PDF(Pubmed)
Abstract：
Cadmium (Cd) pollution is a serious threat to food safety and human health. Minimizing Cd uptake and enhancing Cd tolerance in plants are vital to improve crop yield and reduce hazardous effects to humans. In this study, we designed three Cd concentration stress treatments (Cd1: 0.20 mg·kg-1, Cd2: 0.60 mg·kg-1, and Cd3: 1.60 mg·kg-1) and two foliar silicon (Si) treatments (CK: no spraying of any material, and Si: foliar Si spraying) to conduct pot experiments on soil Cd stress. The results showed that spraying Si on the leaves reduced the Cd content in brown rice by 4.79-42.14%. Si application increased net photosynthetic rate (Pn) by 1.77-4.08%, stomatal conductance (Gs) by 5.27-23.43%, transpiration rate (Tr) by 2.99-20.50% and intercellular carbon dioxide (CO2) concentration (Ci) by 6.55-8.84%. Foliar spraying of Si significantly increased the activities of superoxide dismutase (SOD) and peroxidase (POD) in rice leaves by 9.84-14.09% and 4.69-53.09%, respectively, and reduced the content of malondialdehyde (MDA) by 7.83-48.72%. In summary, foliar Si spraying protects the photosynthesis and antioxidant system of rice canopy leaves, and is an effective method to reduce the Cd content in brown rice.
摘要：
镉污染严重威胁着食品安全和人类健康。最大限度地减少植物对Cd的吸收和增强植物对Cd的耐受性对于提高作物产量和减少对人类的危害至关重要。在这项研究中,我们设计了三种Cd浓度胁迫处理（Cd1：0.20mg·kg-1，Cd2：0.60mg·kg-1和Cd3：1.60mg·kg-1）和两种叶面硅（Si）处理（CK：不喷涂任何材料，和Si：叶面Si喷施）进行土壤Cd胁迫的盆栽实验。结果表明,喷施Si可使糙米中Cd含量降低4.79~42.14%。施硅使净光合速率(Pn)提高1.77-4.08%,气孔导度（Gs）5.27-23.43%，蒸腾速率（Tr）为2.99-20.50％，胞间二氧化碳（CO2）浓度（Ci）为6.55-8.84％。叶面喷施Si可显著提高水稻叶片中超氧化物歧化酶(SOD)和过氧化物酶(POD)的活性,分别提高9.84-14.09%和4.69-53.09%,分别,丙二醛（MDA）含量降低7.83-48.72％。总之,叶面喷施硅保护水稻冠层叶片的光合作用和抗氧化系统,是降低糙米中Cd含量的有效方法。
