Cytological characteristics of microconidia of Magnaporthe oryzae
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The inner cellular structure of microconidia of Magnaporthe oryzae was examined using fluorescent probes and electron microscopic techniques. The volume of the nucleus relative to the cell was significantly larger in microconidia than in macroconidia or vegetative hyphae, similar to observations for spermatia of other fungi. Selective fluorescent staining revealed that cytosolic RNA was less abundant in microconidia than in macroconidia and germ tubes, suggesting that general metabolic activity in microconidia is low. Consistently, GFP expression driven by the TrpC promoter was highly active during the formation of phialides and microconidia but gradually decreased as the microconidia matured. Such data suggest that microconidia are in a quiescent or dormant state.
KeywordsMagnaporthe oryzae Pyricularia oryzae Microconidia
We thank Dr. H. Kato, former professor of Kobe University, for valuable suggestions and technical support.
- Kato H, Yamaguchi T, Nishihara N (1976) The perfect state of Pyricularia oryzae Cav. in culture. Ann Phytopathol Soc Jpn 42:507–510Google Scholar
- Kato H, Mayama S, Sekine R, Kanazawa E, Izutani Y, Urashima AS, Kunoh H (1994) Microconidium formation in Magnaporthe grisea. Ann Phytopathol Soc Jpn 60:175–185Google Scholar
- Kato H, Yamamoto M, Yamaguchi-Ozaki T, Kadouchi H, Iwamoto Y, Nakayashiki H, Tosa Y, Mayama S, Mori N (2000) Pathogenicity, mating ability and DNA restriction fragment length polymorphisms of Pyricularia populations isolated from Gramineae, Bambusideae and Zingiberaceae plants. J Gen Plant Pathol 66:30–47CrossRefGoogle Scholar
- Park P, Unno K, Ishii H, Adachi Y, Kanematsu S, Uehara T (1996) An efficient and confirmative electron microscopy for observing the infection sites of fungi on plant tissues (Abstract in Japanese). Ann Phytopathol Soc Jpn 62:285Google Scholar
- Ueyama A, Tsuda M (1975) Formation of the perfect state in culture of Pyricularia sp. from some graminaceous plants (preliminary report). Trans Mycol Soc Jpn 16:420–422Google Scholar
- Yaegashi H, Nishihara N (1976) Production of the perfect stage in Pyricularia from cereals and grasses. Ann Phytopathol Soc Jpn 42:511–515Google Scholar