Divergent Mycorrhizal Lineages: Different Morphology and Colonization Rates in a Model Grass

Presenter

Veronica Hoac

Campus

UMass Amherst

Sponsor

Rachel Hestrin, Stockbridge School of Agriculture, UMass Amherst

Schedule

Session 3, 1:30 PM - 2:15 PM [Schedule by Time][Poster Grid for Time/Location]

Location

Poster Board A49, Campus Center Auditorium, Row 3 (A41-A60) [Poster Location Map]

Abstract

Arbuscular mycorrhizal fungi (AMF) associate with the majority of terrestrial plants to form symbiotic relationships, providing the host plant with mineral nutrients in return for photosynthates. We seek to understand how AMF phylogenetic and physiological diversity influence root colonization dynamics and resource exchange between AMF and their host plants. We hypothesized that earlier diverging lineages would colonize roots more slowly, have different morphology, and provide lesser benefits to the host plant compared to recently diverging lineages. To test these hypotheses, we inoculated the model grass species Brachypodium distachyon with one of two mycorrhizal species–the ancient lineage Archaeospora trappei or the more recently diverging Rhizophagus intraradices. After 3 weeks, we harvested the plants destructively, stained the roots, and quantified the extent of root colonization using the Magnified Intersections Method. While these two lineages displayed differing ratios of morphological structures, the total colonization rate of the ancient lineage was similar to that of the recently diverging lineage. This is contrary to recent findings that Archaeospora colonization levels may be lower than those of more recently diverging AMF lineages. In our ongoing work, we will continue to quantify colonization rates, morphological differences, and plant responses at later time points. A better understanding of the relationship between AMF diversity, colonization rates, and plant nutrient exchange could inform the development of AMF inocula for agricultural production systems.

Keywords

Plant-Microbe Interactions, Arbuscular Mycorrhizal Fungi, Symbiosis

Research Area

Biological Organisms

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