Increased protein content in transgenic Arabidopsis thaliana over-expressing nitrate reductase activity

Arabidopsis thaliana was engineered to over-express nitrate reductase (NR) by virtue of the light inducible chimeric gene Lhcb1*3:Nia1*2. The transgenic lines obtained displayed NR activity 2-4 times the level in the wild type, depending on the line. While not displaying advantage with respect to fresh or dry weight, 7-day-old transgenic seedlings did show up to 200% higher protein content than the wild type when grown on solid medium. Up to 30% increase in protein content was also obtained when grown in peat moss for at least 3 weeks. The increase in protein content was evident in several protein bands but was most apparent in that of the large subunit of RuBisCo. (C) 1997 Elsevier Science Ireland Ltd.