To explore the effect of exogenous application of chlorinated amino acetic acid on cadmium (Cd) transport characteristics in rice seedlings, X24 and Z35 rice were taken as the research objects to carry out hydroponics experiments, and the changes of Cd content in rice seedlings, rice mineral elements and amino acid content in rice were analyzed. The results showed that exogenous application of 1.2 mmol·L⁻¹ chlorinated amino acetic acid inhibited cadmium in shoots and roots of rice seedlings; Cd content in shoots and roots were reduced by up to 62.19% and 45.61%, respectively. The majority of cadmium was in the cell wall of shoots and roots; this decreased with the increase of the concentration of chlorinated acetic acid. In addition, the Mn content in shoots and Ca content in roots of rice seedlings increased significantly after the application of chlorinated amino acetic acid. The results of amino acid analysis showed that the contents of aspartic acid, glutamic acid and cystine in rice seedlings were increased. These results indicate that exogenous application of chlorinated amino acetic acid is beneficial to the synthesis of aspartic acid, glutamic acid and cysteine in rice seedlings, increases the content of Mn in shoots and Ca in roots of rice seedlings, and significantly alleviates cadmium stress in seedlings. This provides a theoretical basis for the development of an environmentally friendly Cd-lowering foliar fertilizer for rice.

A field experiment with double cropping rice was carried out to study the foliar application effects of dicarboxylicdimethylammonium chloride (DDAC) on cadmium (Cd) and arsenic (As) accumulation in rice grains. The results showed that the spraying of DDAC could significantly reduce the accumulation of Cd and As in rice grains. The highest reductions in Cd and As content were observed when 1.5 mmol L⁻¹ DDAC was sprayed, with 49.1% and 27.4% reductions in Cd and As content in early rice grains and 56.5% and 28.1% reductions in Cd and As content in late rice grains, respectively. In addition, the content of calcium (Ca) in rice grains increased significantly after DDAC foliar application, which was also conducive to the synthesis of amino acids such as glutamate (Glu), glycine (Gly) and cysteine (Cys) in rice grains. The results indicated that the foliar spraying of DDAC can inhibit the absorption, transport, accumulation and toxicity of Cd and As in rice grains by increasing amino acid synthesis and regulating the absorption and transport of essential elements.

Against the challenge of extreme lead (Pb) contamination (>15,000 ppm) in industrial polluted soils, where conventional agents fail to disrupt stable Pb–soil complexes—this study extends our prior cadmium (Cd) remediation research to validate amino acid ionic liquids (AAILs) for highly recalcitrant metals. Fifteen AAILs were screened via batch washing, with [Met][NO₃] (methionine-based) demonstrating the highest Pb removal efficiency. Single-factor optimization revealed that under the conditions of 0.8 mol/L, 6:1 liquid–soil ratio, 60 min, 85.4% Pb was removed from severely contaminated soil by [Met][NO₃]. Kinetic analysis using four common models showed that the second-order kinetic equation provided the best fit, indicating that Pb removal was predominantly driven by chemical reactions such as complexation or ion exchange. After washing, the contents of various Pb species were significantly reduced, thereby mitigating environmental risks. Notably, no substantial changes in soil texture were observed. However, a marked increase in organic matter content was detected, accompanied by decreases in soil pH and mineral element concentrations. Analysis of soil mineral composition, functional groups, and chemical speciation revealed that [Met][NO₃] primarily facilitated Pb removal through ion-exchange and coordination reactions. This study establishes [Met][NO₃] as a green agent with dual efficacy: it achieves high-efficiency remediation of severely Pb-contaminated soil while ensuring environmental sustainability, thus highlighting its potential for practical application.

Rice is the main source of cadmium (Cd) and arsenic (As) in Chinese diet. The formulation of targeted agronomic interventions for mitigating Cd and As bioaccumulation in rice grains constitutes a critical pathway toward ensuring food safety and public health security. Foliar spraying technology with ionic liquids, effectively reduces Cd/As content in rice. In this study, an ionic liquid of amino acids ([Glu][H₂PO₄]) as a foliar conditioner was applied to two varieties of rice (X24 and Z35) to explore the mechanism of reducing the accumulation of Cd/As in rice. The results showed that [Glu][H₂PO₄] reduced Cd/As levels by up to 58.57% and 44.09%, respectively. [Glu][H₂PO₄] reduced the transfer factor from the root system to flag leaves, nodes, and other organs, thus reducing the Cd/As content in them. [Glu][H₂PO₄] promoted amino acid synthesis in seeds, increased Ca²⁺ level, increased OsGLR3.1–3.5 expression, and decreased OsLsi1–3 expression in flag leaves, thereby Cd/As was inhibited from being absorbed and transported by rice. The results demonstrated that the foliar application of [Glu][H₂PO₄] significantly mitigated the accumulation of Cd/As in rice. This study introduces a novel and effective strategy for reducing Cd/As accumulation in rice, hoping to enhance the safety and quality of rice crops.