Effects of exogenous amino acids on yttrium uptake and accumulation in tomato ( <i>Solanum lycopersicum</i> )

This study investigated the impacts of exogenous amino acid supplementation on the uptake, translocation, and accumulation of yttrium (Y) in tomato plants (<i>Solanum lycopersicum)</i>. To understand how amino acids enhance nutrient uptake and plant growth by using Hoagland nutrient solution. The results indicated that the combination of Y with glutamic acid (Y + Glu) significantly increased Y concentration in the leaves to 28.5 ± 1.42 µg g^-1, while the combination with histidine (Y + His) resulted in a markedly lower concentration of 2.7 ± 0.06 µg g^-1. Notably, glutamic acid proved to be particularly effective in enhancing Y accumulation in xylem sap. The control plants exhibited a higher xylem sap flow rate of 0.27 ± 0.008 g h^-1, which was significantly greater than those treated with amino acids (<i>p</i> < 0.05). Histidine levels were elevated in the Y + His treatment, reaching 194.78 ± 13.79 μmol L^-1, while tryptophan and aspartic acid showed their highest concentrations in their respective treatments at 109.92 ± 14.43 μmol L^-1 and 212.95 ± 13.65 μmol L^-1. These findings demonstrated that amino acid supplementation substantially enhanced the phytoextraction of Y in tomato plants, through the application of glutamic acid. Further exploration into the molecular mechanisms governing Y complexation and transport within plants through phytoremediation is needed.