Effects of ATP production on silicon uptake by roots of rice seedlings

Abstract The activities of several respiratory metabolism enzymes and ATP concentrations in the roots of four genotypes of rice raised in hydroponic culture and treated with three levels of silicon (Si) (0, 1.25, and 2.00 mM) were studied. ATP concentrations in roots of the four rice cultivars were significantly higher with Si application than in the control. Phosphoglucose isomerase (PGI) activity and the combined activity of glucose-6-phosphate dehydrogenase (G-6-PDH) and 6-phosphogluconate dehydrogenase (6-PGDH) in roots were also significantly enhanced by Si addition, as was malate dehydrogenase (MDH) activity. PGI and MDH activity increased more than 50% and 25%, respectively, in TN1 roots supplied with Si compared to the control. Among the four genotypes, higher MDH activity and combined activity of G-6-PDH and 6-PGDH were detected in roots of TN1 and Bai Xiang Jing, which had higher Si uptake. ATPase activity and ATP concentrations were inhibited by four metabolic inhibitors: HgCl2, 2,4-dinitrophen...