scholarly journals An Apoplastic Defensin of Wheat Elicits the Production of Extracellular Polysaccharides in Snow Mold

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1607
Author(s):  
Ayako Isobe ◽  
Chikako Kuwabara ◽  
Michiya Koike ◽  
Keita Sutoh ◽  
Kentaro Sasaki ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Antifungal Activity ◽  
Low Temperature ◽  
Microdochium Nivale ◽  
Extracellular Polysaccharides ◽  
Plant Defensin ◽  
Physical Barrier ◽  
Antimicrobial Proteins ◽  
Snow Mold ◽  
Cellulase Treatment

TAD1 (Triticum aestivum defensin 1) is a plant defensin specifically induced by low temperature in winter wheat. In this study, we demonstrated that TAD1 accumulated in the apoplast during cold acclimation and displayed antifungal activity against the pink snow mold fungi Microdochium nivale. When M. nivale was treated with TAD1, Congo red-stainable extracellular polysaccharides (EPS) were produced. The EPS were degradable by cellulase treatment, suggesting the involvement of β-1,4 glucans. Interestingly, when the fungus was treated with FITC-labeled TAD1, fluorescent signals were observed within the EPS layer. Taken together, these results support the hypothesis that the EPS plays a role as a physical barrier against antimicrobial proteins secreted by plants. We anticipate that the findings from our study will have broad impact and will increase our understanding of plant–snow mold interactions under snow.

Production of low temperature active lipase from the pink snow mold, Microdochium nivale (syn. Fusarium nivale)

1996 ◽  
Vol 18 (5) ◽  
pp. 509-510 ◽  
Author(s):  
Tamotsu Hoshino ◽  
Satoru Ohgiya ◽  
Tadayuki Shimanuki ◽  
Kozo Ishizaki
Keyword(s):  
Low Temperature ◽  
Microdochium Nivale ◽  
Snow Mold ◽  
Fusarium Nivale ◽  
Active Lipase

Permeabilization of Fungal Membranes by Plant Defensins Inhibits Fungal Growth

1999 ◽  
Vol 65 (12) ◽  
pp. 5451-5458 ◽  
Author(s):  
Karin Thevissen ◽  
Franky R. G. Terras ◽  
Willem F. Broekaert
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Antifungal Activity ◽  
Raphanus Sativus ◽  
Plasma Membranes ◽  
Fungal Growth ◽  
Membrane Permeabilization ◽  
Plant Defensin ◽  
Sytox Green ◽  
Plant Defensins ◽  
Fungal Growth Inhibition

ABSTRACT We used an assay based on the uptake of SYTOX Green, an organic compound that fluoresces upon interaction with nucleic acids and penetrates cells with compromised plasma membranes, to investigate membrane permeabilization in fungi. Membrane permeabilization induced by plant defensins in Neurospora crassa was biphasic, depending on the plant defensin dose. At high defensin levels (10 to 40 μM), strong permeabilization was detected that could be strongly suppressed by cations in the medium. This permeabilization appears to rely on direct peptide-phospholipid interactions. At lower defensin levels (0.1 to 1 μM), a weaker, but more cation-resistant, permeabilization occurred at concentrations that correlated with the inhibition of fungal growth. Rs-AFP2(Y38G), an inactive variant of the plant defensin Rs-AFP2 from Raphanus sativus, failed to induce cation-resistant permeabilization in N. crassa. Dm-AMP1, a plant defensin from Dahlia merckii, induced cation-resistant membrane permeabilization in yeast (Saccharomyces cerevisiae) which correlated with its antifungal activity. However, Dm-AMP1 could not induce cation-resistant permeabilization in the Dm-AMP1-resistantS. cerevisiae mutant DM1, which has a drastically reduced capacity for binding Dm-AMP1. We think that cation-resistant permeabilization is binding site mediated and linked to the primary cause of fungal growth inhibition induced by plant defensins.

scholarly journals Canopy hyperspectral characteristics and yield estimation of winter wheat (Triticum aestivum) under low temperature injury

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yongkai Xie ◽  
Chao Wang ◽  
Wude Yang ◽  
Meichen Feng ◽  
Xingxing Qiao ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Low Temperature ◽  
Winter Wheat ◽  
Yield Estimation

scholarly journals A recessive gene controlling male sterility sensitive to short daylength/low temperature in wheat (Triticum aestivum L.)

2011 ◽  
Vol 12 (11) ◽  
pp. 943-950 ◽  
Author(s):  
Xiao-dong Chen ◽  
Dong-fa Sun ◽  
De-fu Rong ◽  
Jun-hua Peng ◽  
Cheng-dao Li
Keyword(s):  
Triticum Aestivum ◽  
Low Temperature ◽  
Male Sterility ◽  
Recessive Gene ◽  
Triticum Aestivum L

THE INFLUENCE OF MINERAL NUTRITION ON THE EXPRESSION OF TRAITS ASSOCIATED WITH WINTERHARDINESS OF TWO WINTER WHEAT (Triticum aestivum L.) CULTIVARS

1990 ◽  
Vol 70 (2) ◽  
pp. 443-454 ◽  
Author(s):  
P. RICHARD HETHERINGTON ◽  
BRYAN D. McKERSIE ◽  
LISA C. KEELER
Keyword(s):  
Triticum Aestivum ◽  
Low Temperature ◽  
Moisture Content ◽  
Winter Wheat ◽  
Mineral Nutrition ◽  
Triticum Aestivum L ◽  
Relative Ranking ◽  
Acclimation Period ◽  
Ice Encasement ◽  
Nutrient Solutions

Two winter wheat (Triticum aestivum L.) cultivars, Fredrick and Norstar, which differ in their winterhardiness potential, were compared with regard to the effects of nitrogen (N), phosphorus (P) and potassium (K) application, during acclimation, on the expression of four traits associated with winterhardiness — freezing, ice-encasement, and low temperature flooding tolerances and crown moisture content. Modified Hoagland’s nutrient solutions containing five levels of each nutrient were applied to the seedlings during a 5-wk acclimation period at 2 °C, and subsequently the crowns were tested for their ability to survive varying intensities of the stress treatments. Increasing the level of applied N from 0, caused a reduction in the level of all stress tolerances. Increased P did not significantly alter the expression of freezing tolerance, but tended to increase tolerance of the anaerobic stresses, icing and low temperature flooding, to an optimum. Increased K had minimal effects on stress tolerance at the levels tested. Increased levels of each nutrient increased crown moisture content. The cultivar Norstar was consistently more tolerant of freezing and icing stress than Fredrick and this relative ranking was not influenced by mineral nutrition. However, the relative ranking for low temperature flooding tolerance varied depending on the nutrients provided to the seedlings. The results suggest that environmental and growth regulatory factors which influence the uptake of mineral nutrients would be expected to influence crown moisture content, and the expression of stress tolerance.Key words: Freezing, ice-encasement, flooding

scholarly journals Specific Binding Sites for an Antifungal Plant Defensin from Dahlia (Dahlia merckii) on Fungal Cells Are Required for Antifungal Activity

2000 ◽  
Vol 13 (1) ◽  
pp. 54-61 ◽  
Author(s):  
Karin Thevissen ◽  
Rupert W. Osborn ◽  
David P. Acland ◽  
Willem F. Broekaert
Keyword(s):  
Antifungal Activity ◽  
Plasma Membranes ◽  
Specific Binding ◽  
Plant Defensin ◽  
Wild Type ◽  
Whole Cells ◽  
Specific Binding Sites ◽  
Plant Defensins ◽  
Related Plant ◽  
Wild Type Yeast

Dm-AMP1, an antifungal plant defensin from seeds of dahlia (Dahlia merckii), was radioactively labeled with t-butoxycarbonyl-[35S]-L-methionine N-hydroxy-succinimi-dylester. This procedure yielded a 35S-labeled peptide with unaltered antifungal activity. [35S]Dm-AMP1 was used to assess binding on living cells of the filamentous fungus Neurospora crassa and the unicellular fungus Saccharomyces cerevisiae. Binding of [35S]Dm-AMP1 to fungal cells was saturable and could be competed for by preincubation with excess, unlabeled Dm-AMP1 as well as with Ah-AMP1 and Ct-AMP1, two plant defensins that are highly homologous to Dm-AMP1. In contrast, binding could not be competed for by more distantly related plant defensins or structurally unrelated antimicrobial peptides. Binding of [35S]Dm-AMP1 to either N. crassa or S. cerevisiae cells was apparently irreversible. In addition, whole cells and microsomal membrane fractions from two independently obtained S. cerevisiae mutants selected for resistance to Dm-AMP1 exhibited severely reduced binding affinity for [35S]Dm-AMP1, compared with wild-type yeast. This finding suggests that binding of Dm-AMP1 to S. cerevisiae plasma membranes is required for antifungal activity of this protein.

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