Characteristics of NH₄⁺ and NO₃^- fluxes in tea (Camellia sinensis) roots measured by scanning ion-selective electrode technique.

ABSTRACT: As a vital beverage crop, tea has been extensively planted in tropical and subtropical regions. Nitrogen (N) levels and forms are closely related to tea quality. Based on different N levels and forms, we studied changes in NO₃^- and NH₄⁺ fluxes in tea roots utilizing scanning ion-selective electrode technique. Our results showed that under both single and mixed N forms, influx rates of NO₃^- were much lower than those of NH₄⁺, suggesting a preference for NH₄⁺ in tea. With the increase in N concentration, the influx rate of NO₃^- increased more than that of NH₄⁺. The NH₄⁺ influx rates in a solution without NO₃^- were much higher than those in a solution with NO₃^-, while the NO₃^- influx rates in a solution without NH₄⁺ were much lower than those in a solution with NH₄⁺. We concluded that (1) tea roots showed a preference for NH₄⁺, (2) presence of NO₃^- had a negative effect on NH₄⁺ influx, and (3) NH₄⁺ had a positive effect on NO₃^- influx. Our findings not only may help advance hydroponic tea experiments but also may be used to develop efficient fertilization protocols for soil-grown tea in the future.

SUBMITTER: Ruan L 

PROVIDER: S-EPMC5137579 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature