Reasonable nitrogen(N) application is a promising strategy for reducing crop cadmium(Cd) toxicity. However, the specific form of N and the required amount that affect Cd tolerance and accumulation in rice remain uncle...Reasonable nitrogen(N) application is a promising strategy for reducing crop cadmium(Cd) toxicity. However, the specific form of N and the required amount that affect Cd tolerance and accumulation in rice remain unclear. This study explored the influence of different N-fertilizer forms(NH_4NO_3, NH_4Cl, and KNO_3) and dosages on Cd tolerance and uptake in Cd-stressed N-sensitive and N-insensitive indica rice accessions. The results indicated that the Cd tolerance of N-sensitive indica accessions is more robust than that of N-insensitive ones. Furthermore, the shoot Cd content and Cd translocation rate in both N-sensitive and N-insensitive indica accessions decreased with an appropriate supply of NH_4NO_3 and NH_4Cl, whereas they were comparable or slightly increased with increased KNO_3. Unfortunately, we did not find significant and regular differences in Cd accumulation or translocation between N-sensitive and N-insensitive rice accessions. Consistent with the reduction of shoot Cd content, the addition of NH_4NO_3 and NH_4Cl also inhibited the instantaneous root Cd^(2+) uptake. The expression changes of Cd transport-related genes under different N forms and dosages suggested that the decreased shoot Cd content, caused by the increased supply of NH_4NO_3 and NH_4Cl, is likely achieved by reducing the transcription of OsNRAMP1 and OsIRT1. In summary, our findings reveal that an appropriate supply of NH_4NO_3 and NH_4Cl could reduce Cd uptake and transport in rice seedlings, suggesting that rational N management could reduce the Cd risk in rice production.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 31971872)the Open Research Fund of State Key Laboratory of Hybrid Rice, China (Grant No. 2022KF02)+3 种基金the National Natural Science Foundation of China (Grant Nos. 32101755 and 32188102)the Zhejiang Provincial Natural Science Foundation, China (Grant No. LY22C130005)the Key Research and Development Program of Zhejiang Province, China (Grant No. 2021C02056)the ‘Pioneer’ and ‘Leading Goose’ R&D Program of Zhejiang, China (Grant No. 2023C02014)。
文摘Reasonable nitrogen(N) application is a promising strategy for reducing crop cadmium(Cd) toxicity. However, the specific form of N and the required amount that affect Cd tolerance and accumulation in rice remain unclear. This study explored the influence of different N-fertilizer forms(NH_4NO_3, NH_4Cl, and KNO_3) and dosages on Cd tolerance and uptake in Cd-stressed N-sensitive and N-insensitive indica rice accessions. The results indicated that the Cd tolerance of N-sensitive indica accessions is more robust than that of N-insensitive ones. Furthermore, the shoot Cd content and Cd translocation rate in both N-sensitive and N-insensitive indica accessions decreased with an appropriate supply of NH_4NO_3 and NH_4Cl, whereas they were comparable or slightly increased with increased KNO_3. Unfortunately, we did not find significant and regular differences in Cd accumulation or translocation between N-sensitive and N-insensitive rice accessions. Consistent with the reduction of shoot Cd content, the addition of NH_4NO_3 and NH_4Cl also inhibited the instantaneous root Cd^(2+) uptake. The expression changes of Cd transport-related genes under different N forms and dosages suggested that the decreased shoot Cd content, caused by the increased supply of NH_4NO_3 and NH_4Cl, is likely achieved by reducing the transcription of OsNRAMP1 and OsIRT1. In summary, our findings reveal that an appropriate supply of NH_4NO_3 and NH_4Cl could reduce Cd uptake and transport in rice seedlings, suggesting that rational N management could reduce the Cd risk in rice production.
