School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
J Hazard Mater. 2024 Oct 5;478:135559. doi: 10.1016/j.jhazmat.2024.135559. Epub 2024 Aug 17.
Chromium (Cr) soil contamination is a critical global environmental concern, with hexavalent chromium (Cr[VI]) being especially perilous due to its high mobility, bioavailability, and phytotoxicity. This poses a significant threat to the cultivation of crops, particularly rice, where the mechanisms of Cr(VI) absorption remain largely unexplored. This study uncovered a competitive interaction between Cr(VI) and essential nutrients-sulfate and phosphate during the uptake process. Notably, deficiencies in sulfate and phosphate were associated with a marked increase in Cr(VI) accumulation in rice, reaching up to 76.5 % and 77.7 %, respectively. Employing q-PCR, this study identified significant up-regulation of the sulfate transporter gene, OsSultr1;2, and the phosphate transporter gene, OsPht1;1, in response to Cr(VI) stress. Genetic knockout studies have confirmed the crucial role of OsSultr1;2 in Cr(VI) uptake, with its deletion leading to a 36.1 % to 69.6 % decrease in Cr uptake by rice roots. Similarly, the knockout of OsPht1;1 resulted in an 18.1 % to 25.7 % decrease in root Cr accumulation. These findings highlight the key role of the sulfate transporter OsSultr1;2 in Cr(VI) uptake, with phosphate transporters also contributing significantly to the process. These insights are valuable for developing rice varieties with reduced Cr(VI) accumulation, ensuring the safety of rice grain production.
铬（Cr）土壤污染是一个全球性的环境问题，其中六价铬（Cr[VI]）由于其高迁移性、生物可利用性和植物毒性而特别危险。这对作物的种植构成了重大威胁，特别是水稻，而 Cr(VI)的吸收机制在很大程度上仍未得到探索。本研究发现，在吸收过程中，Cr(VI)与必需营养物质——硫酸盐和磷酸盐之间存在竞争相互作用。值得注意的是，硫酸盐和磷酸盐的缺乏与水稻中 Cr(VI)积累的显著增加有关，分别达到 76.5%和 77.7%。本研究通过 q-PCR 发现，硫酸盐转运基因 OsSultr1;2 和磷酸盐转运基因 OsPht1;1 对 Cr(VI)胁迫有显著的上调作用。遗传敲除研究证实了 OsSultr1;2 在 Cr(VI)摄取中的关键作用，其缺失导致水稻根系对 Cr 的摄取减少 36.1%至 69.6%。同样，OsPht1;1 的敲除导致根 Cr 积累减少 18.1%至 25.7%。这些发现强调了硫酸盐转运体 OsSultr1;2 在 Cr(VI)摄取中的关键作用，而磷酸盐转运体也对该过程有重要贡献。这些见解对于开发 Cr(VI)积累减少的水稻品种，确保稻米生产的安全具有重要意义。
