Light-induced formation of fruit-bodies in a basidiomycete, Favolus arcularius (FR.) AMES

fruit-bodies in Favolus arcularius. The effect of light lastedfor about one day after transfer to darkness. The mycelium became sensitive to light about 2.5 days afterinoculation; i.e., at the beginning of the rapid growth phase.The site of fruiting was 2–5 mm inside the edge of colony(actively dividing zone) at the start of illumination. Whenone half of the plate culture was illuminated, fruiting wasrestricted to the illuminated half of the colony ; i.e., theeffect of light was localized. These results suggest that thecells sensitive to light are the actively dividing cells. Under a fixed light intensity, the total irradiation time requiredfor the initiation of fruiting was nearly constant, irrespectiveof the durations of pre-incubation in darkness and the dailyillumination period. With increasing light intensities, up toabout 500 lux, fruiting was promoted, however, a further increasein light intensity was inhibitory. (Received March 27, 1968; )     

Effect of light on the initiation of pileus formation in a basidiomycete, Favolus arcularius

Pileus formation in Favolus arcularius is induced by light,but no photoinduction occurred in young epileate stipes. Thestipes usually had to attain a length of about 5 mm to be photosensitive.Synchronous pileus formation could be induced by exposure tolight using epileate stipes which had been preincubated in darknessfor 48 to 72 hr. The pileus primordium formed about 24 hr afterthe start of illumination, however, continuous illuminationwas not necessary to produce this effect. A dark period givenbetween 1 and 8 hr after the start of illumination did not retardpileus formation. The photoinduction of pileus formation involvedtwo light-requiring processes, one occurring during the firsthour (the first light process) and the other from the 8th tothe 24th hr (the second light process). The photoresponse inthe first light process was saturated with 5 lux of light, buta light intensity below 1 lux was essentially ineffective. Onthe other hand, the reaction in the second light process couldbe started by less than 2 lux, and was accelerated by increasingthe light intensities up to about 150 lux. Further increasesin light intensity did not improve any significant effect. (Received April 30, 1974; )     

Anthranilic Acid,as a Fruiting Body Inducing Substance in Favolus arcularius,from a Strain TA 7 of Actinomycetes

The stereochemical inversion of (R)-5-hydroxymethyl-3-tert-butyl-2-oxazolidinone (la) or (R)-5-hydroxymethyl-3-isopropyl-2-oxazolidinone (lb) to the corresponding (S)-isomer was accomplished via a key intermediate, (R)-3-N-ethoxycarbonyl-N-tert-butylamino-l,2-epoxypropane (5a) or (R)-3-N-ethoxycarbonyl-N-isopropylamino-l,2-epoxypropane (5b), in a high enantiomeric excess. (S)-la (99%e.e.) or (S)-lb (91%e.e.) was thus obtained from the respective (R)-isomer (la; 99%e.e., lb; 95%e.e.).     

Action Spectrum for Light-induced Chloroplast Accumulation in a Marine Coenocytic Green Alga, Bryopsis plumosa

A marine coenocytic green alga, Bryopsis plumosa exhibited multistriatetype protoplasmic streaming of a velocity less than 100 µm.min^–1.When the alga was illuminated locally, chloroplasts and othercell organelles accumulated in the illuminated zone. The actionspectrum for this reaction showed that blue light between 380and 500 nm was most effective. The velocity of chloroplast movement decreased when the cellwas totally illuminated with blue light, but no comparable changewas observed under red light illumination. Therefore, chloroplastaccumulation probably was caused by the reduced streaming ratein the illuminated zone. Electron microscopy showed cytoplasmic microtubules arrangedparallel to the cell axis in the vicinity of the chloroplasts.Chloroplast movement was inhibited heavily by treatment withantimicrotubule agents, but was little affected by cytochalasinB at a concentration of 10 µg/ml. (Received May 30, 1981; Accepted August 24, 1981)     

Action Spectrum for Photosporogenesis in Botrytis cinerea Pers. ex Fr

An action spectrum for photoinduced conidium formation in the fungus Botrytis cinerea Pers. ex Fr. was determined by exposing colonies to monochromatic radiation obtained from a diffraction grating monochromator. Wavelengths longer than 355 nm were ineffective even after exposures of 8 hours at intensities of 4,068 to 8,276 erg per cm² per second. Colonies were exposed at 22.5 C from 226 to 355 nm at about 5 nm intervals. Three prominent peaks of effectiveness occurred at about 231, 268, and 283 nm, and there was also a minor peak at about 303 nm. The most effective wavelength for inducing sporulation was 231 nm; it was 25% more effective than the second most effective wavelength (283 nm).     

Effects of high-temperature treatment on two essential light processes and an intervening dark process in photoinduced pileus primordium formation of a basidiomycete,Favolus arcularius

The photoinduced formation of pileus primordia inFavolus arcularius involves two essential light processes and an inserting dark process. The nature of these elementary proceses in epileate stipes was examined by the use of high temperature under a 1-h light-7-h dark-continuous light regimen. Epileate stipes were exposed to a temperature treatment of 37°C for 15 min after the beginning of pileus primordium formation, which disrupted the photomorphogenetic progress without any after-effects. When high temperature was applied in the first light process or the early phase of the dark process, it completely voided the established career. A temperature-sensitive key dark reaction may have occurred in the period of 0–2 h. When high temperature was applied during the late phase of the dark period, it caused only a delay in pileus primordium, formation, suggesting that the high temperature might only retard the progression of the dark morphogenetic reaction in this period. In addition, the early phase of the second light process was effectively disrupted by the use of high temperature, but sensitivity to high temperature gradually decreased with the progress of pileus differentiation.     

Light-induced Cell Division in Chlorella vulgaris, Beijerinck (Emerson Strain)

The inability of the Emerson strain of Chlorella vulgaris togrow and divide actively in a glucose medium in the dark hasbeen confirmed. It has been shown that although glucose doesnot enhance the rate of cell-division when added to culturesgrowing under saturating photosynthetic conditions, it neverthelessmarkedly increases the growth-rate when supplied to culturesin which photosynthesis is limited by an inadequate CO₂ supply. Transfer of actively growing cultures from light to darknessis followed by a limited period of active cell-division if glucoseis added to the medium; this has been interpreted as indicatingglucose utilization and the synthesis in light only, of somesubstance(s) essential for cell-division. Further evidence forthis view has been obtained from studies of the effect of alight pretreatment on subsequent growth in the dark. With cultures aerated with CO₂-free air, re-exposure to lightafter a period in the dark has been shown to bring about a resumptionof active cell-division accompanied by a decrease in the percentageof ‘giant’ cells in the population. This also suggeststhe participation of some photo-reaction, other than photosynthesis,in the control of active cell-division in this strain of C.vulgaris.     

Action Spectrum of the Activity of Acifluorfen-methyl, a Diphenyl Ether Herbicide, in Chlamydomonas eugametos

Light is required for the herbicide activity of diphenyl ether herbicides. An action spectrum of acifluorfen-methyl activity with Chlamydomonas eugametos (Moewus) determined that cell death occurred at two peaks of light; 450 and 670 nanometers. These data indicate both chlorophyll and carotenoids, but not riboflavin, are involved in herbicide toxicity.     

The Mode of Origin of a Leaf Primordium in the Shoot Apex of the Pea (Pisum sativum)

The movement of carbon-particle markers on the surface of acultured pea apex resembled that previously found for the tomatoapex. In the pea the primordium originated lower down on theside of the apical dome than in the tomato, and its generaldirection of growth was more upright. The results accord wellwith existing data on the rates and directions of cell divisionin the pea apex, and show that the primordium is formed by increasedcell division on the flank of the apex in a growth centre (orregion) analagous to that found in the tomato apex. Becauseof the distichous phyllotaxis of the pea it appears that inlongitudinal section two such growth centres at different stagesare visible, whereas in the tomato, which has spiral leaf arrangement,only one is apparent. It is concluded that, while a change indirection of division inevitably occurs in the primordium asit begins to bulge outwards away from the centre of the apex,its initiation can be traced to a local increase in the rateof division some 2 plastochrons before the bulge is well formed.     

Light-induced modulation of retinal development in the cichlid fish Haplochromis sauvagei (PfefFer, 1896)

Phenotypic modulation is a common feature in haplochromine cichlids. External changes influence the phenotype within the limits set by the genetic program. Retinal development in the cichlid Haplochromis sauvagei has been observed in specimens reared in various chromatic environments and in darkness. Rearing in darkness led to the reduction of photoreceptor densities, the apparent loss of single cones and the enlargement of double cones. To a lesser degree, similar effects were observed in specimens deprived from short-wave light. Ganglion cell densities were not affected by light deprivation. The light-induced alterations could be the result of changes in developmental rates within the retina or of early degeneration. The modulation seems to cause a reduction of blue sensitivity, possibly for the benefit of luminosity or long-wavelength detection. This would agree with the combination of decreased light intensity and a spectral shift towards the longer wavelengths as is the case in the natural environment of the Lake Victorian haplochromines. In that sense, the modulation is probably adaptive.     

Structural analysis of a water-soluble glucan (Fr.I) of an edible mushroom, Pleurotus sajor-caju

A water-soluble glucan was obtained from the fruit bodies of an edible mushroom, Pleurotus sajor-caju, by hot water extraction, ethanol precipitation, dialysis, and Sepharose 6B gel filtration. On the basis of total hydrolysis, methylation analysis, periodate oxidation, and NMR studies ((1)H, (13)C, DQF-COSY, TOCSY, NOESY, and HSQC), the structure of the repeating unit of the glucan is determined as [carbohydrate structure: see text].