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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Photosynthate transfer from an autotrophic orchid to conspecific heterotrophic protocorms through a common mycorrhizal network
AU - Read, David J.
AU - Haggar, John
AU - Magkourilou, Emily
AU - Durant, Emily
AU - Johnson, David
AU - Leake, Jonathan R.
AU - Field, Katie J.
N1 - Publisher Copyright: © 2024 The Authors. New Phytologist © 2024 New Phytologist Foundation.
PY - 2024/7/31
Y1 - 2024/7/31
N2 - The minute ‘dust seeds’ of some terrestrial orchids preferentially germinate and develop as mycoheterotrophic protocorms near conspecific adult plants. Here we test the hypothesis that mycorrhizal mycelial connections provide a direct pathway for transfer of recent photosynthate from conspecific green orchids to achlorophyllous protocorms. Mycelial networks of Ceratobasidium cornigerum connecting green Dactylorhiza fuchsii plants with developing achlorophyllous protocorms of the same species were established on oatmeal or water agar before the shoots of green plants were exposed to 14CO2. After incubation for 48 h, the pattern of distribution of fixed carbon was visualised in intact entire autotrophic/protocorm systems using digital autoradiography and quantified in protocorms by liquid scintillation counting. Both methods of analysis revealed accumulation of 14C above background levels in protocorms, confirming that autotrophic plants supply carbon to juveniles via common mycorrhizal networks. Despite some accumulation of plant-fixed carbon in the fungal mycelium grown on oatmeal agar, a greater amount of carbon was transferred to protocorms growing on water agar, indicating that the polarity of transfer may be influenced by sink strength. We suggest this transfer pathway may contribute significantly to the pattern and processes determining localised orchid establishment in nature, and that ‘parental nurture’ via common mycelial networks may be involved in these processes.
AB - The minute ‘dust seeds’ of some terrestrial orchids preferentially germinate and develop as mycoheterotrophic protocorms near conspecific adult plants. Here we test the hypothesis that mycorrhizal mycelial connections provide a direct pathway for transfer of recent photosynthate from conspecific green orchids to achlorophyllous protocorms. Mycelial networks of Ceratobasidium cornigerum connecting green Dactylorhiza fuchsii plants with developing achlorophyllous protocorms of the same species were established on oatmeal or water agar before the shoots of green plants were exposed to 14CO2. After incubation for 48 h, the pattern of distribution of fixed carbon was visualised in intact entire autotrophic/protocorm systems using digital autoradiography and quantified in protocorms by liquid scintillation counting. Both methods of analysis revealed accumulation of 14C above background levels in protocorms, confirming that autotrophic plants supply carbon to juveniles via common mycorrhizal networks. Despite some accumulation of plant-fixed carbon in the fungal mycelium grown on oatmeal agar, a greater amount of carbon was transferred to protocorms growing on water agar, indicating that the polarity of transfer may be influenced by sink strength. We suggest this transfer pathway may contribute significantly to the pattern and processes determining localised orchid establishment in nature, and that ‘parental nurture’ via common mycelial networks may be involved in these processes.
KW - carbon
KW - common mycorrhizal networks
KW - Dactylorhiza fuchsii
KW - distribution
KW - fungi
KW - mycorrhiza
KW - orchids
KW - parental nurture
U2 - 10.1111/nph.19810
DO - 10.1111/nph.19810
M3 - Journal article
C2 - 38757767
AN - SCOPUS:85193632967
VL - 243
SP - 398
EP - 406
JO - New Phytologist
JF - New Phytologist
SN - 0028-646X
IS - 1
ER -