Focus on Activation, Regulation, and Evolution of MTI and ETI

MAMP- or effector-triggered immunity processes are key components of plant disease resistance and have been studied intensively. We are now in a golden age of ETI and MTI research, in which mechanistic and evolutionary understanding of both processes is emerging rapidly. Accordingly, in this Focus issue, we explore diverse aspects of MTI and ETI, with a unifying theme of integration at multiple levels.