US EPA

2504452 

Journal Article 

Review 

Challenges to develop nitrogen-fixing cereals by direct nif-gene transfer 

Curatti, L; Rubio, LM 

2014 

1 

Plant Science
ISSN: 0168-9452
EISSN: 1873-2259 

225 

130-137 

English 

25017168 

10.1016/j.plantsci.2014.06.003 

WOS:000340317400016 

Some regions of the developing world suffer low cereal production yields due to low fertilizer inputs, among other factors. Biological N-2 fixation, catalyzed by the prokaryotic enzyme nitrogenase, is an alternative to the use of synthetic N fertilizers. The molybdenum nitrogenase is an O-2-labile metalloenzyme composed of the NifDK and NifH proteins, which biosyntheses require a number of nif gene products. A challenging strategy to increase cereal crop productivity in a scenario of low N fertilization is the direct transfer of nif genes into cereals. The sensitivity of nitrogenase to 02 and the apparent complexity of nitrogenase biosynthesis are the main barriers identified so far. Expression of active NifH requires the products of nifM, nifH, and possibly nifU and nifS, whereas active NifDK requires the products of nifH, nifD, nifK, nifB, nifE, nifN, and possibly nifU, nifS, nifQ, nifV, nafY, nifW and nifZ. Plastids and mitochondria are potential subcellular locations for nitrogenase. Both could provide the ATP and electrons required for nitrogenase to function but they differ in their internal O-2 levels and their ability to incorporate ammonium into amino acids. (C) 2014 Elsevier Ireland Ltd. All rights reserved. 

Food security; Nitrogen fixation; Cereals; Nif; Nitrogenase