Shang Bo, Fu Rao, Agathokleous Evgenios, Dai Lulu, Zhang Guoyou, Wu Rongjun, Feng Zhaozhong
Key Laboratory of Agrometeorology of Jiangsu Province, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing, China.
Key Laboratory of Agrometeorology of Jiangsu Province, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing, China; Rural Energy and Environment Agency, Ministry of Agriculture and Rural Affairs, Beijing, China.
Sci Total Environ. 2022 Feb 1;806(Pt 3):151341. doi: 10.1016/j.scitotenv.2021.151341. Epub 2021 Oct 30.
Tropospheric ozone (O) is the main phytotoxic air pollutant threatening food security, while ethylenediurea (EDU) can effectively mitigate O-induced crop yield loss. EDU's mode of action, however, remains unclear, and the underlying physiological mechanisms of mitigating O-induced crop yield loss are poorly understood. We cultivated hybrid rice seedlings under two O treatments (NF, nonfiltered ambient air; and NF60, ambient air plus 60 ppb O) and sprayed foliage with 0 or 450 ppm EDU every ten days and determine photosynthesis-related traits, biomass indicators, and yield components. We found that EDU significantly increased the leaf nitrogen (N) allocation to photosynthesis (N) and the grain N accumulation, while the grain N accumulation was positively correlated with N and root biomass. EDU significantly increased the rice yield mainly by increasing the individual grain weight rather than the number of panicles and grains. While EDU protected from yield loss, the degree of protection was only 31% under NF60 treatment, thus EDU was unable to offer complete protection under high O pollution. These results will be conducive to a better understanding of the EDU protection mechanism and better application of EDU under high O pollution in the future.
对流层臭氧（O）是威胁粮食安全的主要植物毒性空气污染物，而乙二脲（EDU）可以有效减轻臭氧引起的作物产量损失。然而，EDU的作用模式仍不明确，减轻臭氧引起的作物产量损失的潜在生理机制也知之甚少。我们在两种臭氧处理（NF，未过滤的环境空气；NF60，环境空气加60 ppb臭氧）下培育杂交水稻幼苗，每十天用0或450 ppm的EDU对叶片进行喷雾处理，并测定光合作用相关性状、生物量指标和产量构成因素。我们发现，EDU显著增加了叶片中分配到光合作用的氮（N）以及籽粒中的氮积累，而籽粒中的氮积累与叶片氮和根生物量呈正相关。EDU主要通过增加单粒重而非穗数和粒数显著提高了水稻产量。虽然EDU能防止产量损失，但在NF60处理下的保护程度仅为31%，因此在高臭氧污染下EDU无法提供完全保护。这些结果将有助于更好地理解EDU的保护机制，并在未来高臭氧污染下更好地应用EDU。
