Is Important for Vegetative Growth, Conidiogenesis, Maintenance of Cell Wall Integrity and Pathogenesis of .

Glutamine is a non-essential amino acid that acts as a principal source of nitrogen and nucleic acid biosynthesis in living organisms. In , glutamine synthetase catalyzes the synthesis of glutamine. To determine the role of glutamine synthetase in the development and pathogenicity of plant fungal pathogens, we used Gln1 amino acid sequence to identify its orthologs in and named them MoGln1, MoGln2, and MoGln3. Deletion of and showed that they are not involved in the development and pathogenesis of . Conversely, Δ was reduced in vegetative growth, experienced attenuated growth on Minimal Medium (MM), and exhibited hyphal autolysis on oatmeal and straw decoction and corn media. Exogenous l-glutamine rescued the growth of Δ on MM. The Δ mutant failed to produce spores and was nonpathogenic on barley leaves, as it was unable to form an appressorium-like structure from its hyphal tips. Furthermore, deletion of altered the fungal cell wall integrity, with the Δ mutant being hypersensitive to HO. MoGln1, MoGln2, and MoGln3 are located in the cytoplasm. Taken together, our results shows that is important for vegetative growth, conidiation, appressorium formation, maintenance of cell wall integrity, oxidative stress tolerance and pathogenesis of .