Better utilization of inorganic nitrogen compared to organic nitrogen by a plant symbiotic fungal isolate of Alternaria alternata

Alternaria alternata , a fungus that causes plant diseases, is also a Dark Septate Endophyte (DSE) that can enhance host plant growth by improving access to soil nutrients like nitrogen. To test the environmental factors influencing this relationship, we explored whether A. alternata can utilize both organic and inorganic nitrogen. Our results showed that an A. alternata isolate grew 133% larger in an inorganic nitrogen medium than in an organic nitrogen medium. These findings suggest the need for further research on other DSE taxa and nitrogen forms to better understand fungal nitrogen use.