Continuous variation within isolates of Typhula ishikariensis bio types B and C associated with habitat differences

Isolates of the snow mold fungus, Typhula ishikariensis, were collected from seven localities in northern Japan where snow cover conditions differ. The isolates were identified as T. ishikariensis biotype B, which produces large sclerotia, biotype C with smaller sclerotia, and large sclerotial and intermediate forms. Mating experiments with tester monokaryons indicated that all populations were related. Populations from localities with deep, persistent snow cover produced larger sclerotia, which germinated more readily carpogenically (biotype B and the large sclerotial form) than those from localities where snow cover was shorter and intermittent (biotype C). The aggressiveness of the former was more variable, whereas the latter was without exception aggressive. There was no apparent correlation between growth rate at 0 °C and duration of snow cover. It was concluded that biotype C has been selected for localities with ephemeral snow cover, but that biotypes B and C and the related forms do not form distinct populations and should be regarded as a single taxon.

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Snow mold fungus, Typhula ishikariensis group III, in Arctic Norway can grow at a sub-lethal temperature after freezing stress and during flooding

Sommerfeltia ◽

10.2478/v10208-011-0006-4 ◽

2008 ◽

Vol 31 (1) ◽

pp. 125-131 ◽

Cited By ~ 4

Author(s):

T. Hoshino ◽

A. Tronsmo ◽

I. Yumoto

Keyword(s):

Mycelial Growth ◽

Freezing Stress ◽

The Arctic ◽

Liquid Media ◽

Lethal Temperature ◽

Snow Mold ◽

Group Iii ◽

Typhula Ishikariensis ◽

Group I ◽

Mold Fungus

Snow mold fungus, Typhula ishikariensis group III, in Arctic Norway can grow at a sub-lethal temperature after freezing stress and during floodingIsolates of the snow mold fungus Typhula ishikariensis group III, which is predominant in Finnmark (northern Norway) and Svalbard, are more resistant to freezing stress than group I isolates from the southern part of Norway. Group III isolates showed irregular growth on potato dextrose agar (PDA) plates when subjected to heat stress at 10°C. However, group III isolates showed relatively good growth on PDA at 10°C after freezing treatment. The optimal temperatures for mycelial growth were 5°C on PDA and 10°C in potato dextrose broth (PDB), and group III isolates showed normal mycelial growth at 10°C in PDB. Mycelium of group III isolates cultivated in water poured into PDA plates, and normal hyphal extension was observed only in the liquid media. Hyphal growth became irregular when mycelia had extended above the surface of the liquid media. These results suggested that group III isolates can grow at a sub-lethal temperature after freezing stress and during flooding. Soil freezing and thawing occurs regularly in the Arctic, and physiological characteristics of group III isolates are well adapted to climatic conditions in the Arctic.

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Effect of cropping history on the population structure of Typhula incarnata and Typhula ishikariensis

Canadian Journal of Botany ◽

10.1139/b93-173 ◽

1993 ◽

Vol 71 (11) ◽

pp. 1434-1440 ◽

Cited By ~ 14

Author(s):

Naoyuki Matsumoto ◽

Akitoshi Tajimi

Keyword(s):

Population Structure ◽

Host Plants ◽

Structure Change ◽

Perennial Grasses ◽

Agricultural Fields ◽

Snow Mold ◽

Vegetative Compatibility Groups ◽

Typhula Ishikariensis ◽

Habitat Differences ◽

Typhula Incarnata

Population structure of Typhula incarnata and Typhula ishikariensis, snow mold fungi, was determined by vegetative incompatibility on agar plates using isolates from 10 sites that differed in the extent of disturbance. Typhula incarnata populations were always diverse, with many different vegetative compatibility groups regardless of habitat differences, whereas diversity of T. ishikariensis populations differed according to habitat. Typhula ishikariensis populations in uncultivated lands were diverse; however, those from agricultural fields planted with perennial grasses became simpler with increasing number of years after the establishment of the host plant community. As a population, isolates from a new habitat were fast growers, less aggressive, and less competitive, and their sclerotia tended to germinate more rapidly than those from an old habitat. Where host plants were annual and the habitat was disturbed annually by tillage, population structure of T. ishikariensis was very simple. These results are discussed in terms of epidemiological differences between the pathogens and the effect of cultivation on population structure change. Key words: Typhula incarnata, Typhula ishikariensis, population structure, disturbance, snow mold fungi.

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3P043 Mutagenesis study of an antifreeze protein isoform from a snow-mold fungus, Typhula ishikariensis(01B. Protein: Structure & Function,Poster,The 52nd Annual Meeting of the Biophysical Society of Japan(BSJ2014))

Seibutsu Butsuri ◽

10.2142/biophys.54.s256_1 ◽

2014 ◽

Vol 54 (supplement1-2) ◽

pp. S256

Author(s):

Jing Cheng ◽

Yuichi Hanada ◽

Hidemasa Kondo ◽

Sakae Tsuda

Keyword(s):

Protein Structure ◽

Structure Function ◽

Annual Meeting ◽

Antifreeze Protein ◽

Snow Mold ◽

Typhula Ishikariensis ◽

Mold Fungus ◽

Biophysical Society ◽

Protein Isoform ◽

Mutagenesis Study

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Resistance to Snow Mold Fungi (Microdochium nivale and Typhula ishikariensis) in Grasses and Cereals

Durability of Disease Resistance - Current Plant Science and Biotechnology in Agriculture ◽

10.1007/978-94-011-2004-3_79 ◽

1993 ◽

pp. 353-353

Author(s):

A. M. Tronsmo

Keyword(s):

Microdochium Nivale ◽

Snow Mold ◽

Typhula Ishikariensis

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The BMP1 Gene Is Essential for Pathogenicity in the Gray Mold Fungus Botrytis cinerea

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2000.13.7.724 ◽

2000 ◽

Vol 13 (7) ◽

pp. 724-732 ◽

Cited By ~ 157

Author(s):

Li Zheng ◽

Mathew Campbell ◽

Jennifer Murphy ◽

Stephen Lam ◽

Jin-Rong Xu

Keyword(s):

Growth Rate ◽

Map Kinase ◽

Botrytis Cinerea ◽

Magnaporthe Grisea ◽

Pathogenic Fungi ◽

Gray Mold ◽

Necrotrophic Pathogen ◽

Kinase Gene ◽

Plant Infection ◽

Mold Fungus

In Magnaporthe grisea, a well-conserved mitogen-activated protein (MAP) kinase gene, PMK1, is essential for fungal pathogenesis. In this study, we tested whether the same MAP kinase is essential for plant infection in the gray mold fungus Botrytis cinerea, a necrotrophic pathogen that employs infection mechanisms different from those of M. grisea. We used a polymerase chain reaction-based approach to isolate MAP kinase homologues from B. cinerea. The Botrytis MAP kinase required for pathogenesis (BMP) MAP kinase gene is highly homologous to the M. grisea PMK1. BMP1 is a single-copy gene. bmp1 gene replacement mutants produced normal conidia and mycelia but were reduced in growth rate on nutrient-rich medium. bmp1 mutants were nonpathogenic on carnation flowers and tomato leaves. Re-introduction of the wild-type BMP1 allele into the bmp1 mutant restored both normal growth rate and pathogenicity. Further studies indicated that conidia from bmp1 mutants germinated on plant surfaces but failed to penetrate and macerate plant tissues. bmp1 mutants also appeared to be defective in infecting through wounds. These results indicated that BMP1 is essential for plant infection in B. cinerea, and this MAP kinase pathway may be widely conserved in pathogenic fungi for regulating infection processes.

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Hydrophobic ice-binding sites confer hyperactivity of an antifreeze protein from a snow mold fungus

Biochemical Journal ◽

10.1042/bcj20160543 ◽

2016 ◽

Vol 473 (21) ◽

pp. 4011-4026 ◽

Cited By ~ 26

Author(s):

Jing Cheng ◽

Yuichi Hanada ◽

Ai Miura ◽

Sakae Tsuda ◽

Hidemasa Kondo

Keyword(s):

Binding Sites ◽

Antifreeze Protein ◽

Protein Isoforms ◽

Snow Mold ◽

Shape Complementarity ◽

Loop Region ◽

Ice Binding ◽

Mold Fungus ◽

Β Sheet ◽

Antifreeze Activity

Snow mold fungus, Typhula ishikariensis, secretes seven antifreeze protein isoforms (denoted TisAFPs) that assist in the survival of the mold under snow cover. Here, the X-ray crystal structure of a hyperactive isoform, TisAFP8, at 1.0 Å resolution is presented. TisAFP8 folds into a right-handed β-helix accompanied with a long α-helix insertion. TisAFP8 exhibited significantly high antifreeze activity that is comparable with other hyperactive AFPs, despite its close structural and sequence similarity with the moderately active isoform TisAFP6. A series of mutations introduced into the putative ice-binding sites (IBSs) in the β-sheet and adjacent loop region reduced antifreeze activity. A double-mutant A20T/A212S, which comprises a hydrophobic patch between the β-sheet and loop region, caused the greatest depression of antifreeze activity of 75%, when compared with that of the wild-type protein. This shows that the loop region is involved in ice binding and hydrophobic residues play crucial functional roles. Additionally, bound waters around the β-sheet and loop region IBSs were organized into an ice-like network and can be divided into two groups that appear to mediate separately TisAFP and ice. The docking model of TisAFP8 with the basal plane via its loop region IBS reveals a better shape complementarity than that of TisAFP6. In conclusion, we present new insights into the ice-binding mechanism of TisAFP8 by showing that a higher hydrophobicity and better shape complementarity of its IBSs, especially the loop region, may render TisAFP8 hyperactive to ice binding.

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Growth response of Norway spruce saplings in two forest gaps in the Swiss Alps to artificial browsing, infection with black snow mold, and competition by ground vegetation

Canadian Journal of Forest Research ◽

10.1139/x06-156 ◽

2006 ◽

Vol 36 (11) ◽

pp. 2782-2793 ◽

Cited By ~ 15

Author(s):

Catherine Cunningham ◽

Niklaus E Zimmermann ◽

Veronika Stoeckli ◽

Harald Bugmann

Keyword(s):

Snow Cover ◽

Norway Spruce ◽

Model Performance ◽

Swiss Alps ◽

Ground Vegetation ◽

Strong Impact ◽

European Alps ◽

Snow Mold ◽

Forest Gaps ◽

Sapling Growth

Black snow mold (Herpotrichia juniperi (Duby) Petr.) infection and browsing byungulates influence the growth of Norway spruce (Picea abies (L.) Karst.) saplings in subalpine forests in the European Alps. To isolate the impacts of artificial browsing (clipping of shoots) and snow mold infection on growth, we conducted a 2 year field experiment with planted saplings in two forest gaps in the subalpine zone of the Swiss Alps. In the first year (2003) saplings responded slightly positively to clipping and negatively to snow mold infection; sapling growth behavior was site-specific (ANOVA, r2 = 0.35). In 2004, saplings responded negatively to clipping, snow mold infection, long-lasting snow cover, and shading by ground vegetation (ANOVA, r2 = 0.59). The difference in mean annual growth rates between noninfected and infected saplings was large; long-lasting snow was found to enhance snow mold coverage. Removing these variables from general linear models strongly reduced model performance (d2 = 0.32 for the full model, d2 = 0.23 for no clipping, d2 = 0.16 for no snow cover). Sapling growth was negatively related to shading by ground vegetation, especially in 2004. We conclude that these biotic factors have a strong impact on growth, both individually and in combination, and that their effect is enhanced by interaction with environmental factors such as snow duration.

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Warming, soil moisture, and loss of snow increase Bromus tectorum’s population growth rate

Elem Sci Anth ◽

10.12952/journal.elementa.000020 ◽

2014 ◽

Vol 2 ◽

Cited By ~ 11

Author(s):

Aldo Compagnoni ◽

Peter B. Adler

Keyword(s):

Growth Rate ◽

Population Growth ◽

Snow Cover ◽

Population Growth Rate ◽

Experimental Manipulation ◽

Direct Effects ◽

Vital Rates ◽

Positive Effects ◽

The North ◽

Increasing Temperature

Abstract Climate change threatens to exacerbate the impacts of invasive species. In temperate ecosystems, direct effects of warming may be compounded by dramatic reductions in winter snow cover. Cheatgrass (Bromus tectorum) is arguably the most destructive biological invader in basins of the North American Intermountain West, and warming could increase its performance through direct effects on demographic rates or through indirect effects mediated by loss of snow. We conducted a two-year experimental manipulation of temperature and snow pack to test whether 1) warming increases cheatgrass population growth rate and 2) reduced snow cover contributes to cheatgrass’ positive response to warming. We used infrared heaters operating continuously to create the warming treatment, but turned heaters on only during snowfalls for the snowmelt treatment. We monitored cheatgrass population growth rate and the vital rates that determine it: emergence, survival and fecundity. Growth rate increased in both warming and snowmelt treatments. The largest increases occurred in warming plots during the wettest year, indicating that the magnitude of response to warming depends on moisture availability. Warming increased both fecundity and survival, especially in the wet year, while snowmelt contributed to the positive effects of warming by increasing survival. Our results indicate that increasing temperature will exacerbate cheatgrass impacts, especially where warming causes large reductions in the depth and duration of snow cover.

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