EFFECTS OF EXTRANEOUS GLUTAMIC ACID ON NITRATE CONTENTS AND QUALITY OF CHINESE CHIVE

The accumulation of nitrate in vegetables is paid close attention to for one’s health in the world.
This paper highlights researching effects of extraneous glutamic acid (Glu), which is the middle product in the path of nitrogen metabolism, on nitrate accumulation in Chinese chive (Allium tuberosum Rottler Spreng) by means of spraying leaves with the glutamic acid solution.
Glutamic acid solution at the concentration level of 0.5-10 mmol•L^-1 decreased nitrate contents in Chinese chive leaves.
Especially, the treatment of Glu at 5 mmol•L^-1 produced an obvious increase of 15.1%. However, the total-N (nitrogen) content increased in Chinese chive leaves as increasing of Glu concentration at the range of 0.5-10 mmol•L^-1. Meanwhile, activity of nitrate reductase (NR) and glutamine synthetase (GS) raised by a wide margin, and chlorophyll content increased from 13.7 to 29.5%. In addition, the contents of free amino acid, soluble protein, and soluble sugar also increased.
The results showed that extraneous glutamic acid did not only improve activity of NR named as “N-reducing-driving-pump” and activity of GS called “first driving pump” in the path of N assimilation, but also provides enough reducing force e-, ATP and C-framework, e.g., -ketoglutarate for glutamate synthase (GOGAT) which is called “the second driving pump” in the path of N assimilation.
Therefore, spraying the glutamic acid on leaves accelerated assimilation of nitrate in Chinese chive leaves.
As a result, application of glutamic acid did not only reduce nitrate accumulation, but also improved the quality of Chinese chive.

International Symposium on Vegetable Safety and Human Health

Y.P. Cao, Z.K. Gao, J.T. Li, G.H. Xu, M. Wang

nitrate accumulation, nitrate reductase, glutamine synthetase, chlorophyll, amino acid, soluble sugar

https://doi.org/10.17660/ActaHortic.2010.856.11