Combating Nitrification in Wheat Using Wildrye Genes

Nitrification, wherein ammonia is oxidized to nitrites followed by the oxidation of nitrites to nitrates, is a serious problem for agricultural production resulting in costly nitrogen loss. Nitrates are easily removed from the soil profile by leaching. Synthetic nitrification inhibitors, such as dicyandiamide and nitrapyrin, are currently being used to minimize nitrogen loss. Using a recombinant luminescent bacterium that can quantify biological nitrification inhibition (BNI) activity in root hairs, the wheat and barley relative Leymus (mammoth wildrye) was found to have high BNI capacity. Leymus was found to be capable of producing BNI compounds equivalent to 52.5 g of nitrapyrin in a hectare per day. Researchers from Japan, Australia and the US are now studying the possibility of transferring the BNI genes from Leymus to the cultivated wheat variety. Previous efforts of transferring pathogen resistance from the same species to barley proved to be successful. Over expression of the BNI genes in Leymus can also be exploited to produce sufficient nitrogen-loss inhibiting compounds for commercial use.

The complete paper published by the journal Plant and Soil is available to subscribers at http://www.springerlink.com/content/751756757j41r877/fulltext.pdf. Non subscribers can read the abstract at http://www.springerlink.com/content/751756757j41r877/?p=21cf908d69fa4a6ca663ed5869609b3f&pi=6