College of Resources, Sichuan Agricultural University (SAU), Huimin Road 211, Chengdu 611130, China.
College of Resources, Sichuan Agricultural University (SAU), Huimin Road 211, Chengdu 611130, China; Molecular Plant Nutrition, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, Gatersleben 06466, Germany.
Ecotoxicol Environ Saf. 2024 Sep 15;283:116810. doi: 10.1016/j.ecoenv.2024.116810. Epub 2024 Aug 2.
Selecting and breeding rice cultivars that enable strong cadmium (Cd) accumulation in rice straw but low accumulation in brown rice is a promising way to achieve Cd phytoremediation as well as to ensure the food safety of rice. Herein, we isolated a gene OsWNK9 from the quantitative trait locus associated with reducing Cd translocation from rice straw to brown rice and decreasing the Cd concentration in brown rice (BRCdC). Continuous strong expression of OsWNK9 was observed in nodes and internode and was induced after Cd supply. OsWNK9 was localized in the rice cell nucleus and participated in the regulation of Cd transport in yeast. Two independent oswnk9 rice mutants were generated via CRISPR/Cas9 gene-editing and showed significantly higher BRCdC than that of the wild type (WT). The BRCdC of knockout oswnk9 mutants was 0.227 mg kgand 0.238 mg kg, increased by 14 % and 19 % compared with that of the WT due to the lower Cd allocation in the basal stem, internode, and node III, which was unrelated to Cd uptake. Interestingly, OsWNK9 could promote iron (Fe) accumulation in rice under Cd-contaminated conditions, suggesting that OsWNK9 is an ideal gene for Cd phytoremediation and Fe biofortification in rice to support safe food production.
选育稻草中镉（Cd）积累能力强而糙米中镉积累能力低的水稻品种是实现 Cd 植物修复以及确保稻米食品安全的一种有前景的方法。在此，我们从与降低稻谷中 Cd 向糙米转移和降低糙米中 Cd 浓度（BRCdC）相关的数量性状位点中分离出一个基因 OsWNK9。OsWNK9 在节间和节点持续强烈表达，并在 Cd 供应后被诱导。OsWNK9 定位于水稻细胞核内，并参与酵母中 Cd 转运的调节。通过 CRISPR/Cas9 基因编辑产生了两个独立的 oswnk9 水稻突变体，其 BRCdC 明显高于野生型（WT）。由于基础茎、节间和节点 III 中 Cd 分配减少，敲除 oswnk9 突变体的 BRCdC 分别增加了 14%和 19%，达到 0.227 mg kg 和 0.238 mg kg，与 Cd 吸收无关。有趣的是，OsWNK9 可以在 Cd 污染条件下促进水稻中铁（Fe）的积累，表明 OsWNK9 是一种理想的 Cd 植物修复和水稻 Fe 生物强化基因，以支持安全的粮食生产。
