Impact of arbuscular mycorrhizal symbiosis on plant response to biotic stress: The role of plant defence mechanisms

Abstract

Arbuscular mycorrhizal associations imply a remarkable reprogramming-of functions in both plant and fungal symbionts. The consequent alterations on plant physiology have a clear impact on the plant response to biotic stresses. In this chapter we discuss the effects of the mycorrhizal symbiosis on plant susceptibility/resistance to potential deleterious organisms, including root and shoot pathogens, root parasitic plants and phytophagous insects, highlighting the mechanisms that may be operating in each particular case. Special attention is given to the modulation of plant defence responses in mycorrhizal systems, as it may affect all interactions. Finally we focus on the priming of jasmonate regulated plant defence mechanisms that seem to mediate the induction of resistance by arbuscular mycorrhizas.