著者
Yagame Takahiro Yamato Masahide
出版者
Springer Japan
雑誌
Journal of plant research (ISSN:09189440)
巻号頁・発行日
vol.126, no.2, pp.215-222, 2013-03-01
被引用文献数
11

Mixotrophy, obtaining carbon by mycoheterotrophy and photosynthesis, has been suggested in Cephalanthera species (Orchidaceae) by analyses on stable isotopes of carbon. In this study, we examined the growth of Cephalanthera falcata in pot cultured tripartite symbioses with Thelephoraceae fungi and Quercus serrata. Mycorrhizal fungi were isolated from roots of C. falcata in natural habitats. Two fungal isolates identified as Thelephoraceae were cultured and inoculated to fine roots of non-mycorrhizal seedlings of Q. serrata (Fagaceae). After the ectomycorrhizal formation, non-mycorrhizal seedlings of C. falcata were co-planted. The pots with tripartite symbioses were cultured in greenhouse for 30 months, and growth of C. falcata seedlings was examined. Fresh weight of C. falcata seedlings was significantly increased by the tripartite symbioses even in those with no shoot, thus providing further evidence for the mycoheterotrophic nature of this orchid. The achievement of seedling culture in tripartite symbioses would be valuable for conserving many forest orchids and for conducting experiments to understand their physiology and ecology.
著者
Yamamoto Tsuyoshi Nakamura Atsuko Iwai Hiroaki Ishii Tadashi Ma Jian Feng Yokoyama Ryusuke Nishitani Kazuhiko Satoh Shinobu Furukawa Jun
出版者
Springer Japan
雑誌
Journal of plant research (ISSN:09189440)
巻号頁・発行日
vol.125, no.6, pp.771-779, 2012-11
被引用文献数
64 3

Rice (Oryza sativa L.) is a typical Si-accumulating plant and is able to accumulate Si up to >10 % of shoot dry weight. The cell wall has been reported to become thicker under Si-deficient condition. To clarify the relationship between Si accumulation and cell wall components, the physical properties of, and macromolecular components and Si content in, the pectic, hemicellulosic, and cellulosic fractions prepared from rice seedlings grown in hydroponics with or without 1.5 mM silicic acid were analyzed. In the absence of Si (the −Si condition), leaf blades drooped, but physical properties were enhanced. Sugar content in the cellulosic fraction and lignin content in the total cell wall increased under −Si condition. After histochemical staining, there was an increase in cellulose deposition in short cells and the cell layer just beneath the epidermis in the −Si condition, but no significant change in the pattern of lignin deposition. Expression of the genes involved in secondary cell wall synthesis, OsCesA4, OsCesA7, OsPAL, OsCCR1 and OsCAD6 was up-regulated under −Si condition, but expression of OsCesA1, involved in primary cell wall synthesis, did not increase. These results suggest that an increase in secondary cell wall components occurs in rice leaves to compensate for Si deficiency.