Professor SEO Hak Soo of SNU’s Department of Plant Science has announced that he has discovered the mechanism behind the transformation of NO3 absorbed from roots into ammonium, which can be used for compounding substances. Nitrogen is one of three prime nutrients that are important in germination, growth and development, and seed-bearing of plants.

It is estimated that there are 25,000 proteins that are coded in Arabidopsis genomes and that at least 50,000 proteins actually function in practice. The reason is that the functions and stability of lots of proteins that had been coded from genes are controlled after being transformed through post-translational modification.

Generally known forms of protein modification include phosphorylation, glycosylation, acylation, ubiquitination, and sumoylation. Sumoylation takes place due to E3 SUMO ligase that unites SUMO (Small Ubiquitin-Related MOdifier) protein with target protein.

SEO’s research revealed that, after the enzyme nitrate reducase (NR) goes through sumoylation by the activation of E3 SUMO ligase AtSIZ1, the activation that reduces nitric acid is increased. If we produce transformants and mutations that increase the activation of E3 SUMO ligase, the enzymic activation, which is accompanied by the sumolyation of enzymes related to nitrogen consumption, is increased.

These research results are expected to contribute to more effective uses of nitrogen, thereby accelerating the development of crops with increased production and harvest rates, and were published in the July 2011 issue of Nature Communications.

Written by PARK Ziho, SNU English Editor, snuitsm2@snu.ac.kr
Proofread by Brett Johnson, SNU English Editor, morningcalm2@gmail.com