Book of Abstracts (PDF) - International Mycological Association

IMC7 Monday August 12th Lectures
97 - Net transfer of water between plants connected by
common mycorrhizal networks
J.I. Querejeta 1* , L. Egerton-Warburton 2 & M.F. Allen 1
1 University of California Riverside, CCB University
Laboratory BLDG RM 203, Riverside CA 92521, U.S.A. -
2 Chicago Botanic Gardens, 1000 Lake Cook Rd, Glencoe
IL 60022, U.S.A. - E-mail: nachoq@ucrac1.ucr.edu
Common mycorrhizal networks (CMNs) may play a major
role in mediating water parasitism associated with
hydraulic lift. Neighboring plants that share a CMN with
the lifting individual may be able to derive the greatest
benefit from this process. The ability of CMN to directly
transfer significant amounts of water between plants was
evaluated in the obligate mycorrhizal species coast live oak
(Quercus agrifolia). Mycorrhizal (ecto- + arbuscular) oak
seedlings were grown in microcosms comprising two
adjacent compartments separated by air gaps and mesh
barriers that could be crossed by hyphae but not by roots.
Oak seedlings in one of the compartments had access to a
taproot chamber with unlimited supply of water and
conducted hydraulic lift. Following an 11 day drought
period, during which watering was withdrawn from the
upper two compartments, we detected a net transfer of
water from the lifting oaks to neighboring plants through
CMNs. Quercus, Salvia and Eriogonum seedlings in the
adjacent compartment showed up to 20% higher leaf water
content compared with their experimental counterparts
with severed hyphal connections at the onset of the drought
period. Isotopic data obtained after injecting deuteriumdepleted
tracers into the taproot chamber also indicated that
neighboring droughted seedlings received up to 19% of
their water from the lifter oaks through CMNs.
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Book of Abstracts