Throughout the course of evolution plants frequently faced changing environmental conditions, forcing them to adapt in order survive. These changing conditions included temperature fluctuations, scarce water resources, and high UV radiation. Although a precise determination of temporal dynamics of prehistoric climate changes is extremely difficult, it is undeniable that climate change has accelerated in the last century. The fact that anthropogenic greenhouse gas emissions considerably contribute to this acceleration raises the question as to whether plants will be able to adapt to the imposed environmental stress conditions. Possibly, they will run out of time to generate appropriate responses to counteract the detrimental effects. However, assuming that it is not the first time that plants are confronting such conditions, they may have already suitable molecular mechanisms at their disposal, from previous challenges, to withstand the foreseen unfavorable conditions, i.e. increased temperatures and water shortage.
The majority of plant studies, however, only focus on plant responses towards abiotic stresses and disregard the fact that plants normally live in close community with a plethora of different microorganisms, such as bacteria, fungi, oomycetes and protists, and that millions of years of co-evolution have led to the establishment of highly specialized ecosystems in which plants constantly interact with their surrounding communities of commensal, symbiotic and pathogenic microorganisms. In the climate change context, symbiotic relationships are of particular interest, as they are supposed to translate or already have translated into mutually advantageous associations that can provide important fitness improvements.
Here, we review current advances in understanding beneficial plant-fungus interactions, particularly from symbiotic communities found in extreme ecosystems.