Mycochrome system and conidial development in a nonphotoinduced isolate of Helminthosporium oryzae

1978 ◽  
Vol 56 (2) ◽  
pp. 206-208 ◽  
Author(s):  
Saburo Yamamura ◽  
Tadashi Kumagai ◽  
Yoshiharu Oda
Keyword(s):  
Ultraviolet Light ◽  
Blue Light ◽  
Near Ultraviolet ◽  
Aerial Hyphae ◽  
Conidial Development ◽  
Helminthosporium Oryzae ◽  
Effect Of Light

The effect of light on conidial development of a nonphotoinduced isolate of Helminthosporium oryzae was investigated. Near-ultraviolet light was not required for conidiophore induction, but conidial development was suppressed by blue light applied at a definite stage of conidiophore development, and the conidiophores were dedifferentiated into longer, slender aerial hyphae. Furthermore, the effect of blue light could be reversed by immediate exposure to near-ultraviolet light and the effects of these two spectral regions were alternatively reversible.Thus, it is concluded that a photosensitive system, called mycochrome, is involved in the conidial development of this fungus.

scholarly journals A putative transcription factor Gf.BMR1 in Grifola frondosa, the homolog of BMR1 in Bipolaris oryzae, was strongly induced by near-ultraviolet light and blue light

Mycoscience ◽  
2015 ◽  
Vol 56 (2) ◽  
pp. 177-182 ◽  
Author(s):  
Atsushi Kurahashi ◽  
Takafumi Shimoda ◽  
Masayuki Sato ◽  
Fumihiro Fujimori ◽  
Junji Hirama ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Ultraviolet Light ◽  
Blue Light ◽  
Grifola Frondosa ◽  
Bipolaris Oryzae ◽  
Near Ultraviolet ◽  
Putative Transcription Factor

EFFECT OF LIGHT ON GEMMAE FORMATION: IN MYCENA CITRICOLOR

1967 ◽  
Vol 45 (5) ◽  
pp. 675-679 ◽  
Author(s):  
C. J. Rodrigues Jr. ◽  
D. C. Arny
Keyword(s):  
Light Intensity ◽  
Ultraviolet Light ◽  
Exposure Time ◽  
Lesion Size ◽  
Yellow Pigment ◽  
Limited Size ◽  
Maximum Production ◽  
Near Ultraviolet ◽  
Test Conditions ◽  
Effect Of Light

Maximum production of gemmae and yellow pigment by Mycena citricolor occurred under a glass filter which transmitted near ultraviolet light (310–400 mμ) and infrared. Within the limits of test conditions involving four rather broad areas of the spectrum, gemmae formation decreased as wavelength of light increased. Optimum light intensity was between 20 and 160 ft-c. At 740 ft-c the optimum daily exposure time was 6 hours. Infected leaves of Coffee arabicz in the light produced lesions of limited size and having numerous gemmae, but, in the dark, lesion size was indeterminate and no gemmae were formed.

Suppressive effect of preirradiation with blue light on near ultraviolet light induced conidiation in Alternaria tomato

1986 ◽  
Vol 64 (4) ◽  
pp. 896-899 ◽  
Author(s):  
Tadashi Kumagai
Keyword(s):  
Ultraviolet Radiation ◽  
Ultraviolet Light ◽  
Blue Light ◽  
Action Spectrum ◽  
Light Response ◽  
Suppressive Effect ◽  
Ultraviolet Region ◽  
Near Ultraviolet ◽  
Blue Light Response ◽  
A Minor

Conidiophore formation in Alternaria tomato (Cke.) Weber (ATCC 38852) was induced by irradiation with near ultraviolet light, and conidia formed in subsequent darkness. However, blue light applied before the inductive near ultraviolet radiation suppressed the induction. Preirradiation with blue light just before the inductive near ultraviolet radiation was most suppressive. An action spectrum for this suppression showed a peak around 447 nm, with a shoulder between 400 and 440 nm, a minor peak around 478 nm in the blue region, and another near 385 nm in the near ultraviolet region. This action spectrum is very similar to the ubiquitous blue light response (cryptochrome).

Sporulation in Alternaria cichorii is controlled by a blue and near ultraviolet reversible photoreaction

1981 ◽  
Vol 59 (5) ◽  
pp. 626-628 ◽  
Author(s):  
Demetrios J. Vakalounakis ◽  
Christos Christias
Keyword(s):  
Ultraviolet Light ◽  
Blue Light ◽  
Strong Evidence ◽  
Ultraviolet Irradiation ◽  
Inhibitory Action ◽  
Near Ultraviolet ◽  
Pigment System ◽  
Subsequent Exposure ◽  
Reversible Photoreaction

Sporulation in Alternaria cichorii Nattrass was induced by near ultraviolet irradiation (< 340 nm) and inhibited by blue light. The inhibitory action of blue light could be reversed by near ultraviolet irradiation. Induction by near ultraviolet could be annulled by subsequent exposure to blue light. Sporulation during a sequential exposure to blue–near ultraviolet light was always determined by the quality of the last irradiation applied. A series of alternating doses of blue–near ultraviolet light ending in near ultraviolet promoted sporulation whereas a series ending in blue light inhibited sporulation. This is considered strong evidence for the existence of an interconvertible pigment system absorbing at the blue and near ultraviolet regions of the spectrum which controls sporulation in A. cichorii.

THE SPORULATION OF HELMINTHOSPORIUM ORYZAE AS AFFECTED BY EXPOSURE TO NEAR ULTRAVIOLET RADIATION AND DARK PERIODS

1961 ◽  
Vol 39 (3) ◽  
pp. 705-715 ◽  
Author(s):  
Charles M. Leach
Keyword(s):  
Ultraviolet Radiation ◽  
Dark Period ◽  
Extended Period ◽  
Dry Weight ◽  
Single Cycle ◽  
Continuous Darkness ◽  
Continuous Irradiation ◽  
Near Ultraviolet ◽  
Conidial Development ◽  
Helminthosporium Oryzae

Investigated was the interrelation of near ultraviolet radiation (3100–4000 Å) and darkness to the sporulation of Helminthosporium oryzae. When H. oryzae was grown on potato dextrose agar at 70–75° F and irradiated at intensities of 76–470 μw per cm2: (1) Near ultraviolet stimulated sporulation while visible light did not. (2) Conidiophore development was initiated under irradiation but not in darkness. Both continuous irradiation and intermittent irradiation (2-hour ultraviolet, 2-hour dark cycle) caused formation of conidiophores. (3) Conidia developed only when a period of irradiation was followed by a period of darkness. No conidia developed under continuous irradiation or in continuous darkness. (4) Under a single cycle treatment, the minimum dark period necessary for conidial development following an extended period of continuous irradiation was [Formula: see text] hours. (5) Under a single cycle treatment, the minimum exposure to ultraviolet followed by an extended dark period necessary to cause moderate to profuse conidial development was 4 hours, although conidia did form sparsely after shorter exposures. (6) Under alternating cycles of dark and irradiation of 2, 4, 6, 8, and 12 hours (e.g. 2 hours dark, 2 hours ultraviolet, etc.), conidia developed under the 8- and 12-hour cycles, but not under the shorter cycles. Conidia developed under shorter cycles when the cyclical exposures were followed by a dark period of 12 hours. (7) Continuous irradiation of nutrient broth cultures caused a significant increase in dry weight growth over cultures kept in darkness.

A novel near-ultraviolet-light excitable Eu3+-doped Sr2LaTaO6 red phosphor for white-light-emitting diodes

Optik ◽  
2021 ◽  
Vol 240 ◽  
pp. 166908
Author(s):  
Qifeng Tang ◽  
Tao Yang ◽  
Haifeng Huang ◽  
Jinqing Ao ◽  
Biyou Peng ◽  
...  
Keyword(s):  
Ultraviolet Light ◽  
White Light ◽  
Light Emitting Diodes ◽  
Red Phosphor ◽  
Light Emitting ◽  
Near Ultraviolet ◽  
White Light Emitting Diodes

Nerve autofluorescence in near-ultraviolet light markedly enhances nerve visualization in vivo

2021 ◽  
Author(s):  
Fernando Dip ◽  
Pedro Bregoli ◽  
Jorge Falco ◽  
Kevin P. White ◽  
Raúl J. Rosenthal
Keyword(s):  
Ultraviolet Light ◽  
Near Ultraviolet
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