Nutrient Regulation of Biological Clock in Plants

Nitrogen has been found to be a very important nutrient for normal growth and function of plants, as well as in resistance to pests and diseases. A recent finding on the function of nitrogen in the form of organic nitrate showed that it also serve as a signal for the control of gene expression in the model system Arabidopsis. Using the glutamine synthetase inhibitor, MSX, and organic nitrate treatment in Arabidopsis seedings, regulatory genes including CCA1 and other target genes involved in nitrogen assimilation were induced.

The result, published in this week's Proceedings of the National Academy of Sciences also validated some of the predicted interactions, and showed that regulation of the master clock control gene CCA1 by Glutamate or Glutanate-derived metabolite regulates the expression of key N-assimilatory genes. This finding shows that besides light, temperature, and carbon dioxide, organic nitrates can affect the plants' biological clock influencing its normal physiological and developmental functions.

The scientific article can be accessed at: http://www.pnas.org/cgi/reprint/0800211105v1