MPMI publishes significant research on the molecular genetics and molecular biology of pathological, symbiotic, and associative interactions of microbes and plants. For the purposes of this journal, the term microbe encompasses viruses, prokaryotes, and fungi, as well as nematodes and viroids. The term molecular biology includes studies on biochemical or biophysical mechanisms. Although most papers report original, in-depth research, the journal also publishes short reviews and notes.