农业环境科学学报2026，Vol.45Issue(5)：1105-1116,12.DOI:10.11654/jaes.2025-0657
温度和UV-B辐射增加对水稻根系分泌物和土壤氮转化的影响
Effects of elevated temperature and UV-B radiation on rice root exudates and soil nitrogen transformation
摘要
Abstract
To elucidate the differential effects of elevated temperature and enhanced UV-B radiation on rice root exudates and their mediated soil nitrogen cycling responses under climate change scenarios,a field experiment was conducted in the Yuanyang Terraces(1 600 m above sea level)using the local rice cultivar Baijiao Laojing.The study investigated the impacts of elevated atmospheric temperature(+2.0 ℃)and enhanced UV-B radiation(+5.0 kJ·m-2)on rice root exudates and their subsequent effects on soil nitrogen transformation.The results showed that elevated temperature significantly increased the contents of amino acids,soluble sugars,and low-molecular-weight organic acids(except citric acid)in rice root exudates at the jointing stage,with respective increments of 56.4％,30.2％,and 24.6％-143.8％.In contrast,enhanced UV-B radiation reduced the content of amino acids(except for amino acids at the tillering stage)and soluble sugars(except for maturity stage),with decreases of 37.3％and 47.7％-62.5％,respectively.Elevated temperature significantly increased the abundance of nitrogen-fixing and nitrifying bacteria,enhanced nitrate reductase activity,and raised the soil soluble organic nitrogen(SON)content.Conversely,enhanced UV-B radiation reduced the population of denitrifying bacteria and decreased N2O emission flux.Both elevated temperature and UV-B radiation treatments increased the abundance of nitrogen-fixing bacteria and SON content.Mantel test analysis revealed a significant positive correlation between nitrogen-fixing bacteria and SON(P＜0.05),as well as a highly significant positive correlation between nitrifying bacteria and N2O emission flux(P＜0.001).The study demonstrates that elevated temperature increases amino acid and soluble sugar contents in root exudates,thereby enhancing the population of nitrogen-fixing bacteria and subsequently promoting biological nitrogen fixation.Conversely,enhanced UV-B radiation suppresses denitrifying bacterial populations and attenuates the denitrification process,leading to reduced N2O emissions.The synergistic interaction between these factors creates a"nitrogen fixation promotion-emission reduction"effect,which simultaneously increases soil soluble organic nitrogen content while decreasing N2O emissions.关键词
温度/UV-B辐射/根系分泌物/细菌数量/酶活性/氮含量/N2OKey words
temperature/UV-B radiation/root exudates/bacteria number/enzyme activity/nitrogen content/N2O分类
资源环境引用本文复制引用
李海涛,吴泳霖,梁新然,湛方栋,李元,何永美..温度和UV-B辐射增加对水稻根系分泌物和土壤氮转化的影响[J].农业环境科学学报,2026,45(5):1105-1116,12.基金项目
云南省农业联合基金重点项目(202301BD070001-014) （202301BD070001-014）
国家自然科学基金项目(32460294)Key Program of Yunnan Agricultural Joint Funds(202301BD070001-014) （32460294）
National Natural Science Foundation of China(32460294) （32460294）
