Protocol modified for Puccinia striiformis f. sp tritici (Pst), based on:Michielse, C. B., Hooykaas, P. J., van den Hondel, C. A., & Ram, A. F. (2008). Agrobacterium-mediated transformation of the filamentous fungus Aspergillus awamori. Nature protocols, 3(10), 1671-1678. I am grateful for critical suggestions from Prof. John Rathjen and Dr. Benjamin Schwessinger.