title: Surviving freezing in plant tissues by oomycetous snow molds.
abstract: Oomyceteous snow molds, Pythium species, were reported to be less tolerant to chilling and freezing temperatures than other snow mold taxa. However, Pythium species are often found to be pathogenic on mosses in Polar Regions. We investigated the frost resistance of Pythium species from Temperate (Hokkaido, Japan) and Subantarctic Regions. Free mycelia and hyphal swellings, structures for survival, of Pythium iwayamai and Pythium paddicum lost viability within freeze-thaw 3 cycles; however, mycelia in host plants survived the treatment. It was reported that fungi in permafrost are characterized both by the presence of natural cryoprotectants in these ecotopes and by the ability to utilize their inherent mechanisms of protection. It is conceivable that plant substrates or derivatives thereof are natural cryoprotectants, enabling them to provide advantageous conditions to microorganisms under freezing conditions. Our results are the first to experimentally support this hypothesis.
authors: Graduate School of Life Science, Hokkaido University, N10W8, Kita-ku, Sapporo 060-0810, Japan; Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan.
authors: Ryo
authors: R
authors: Murakami
authors: Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan.
authors: Yuka
authors: Y
authors: Yajima
authors: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai 599-8531, Japan.
authors: Ken-ichi
authors: K
authors: Kida
authors: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai 599-8531, Japan.
authors: Katsuyuki
authors: K
authors: Tokura
authors: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai 599-8531, Japan.
authors: Motoaki
authors: M
authors: Tojo
authors: Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan; Graduate School of Life Science, Hokkaido University, N10W8, Kita-ku, Sapporo 060-0810, Japan. Electronic address: tamotsu.hoshino@aist.go.jp.
authors: Tamotsu
authors: T
authors: Hoshino
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D002470:Cell Survival; D003080:Cold Temperature; D003451:Cryoprotective Agents / Q000378:metabolism*; D005615:Freezing / Q000009:adverse effects*; D010944:Plants; D011775:Pythium / Q000502:physiology*
chemical_list: D003451:Cryoprotective Agents
keywords: Environmental adaptation; Frost resistance; Oomycetes; Stramenopiles; Take advantage of host function