Abstract:Nitrous oxide (N ₂O) significantly affects atmospheric environment quality and global climate change. N ₂O emissions intensify greenhouse effects and lead to terrestrial reactive nitrogen loss and stratospheric ozone consumption. Soil is considered the primary source of N ₂O emissions from terrestrial ecosystems. However, recent studies indicate that plants also contribute to terrestrial ecosystem N ₂O emissions. Plant N ₂O emissions have been increasingly studied over the last decade, but a review of the N ₂O plant emission pathway and regulatory mechanisms is lacking. This paper summarized the traditionally recognized N ₂O sources and sinks, and proposed that terrestrial plants may be another unrecognized N ₂O source. Two potential plant N ₂O emission pathways were analyzed: 1) soil microorganisms produce N ₂O which is then emitted by plants or 2) plants produce N ₂O via metabolism or the action of endophytes. Subsequently, key factors were analyzed (e.g., nutrients, light, temperature, plant organs, and growth stage) to determine the effects on and mechanisms of N ₂O plant emissions. This study suggests that specific plant N ₂O production pathways and their contributions to global N ₂O emissions should be explored, with a focus on the physiological and biochemical processes of plants and the role of the symbiotic microorganisms in N ₂O production.