Effects of arbuscular mycorrhizal fungi on herbivory defense in two Solanum (Solanaceae) species

Abstract

Background and aims-Arbuscular mycorrhizal fungi (AMF) are ubiquitous soil organisms that interact with plant roots and exchange soil nutrients for plant-derived carbohydrates, frequently resulting in growth and fitness benefits for plants. These benefits may be due partly to AMF effects on plants' resistance to insect herbivores, particularly through enhancement of induced defenses. Here we studied the impacts of AMF colonization on constitutive and induced resistance in two species of nightshades, Solanum ptycanthum and S. dulcamara. Methods-We used a factorial design manipulating AMF presence and jasmonic acid application to determine if constitutive and induced resistance differ in the presence and absence of mycorrhizae. We measured three protein-based chemical defenses and performed a bioassay by feeding leaves of experimental plants to a specialist herbivore, Manduca sexta. Key results-The presence of AMF influenced chemical defenses in S. dulcamara, including an interaction with jasmonic acid application for polyphenol oxidase activity. Solanum ptycanthum defenses were unaffected by AMF. Caterpillar growth was also unaffected by AMF but reduced by jasmonic acid treatments, indicating that, while AMF may influence certain chemical defenses in some plant species, this does not always translate to resistance against herbivores. Conclusions-Our results emphasize the context dependency of fungi-plant-herbivore interactions and suggest that mycorrhizal effects on plant defense may vary with other plant traits or life history strategies.

Mycorrhizal fungi affect orchid distribution and population dynamics

“…This is especially true for mycorrhizal associations (Brundrett, 2009), which are known to affect plant and population characteristics as diverse as flowering time (Wagner et al, 2014;Panke-Buisse et al, 2015), resistance to pathogens and herbivores (e.g. Vicari et al, 2002;Roger et al, 2013;Minton et al, 2016), the distribution of nonnative (Menzel et al, 2017) and native species, and allowing growth on nutrient-poor substrates (e.g. Denison & Kiers, 2011).…”

How belowground interactions contribute to the coexistence of mycorrhizal and non-mycorrhizal species in severely phosphorus-impoverished hyperdiverse ecosystems

“…The log curve fits for the NM monocot and NM Proteaceae species were better by AIC than linear fits (AIC values: 64.3 versus 91.0 for the NM monocot species; 90.5 versus 121.5 for the NM Proteaceae species). Solid lines indicate significant (P < 0.05) regression relationships: (a) P = 0.006; (b) P = 0.0007 for monocot NM species, P = 0.0001 for Proteaceae species; (c) P = 0.006 Cameron et al 2013), but also includes protection against nematodes (Vos et al 2013) and herbivores (Minton et al 2016).…”

Arbuscular mycorrhizal fungi mediate herbivore‐induction of plant defenses differently above and belowground

“…Plant responses to herbivore feeding are also shaped by interactions with belowground microbial symbionts, such as arbuscular mycorrhizal fungi (AMF) , Kempel et al 2010, Babikova et al 2014, Wang et al 2015, Minton et al 2016, He et al 2017. AMF colonize the roots of over 80% of plant species globally and provide nutrients and water to plants in exchange for sugars (Wang and Qiu 2006, Smith and Read 2008, Soudzilovskaia et al 2015.…”