The plant hormone auxin regulates a whole repertoire of plant growth and development.
Many plant-associated microorganisms, by virtue of their auxin production capability, mediate phytostimulation
effects on plants. Recent studies, however, demonstrate diverse mechanisms whereby plant
pathogens manipulate auxin biosynthesis, signaling and transport pathways to promote host susceptibility.
Auxin responses have been coupled to their antagonistic and synergistic interactions with salicylic acid and jasmonate
mediated defenses, respectively. Here, we discuss that a better understanding of auxin crosstalk to plant immune
networks would enable us to engineer crop plants with higher protection and low unintended yield losses.