Based on aggregate CPM, the Py. ultimum mRNAs were more abundant in early versus late infection, while the opposite trend was seen in Ph. infestans. Despite having 18% fewer ABC transporter genes, total ABC transporter CPM in Py. ultimum was from 25 to 220% higher than Ph. infestans in the tissues, with the largest difference in early tubers. Here, ABCG2 is linked to infection.