Abstract Detail

Mycology

Zhang, Kaile [1], Erhunmwunse, Adesuwa [2], Chen, Ko-Hsuan [3], Tappero, Ryan [4], Bhatnagar, Jennifer [5], Averill, Colin [6], Nicholas, Sarah [4], Vilgalys, Rytas [7], Liao, Hui-Ling [2].

How do ectomycorrhizal fungi affect iron chemistry in the rhizosphere? New evidence from multi-modal X-ray imaging.

Iron (Fe) is vital to the metabolic functions of living organisms. Plants may access occluded iron by interacting with rhizosphere microorganisms and symbionts. It is poorly known what role ectomycorrhizal fungi, critical symbionts of pine trees, play on rhizosphere Fe process and plant Fe acquisition. We used the well-established Pinus-Suillus symbiont system to quantify Fe dynamics across the plant-mycorrhiza-rhizosphere interface. Two isolates of Suillus (Suillus brevipes SB 120 CO isolate and Suillus spraguei EM 44, PA isolate) were paired with P. contorta CO seedlings. The P. contorta-Suillus inoculum pairs were then planted in a nutrient-poor sand culture that supplemented with ferrihydrite coated sand for three months. Stereomicroscope analysis showed that Fe addition had a significant and negative effect on the fungal colonization rate in the early stage (two weeks after inoculation). X-ray fluorescence imaging revealed that mixed inocula of SB120 and EM 44 had stronger iron signal changes over time in the rhizosphere and root tissues, compared to single inoculum or no-inoculum bioassay. The microcosms inoculated with EM 44 induced more rapid responses to Fe in the early stage compared with SB 120, which accumulated a substantial amount of Fe around its mycorrhizae in the late stage. Our findings support our hypothesis that ectomycorrhizal fungi can dissolve Fe coatings in the rhizosphere and transform them into plant-available forms, which in turn enhances plant growth. The effect of the ectomycorrhizal-mediated Fe process on the chemistry of other plant required elements (e.g., K, Ca, Cu, Zn) in root tissues will also be discussed.

1 - University of Florida, Soil and Water Science Department, 155 Research Rd, Quincy, FL, 32351, USA
2 - University of Florida
3 - Academia Sinica
4 - Brookhaven National Laboratory
5 - Boston University
6 - ETH Zürich
7 - Duke University

Keywords:
Pinus-Suillus symbiont system
Iron
X-ray fluorescence imaging
Mycology.

Presentation Type: Oral Paper
Session: MY3, Mycology: Fungus-Plant Interactions - Ectomycorrhizae and Orchid Mycorrhizae
Location: /
Date: Tuesday, July 20th, 2021
Time: 4:15 PM(EDT)
Number: MY3006
Abstract ID:457
Candidate for Awards:None