CDH1 and infection: Although this experiment does not conclusively prove that the source of the 3’-NADP was the rice and not and intercellular X. oryzae, it is well-established that AvrRxo1 is introduced into and active in rice cells during infection [20], and that AvrRxo1 activity is strongly inhibited in bacteria, in vitro, and in planta in the presence of the antitoxin Arc1 [8, 16].