农作物。虽然已经鉴定出少量的水稻根BNI化合物，但这些化合物来自有限数量的基因型，虽然BNI效率的基因型变化在水稻中确定了这种变体的遗传基础，但尚不清楚。此外，尚未探索育种对高BNI有效基因型的潜在影响。研究的目标是通过理解驯养和驯养和野生米的BNI效率自然变异的性质，旨在通过理解自然变异的性质来研究水稻的生物硝化抑制（BNI）效率。这将通过遗传映射和功能基因组学（以确定涉及增加BNI效率的关键基因）来进行，表征了稻米产生的BNI化合物，评估BNI对土壤微生物群落和过程的变化对建模的影响，并使用建模以评估含有稀土氧化氧化物氧化氧化物的BNI效率的影响。 研究目标1）表征BNI在生长季节期间的效率如何变化以及耕种水管理决策如何影响水稻BNI效率。 2）鉴定基因组基因座和基因，用于驯化水稻（Oryza sativa）中BNI效率的自然变异。 3）评估野生水稻加入的BNI效率，以确定野生水稻亲戚的BNI效率是否较高，确定具有BNI特征用于育种的BNI特征的加入，并与O. rufipogon物种进行GWA映射。4）4）4）识别BNI化合物及其对微生物群体的影响。具有高BNI效率的良好产型有可能减慢硝化铵（NH4+）的硝酸盐（NO3-）。由于植物可以同时利用NH4+和NO3-作为氮来源，因此减少硝化不会减少植物的氮利用率。但是，No3-很容易渗入地下水，因为它在土壤环境中比NH4+更容易流动。另外，有氧硝化通过各种过程产生N2O，在适当的条件下，硝化剂也可以通过反硝化过程将NO3-转换为N2O，而N2O是有效的温室气体。因此，如果植物可以用BNI效率提高繁殖，则有可能减少No3浸出，减少土壤中的N2O排放，并减少所使用的氮肥（因为它将在土壤中可用于植物的时间更长）。使用系统建模来评估高BNI有效基因型对温室气体排放的影响，将促进针对特定气候，edaphic和管理方案的高BNI效率的育种优先级。