Plants often form close mutualistic associations with soil
microorganisms such as bacteria and fungi, with the relationship
between legumes (Fabaceae) and nitrogen (N)
fixing bacteria being
one of the most well known. In this case, both types of organisms
directly benefit from the relationship, however, there can be
indirect effects on organisms at different trophic levels, such as on
herbivorous insects (Dean et al., 2009; Thamer et al., 2010 Ballhorn
et al., 2013). Root-associated bacteria (i.e., rhizobia) and mycor-
rhizal fungi can aid plants by increasing resistance to above-
ground herbivores via defensive compounds; however, concomitant
increases in plant growth and nutrition due to these