RICE SCIENCE ›› 2011, Vol. 18 ›› Issue (3): 210-216.

• Research Paper • Previous Articles     Next Articles

High Temperature at Grain-filling Stage Affects Nitrogen Metabolism Enzyme Activities in Grains and Grain Nutritional Quality in Rice

  1. Agronomy College, Sichuan Agricultural University, Chengdu 611130, China
  • Online:2011-09-28 Published:2011-10-12
  • Contact: LI Tian
  • Supported by:

    the International Technological Cooperation Program of Science and Technology Department, Sichuan Province, China (Grant No. 2010HH0015), and the Science and Technological Innovation Project for Youth of Sichuan Agriculture University, China (Grant No. 04030100).

Abstract: Rice plants would more frequently suffer from high temperature (HT) stress at the grain-filling stage in future. A japonica rice variety Koshihikari and an indica rice variety IR72 were used to study the effect of high temperature on dynamic changes of glutamine synthetase (GS) activity, glutamate synthase (GOGAT) activity, glutamic oxalo-acetic transminase (GOT) activity, glutamate pyruvate transminase (GPT) activity in grains and grain nutritional quality at the grain-filling stage. Under HT, the activities of GOGAT, GOT, GPT and soluble protein content in grains significantly increased, whereas GS activity significantly decreased at the grain-filling stage. In addition to the increase of protein and amino acids contents, it was suggested that GOGAT, GOT and GPT in grains played important roles in nitrogen metabolism at the grain-filling stage. Since the decrease of GS activity in grains did not influence the accumulations of amino acids and protein, it is implied that GS might not be the key enzyme in regulating glutamine content in grains.

Key words: high temperature, nitrogen metabolism enzyme, protein, amino acid, rice