Novel Aspects of Regulation of Nitrogen Responses in the Tea Plant (Camellia sinensis (L.))

Abstract

Tea brewed from leaves of Camellia sinensis (L.) is one of the most popular worldwide non-alcoholic beverages, and nitrogen is an essential nutrient that affects the growth and development of the tea plant. Inorganic nitrogen and organic nitrogen are major forms of nitrogen that are absorbed by the tea plant and also play an important role as a vital signaling molecule, which also affects the nitrogen use efficiency (NUE) of C. sinensis in its growth and development period. In addition, improving the NUE of C. sinensis is therefore important for the economic and environmental sustainability of the tea plantation industry. In this review, we discuss recently identified tea plant genes that have an essential role in the responses of different nitrogen forms in the short-term period and in the long-term nitrogen effect. We also focus in particular on how nitrogen regulates the growth and development of the tea plant, mainly on the aspects of root system architecture and leaf metabolism that are important parts of root development and leaf quality. Finally, this review concentrates recent research that has expanded the outline of the mechanisms underlying nitrogen responses and regulation in plants, focusing in particular on tea plants.