Y. Uetake et N. Ishizaka, CYTOCHEMICAL-LOCALIZATION OF ADENYLATE-CYCLASE ACTIVITY IN THE SYMBIOTIC PROTOCORMS OF SPIRANTHES SINENSIS, Mycological research, 100, 1996, pp. 105-112
A cytochemical method has been used to investigate the localization of
adenylate cyclase [EC 4.6.1.1] activity in the protocorms of Spiranth
es sinensis developing with one of its endomycorrhizal fungi, Ceratoba
sidium cornigerum and in seeds cultured without fungi. In both symbiot
ic protocorms and asymbiotic seeds, the reaction products precipitated
on the exterior side of the host plasma membrane in contact with the
host cell wall. The invagination sites of the plasma membrane and vesi
cles near the membrane showed a strong reaction. Non-electron-dense de
posits were found on the host membrane enveloping the hyphae and on th
e fungal plasma membrane. The host membrane enveloping the hyphae stai
ned with the two selective stains for plasma membrane of plant cells,
phosphotungstic acid-chromic acid and alkaline bismuth. The detection
of the adenylate cyclase activity on the host plasma membrane in conta
ct with host cell wall suggested the presence of cAMP in orchid tissue
s, and the absence of activity on the host plasma membrane enveloping
the hyphae suggested that cAMP played no role in the interface between
host and fungus.