Diatom Nitrate Transporter Transgene Promoting Plant Growth on Low Nitrate Soils

Background: Currently many plants require high amounts of added nitrate fertilizers for optimal growth. Plant growth is often limited by the availability of soil nitrate, which is compensated for by the use of nitrate-containing fertilizers. Such fertilizers have numerous and serious environmental side effects, not to mention their occasional diversion by terrorists as a bomb component. Diatom nitrate transporters have an unusually high affinity for nitrate, which they concentrate from seawater (Dugdale, R.C. 1967. Limnol. Oceanog. 12:685; Eppley, et al., 1969. Limnol. Oceanog. 14:912). By transgenic expression, plants that contain them have the potential for growing on soil with lower nitrate levels.

Technology Description: A cDNA clone encoding a nitrate transporter homolog has been isolated from the diatom Cylindrotheca fusiformis. The gene contains no introns, and so is well suited to expression in other organisms. Constructs are made placing the cDNA clone under the control of plant root-specific promoters. Plant growth can then be optimized for low nitrate soils.

Advantages: The advantages of this invention are that it could reduce or eliminate the need for nitrate fertilizers in crop plants, resulting in similar yield, but without the environmental contamination resulting from high amounts of nitrate.

Case Number : SD1998-083

Inquiries To : invent@ucsd.edu