Present status and development on biological nitrogen fixation research in China

Abstract

This presentation introduces the advances in biological nitrogen fixation research abroad, in particular, describes the great progress and achievements on its research in China as follows: collection of rhizobial resources and establishment of the largest database ofRhizobium in China, correction and development ofRhizobium taxonomy in international; discovery of a couple ofnif genes, identification and unification of linkage among thenif gene operonsof Klebsiella pneumoniae, finding of regulative mechanism of positive regulationnif gene and its sensitivity to oxygen, temperature; finding of the activity of nodulation genenodD3 product inSinorhizobium meliloti which is not controlled by flavonoid produced from its host alfalfa; finding of the association between expression of genes coding the products for carbon utilization and nitrogen metabolism and their regulations; chemical synthesis of nodulation factor ofSinorhizobium meliloti; constructions of engineered nitrogen fixers and utilization in practice based on the research of gene expression and regulation; chemical simulation of the structure and function of nitrogenase and bringing forward the model of nitrogenase active center for the first time in international and synthesis of model compounds which were paid attention by colleagues abroad. Finally, the development of nitrogen fixation research in China in future has been put forward, suggesting that thenif gene regulation and its role in providing crops with nitrogen element, signal transduction and molecular interactions betweenRhizobium and legume, coupling between carbon and nitrogen metabolisms, nitrogen fixation and photosynthesis, and functional genomics of nitrogen-fixing nodule symbiosis, etc., would be actively worked on.