Arbuscular mycorrhizal fungi nitrate assimilation: Genes and ecophysiological aspects

Abstract

A review. Plants and many microorganisms are N-autotrophs. They meet their demand for org. nitrogen by the conversion of nitrate to ammonia. The ammonia thus formed or directly taken up from the soil is incorporated into amino acids and heterocyclic N-compds. Fungi can assimilate nitrate, however, any occasional claim in the past that fungi can fix N2 has not been confirmed by crit. re-examn. The involvement of arbuscular mycorrhizal fungi (AMF) in the biol. nitrogen cycle is described. The role of AMF in the acquisition of nitrogen by plants is discussed. The enzymes of nitrate assimilation and their expression in the AMF plant symbiosis are also discussed. [on SciFinder (R)]