Cytological studies of early stages of powdery mildew in barley and wheat. IX. Effect of various inorganic salts on the occurrence of autofluorescence at penetration sites of appressoria of Erysiphe graminis hordei

1983 ◽  
Vol 61 (8) ◽  
pp. 2181-2185 ◽  
Author(s):  
H. Kunoh ◽  
K. Yamamori ◽  
H. Ishizaki
Keyword(s):  
Powdery Mildew ◽  
Fluorescence Microscopy ◽  
Ethylenediaminetetraacetic Acid ◽  
Divalent Cations ◽  
Erysiphe Graminis ◽  
Inorganic Salts ◽  
Monovalent Cations ◽  
Enhanced Fluorescence ◽  
Enhancing Effect ◽  
Erysiphe Graminis Hordei

The effect of various inorganic salts on the occurrence of autofluorescence at penetration sites of appressoria of Erysiphe graminis hordei in barley coleoptiles was examined by fluorescence microscopy. Divalent cations such as Ca2+, Mg2+, and Mn2+ enhanced fluorescence to varying degrees. Among them, Ca2+ had the greatest enhancing effect; intense fluorescence occurred around penetration sites within 10 min after the inoculated coleoptiles were transferred from water to CaCl2 solution. However, other divalent cations such as Zn2+ and Fe2+ showed cytotoxicity to coleoptiles and did not elicit fluorescence. Monovalent cations such as K+, Na+, and Li+ did not show any enhancing effect independently. Anions seemed to be associated with enhancement of the flurorescence in combination with their related divalent cations but not independently. An observed elimination of fluorescence by ethylenediaminetetraacetic acid suggests that the enhancing effect of some of the divalent cations may be associated with their interaction with a substance(s) which fluoresces only in combination with these cations.

Cytological studies of early stages of powdery mildew in barley and wheat. V. Effects of calcium on the infection of coleoptiles of barley by Erysiphe graminis hordei

1978 ◽  
Vol 56 (20) ◽  
pp. 2544-2549 ◽  
Author(s):  
Susumu Takamatsu ◽  
Hiroshi Ishizaki ◽  
Hitoshi Kunoh
Keyword(s):  
Powdery Mildew ◽  
Calcium Chloride ◽  
Calcium Nitrate ◽  
Infection Process ◽  
Erysiphe Graminis ◽  
Calcium Salts ◽  
Early Stages ◽  
Erysiphe Graminis Hordei ◽  
The Times ◽  
Chloride Treatment

Some effects of calcium salts on the infection process of Erysiphe graminis hordei in coleoptiles of barley were investigated. Calcium chloride enhanced the incidence of haustoria but depressed that of papillae. Calcium bromide and calcium nitrate likewise enhanced the incidence of haustoria. Calcium chloride treatment at varied times and with varied durations during incubation after inoculation showed that events occurring in coleoptiles between 9 and 13 h after inoculation were most affected by the treatment. This period included the times that appressoria matured, cytoplasm aggregated, papillae were produced, and haustoria were formed, and the effect of calcium might be associated with one or more of these events.

Cytological studies of early stages of powdery mildew in barley and wheat. VI. Antagonistic effects of calcium and lithium on the infection of coleoptiles of barley by Erysiphe graminis hordei

1979 ◽  
Vol 57 (4) ◽  
pp. 408-412 ◽  
Author(s):  
S. Takamatsu ◽  
H. Ishizaki ◽  
H. Kunoh
Keyword(s):  
Powdery Mildew ◽  
Binding Site ◽  
Calcium Chloride ◽  
Lithium Chloride ◽  
Calcium Ions ◽  
Infection Process ◽  
Erysiphe Graminis ◽  
Antagonistic Effects ◽  
Early Stages ◽  
Erysiphe Graminis Hordei

Earlier researchers have shown that the susceptibility of barley to infection by Erysiphe graminis hordei is enhanced by calcium ions but inhibited by lithium. Some effects of these ions on the infection process of E. graminis hordei in coleoptiles of barley were investigated in this study. Whereas 1 mM lithium chloride inhibited appressorial formation considerably and haustorial formation completely, these effects were totally offset by 10 mM calcium chloride. Moreover, whereas 5 and 10 mM lithium chloride inhibited both appressorial and haustorial formation completely, the former was offset considerably by 10 mM calcium chloride, but the latter was not.Sequential calcium chloride − lithium chloride or lithium chloride − calcium chloride treatments carried out at different times and for various durations showed that events occurring in coleoptiles 11 to 13 h after inoculation were most vulnerable to the treatments. These events correspond to infection stages involving the development of cytoplasmic aggregates, papillae, and haustoria. The data suggest that the two ions in question might compete for a common binding site in a reaction(s) associated with certain stages of appressorial and haustorial development.

Cytological studies of the early stages of powdery mildew in barley and wheat. XI. Autofluorescence and haloes at penetration sites of appressoria of Erysiphe graminis hordei and Erysiphe pisi on barley coleoptiles

1985 ◽  
Vol 63 (9) ◽  
pp. 1535-1539 ◽  
Author(s):  
H. Kunoh ◽  
K. Kuno ◽  
H. Ishizaki
Keyword(s):  
Host Cell ◽  
Cell Walls ◽  
Time Course ◽  
Divalent Cations ◽  
Erysiphe Graminis ◽  
Erysiphe Pisi ◽  
Acid Dyes ◽  
Erysiphe Graminis Hordei ◽  
Barley Leaves

Cytological and physiological comparisons between autofluorescence and haloes which appeared at penetration sites of appressoria of Erysiphe graminis and Erysiphe pisi on barley coleoptiles were made using dye stains and fluorescence microscopy. Haloes induced by these fungi on barley coleoptiles were successfully detected by various dyes when the inoculated coleoptiles were treated with 70% ethanol at 80 °C for 30 min before staining. Responses of haloes on coleoptiles to basic and acid dyes were very similar to those on barley leaves which have been reported earlier. In time-course studies, haloes were not detected until at least 15 min after initiation of cytoplasmic aggregation. The occurrence of haloes was suppressed by supplemental Ca2+, but unaffected by K+, Na+, and Li+. Similar results were obtained in haloes induced by both fungi. Autofluorescent regions remained in situ after the inoculated coleoptile cells were plasmolyzed, suggesting that this phenomenon might be closely associated with host cell walls. As reported earlier, autofluorescence preceded the appearance of cytoplasmic aggregates by 1–10 min and, moreover, its appearance was enhanced by divalent cations such as Ca2+, Mg2+, and Mn2+, but not by monovalent cations such as K+, Na+, and Li+. Based on these results and earlier studies, it was concluded that the autofluorescence and haloes represented different responses in host cell walls to the penetration activities of both pathogenic and nonpathogenic fungi.

Nuclear movement in Erysiphe graminis hordei

1972 ◽  
Vol 18 (8) ◽  
pp. 1333-1336 ◽  
Author(s):  
W. E. McKeen
Keyword(s):  
Powdery Mildew ◽  
Cytoplasmic Streaming ◽  
Erysiphe Graminis ◽  
Nuclear Movement ◽  
Nuclear Membranes ◽  
Erysiphe Graminis Hordei

The nucleus in the powdery mildew cell may move before, during, and after division. Sometimes the nucleus was surrounded by several membranes and sometimes microtubules which originated in the spindle plaque and fanned out into the cytoplasm. Long straight or undulating strands, about 0.5–1 μ, in width and many microns in length composed of microtubules or laminated membranes, were observed in Erysiphe graminis cells in which nuclei move, but were not observed in conidia, where nuclei remain stationary. The end of the strand, sometimes, was attached to the nuclear membranes, and other times extended past the nucleus. It is postulated that the strands, astral microtubules, and spindle plaques are associated with controlled nuclear movement which is independent of cytoplasmic streaming.

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