Camellia sinensis L. is one of the most economically important crops in the world today. The leaves of this plant are harvested for tea production on a massive scale through a process that requires a large amount of inorganic nitrogen (N). However, knowledge of how inorganic nitrogen regulates the growth physiology of C. sinensis L. remains limited. | Turkish Journal of Agriculture and Forestry Research Article Turk J Agric For (2015) 39: 28-38 © TÜBİTAK doi: Inorganic nitrogen fertilizers induce changes in ammonium assimilation and gas exchange in Camellia sinensis L. 1, 2 3 2 1 2 1 Xu Hua DU *, Fang Ren PENG , Jiang JIANG , Peng Peng TAN , Zhi Zhuang WU , You Wang LIANG , Zhe Ke ZHONG 1 China National Bamboo Research Center, State Forestry Administration, Hangzhou, Zhe Jiang, . China 2 College of Forest Resources and Environment, Nanjing Forestry University, Nanjing, Jiang Su, China 3 National Institute for Mathematical and Biological Synthesis, University of Tennessee, Knoxville, TN, USA Received: Accepted: Published Online: Printed: Abstract: Camellia sinensis L. is one of the most economically important crops in the world today. The leaves of this plant are harvested for tea production on a massive scale through a process that requires a large amount of inorganic nitrogen (N). However, knowledge of how inorganic nitrogen regulates the growth physiology of C. sinensis L. remains limited. In order to investigate its effects on gas exchange, N assimilation, and the efficiency of N use in C. sinensis L., we carried out experiments with 4 cultivars (WNZ, YS, ZN139, and LJ43) under 4 different treatments: 1) a control treatment, 2) a treatment fed only with NO3−-N, 3) a treatment fed only with NH4+-N, and 4) a treatment fed with a mixture of NO3−-N and NH4+-N in a 1:1 ratio. We found that the application of N, especially in a mixture, encouraged higher foliar N content per unit area (Nf ), which in turn promoted glutamine synthetase (GS) activity and glutamate synthase (GOGAT) activity. Our mixture-fed treatment increased Nf, GS, and GOGAT activity by , , and , respectively, for the WNZ cultivar. The mixed-fed treatment also had the highest net photosynthetic (Pn), stomatal
