Ministry of Education (MOE) Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou 310058, People's Republic of China.
Agriculture Technical Extension Center of Qujiang, Quzhou 324002, People's Republic of China.
Sci Total Environ. 2023 Apr 1;867:161564. doi: 10.1016/j.scitotenv.2023.161564. Epub 2023 Jan 12.
Humans are mainly exposed to cadmium (Cd) due to the rice consumption, however there exist considerable differences across rice cultivars in terms of Cd absorption and accumulation in the grains, and subsequent release after digestion (bioaccessibility), as well as uptake by Caco-2 cells of humans (bioavailability). This study comprised of field and lab simulation trials where in the field, firstly 39 mid-rice cultivars were screened for their phytoremediation potential coupled with safe production in relation to uptake and translocation of Cd. Lower Cd concentrations (˂0.2 mg kg) in polished rice of 74 % cultivars were ascribed to the increased root to straw translocation indicating that straw may acquire higher accumulation of Cd. Furthermore, the ionomic profile demonstrated that the spatial distribution of metals in different rice organs corresponds to the plant growth morphology. In the second year, in vitro-in vivo assay model was employed to assess the bioaccessibility and bioavailability of Cd in polished rice and to further estimate the daily Cd intake by humans through rice grains. The results of bioaccessibility and bioavailability assays and daily estimated Cd intake presented the corresponding values of 39.02-59.76 %, 8.69-24.26 %, and 0.0185-0.9713 μg kg body weight day, respectively. There exists a strong connection between total Cd and bioaccessible Cd to humans (R = 0.94, P < 0.01). Polynomial fitting (R = 0.91, P < 0.01) showed a better statistically significant correlation between total Cd contents and bioavailable levels, suggesting that in vitro-in vivo assays should be considered in future studies. The results of field experiments and in vitro-in vivo assays recommended the Tianyouhuazhan (MR-29), Heliangyou1hao (MR-17), and Yongyou15 (MR-1) as suitable mid-rice cultivars for the phytoremediation of slightly Cd contaminated soils coupled with rice agro-production due to their high nutritional value and low total and bioavailable Cd for human.
人类主要通过食用大米摄入镉（Cd），然而，不同水稻品种在稻米中对镉的吸收和积累、消化后（生物可给性）的释放以及人源 Caco-2 细胞的摄取（生物利用度）方面存在相当大的差异。本研究包括田间和实验室模拟试验，在田间试验中，首先筛选了 39 个中稻品种，以评估它们在吸收和转运 Cd 方面的植物修复潜力和安全生产能力。74%的品种精米中 Cd 浓度较低（<0.2mgkg），这归因于根到秸秆的转运增加，表明秸秆可能会积累更高浓度的 Cd。此外，离子组学分析表明，不同水稻器官中金属的空间分布与植物生长形态相对应。在第二年，采用体外-体内试验模型评估精米中 Cd 的生物可给性和生物利用度，并进一步估计人体通过稻米摄入的 Cd 量。生物可给性和生物利用度试验以及每日估计的 Cd 摄入量的结果分别为 39.02-59.76%、8.69-24.26%和 0.0185-0.9713μgkg体重日。人体总 Cd 与可生物利用 Cd 之间存在很强的相关性（R=0.94，P<0.01）。多项式拟合（R=0.91，P<0.01）显示，总 Cd 含量与生物可利用水平之间存在更好的统计学显著相关性，这表明在未来的研究中应考虑体外-体内试验。田间试验和体外-体内试验的结果推荐天优华占（MR-29）、航天诱变 1 号（MR-17）和甬优 15（MR-1）为轻度 Cd 污染土壤的植物修复及兼顾水稻农业生产的适宜中稻品种，因为它们具有高营养价值和低总 Cd 及生物可给性 Cd。
