Figure legends

Figure. 1. Sugar compositions of developing G. elatatubers
Sugar contents of developing tubers. Metabolites were extracted from freeze-dried samples and analyzed by GC-MS. Results are means ± SE from three biological samples.
Figure. 2. Cell morphology of G. elata tubers inoculated with Armillaria.
(a) Developing tubers in association with Armillaria isolates. (b) Histological images of inoculated cortical cells in (a). Red dye indicated formation of thick cell walls. (c) Zoom-in micrograph of fungal matrix in infected cortical cell. (d) Zoom-in image of the interface between the infected cell and the neighboring large cell in the white box in (c). (e) Zoom-in image of curving ingrowth of cell wall (white arrows) and plasma membrane (*) in the white box in (d). (f) Micrograph of transmission electron microscopy showing the protruding of wall ingrowth (white arrows). Abbreviation: f: fungal hyphae; IC: infected cortex cells; N: nucleus; S: starch grain; V: vacuole; WI: wall ingrowth. Scale: 1cm in (a), 100 µm in (b), (c), (d); 10 µm in (f), (e).