关键词: 高CO2浓度, 高CO2浓度, CO2排放, N水平, C4土壤, 13C

Abstract: 【OBJECTIVE】Water stress is one of the most important ecological factors which affect yield and quality of rice (Oryza sativa L. ), heading stage is the most sensitive stage to water stress for rice growth. Our objective was to elucidate the physiological response of leaf and root system to drought at heading stage; 【METHOD】Rice variety Feng-Hua-Zhan was chosen through pot experiment to study the effects of soil drying at heading stage on leaf water potential, root system activity, protective enzyme activity in leaf and root; 【RESULTS】Leaf water potential was significantly decreased after soil drying and it could be restored to the normal level after re-irrigation. Root activity was increased by 28.83%, 123.30% and 50.16% when soil drying lasted 3 d, 6 d and 9 d at heading stage, it could restore to normal level except 9 d treatment after re-irrigation, but root system activity was decreased by 82.25% when soil drying lasted 12 d. Except for the treatment with 12 days of soil drying, superoxide dismutase（SOD），catalase（CAT）and peroxidase（POD）activity in leaf and root increased significantly after soil drying, and they could restore to normal level after re-irrigation. SOD, POD and CAT activity in leaf had higher level than that in root whatever irrigation or not;【CONCLUSION】Rice plant could effectively adjust physiological equilibrium after short-term drought at heading stage, root system and leaves had the similar change trend.