RICE SCIENCE ›› 2013, Vol. 20 ›› Issue (5): 343-348.DOI: 10.1016/S1672-6308(13)60146-8

• Research Paper • Previous Articles     Next Articles

High Temperature During Rice Grain Filling Enhances Aspartate Metabolism in Grains and Results in Accumulation of Aspartate-Family Amino Acids and Protein Components

  1. 1Key Laboratory of Crop Physiology, Ecology, and Cultivation in Southwest China, Ministry of Agriculture, Sichuan Agricultural University, Chengdu 611130, China; 2Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan
  • Online:2013-09-28 Published:2013-07-30
  • Contact: LI Tian
  • Supported by:

    This work was financed by the International Technological Cooperation Program of Science and Technology Department, Sichuan Province, China (Grant No. 2010HH0015). The authors greatly thank for the State Scholarship Fund financed by China Scholarship Council (Grant No. 201206910010).

Abstract:

Global warming causes the exacerbation of rice growing environment, which seriously affects rice growth and reproduction, and finally results in the decrease of rice yield and quality. We investigated the activities of aspartate metabolism enzymes in grains, and the contents of Aspartate-family amino acids and protein components to further understand the effects of high temperature (HT) on rice nutritional quality during rice grain filling. Under HT, the average activities of aspartate aminotransferase (AAT) and aspartokinase (AK) in grains significantly increased, the amino acid contents of aspartate (Asp), lysine (Lys), threonine (Thr), methionine (Met) and isoleucine (Ile) and the protein contents of albumin, globulin, prolamin and glutelin also significantly increased. The results indicated that HT enhanced Asp metabolism during rice grain filling and the enhancement of Asp metabolism might play an important role in the increase of Asp-family amino acids and protein components in grains. In case of the partial appraisal of the change of Asp-family amino acids and protein components under HT, we introduced eight indicators (amino acid or protein content, ratio of amino acid or protein, amino acid or protein content per grain and amino acid or protein content per panicle) to estimate the effects of HT. It is suggested that HT during rice grain filling was benefit for the accumulation of Asp-family amino acids and protein components. Combined with the improvement of Asp-family amino acid ratio in grains under HT, it is suggested that HT during grain filling may improve the rice nutritional quality. However, the yields of parts of Asp-family amino acids and protein components were decreased under HT during rice grain filling.

Key words: high temperature, aspartate aminotransferase, aspartokinase, aspartate-family amino acid, protein component