Desiccator assay and sulfur labeling experiment
Twenty-one 10-d old Arabidopsis seedlings germinated on MS were
transferred to a Petri dish with sucrose-free MS medium (14.5 cm in
diameter). In a 2.5 L desiccator, a 7-d old fungal culture grown on PDA
was placed at the bottom. A plastic inlay with holes was inserted in the
middle of the desiccator, and the big Petri-dish with seedlings was
placed on top of it. To ensure sterility of the experiment, the seam of
the desiccator was wrapped with 3MTM Micropore tape
(Figure S2). Fungus and seedlings were incubated at 22 °C under long day
conditions (16 hours light/ 8 hours dark; 80 μmol
m−2s−1) for 14 days. Number of
inflorescence (flower stalk) and shoot fresh weight were measured.
The same procedure was followed for sulfur labeling experiments, in
which a 7-d old M. hyalina culture grown on labeled/unlabeled KM
medium and 16 10-d old Arabidopsis seedlings were used. Root and
shoot tissues were collected after 14 days for analysis.