生态环境学报2024，Vol.33Issue(5)：781-790,10.DOI:10.16258/j.cnki.1674-5906.2024.05.011
施硅水平对水稻根表铁膜和体内Cd累积分布的影响
The Impact of Silicon Application Levels on the Iron Plaque of Rice Roots and the Accumulation and Distribution of Cadmium Within the Plant
摘要
Abstract
The management of cadmium(Cd)pollution in rice fields is a pressing scientific issue that needs to be addressed in China.The iron plaque on the root surface serves as a crucial barrier for Cd absorption by rice roots.The application of silicon(Si)has been found to regulate the activity of antioxidant and ethylene synthase enzymes in rice roots,affecting the adsorption of Cd by the root iron plaque and altering the accumulation and distribution of Cd within the rice plant.However,the effects of different Si application levels on the iron plaque of rice roots and the accumulation and distribution of Cd within the plant are not yet fully understood.A pot experiment with rice was conducted to explore the content and distribution pattern of Cd in different tissues and organs at the mature stage of rice under high and low Si application levels,as well as the Cd transport capacity within the rice plant.The content of Cd in the iron plaque on the root surface,the morphological characteristics,and the expression of genes related to antioxidant enzymes and ethylene synthase during the heading stage were also investigated,aiming to reveal the impact of different Si levels on the adsorption of Cd by the root iron plaque and the accumulation and distribution of Cd within the plant.The results indicated that Si application reduced the Cd content in the stems at maturity,increased the distribution ratio of Cd in the roots,and at a high Si level(0.66 g·kg-1),further decreased the Cd content and distribution ratio in the stem nodes and brown rice,inhibiting the ability of the roots to transport Cd to the brown rice.Additionally,Si application was shown to enhance the expression of genes for superoxide dismutase(OsSOD-Cu/Zn and OsSOD-Fe),catalase(OsCATa and OsCATb),and ethylene synthase(OsACS1)during the heading stage.A high level of Si(0.66 g·kg-1)significantly increased the content of DCB-Fe and DCB-Cd in the root iron plaque,increased the surface roughness of the iron plaque,and further enhanced the expression of OsSOD-Fe and OsACS1 in the roots.The study confirmed that the level of Si application is a key factor affecting the iron plaque on rice roots and the accumulation and distribution of Cd within the plant.A high level of Si application more significantly promoted the expression of antioxidant enzyme genes in the rice roots,enhanced the formation of the iron plaque and its adsorption of Cd,and inhibited the transport of Cd from the roots to the brown rice and the distribution of Cd in the stem nodes,thereby reducing the accumulation of Cd in the brown rice.These findings provide a theoretical basis for addressing the challenge of Cd pollution management in rice fields in China.关键词
水稻/施硅水平/镉/铁膜/累积分布/基因表达Key words
rice/silicon application levels/cadmium/iron plaque/accumulation and distribution/gene expression分类
资源环境引用本文复制引用
李林峰,徐梓盛,陈勇,李奇,林晓扬,李义纯..施硅水平对水稻根表铁膜和体内Cd累积分布的影响[J].生态环境学报,2024,33(5):781-790,10.基金项目
广东省自然科学基金项目(2020A1515011190) （2020A1515011190）
广东农业科技创新及推广项目(2023KJ118) （2023KJ118）
