Tobacco hornworm on a tomato plant. From
Home » Does mycorrhizal status alter herbivore-induced changes in whole-plant resource partitioning?

Does mycorrhizal status alter herbivore-induced changes in whole-plant resource partitioning?

State of the World's FungiPlants simultaneously interact with beneficial and antagonistic organisms such as mycorrhizal fungi and herbivores, respectively. Both mycorrhizae and herbivore damage cause rapid changes in source–sink dynamics within a plant. Mycorrhizae create long-term sinks for carbon within the roots while damage by leaf-chewing herbivores causes temporary whole-plant shifts in carbon and nitrogen allocation. Thus, induced responses to herbivory might depend on the presence or absence of mycorrhizae.

Tobacco hornworm on a tomato plant. From
Tobacco hornworm (M. sexta) in frozen defensive posture on Florida tomato plant. Image credit: Ignodth [CC BY-SA 3.0 or GFDL], from Wikimedia Commons.

In a study published in AoBP, Orians et al. studied the net effects of such interactions on plant internal resources and growth. They examined the effects of mycorrhizal presence on induced resource partitioning in tomato (Solanum lycopersicon) in response to cues from a specialist herbivore, the tomato hornworm (Manduca sexta). Differences in plant size, growth and in the concentrations of carbon-based and nitrogen-based resources in three tissue types (apex, stem and roots) were quantified. The presence of mycorrhizae promoted plant growth, and altered sugar and starch levels. Simulated herbivory resulted in lower concentrations of most resources (sugar, starch and protein) in the rapidly growing apex tissue, while causing an increase in stem protein. Although they found mycorrhizae and herbivory had effects on the plant individually, the magnitude or direction of the individual effects generally did not differ when both organisms were present at the same time. These results suggest that herbivore cues, regardless of plant mycorrhizal status, reduce allocation of resources to the growing apex while promoting protein storage in the stem, a possible mechanism that could increase the tolerance of plants to damage.

William Salter

William (Tam) Salter is a Postdoctoral Research Fellow in the School of Life and Environmental Sciences and Sydney Institute of Agriculture at the University of Sydney. He has a bachelor degree in Ecological Science (Hons) from the University of Edinburgh and a PhD in plant ecophysiology from the University of Sydney. Tam is interested in the identification and elucidation of plant traits that could be useful for ecosystem resilience and future food security under global environmental change. He is also very interested in effective scientific communication.

Read this in your language

The Week in Botany

On Monday mornings we send out a newsletter of the links that have been catching the attention of our readers on Twitter and beyond. You can sign up to receive it below.

@BotanyOne on Mastodon

Loading Mastodon feed...