Submitted to: Physiological and Molecular Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/1/2008
Publication Date: 7/1/2008
Publication URL: http://hdl.handle.net/10113/49650
Citation: Bolton, M.D., Thomma, B.P.H.J. 2008. The complexity of nitrogen metabolism and nitrogen-regulated gene expression in plant pathogenic fungi. Physiological and Molecular Plant Pathology. 72:104-110. Interpretive Summary: Plant pathogens produce molecules called “effector proteins” that are important for causing disease on their plant hosts. Identification of these proteins is important to understand the biology of the pathogen and the disease process. Early research suggested that starving fungal pathogens of nitrogen sources during growth in culture was a cue for the pathogen to produce effector proteins and mimicked the environment that a pathogen encounters during growth in the host. Although this relationship has been implied in several studies, little is known regarding the availability of nitrogen during colonization of the host. This review article will focus on the effect of nitrogen starvation on fungal effector genes to gain an understanding on whether nitrogen availability within the host is an important factor in disease development.
Technical Abstract: Plant pathogens secrete effector molecules that contribute to the establishment of disease in their plant hosts. The identification of cellular cues that regulate effector gene expression is an important aspect of understanding the infection process. Nutritional status in the cell has been postulated to be a cue for effector gene expression. Several studies have shown the induction of the same effector genes during growth under nitrogen-starved conditions in vitro as during growth in planta, suggesting that a nitrogen-poor environment exists during colonization. As a consequence, it has been proposed that growth in nitrogen-starved media mimics the environment that a pathogen encounters during growth in planta. Although this relationship has been implied in several studies, there is little known regarding available nitrogen during colonization for fungal pathogens. This review will focus on the effect of nitrogen starvation on fungal effector gene expression and will examine the role of fungal nitrogen regulatory genes to help gain an understanding of whether nitrogen availability within the host is an important factor in disease development.