Control of basidiospore production by a nuclear gene in the fungus Coprinus congregatus

Summary The genetical control of basidiospore production by sporophores of the fungus Coprinus congregatus was studied. This species is characterized by a bipolar compatibility control, and homokaryons with complementary alleles A1 and A2 can be distinguished apart. We confirmed that the pale mushroom phenotype of the fungus is determined by a nuclear gene symbolized pal. This gene also controls a sporeless character and segregates independently of the mating-type locus. Dikaryons homoallelic for the pal ^– allele produce typical pale and sporeless sporophores, while heteroallelic (pal ⁺, pal ^–) and homoallelic (pal ⁺, pal ⁺) dikaryons produce normal or almost normal sporulating sporophores. In order to segregate homokaryons homoallelic for the pal gene (A1, pal ^–; A1, pal ⁺, A2, pal ^–; A2, pal ⁺), the following protocols were used: (a) the dikaryotization of stock homokaryons containing the pal ⁺ allele and of each mating type, A1 or A2, by dikaryotic mycelia homoallelic for the pal ^– allele; (b) the culturing of homokaryotic mycelia issuing from the germination of basidiospores from sporophores produced by dikaryotic mycelia heterokaryotic for the pal gene; (c) the culturing of mycelia grown from protoplasts obtained from dikaryons homoallelic for the pal ^– allele (D6 strain), and from homokaryons heteroallelic for the pal gene (H8), or homoallelic for pal ^#x002B;+ allele (H7). These techniques enabled us to segregate homokaryons of the four types defined above and were indispensable in the segregation of the pal ^– homoallelic homokaryons as no basidiospores were produced by typical pale mushrooms.     

Photoperiodic response of Coprinus congregatus: Effects of light breaks on fruiting

Light initiated fruit-body primordia of Coprinus congregatus Bull, ex Fr. were subjected to different dark periods (4 h to 24 h) and exposed to short blue light pulses at different times. The light break inhibited the development of primordia as did continuous light. The time of maximum sensitivity to a light break was dependent on the duration of the dark period. A short light break imposed two-thirds of the way through the dark period produced strong inhibition of fruiting. The higher the temperature during the dark period, the lower the irradiance required for 50% inhibition of fruiting at the time of maximal sensitivity. During a very long dark period (48 h) a light break was no longer inhibitory. The light break fulfilled the light requirement for normal morphogenesis and defined the time the fruit-bodies sporulated.     

Sequential production of enzymes and basidiospore formation in fruiting bodies of Coprinus macrorhizus

The production of NADP-dependent glutamate dehydrogenase was initiated at the stage of first meiotic prophase in pileus cells but not in stipe cells of dikaryotic and monokaryotic fruiting bodies in Coprinus macrorhizus. The production of chitinase and glucanases assayed with laminarin and lichenan was observed after the completion of meiosis only in pileus cells. The light conditions that were effective for the delay or inhibition of cellular events in the pileus cells were also effective for the delay or inhibition of enzyme production. But all sporeless mutants tested, which were defective at the various stages of basidiospore formation, produced the normal levels of these enzymes. The results indicate that the sequential production of enzymes and cellular events leading to basidiospore formation in pileus cells are independent from each other.Abbreviation GDH_NADP NADP-dependent glutamate dehydrogenase     

Photosporogenesis of Coprinus congregatus: Correlations between the physiological age of lamellae and the development of their potential for renewed fruiting

When the hymenial lamellae of Coprinus congregatus Bull ex Fr. are used as implants, their potential for renewed fruiting varies according to the photocontrolled meiosis and the consecutive sporogenesis. In the case of young lamellae, whose basidia are still at the dikaryon stage, one can observe immediate start of mycelial growth all around the lamellae and production of the first mature sporophores directly on the lamellae (direct fruiting). Simultaneously, meiosis does not occur in hymenial cells. Conversely, in the case of implantation of the oldest lamellae, whose basidia are characterized by meiotic nuclei beyond prophase 1 and rather near telophase 2 (tetranucleate stage), vegetative growth starts slowly and the first mature sporophores are not produced on the lamellae but on the surrounding vegetative mycelium (indirect fruiting). When the lamellae are isolated from photoindifferent primordia – for instance, 12 h before maturity – sporogenesis in hymenial cells proceeds normally until autolysis of the isolated lamellae. Such isolated lamellae no longer show direct fruiting where the first flush is concerned.     

Improved fruiting of Coprinus atramentarius using cold-shock treatment during growth

Coprinus atramentarius was grown on two commercial composts at a constant 20°C or with a cold shock (25°C20°C) after 10 days. Cold shock was required for it to form fruiting bodies.The authors are with the University of Western Sydney, Hawkesbury, School of Horticulture, Locked Bag 1, Richmond NSW 2753, Australia     

Action spectrum for the blue-light-dependent morphogenesis of hair whorls in Acetabularia mediterranea

In young Acetabularia mediterranea Lamouroux (=A. acetabulum (L.) Silva) the formation of the lateral hair whorls can be induced by a short pulse of blue light after continuous red preillumination. In this paper we describe the experimental conditions for optimum response and the properties of the action spectrum. The probit of the cells which eventually form hair whorls is linearly correlated to the logarithm of the incident quanta of blue light. Parallel fluence-response curves for all wavelengths indicate the involvement of only one photoreceptor pigment. The action spectrum shows no effectiveness of wavelengths above 520 nm, a high action peak at 470 nm and two lower ones at 425 and 370 nm, and is in accordance with those of cryptochrome-like photoreceptors.     

Basidiospore formation in monokaryotic fruiting bodies of a mutant strain of Coprinus macrorhizus

The process of basidiospore formation in a mutant strain Fis^c of Coprinus macrorhizus, a heterothallic species of Basidiomycete, which forms monokaryotic fruiting bodies was examined. A single nucleus in a young basidium divided mitotically and two daughter nuclei were fused subsequently. The fused nucleus then divided meiotically forming four basidiospores on a basidium. The typical chromosome behaviours in the first meiotic prophase were observed. Synaptonemal complexes were observed in a basidium at the first meiotic prophase. A continuous illumination of fruiting bodies was effective to arrest meiosis in monokaryotic fruiting bodies at the particular stage of meiotic division.     

Action spectra for phototaxis in zoospores of the brown algaPseudochorda gracilis

Summary Action spectra for phototaxis in zoospores of brown alga,Pseudochorda gracilis (Laminariales), were examined in the wavelength range between 300 and 600 nm using the Okazaki Large Spectrograph and a video tracking system. The direction of swimming (both in percent cells swimming in parallel with the stimulating light, and in mean angle of cell movement) was dependent on the wavelength. The action spectra had two peaks at 420 and 460 nm, while light above 500 nm was not effective in changing the swimming direction of the cells.Abbreviations TCMA tracker-cell movement analyzer system - CMA cell movement analyzer program     

Action spectra for the light inhibition of flowering and its reversal inLemna paucicostata T-101

Lemna paucicostata Hegelm. T-101, a short-day plant, flowers when plants preirradiated with red light (R) for 24 h are subjected to inductive darkness for 72 h followed by two short-day cycles (6 h R+ 18 h dark). However, flowering is inhibited by blue-or far-red-light pulses applied at the beginning of the inductive dark period. These inhibitory light effects are fully reversible by a R pulse. The action spectra for the inhibitory light effect and for its reversal show that the light pulses act exclusively through phytochrome. It is concluded that a low level of Pfr at the beginning of the inductive dark period prevents flowering.Abbreviations R red (light) - B blue (light) - FR far-red (light)     

Action spectra of the light-growth response of Phycomyces

The light-growth response of Phycomyces blakesleeanus (Burgeff) is a transient change in elongation rate of the sporangiophore caused by a change in light intensity. Previous investigators have found that the light-growth response has many features in common with phototropism; the major difference is that only the light-growth response is adaptive. In order to better understand the light-growth response and its relationship to phototropism, we have developed a novel experimental protocol for determining light-growth-response action spectra and have examined the effect of the reference wavelength and intensity on the shape of the action spectrum. The null-point action spectrum obtained with broadband-blue reference light has a small peak near 400 nm, a flat region from 430 nm to 470 nm, and an approximately linear decline in the logarithm of relative effectiveness above 490 nm. The shape of the action spectrum is different when 450-nm reference light is used, as has been shown previously for the phototropic-balance action spectrum. However, the action spectrum of the light-growth response differs from that for phototropic balance, even when the same reference light (450 nm) is used. Moreover, for the light-growth response, the relative effectiveness of 383-nm light decreases as the intensity of the 450-nm reference light increases; this trend is the opposite of that previously found for phototropic balance. The dependence of the lightgrowth-response action spectrum on the reference wavelength, its difference from the phototropic-balance action spectrum, and the reference-intensity dependence of the relative effectiveness at 383 nm may be attributable to dichroic effects of the oriented photoreceptor(s), and to transduction processes that are unique to the light-growth response.I dedicated to Masaki Furuya on the occasion of his 65th birthdayThis work was supported by a grant from the National Institutes of Health (GM29707) to E.D. Lipson. Anuradha Palit, Promod Pratap, and Benjamin Horwitz participated in the early phases of this work. We thank Leonid Fukshansky and Benjamin Horwitz for helpful discussions, David Durant for computer programming, and Steven Block for providing us with a C-language program of Reinsch's procedure for cubic spline interpolation. One of us (R.S.) gratefully acknowledges a junior faculty fellowship leave from the Department of Physics at Yale University.     

Action spectra for photosynthetic adaptation in Scenedesmus obliquus

Photosynthetic adaptation of the unicellular green alga Scenedemus obliquus to different light conditions was investigated with respect to chlorophyll synthesis. Cultures were grown under white light (20 W · m^–2) from fluorescent lamps and were then transferred and subjected to the actual adaptation regime which consisted of a 24-h irradiation by different fluence rates and wavelengths. Fluence rate-response curves for chlorophyll synthesis were measured between 4 · 10^–2 and 1 · 10² W · m^–2. In white light from incandescent lamps, in blue and red light the fluence rate-response curves for chlorophyll (Chl) a and also for Chl b were bell-shaped. In red light the threshold was about the same as under blue light. The maximal amounts of Chl a and b were about twofold increased under blue light relative to the values obtained with red light. Action spectra for the stimulation of chlorophyll synthesis (Chl a + Chl b) as well as those for the separate chlorophylls showed two maxima near 450 and 500 nm. However, the action spectrum for Chl b synthesis demonstrated a considerably higher value in the 450-nm peak. Experiments with the photosynthesis inhibitor 3-(3,4-dichlorphenyl)-1,1-dimethylurea (DCMU) indicated that photosynthetic energy supply supported the photostimulation of chlorophyll synthesis. The action spectra indicate the cooperation of two photoreceptors. The 460-nm peak is attributed to the typical blue-light receptor, being more active in Chl b formation. The peak at 500 nm may represent carotenoproteins acting as an accessory pigment system.Abbreviations PCV packed cell volume - Chl total amount of chlorophyll - Chl a, b chlorophyll a, b - DCMU 3-(3,4-dichlorphenyl)-1,1-dimethylurea This project was supported by the Deutsche Forschungsgemeinschaft. We thank Ms. K. Bölte for technical assistance.     

Action spectra for light-induced germination in dormant lettuce seeds

Fluence response curves for red light-induced germination of thermodormant (TD) seeds of Lactuca sativa L. show two regions that differ in their light sensitivity. In the region of high sensitivity, the germination responses differ between seed batches and can be altered by dark storage or far red irradiation. Induction of germination in far red dormant (FRD) seeds requires far higher fluences. Action spectra for induction to 60% germination were determined for these various response types. Spectra for the regions of low sensitivity response are similar for TD and FRD seeds. In comparison, the action spectrum for the highly sensitive response in TD seeds is significantly shifted to longer wavelengths. Analogous differences exist in the action spectra for far red reversal of the red induced germination responses. Germination induction in the low sensitivity region shows repeated red-far red reversibility. Far red reversal of red induction in the high sensitivity region does not saturate even at the highest far red fluences available and requires increased red fluences for subsequent reinduction. A model quantitatively accounting for these observations is presented. It is pointed out that action spectra of processes involving photoreversible pigments with partly overlapping absorption spectra in general are not identical with the absorption spectra of the partners. They should depend upon the degree of phototransformation required to elicit a given physiological response. In the case of induction of lettuce seed germination the observed action spectra can be interpreted as reflecting different requirements for P _fr of the various response types. Our results do not necessitate the assumption of spectroscopically different forms of phytochrome in these seeds.Abbreviations TD thermodormant - FRD far red dormant - P phytochrome - P _r red absorbing form of P - P _fr far red absorbing form of P     

A distinctive phenotype in the common-<Emphasis Type="Italic">A</Emphasis> heterokaryon of <Emphasis Type="Italic">Coprinus cinereus</Emphasis>

The homobasidiomycete Coprinus cinereus, unlike Schizophyllum commune, is not known to exhibit an obvious heterokaryotic phenotype in common-A matings. In the present study we found that progeny isolated from a fruit-body collected in the field exhibit a distinctive mycelial development in common-A matings. Genetic analysis suggested that the common-A heterokaryotic phenotype is brought about by a nuclear factor(s) other than the mating type genes. Received: March 30, 2001 / Accepted: October 1, 2001     

Action spectra of the light-growth response in three behavioral mutants of Phycomyces

Null-point action spectra of the light-growth response were measured for three mutants of Phycomyces blakesleeanus (Burgeff) and compared with the action spectrum of the wild type (WT). The action spectrum for L150, a recently isolated night-blind mutant, differs from the WT spectrum. The L150 action spectrum has a depression near 450 nm and small alterations in its long-wavelength cutoff, the same spectral regions where its photogravitropism action spectrum is altered. This indicates that the affected gene product influences both phototropism and the light-growth response. For L85, a hypertropic (madH) mutant, the light-growth-response action spectrum is very similar to that of WT even though the photogravitropism action spectrum of L85 has been shown previously to be altered in the near-UV region. The affected gene product in this mutant appears to affect phototropic transduction but not light-growth-response transduction. The action spectrum of C110, a stiff (madE) mutant, differs significantly from the WT spectrum near 500 nm, the same spectral region where sporangiophores of madE mutants have been shown to have small alterations in second-derivative absorption spectra. This indicates that the madE gene product may be physically associated with a photoreceptor complex, as predicted by system-analysis studies.Abbreviations SE standard error of the mean - UV ultraviolet light - Wt wild type I dedicated to Masaki Furuya on the occasion of his 65th birthdayWe thank H. Reiner Schaefer for performing some of the experiments and for help in data analysis, David Durant for computer programming, and Benjamin Horwitz for helpful discussions. This work was supported by a grant from the National Institutes of Health (GM29707) to E.D. Lipson.     

Segregation of genetic markers in the two-spored secondarily homothallic basidiomycete Coprinus bilanatus

Summary Secondarily homothallic basidiomycetes, of which the cultivated mushroom Agaricus bisporus is an example, produce both self-fertile and non self-fertile spores. The random migration of nuclei from the basidia to give binucleate spores provides the simplest explanation for the regulation of breeding behaviour in this group of fungi. To test the predictions of the random migration hypothesis, the segregation of mating-type, auxotrophy and antimetabolite resistance has been determined in the secondarily homothallic ink-cap fungus, Coprinus bilanatus. In 41 of a total of 56 spore progenies tested, the segregation ratios conformed to the predictions of the random migration hypothesis. Poor fits to the predicted ratios were, in many instances, associated with an adenine auxotrophy. On the basis of the data reported, random migration can be regarded as the primary control of secondary homothallism.     

Secretional expression of a Bacillus subtilis xylanase gene in the Basidiomycete Coprinus cinereus

The Bacillus subtilis endo (β-1,4-) D-xylanase structural gene (xyn) was trimmed away from its signal sequence and then fused after the signal sequence of the basidiomycete Pleurotus ostreatus manganese(II) peroxidase cDNA. The resulting modified gene (xyn′) was inserted between the promoter and terminator of two chromosome-integrating, heterologous protein expression vectors. These recombinant plasmids were introduced into protoplasts of the monokaryotic Coprinus cinereus trp1 strain with the C. cinereus TRP1-containing plasmid. One Trp⁺ Xyn⁺ transformant for each of the recombinant plasmids was obtained, which showed a markedly high xylan-degrading activity as compared with the control Trp⁺ transformant.     

毛头鬼伞子实体化学成分及抗糖尿病活性初探

从毛头鬼伞子实体中萃取得到乙醇、乙酸乙酯、石油醚3种有机提取物,采用α-葡萄糖苷酶活性抑制实验对3种有机提取物的抗糖尿病活性进行评价,结果显示,乙酸乙酯提取物对α-葡萄糖苷酶有较强的抑制活性。采用柱层析技术从乙酸乙酯提取物中分离纯化出10种化合物,经核磁等方法鉴定为：（1）顺,顺-9,12-十八(碳)二烯酸;（2）顺式-9-十八烯酸;（3）(22E,24R)-麦角甾烷-5,7,22-三烯-3β醇;（4）3β-5α-6α-22E-麦角甾-7,22-双烯-3,5,6-三醇-6-亚油酸酯;（5）3β-5α-6α-22E-麦角甾-7,22-双烯-3,5,6-三醇-6-油酸酯;（6）邻苯二甲酸二异丁酯;（7）对羟基苯乙醇;（8）4-羟基苯乙基乙酸酯;（9）3-(4-羟基-3-甲氧苯基)败脂酸;（10）N-反式-3,4亚甲二氧基肉桂酰基-3-甲氧基酪胺。对分离化合物的α-葡萄糖苷酶活性抑制实验结果显示,N-反式-3,4亚甲二氧基肉桂酰基-3-甲氧基酪胺对α-葡萄糖苷酶具有较强的抑制活性,其IC₅₀值为4.17mg/mL。     

Action spectra for the photoperiodic control of polymorphism in the aphid Megoura viciae

Energy compensated action spectra are given for the photoperiodic control of polymorphism in Megoura. The production of ‘long day’ parthenogenetic virginoparae and ‘short day’ oviparae mainly depend on the night length. Light has three different effects. ‘Early’ interruptions of the dark phase in a long night cycle reverse the time-measuring dark response. The action spectrum for a 1 hr interruption placed 1.5 hr after the onset of darkness (during dark stage 1) shows a relatively narrow band of activity, mainly in the blue (450–470 nm). The threshold is ca. 0.25 μW cm^?2. ‘Late’ interruptions placed 7.5 or 8 hr after dark hour 0 (during dark stage 3) strongly promote the production of virginoparae without causing a reversal of the response. The action spectrum has the same blue maximum but sensitivity extends into the yellow and red spectral regions. The third photosensitive component, the main photoperiod itself, is required for initiating the dark timing response and has an intermediate action spectrum. Time/intensity curves for a single wavelength (471 nm) show that the responses during stages 1 and 3 depart markedly from reciprocity. Short durations cannot be compensated by high intensities. The shape of the reciprocity curve for an ‘early’ interruption suggests that the stage 1 response is complete after ca. 1.25 hr.The action spectra are believed to be compatible with the view that the photoreceptor is a caroteno-protein. It is suggested that all three pigment forms are related and that time measurement is largely a function of spontaneous ‘dark reaction’ changes in the pigment system. Stage 1 may represent the reversible conjugation phase of the protein/chromophore moieties. In Stage 2 the pigment is presumably photorefractory and is transitional to the highly sensitive broad spectrum form of stage 3.     

Photomorphogenesis inPhycomyces: Fluence-response curves and action spectra

Blue light regulates vegetative reproduction inPhycomyces blakesleeanus Bgff. by inhibiting the development of microphores and stimulating that of macrophores. Fluence-response curves were obtained at twelve different wavelengths. Each response exhibits a two-step (biphasic) dependence on fluence, as if it resulted from the addition of two separate components with different thresholds, midpoints, and amplitudes. The absolute threshold is close to 10 photons·m². The threshold fluence of the low-intensity component is about 10⁴ times smaller than that of the high-intensity component. The action spectra for each of the two components of the two responses share general similarities, but exhibit significant differences that might be taken to favour four separate photosystems. Additional complexity is indicated by the wavelength dependence of the saturation levels.     

Molecular characterization,relatedness and antifungal susceptibility of the basidiomycetous hormographiella species and Coprinus cinereus from clinical and environmental sources

Hormographiella-like strains, isolated from different natural substrates and producing sclerotia and occasionally basidiomata of Coprinus cinereus, were compared morphologically and using molecular techniques with clinical strains of Hormographiella aspergillata and H. verticillata. Analysis of restriction fragment length polymorphisms of ribosomal and mitochondrial-like DNA confirmed interspecific differences between H. aspergillata and H. verticillata, supporting the morphological data, and helped demonstrate that H. aspergillata is the anamorph of C. cinereus. The latter was confirmed also by crossing tests. The analysis of the mtDNA restriction profiles revealed intraspecific variability in C. cinereus, which allowed differentiation of clinical and environmental strains. Due to the implication of C. cinereus and Hormographiella in human opportunistic infections, the antifungal susceptibility test is included. Results show that all strains were susceptible to miconazole, itraconazole and ketoconazole but not to flucytosine and fluconazol. Susceptibility against amphotericin B was variable; while H. verticillata was susceptible, four out of seven C. cinereus strains tested were resistant.