Effect of nitrogen deficiency on recombinant protein production and dimerization and growth in transgenic plants

This study investigated the effects of nitrogen (NH (4) (+) ) in the soil on the expression of prostatic acid phosphatase (PAP)-IgA Fc and PAP-IgA FcK recombinant proteins in transgenic plants, and on plant growth in the greenhouse. Plant height and leaf length were greater in soil A (NH (4) (+) : 51 mg center dot L-1) than in soil B (NH (4) (+) : 1 mg center dot L-1). In soil B, the plant leaves turned yellow, with chlorophyll concentrations that were significantly lower than the chlorophyll concentration of leaves from plants grown in soil A. The expression level of the PAP-IgA Fc and PAP-IgA FcK proteins and the protein dimerization rates were lower in soil B when compared with soil A. In addition, PAP-IgA Fc and PAP-IgA FcK expression and dimerization levels were significantly lower in transgenic plants grown in soil B, when compared with transgenic plants grown in soil A. Soil characteristics such as hydrogen ion concentration (pH), electric conductivity (EC), and bulk density did not differ between soil A and B. Thus, appropriate soil NH (4) (+) concentrations are essential for optimized plant growth and enhanced expression of dimerized PAP-IgA Fc and PAP-IgA FcK recombinant proteins in transgenic plants.