Effect of lignin-derived phenolic monomers on the growth of the edible mushrooms Lentinus edodes,Pleurotus sajor-caju and Volvariella volvacea

Pleurotus sajor-caju was generally more tolerant to lignin-related phenolic monomers and tannin derivatives than Lentinus edodes and the straw mushroom, Volvariella volvacea. Several phenols, at up to 5 mM, enhanced mycelial growth of P. sajor-caju. No clear pattern was evident when the effects of phenols and tannins on the growth of V. volvacea and L. edodes were compared, but the lower concentrations of 4-hydroxybenzaldehyde and vanillin which were tested were markedly more toxic to the straw mushroom. The distribution of phenolic monomers and tannin derivatives in the agricultural wastes used for mushroom cultivation may be an important growth determinant. However, the differences in the growth inhibition profiles of L. edodes, P. sajor-caju and V. volvacea suggest that, alone, the effect of these compounds on fungal growth is unlikely to account for the varying abilities of the three mushroom species to grow and fruit on a particular lignocellulosic substrate.     

草菇VvLaeA调控球孢白僵菌的生长发育

食用真菌草菇[Volvariella volvacea(Bull.ex.Fr.)Sing.]VvLaeA在调控真菌发育方面的功能并不清楚。本研究在对草菇VvLaeA进行生物信息学分析基础上,通过聚合酶链式反应(polymerase chain reaction,PCR)的方法将超量表达启动子Vvgpd和草菇VvlaeA基因的开放阅读框(open reading frame,ORF)进行融合,并将融合片段克隆入pK2(bar)载体。采用农杆菌介导的转化方法将重组载体pK2(bar)-OEVvlaeA转入球孢白僵菌中进行表达,测定转化子的菌株发育情况。结果表明,草菇VvLaeA与其他真菌的蛋白同源性较低;和野生型相比,转化菌株的菌落直径显著增大,色素减少,分生孢子产量和萌发率均显著下降,对胁迫反应的敏感性增强。进一步研究发现,转化菌株分生孢子的细胞壁结构成分发生改变,和分生孢子发育相关基因的表达被显著下调。提示草菇VvLaeA能提高球孢白僵菌菌株的生长速率,而负调控色素沉积和分生孢子发育,这为草菇基因功能鉴定提供了启示。     

草菇过氧化氢酶基因(VvCAT1)异源表达及耐温度胁迫功能分析

[背景] 过氧化氢酶（catalase,CAT）参与真菌的生长发育,逆境胁迫时保护真菌免受氧化损伤。[目的] 实现草菇过氧化氢酶基因（VvCAT1）的异源表达,分析VvCAT1耐温度胁迫的功能。[方法] 克隆VvCAT1,构建过表达载体pBAR GPE1/VvCAT1,转化到大肠杆菌（Escherichia coli）菌株Stbl3中,异源表达草菇过氧化氢酶。测定温度胁迫后重组菌（pBAR GPE1/VvCAT1/Stbl3）与对照菌（pBAR GPE1/Stbl3）的过氧化氢酶活性和生长情况,验证VvCAT1的功能。[结果] 重组菌的CAT酶活性显著提高,生长情况显著优于对照菌。[结论] VvCAT1的导入及表达显著提高了大肠杆菌Stbl3的耐温度胁迫功能。     

The effect of root temperature on growth of curled parsley

Summary Curled parsley was grown at root-zone temperature (RZT) of 18, 21, 24, 27 and 36°C at air temperature (AT) of 18 and 21°C. Maximum growth was obtained at 18°C AT and 24°C RZT, but there were no significant differences between 18 and 27°C RZT. Shoot and root growth were severely inhibited at 36°C constant RZT. The growth was also retarded when RZT rose to 36°C for 30 minutes per day, even when compared to a RZT of constant 27°C. This indicates that a short exposure to RZT above 30°C retards growth. A relatively low daily average RZT did not compensate for the damage caused by a short daily high temperature exposure. Optimum temperature for curled parsley seems to be about 21°C. Report No. 316.     

Profile of the extracellular lignocellulolytic enzymes activities as a tool to select the promising strains of Volvariella volvacea (Bull. ex Fr.) sing

Out of 26 strains of Volvariella volvacea used, 18 were of ‘typical’ type and possessed all the characteristics of a normal V. volvacea mycelium, while the rest 4 ‘atypical’ type strains showed completely distinct mycelial growth characteristics. The remaining 4 strains grew very slowly and exhibited growth characteristics of single spore isolates of V. volvacea. Strains varied in their extracellular lignocellulolytic activities and strains; OE-274, OE-272 and OE-210 with high ligninase enzymes (laccase and polyphenol oxidase) activities, gave highest mushroom yield on pasteurized paddy straw substrate. On the composted paddy straw substrate, additional two strains, OE-213 and OE-215 with lower activities of ligninases also gave higher mushroom yield. Mushrooms were harvested 3 to 4 d early from the composted substrate than on the pasteurized substrate. Activities of endoglucanase, laccase and polyphenol oxidase were found to be more crucial for mushroom yield on pasteurized substrate, while xylanase and β-glucosidase were more important for composted substrate. Strains also varied in their fruiting bodies quality and the substrate used for mushroom cultivation also affected the fruiting body quality. The superior yielding strains varied in shape, size, weight, colour and contents of sodium and potassium in their fruiting bodies; while contents of carbon, calcium and protein did not vary much with the strains.     

Effect of growth temperature on ether lipid biochemistry in Archaeoglobus fulgidus

The archaea are distinguished by their unique isoprenoid ether lipids, which typically consist of the sn-2,3-diphytanylglycerol diether or sn-2,3-dibiphytanyldiglycerol tetraether core modified with a variety of polar headgroups. However, many hyperthermophilic archaea also synthesize tetraether lipids with up to four pentacyclic rings per 40-carbon chain, presumably to improve membrane thermal stability at temperatures up to∼110 °C. This study aimed to correlate the ratio of tetraether to diether core lipid, as well as the presence of pentacyclic groups in tetraether lipids, with growth temperature for the hyperthermophilic archaeon, Archaeoglobus fulgidus. Analysis of the membrane core lipids of A. fulgidus using APCI–MS analysis revealed that the tetraether-to-diether lipid ratio increases from 0.3 ± 0.1 for cultures grown at 70°C to 0.9 ± 0.1 for cultures grown at 89°C. Thin-layer chromatography (TLC) followed by APCI–MS analysis provided evidence for no more than one pentacycle in the hydrocarbon chains of tetraether lipid from cultures grown at 70°C and up to 2 pentacycles in the tetraether lipid from cultures grown at higher temperatures. Analysis of the polar lipid extract using TLC and negative-ion ESI–MS suggested the presence of diether and tetraether phospholipids with inositol, glycosyl, and ethanolamine headgroup chemistry.     

Bioconversion of agricultural lignocellulosic wastes through the cultivation of the edible mushrooms Agrocybe aegerita,Volvariella volvacea and Pleurotus spp.

Ten selected wild and commercial strains of Pleurotus ostreatus,Pleurotus eryngii,Pleurotus pulmonarius, Agrocybe aegerita andVolvariella volvacea were cultivated on three agricultural wastes, i.e. wheat straw (WS), cotton waste (CW) and peanut shells (PS). All species demonstrated significantly higher colonization rates on WS and CW than on PS. WS supported faster growth of A. aegerita and Pleurotus spp., whereas V. volvacea performed better on CW. Comparison of growth rates on composted and non-composted WS and CW substrates revealed that in the latter case faster colonization was achieved, particularly for Pleurotus spp. However, one commercial strain of V. volvacea presented higher growth rates when the composted CW medium was used. Furthermore, earliness in the fructification of P. ostreatus, P. pulmonarius and V. volvacea strains was promoted in CW substrates, while WS favoured earliness of P. eryngii and A. aegerita. Similarly, high sporophore yields were obtained by P. ostreatus and P. pulmonarius on both wastes, whereas WS enhanced yield and basidioma size of P. eryngii and A. aegerita strains and CW production of V. volvacea. The substrates cellulose:lignin ratios were found to be positively correlated to mycelial growth rates and to mushroom yield of P. ostreatus and P. pulmonarius; in addition, positive correlation was also detected for carbon:nitrogen ratio and mushroom yield in P. eryngii and A. aegerita and between cellulose content and mushroom yield for V. volvacea strains.     

草菇热激蛋白60基因(Vvhsp60)生物信息学分析及低温下的表达

【背景】生物受到温度胁迫时,热激蛋白被诱导并在短时间内大量产生,可以使受损的蛋白质恢复正常构象,增强生物对逆境胁迫的耐受性。【目的】初步探究草菇热激蛋白60(Vvhsp60)与低温耐受性的关系,为深入开展草菇不耐低温特性的遗传改良奠定理论基础。【方法】对Vvhsp60进行生物信息学分析,以低温敏感型草菇菌株V23及耐低温菌株VH3为实验材料,利用实时荧光定量PCR技术分析低温胁迫及热激诱导后在低温下草菇菌丝体中Vvhsp60基因的表达水平。【结果】草菇Vvhsp60编码蛋白不存在信号肽,不属于分泌蛋白,在线粒体和细胞质内发挥生物学作用,属于双向跨膜蛋白。低温处理显著提高了V23与VH3菌丝体中Vvhsp60基因的表达量,而且VH3中的表达量显著高于V23,推测Vvhsp60基因的表达量高可能有助于增强草菇对低温胁迫的耐受性。经热激处理后两菌株Vvhsp60基因的表达量显著高于各自未热激处理的对照组,表明热激处理可诱导Vvhsp60基因的表达。【结论】Vvhsp60与草菇低温耐受性相关,并且热激可以诱导Vvhsp60基因的表达。     

Production and characterization of somatic hybrids raised through protoplast fusion between edible mushroom strains Volvariella volvacea and Pleurotus florida

Twelve somatic hybrid lines were raised through polyethylene glycol-mediated intergeneric protoplast fusion between Volvariella volvacea and Pleurotus florida using a double selection method. Four hybrid lines belonging to two distinct colony morphology types could be maintained in culture. Basidiocarps could be generated from two hybrid lines, one of which showed resemblance to the P. florida parent while the other showed intermediate parental morphology. Hybridity of the fusant lines was established on the basis of colony morphology, mycelial growth rate, hyphal traits, fruit body morphology, isozyme and RAPD analysis. Four isozyme activities were analyzed to provide biochemical criteria for detection of polymorphism among the hybrids and their parents. Using 20 random decamers a total of 203 RAPD bands ranging from 0.09 to 1.6 kb were observed. The UPGMA method of clustering exhibited two major phylogenetic clusters, the first of which comprised of the parents, two fruit body generating hybrid lines and their subsequent fruit body derived lines, while the two non-fruit body generating hybrid lines formed the out group of the first major cluster. Screening of a Pleurotus type hybrid line having high biological efficiency and generation of a temperature tolerant Pleurotus type line through backcross mating between a non-fruit body generating somatic hybrid and V. volvacea parent are the key achievements of this fusion programme.     

草菇低温胁迫初期应答关键通路的探究

本研究利用表达谱芯片技术解析了低温胁迫初期（0-120min）不同低温处理时间草菇转录组水平的变化。芯片结果分析发现在低温诱导过程中,低温处理20min内变化基因的功能为单加氧酶、氧化还原酶和细胞内的氧化还原。低温处理40min时表达差异基因具有结合RNA的功能。80min的时间段内,基因的功能比较集中于核酸物质和能量的代谢。CYP450的代谢途径在20-40min、60-80min和100-120min低温处理的菌丝体中均有显著性变化,表明这一通路在草菇低温处理过程中表现活跃。基因表达趋势分析发现34个表达差异基因富集到显著表达趋势模型,基因共表达网络分析发现VVO_04066位于网络的核心地位,推测VVO_04066通过提高磷酸肌醇特异性磷脂酶C（PI-PLC）的胞内水平,促进糖蛋白和几丁质的合成,从而完成草菇细胞的低温胁迫应答。     

五种矿质元素对草菇菌丝生长和活性氧清除能力的影响

【背景】菌种退化是草菇生产中面临的难题,探究一种简单高效的复壮方法是草菇产业亟须解决的问题。【目的】探讨外源添加5种矿质元素对草菇退化菌株的菌丝性状和活性氧(reactive oxygen species, ROS)清除能力的影响。【方法】筛选出5种矿质元素的最佳浓度并添加于PDA培养基中,测定草菇菌落形态、菌丝生长速度、菌丝生物量、ROS含量、抗氧化酶活性及抗氧化物质含量。【结果】MnSO4、Na2SeO3、CaSO4、FeSO4可有效提高草菇退化菌株D1和D2的菌丝生长速度和生物量;降低O2·-、H2O2等ROS的含量,并增加还原型谷胱甘肽(glutathione, GSH)、氧化型谷胱甘肽(glutathionedisulfide,GSSG)的含量及超氧化物歧化酶(superoxidedismutase,SOD)、过氧化氢酶(catalase, CAT)、谷胱甘肽...     

The effect of dietary ethanol on the composition of lipids of Drosophila melanogaster larvae

At a moderate concentration (2.5%, v/v) dietary ethanol reduced the chain length of total fatty acids (FA) and increased the desaturation of short-chain FA in Drosophila melanogaster larvae with a functional alcohol dehydrogenase (ADH). The changes in length in total FA were postulated to be due to the modulation of the termination specificity of fatty acid synthetase. Because the ethanol-stimulated reduction in the length of unsaturated FA was blocked by linoleic acid, it was thought to reflect the properties of FA 9-desaturase. Although the ethanol-stimulated reduction in chain length of unsaturated FA was also observed in ADH-null larvae, ethanol promoted an increase in the length of total FA of the mutant larvae. Thus, the ethanolstimulated change in FA length was ADH dependent but the ethanol effect on FA desaturation was not. Ethanol also stimulated a decrease in the relative amount of phosphatidylcholine and an increase in phosphatidylethanolamine. Because similar ethanol-induced changes have been found in membrane lipids of other animals, ethanol may alter the properties of membranes in larvae. It is proposed that ethanol tolerance in D. melanogaster may be dependent on genes that specify lipids that are resistant to the detrimental effects of ethanol.This research was supported by National Institutes of Health Grant GM-28779 to B.W.G. and a Monash University Research Grant to S.W.M.     

The effect of daily exposure to low hardening temperature on plant vital activity

Phenomenological responses of plants to daily short-term exposure to low hardening temperature was studied under chamber and field conditions. Experiments were carried out on cucumber (Cucumis sativus L.), barley (Hordeum vulgare L.), marigolds (Tagetes L.), and petunia (Petunia × hybrida) plants. The obtained data demonstrated a similar pattern of response in all studied plant species to different variants of exposure to low hardening temperature. The main features of plant response to daily short-term exposure to low hardening temperature include: a higher increment in cold tolerance (cf. two-or threefold increase relative to constant low hardening temperature) that peaked on day 5 (cf. day 2 at constant low hardening temperature) and was maintained for 2 weeks (cf. 3–4 days at constant low hardening temperature); a simultaneous increase in heat tolerance (cf. twofold relative to constant low hardening temperature) maintained over a long period (cf. only in the beginning of the exposure to constant low hardening temperature); a sharp drop in the subsequent cold tolerance after plant incubation in the dark (cf. a very low decrease in cold tolerance following the exposure to constant low hardening temperature); a combination of high cold tolerance and high photochemical activity of the photosynthetic apparatus (cf. a low non-photochemical quenching at constant low hardening temperature); and the capacity to increase cold tolerance in response to repeated short-term exposures to low hardening temperature in plants grown outdoors (cf. a gradual increase after repeated exposure to constant low hardening temperature). Possible mechanisms underlying the plant response to daily short-term exposure to low temperature are proposed.     

Effects of growth temperature on transport and membrane viscosity in Streptococcus faecalis

A shift in the growth temperature of Streptococcus faecalis from 37 to 10°C resulted in an 18% increase in the proportion of unsaturated fatty acids. Electron spin resonance spectra of spin-labeled membranes and extracted phospholipids indicated viscosity changes consistent with the alterations in fatty acid composition. Growth temperature had no significant effect on the active transport of leucine and alanine; uptake rates assayed at 10 or 35°C were essentially the same in cells grown at either 10 or 37°C. The relative rapidity of amino acid transport, which presumably contributes to the ability of S. faecalis to thrive in cold environments, is evidently unrelated to adaptive changes in the viscosity of membrane lipids.Abbreviations doxyl 4-4-dimethyloxazolidine-N-oxyl - proxyl 2,2-disubstituted 5,5-dimethylpyrrolidine-N-oxyl     

The effect of aluminium on growth of and nitrogen fixation in vegetable soybean germplasm

Vegetable soybeam germplasm was screened for its tolerance to 0, 50 and 100 μM Al in solution culture. Plants were inoculated with prescreened acid-Al tolerantBradyrhizobium japonicum strain USDA 110 and a localRhizobium isolate SM867. Aluminum concentrations of 0, 50, and 100 μM affected the root lengths of all germplasm lines in the first few weeks of their growth. At 100 μM, the plants had severely stunted roots throughout the growing period of 35 days, but at 50 μM the initial stunting of the roots was overcome after the third week of growth, and there were no significant differences between the root lengths of these plants and of the controls. The appearance of the first nodule was delayed for 2–3 and 4–5 days at 50 μM and 100 μM Al, respectively. There was a significant reduction in nodule numbers and acetylene reduction activity (ARA) at 100 μM Al. At 50 μM Al, even though the number of nodules was decreased significantly, nodules were larger in size, so there was no significant reduction in nodule fresh weight and ARA. No significant differences in nitrogen fixing abilities of the soybean lines were observed between the twoRhizobium strains. Germplasm line Kahala showed the greatest tolerance to 50 μM Al, and Kahala, Kim and Wolverine tolerated 100 μM Al better than other germplasm lines.     

Inhibition of Chlorella growth by the lipids of cyanobacterium Microcystis aeruginosa

The total lipids of the cyanobacterium Microcystis aeruginosa have been isolated and fractionated into its components. Of these lipid components, only the fatty acid-containing fraction inhibited the growth of the green alga Chlorella pyrenoidosa. The inhibitory activity appears to be due to linoleic and linolenic acids, which are both present in significants quantities. These acids may be the substances responsible for the reported toxicity of Microcystis aeruginosa to Chlorella.     

The quantum efficiency of photosystem II and its relation to non-photochemical quenching of chlorophyll fluorescence; the effect of measuring-and growth temperature

The relation between the quantum yield of oxygen evolution of open photosystem II reactions centers (_p), calculated according to Weis and Berry (1987), and non-photochemical quenching of chlorophyll fluorescence of plants grown at 19°C and 7°C was measured at 19°C and 7°C. The relation was linear when measured at 19°C, but when measured at 7°C a deviation from linearity was observed at high values of non-photochemical quenching. In plants grown at 7°C this deviation occurred at higher values of non-photochemical quenching than in plants grown at 19°C. The deviations at high light intensity and low temperature are ascribed to an increase in an inhibition-related, non-photochemical quenching component (q_I).The relation between the quantum yield of excitation capture of open photosystem II reaction centers (_exe), calculated according to Genty et al. (1989), and non-photochemical quenching of chlorophyll fluorescence was found to be non-linear and was neither influenced by growth temperature nor by measuring temperature.At high PFD the efficiency of overall steady state electron transport measured by oxygen-evolution, correlated well with the product of q _N and the efficiency of excitation capture (_exe) but it deviated at low PFD. The deviations at low light intensity are attributed to the different populations of chloroplasts measured by gas exchange and chlorophyll fluorescence and to the light gradient within the leaf.Abbreviations F₀ basic fluorescence - F₀ basic fluorescence, thylakoid in energized state - F_m maximal fluorescence - F_m maximum fluorescence in energized state - F_s steady state fluorescence - F_v maximal variable fluorescence - PFD photon flux density - PS II_rc Photosystem II reaction center - q_F0 quenching of basic fluorescence - q_E energy related quenching - q_N non-photochemical quenching:-q_f-total quenching - q_I inhibition-related quenching - q_p photochemical quenching - q_r quenching due to state transition - R_d dark respiration - _p PS II efficiency of excitation capture of open PS II_rc - _pe extrapolated minimal value of _p - _p0 extrapolated maximal value of _p - _si quantum efficiency of linear electron transport, calculated from gas exchange measurements based on incident light - _sf quantum efficiency of linear electron transport, calculated from fluorescence measurements, based on incident measuring light     

The effect of grasses on the quality of transmitted radiation and its influence on the growth of white clover Trifolium repens

Summary Plants of white clover Trifolium repens were grown under the canopies of three grass species, Lolium perenne, Agrostis tenuis and Holcus lanatus, and under simulated canopies of black polythene and controls were exposed to unfiltered natural radiation. The canopies were adjusted so that they transmitted equal intensities of Photosynthetically Active Radiation (P.A.R.). The ratio of red to far red radiation () was unchanged under the black polythene canopies but was reduced under canopies of Lolium and Agrostis and even more so under Holcus. The effect of canopy filtered radiation on the growth of clover was greatly to reduced internode length, mean number of nodes, the number of branched nodes and the number of rooted nodes and greatly to increase petiole length. The effect of canopies of Holcus was greater than that of the other grass species both in its effect on and on the responses of the clover plant to its shade.     

Upper limits of temperature for growth inChlorella (Chlorophyceae)

The upper limit of temperature for growth is a species-specific character in the genusChlorella. The limits of 14Chlorella species range from 26–30°C (C. saccharophila) to 38–42°C (C. sorokiniana), withC. fusca var.vacuolata (34°C) andC. kessleri (34–36°C) assuming an intermediate position. Thus, there is no wide gap in the temperature limits between the normal (“low-temperature”) species ofChlorella and the “high-temperature” species,C. sorokiniana.     

Photoinhibition of photosynthesis in intact kiwifruit (Actinidia deliciosa) leaves: effect of growth temperature on photoinhibition and recovery

Intact leaves of kiwifruit (Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson) from plants grown in a range of controlled temperatures from 15/10 to 30/25°C were exposed to a photon flux density (PFD) of 1500 μmol·m⁻²·s⁻¹ at leaf temperatures between 10 and 25°C. Photoinhibition and recovery were followed at the same temperatures and at a PFD of 20 μmol·m⁻²·s⁻¹, by measuring chlorophyll fluorescence at 77 K and 692 nm, by measuring the photon yield of photosynthetic O₂ evolution and light-saturated net photosynthetic CO₂ uptake. The growth of plants at low temperatures resulted in chronic photoinhibition as evident from reduced fluorescence and photon yields. However, low-temperature-grown plants apparently had a higher capacity to dissipate excess excitation energy than leaves from plants grown at high temperatures. Induced photoinhibition, from exposure to a PFD above that during growth, was less severe in low-temperature-grown plants, particularly at high exposure temperatures. Net changes in the instantaneous fluorescence,F ₀, indicated that little or no photoinhibition occurred when low-temperature-grown plants were exposed to high-light at high temperatures. In contrast, high-temperature-grown plants were highly susceptible to photoinhibitory damage at all exposure temperatures. These data indicate acclimation in photosynthesis and changes in the capacity to dissipate excess excitation energy occurred in kiwifruit leaves with changes in growth temperature. Both processes contributed to changes in susceptibility to photoinhibition at the different growth temperatures. However, growth temperature also affected the capacity for recovery, with leaves from plants grown at low temperatures having moderate rates of recovery at low temperatures compared with leaves from plants grown at high temperatures which had negligible recovery. This also contributed to the reduced susceptibility to photoinhibition in low-temperature-grown plants. However, extreme photoinhibition resulted in severe reductions in the efficiency and capacity for photosynthesis.