Watado Shohei, Higuchi Kyoko, Saito Akihiro, Ohyama Takuji
Laboratory of Biochemistry in Plant Productivity, Department of Agricultural Chemistry, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan.
Department of Agriculture, Niigata University, Niigata 950-2102, Japan.
Plants (Basel). 2025 Apr 8;14(8):1154. doi: 10.3390/plants14081154.
The nutrients absorbed in the plant roots are transported to the shoots through the xylem. The effects of concentrations of N, P, K, Mg, and Ca in a culture solution on N transport forms have not been fully elucidated. In this study, rice plants were grown with five concentrations of N, P, K, Mg, and Ca for three days, and the concentrations of major N compounds in the xylem sap were determined. In the control plants, nitrate, glutamine, and asparagine were the principal N compounds. The concentrations of nitrate, glutamine, and asparagine decreased consistently with a decrease in the N concentration in the culture solution. Different P concentrations did not affect the N components. With lower K concentrations, only the nitrate concentration decreased. While the glutamine and asparagine concentrations decreased with a decrease in the Mg concentration. The Ca concentration did not affect the N concentration, except for Ca deprivation. The citrate and malate concentrations markedly increased when the plants grew with an N-free solution due to regulating the cation-anion balance. The results of this study indicate that changes in the concentrations of N, K, Mg, and Ca affected the concentrations of N transport forms, especially nitrate, glutamine, and asparagine.
植物根系吸收的养分通过木质部运输到地上部分。培养液中氮、磷、钾、镁和钙的浓度对氮运输形式的影响尚未完全阐明。在本研究中，将水稻植株在含有五种浓度的氮、磷、钾、镁和钙的培养液中培养三天，并测定木质部汁液中主要氮化合物的浓度。在对照植株中，硝酸盐、谷氨酰胺和天冬酰胺是主要的氮化合物。随着培养液中氮浓度的降低，硝酸盐、谷氨酰胺和天冬酰胺的浓度持续下降。不同的磷浓度不影响氮组分。钾浓度较低时，只有硝酸盐浓度下降。而谷氨酰胺和天冬酰胺的浓度随着镁浓度的降低而下降。除了钙缺乏外，钙浓度不影响氮浓度。当植株在无氮溶液中生长时，由于调节阳离子-阴离子平衡，柠檬酸盐和苹果酸盐的浓度显著增加。本研究结果表明，氮、钾、镁和钙浓度的变化影响了氮运输形式的浓度，尤其是硝酸盐、谷氨酰胺和天冬酰胺。
