Fungal infestation boosts fruit aroma and fruit removal by mammals and birds

摘要

For four decades, an influential hypothesis has posited that competition for food resources between\udmicrobes and vertebrates selects for microbes to alter these resources in ways that make them\udunpalatable to vertebrates. We chose an understudied cross kingdom interaction to experimentally\udevaluate the effect of fruit infection by fungi on both vertebrate (mammals and birds) fruit preferences\udand on ecologically relevant fruit traits (volatile compounds, toughness, etc). Our well-replicated field\udexperiments revealed that, in contrast to previous studies, frugivorous mammals and birds consistently\udpreferred infested over intact fruits. This was concordant with the higher level of attractive volatiles\ud(esters, ethanol) in infested fruits. This investigation suggests that vertebrate frugivores, fleshyfruited\udplants, and microbes form a tripartite interaction in which each part could interact positively\udwith the other two (e.g. both orange seeds and fungal spores are likely dispersed by mammals). Such\uda mutualistic view of these complex interactions is opposed to the generalized idea of competition\udbetween frugivorous vertebrates and microorganisms. Thus, this research provides a new perspective\udon the widely accepted plant evolutionary dilemma to make fruits attractive to mutualistic frugivores\udwhile unattractive to presumed antagonistic microbes that constrain seed dispersal.