Jiménez Juan de la Cruz, Pedersen Ole
Department of Biology, University of Copenhagen, Universitetsparken 4, 3rd floor, Copenhagen, 2100, Denmark.
School of Agriculture and Environment, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.
Rice (N Y). 2023 May 10;16(1):24. doi: 10.1186/s12284-023-00638-z.
Rice production worldwide represents a major anthropogenic source of greenhouse gas emissions. Nitrogen fertilization and irrigation practices have been fundamental to achieve optimal rice yields, but these agricultural practices together with by-products from plants and microorganisms, facilitate the production, accumulation and venting of vast amounts of CO, CH and NO. We propose that the development of elite rice varieties should target root traits enabling an effective internal O diffusion, via enlarged aerenchyma channels. Moreover, gas tight barriers impeding radial O loss in basal parts of the roots will increase O diffusion to the root apex where molecular O diffuses into the rhizosphere. These developments result in plants with roots penetrating deeper into the flooded anoxic soils, producing higher volumes of oxic conditions in the interface between roots and rhizosphere. Molecular O in these zones promotes CH oxidation into CO by methanotrophs and nitrification (conversion of NH into NO), reducing greenhouse gas production and at the same time improving plant nutrition. Moreover, roots with tight barriers to radial O loss will have restricted diffusional entry of CH produced in the anoxic parts of the rhizosphere and therefore plant-mediated diffusion will be reduced. In this review, we describe how the exploitation of these key root traits in rice can potentially reduce greenhouse gas emissions from paddy fields.
全球水稻生产是温室气体排放的主要人为来源。氮肥施用和灌溉措施对于实现水稻最佳产量至关重要，但这些农业措施连同植物和微生物的副产品，促进了大量二氧化碳、甲烷和一氧化二氮的产生、积累和排放。我们建议，优良水稻品种的培育应着眼于通过扩大通气组织通道来实现有效内部氧气扩散的根系性状。此外，阻止根部基部径向氧气损失的气密屏障将增加氧气向根尖的扩散，在根尖处分子氧扩散到根际。这些进展使植物根系能够更深地穿透淹水缺氧土壤，在根与根际的界面处产生更多的有氧条件。这些区域中的分子氧通过甲烷营养菌促进甲烷氧化为二氧化碳以及硝化作用（将铵转化为一氧化二氮），减少温室气体排放，同时改善植物营养。此外，对径向氧气损失具有紧密屏障的根系将限制根际缺氧部分产生的甲烷的扩散进入，因此植物介导的扩散将减少。在本综述中，我们描述了如何利用水稻中的这些关键根系性状来潜在地减少稻田的温室气体排放。
