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Paulownia tree canker is a major disease of Paulowniae tomentosa in Japan. The pathogen was described as Valsa paulowniae in 1916 by Hemmi and Miyabe. However, its current taxonomic status and phylogenetic position are uncertain. In this study, we reviewed the protologue of this species and rediscovered the syntypes maintained at the Hokkaido University Museum (SAPA). From these specimens, a lectotype was selected. The molecular phylogenetic position of this species was examined with newly collected samples. Based on the result of phylogeny and morphology, an epitype of this species was designated and transferred to the genus Cytospora. [ABSTRACT FROM AUTHOR]

Apples are a popular fruit worldwide and are cultivated in the Xinjiang Uygur Autonomous Region (XUAR) in China. Cytospora canker disease is a serious problem in the apple industry in China. Pathogenicity of all historically recorded Cytospora species from Malus hosts was tested on the leaves and breaches of 13 varieties of apple (Malus domestica) and wild apple (Malus sieversii). Cytospora leucosperma and Cytospora pruinopsis were the most aggressive pathogens on apple and wild apple trees in Xinjiang. Meanwhile, Cytospora leucostoma, Cytospora nivea and Cytospora parakantschavelii were the least aggressive. In addition, Fuji and Golden Delicious were the most Cytospora canker disease‐resistant apple varieties and are recommended for future promotion. However, Sitagan and Erzizi were readily infected by Cytospora. Our findings provide a theoretical basis for field disease epidemic monitoring and tailoring disease prevention and control strategies based on the disease resistance of the variety and the aggressiveness of the pathogen. [ABSTRACT FROM AUTHOR]

Este artigo pretende constatar, tendo os elementos da valsa (gênero) e da Banda (agrupamento formador) como pano de fundo, os desvios e adaptações a partir de uma perspectiva prática de arranjador. A relação entre esses dois elementos se dá dentro de uma perspectiva de tensão entre um ideário de brasilidade e elementos estrangeiros. A partir de uma formação padrão (Banda), elementos musicais se infiltram no gênero da valsa. Especificamente tratará do gênero para as formações de orquestra Típica e Big Band, tendo como ponto de partida as considerações retiradas sobre a versão de “Tenra Saudade” (ou “Por Um Beijo” de Anacleto de Medeiros) para a Banda da Casa Edson. Será realizada a análise e contexto do tema “Bebel” (de João Gilberto) e descrição do seu arranjo para Big Band; análise e contexto do tema “Valsa Brasileira” de Edu Lobo & Chico Buarque e descrição da elaboração do arranjo para a formação de uma Orquestra Típica e, por fim, descrição da elaboração da composição de um tema para mesmo gênero (“Valsa Moura”) para o agrupamento da Orquestra Típica reduzida ao formato de Ensemble. A partir de tais levantamentos, uma série de considerações serão levantadas a partir do cotejamento de dados realizados nas etapas anteriores à luz de novos autores.

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Cytospora is a genus of fungi belonging to the Cytosporaceae family (Sordariomycetes, Ascomycota) considered as a prolific source of specialized metabolites due to their ability to produce diverse secondary metabolites with a broad range of biological activities. Since the first chemical investigation of this genus in the 1980s, further studies have led to the isolation and structural elucidation of several bioactive compounds including cytosporones, nonanolides, macrocyclic dilactones, and terpenoids. This review summarizes, for the first time, the chemical diversity of bioactive secondary metabolites from the genus Cytospora and highlights its potential as an alternative source of secondary metabolites for pharmacological studies. Moreover, this review will serve as a basis for future investigations of compounds of this genus. [ABSTRACT FROM AUTHOR]

The Creole waltz is a musical genre practiced in Peru since the end of the 19th century. It has an important function in Valses y otra falsas confesiones (1972) by the Peruvian poet Blanca Varela, a member of the "Generation of '50". Some representative poems of Valses y otras falsas confesiones [Waltzes and other false confessions] are analyzed through the concept of demystification (proposed by Umberto Eco) and the theoretical framework of Stefano Arduini's General Textual Rhetoric. Our central purpose is to state that, for Varela, there are two types of waltz: the criollo and the one that defends marginal groups. Varela demystifies the Creole waltz and, at the same time, formulates another type of waltz that takes the side of peripheral groups. [ABSTRACT FROM AUTHOR]

Cytospora is a genus of fungi belonging to the Cytosporaceae family (Sordariomycetes, Ascomycota) considered as a prolific source of specialized metabolites due to their ability to produce diverse secondary metabolites with a broad range of biological activities. Since the first chemical investigation of this genus in the 1980s, further studies have led to the isolation and structural elucidation of several bioactive compounds including cytosporones, nonanolides, macrocyclic dilactones, and terpenoids. This review summarizes, for the first time, the chemical diversity of bioactive secondary metabolites from the genus Cytospora and highlights its potential as an alternative source of secondary metabolites for pharmacological studies. Moreover, this review will serve as a basis for future investigations of compounds of this genus.

Paulownia tree canker is a major disease of Paulowniae tomentosa in Japan. The pathogen was described as Valsa paulowniae in 1916 by Hemmi and Miyabe. However, its current taxonomic status and phylogenetic position are uncertain. In this study, we reviewed the protologue of this species and rediscovered the syntypes maintained at the Hokkaido University Museum (SAPA). From these specimens, a lectotype was selected. The molecular phylogenetic position of this species was examined with newly collected samples. Based on the result of phylogeny and morphology, an epitype of this species was designated and transferred to the genus Cytospora ., (2024, by The Mycological Society of Japan.)

Members of the genus Cytospora are often reported as endophytes, saprobes or phytopathogens, primarily causing canker diseases of woody host plants. They occur on a wide range of hosts and have a worldwide distribution. Although several species have in the past been reported from China, the vast majority are not known from culture or DNA phylogeny. The primary aim of the present study was thus to clarify the taxonomy and phylogeny of a large collection of Cytospora species associated with diverse hosts in China. Cytospora spp. were collected in northeast, northwest, north and southwest China, indicating that the cold and dry environments favour these fungi. In this paper, we provide an assessment of 52 Cytospora spp. in China, focussing on 40 species represented by 88 isolates from 28 host genera. Based on a combination of morphology and a six-locus phylogeny (ITS, LSU, act1, rpb2, tef1-a and tub2), 13 new species and one new combination are introduced. The majority of the species investigated here appear to be host-specific, although further collections and pathogenicity studies will be required to confirm this conclusion. [ABSTRACT FROM AUTHOR]

This paper introduces all the possible topologies of the Wien bridge oscillator family. This family has 72 topologies, 24 of them contain only RC or RL pairs, and the rest contain mixed pairs. The complete mathematical analysis of all twelve possible capacitive-based topologies is proposed in the fractional-order domain. The investigated circuits can be categorized into two groups, each with a similar characteristic equation. Three integer-order approximation techniques for the Laplacian operator s α are employed to solve and simulate the Wien bridge system. The studied approximations are those of Matsuda, Oustaloup, and Valsa's network. Fractional-order capacitor (FOC) emulators are built using these approximations and applied in the circuit simulation. Comparisons are made on different levels, starting with the mathematical solution of the characteristic equation, followed by PSpice simulation, which compares topologies of the Wien bridge oscillator family. Hardware implementation of the FOC emulators is presented applying passive discrete components using the Foster-I technique. Additionally, sensitivity tests of the discrete components of the FOC emulators are performed using Monte Carlo analysis. Experimental results are introduced to validate the theoretical findings. [ABSTRACT FROM AUTHOR]

Having an approximate realization of the fractance device is an essential part of fractional-order filter design and implementation. This encouraged researchers to introduce many approximation techniques of fractional-order elements. In this paper, the fractional-order KHN low-pass and high-pass filters are investigated based on four different approximation techniques: Continued Fraction Expansion, Matsuda, Oustaloup, and Valsa. Fractional-order filter fundamentals are reviewed then a comparison is made between the ideal and actual characteristic of the filter realized with each approximation. Moreover, stability analysis and pole movement of the filter with respect to the transfer function parameters using the exact and approximated realizations are also investigated. Different MATLAB numerical simulations, as well as SPICE circuit results, have been introduced to validate the theoretical discussions. Also, to discuss the sensitivity of the responses to component tolerances, Monte Carlo simulations are carried out and the worst cases are summarized which show good immunity to component deviations. Finally, the KHN filter is tested experimentally. [ABSTRACT FROM AUTHOR]

Abstract The promising capabilities of fractional-order devices challenge researchers to find a way to build it physically. Approximating the Laplacian operator s α can pave the way to emulate the fractional-order devices till its off-the-shelf appearance. This paper introduces three approximations of the Laplacian operator s α : Oustaloup, Matsuda, and Valsa by comparing their behaviors through two types of oscillator circuits. The first two are well-established approximations and the latter is proposed for the first time by converting its model network to an integer polynomial approximation of the fractional operator s α . In addition to that, three emulators for the fractional-order capacitor are introduced based on Foster-I, Foster-II, and Cauer-I techniques. The Wien-bridge family and the phase-shift oscillators are chosen to be examples of two and three fractional-order elements circuits, respectively. The approximation comparison is held through the oscillators based on oscillation condition and frequency. Also, a comparison between the circuit's behavior with three approximations and the exact solution is provided to investigate which approximation has the lowest error. The sensitivity of approximations to emulators' circuit components is investigated through Monte Carlo analysis. The effects of 5 % and 10 % uniform random deviation in the emulators' circuit components are investigated. Numerical simulations using MATLAB and Spice simulations for the two oscillators are provided. Also, some cases are validated experimentally. [ABSTRACT FROM AUTHOR]

Abstract Transcription factor Seb1 contains two C2H2 zinc finger motifs which are similar to the Msn2/4 of Saccharomyces cerevisiae. The homologous proteins of Seb1 function to regulate the response to various stresses or decomposing and utilizing pectin in some fungi. In this study, we characterized a homologue of Seb1 gene, VmSeb1 , in Valsa mali , which causes a highly destructive bark disease on apple. VmSeb1 deletion mutant showed a drastic reduction in growth rate in vitro. It is also important for conidiation because VmSeb1 deletion mutant formed more pycnidia on PDA medium. Deletion mutant of VmSeb1 increased melanin genes expression. In addition, the sensitivity to oxidative stress increased and cell wall inhibitor in VmSeb1 deletion mutant, as its growth was more severely inhibited by H 2 O 2 and Congo red than that in the wild-type. The virulence assay showed that the lesion length caused by the VmSeb1 deletion mutant was smaller compared to wild-type on detached apple twigs. However, expression of pectinase genes and pectinase activity in deletion mutant were the same as those of the wild-type during infection. These results indicate that VmSeb1 plays important roles in growth, asexual development, response to oxidative stress, maintenance of cell wall integrity, and virulence. However, VmSeb1 is not involved in the regulation of pectinase genes expression in V. mali. Highlights • An Msn2/4 transcription factor, VmSeb1, is characterized by gene deletion in Valsa mali. • VmSeb1 is involved in growth, conidiation, oxidative stress, maintenance of cell wall integrity, and virulence in V. mali. • VmSeb1 is not involved in the regulation of pectinase genes expression in V. mali. [ABSTRACT FROM AUTHOR]

Abstract Valsa pyri , an ascomycete pathogen that is a member of the Valsaceae family (Sordariomycetes, Diaporthales), which causes pear or apple canker and leads to tree death and massive yield losses. Here, we selected two V. pyri isolates (Vp14 and Vp297) that exhibited different invasion abilities for transcriptomics analyses. Compared toVp297, Vp14 had stronger virulence and spread faster on host-like nutrients. Four samples, including mycelium or infectious mycelium, of the two isolates were sequenced. Clean reads were mapped to the V. pyri genome, and 12490 transcripts and 178 new genes were identified. There were dramatically fewer differentially expressed genes (DEGs) in Vp14 than in Vp297. According to GO and COG annotations, there were both more up- and down-regulated genes in Vp297 than in Vp14 except for genes involved in amino acid transport and metabolism, carbohydrate transport and metabolism, peroxidases and so on. Specific up-regulated DEGs, including genes encoding cell wall degrading enzymes and genes involved in nitrogen metabolism and peroxidases which play crucial roles in virulence and infectious growth, were especially enriched inVp14. These results indicate that the Vp14 isolate may infect its host and take up nutrition more efficiently, reflecting a stronger ability for invasion or infectious growth. Our analysesindicate that a successful V. pyri infection involves multiple instances of transcriptome remodeling to regulate gene functions. Comparative transcriptomics between isolates of V. pyri may aid in our understanding of the virulence mechanism of this pathogen. Highlights • The two Valsa pyri isolates differ in their utilization of mineral or host nutrition in vitro. • Greater specific genes were upregulated in the stronger virulence isolate Vp14, involve in cell wall degrading enzymes, peroxidases and nitrogen metabolism, which are required for virulence and necrotrophic growth of fungi.. • This is the first comparative transcriptomics research uncovering the difference between Valsa pyri isolates. [ABSTRACT FROM AUTHOR]

In the current study, baseline sensitivity of Valsa mali to propamidine was determined using 80 strains collected from apple orchards in Shaanxi Province, China. The median effective concentration (EC 50 ) values for propamidine inhibiting mycelial growth ranged from 0.086 to 0.852 μg/mL, with a mean of 0.405 ± 0.137 μg/mL. After treated with propamidine, mycelia were contorted with an increased number of branches, loss of fruiting body production, and decreased cell membrane permeability. Moreover, the enzyme activities of the complexes I, II, IV and ATPase in the mitochondrial respiratory chain were increased significantly, while the enzyme activities of complexes III decreased. Importantly, both on detached leaves and branches of apple trees, propamidine applied at 100 μg/mL exhibited over 75% protective and curative efficacies, which were even better than the efficacies obtained by carbendazim at the same concentration. These results indicated that propamidine could be used as an alternative compound in controlling Valsa canker and mitochondrial respiratory chains might be correlated with the action mode of propamidine. This study encourages further investigation for the action mechanism of propamidine against plant pathogens and the information could be valuable for synthesis of new antifungal drugs with novel modes of action. [ABSTRACT FROM AUTHOR]

Sexual reproduction in filamentous ascomycetes is controlled by the mating type (MAT) locus, including two idiomorphs MAT1-1 and MAT1-2. Understanding the MAT locus can provide clues for unveiling the sexual development and virulence factors for fungal pathogens. The genus Valsa (Sordariomycetes, Diaporthales) contains many tree pathogens responsible for destructive canker diseases. The sexual stage of these ascomycetes is occasionally observed in nature, and no MAT locus has been reported to date. Here, we identified the MAT locus of the apple canker pathogen Valsa mali, which causes extensive damage, and even death, to trees. V. mali is heterothallic in that each isolate carries either the MAT1-1 or MAT1-2 idiomorph. However, the MAT structure is distinct from that of many other heterothallic fungi in the Sordariomycetes. Two flanking genes, COX13 and APN2, were coopted into the MAT locus, possibly by intrachromosomal rearrangement. After the acquisition of foreign genes, unequal recombination occurred between MAT1-1/2 idiomorphs, resulting in a reverse insertion in the MAT1-2 idiomorph. Evolutionary analysis showed that the three complete MAT1-1-2, COX13, and APN2 genes in this region diverged independently due to different selection pressure. Null hypothesis tests of a 1:1 MAT ratio of 86 V. mali isolates from four different provinces showed a relatively balanced distribution of the two idiomorphs in the fields. These results provide insights into the evolution of the mating systems in Sordariomycetes. [ABSTRACT FROM AUTHOR]

In fungi, heterotrimeric guanine-nucleotide binding proteins (G-proteins) are key elements of signal transduction pathways, which control growth, asexual and sexual development, as well as virulence. In this study, we have identified two genes encoding heterotrimeric G protein alpha subunits, named Gvm2 and Gvm3, from Valsa mali, the causal agent of apple Valsa canker. Characterization of Gvm2 and Gvm3 mutants indicates that Gvm3 may be a crucial regulator of vegetative growth. Deletion of the corresponding gene results in a 20% reduction in growth rate. Besides, Gvm2 and Gvm3 seem to be involved in asexual reproduction, and mutants are hypersensitive to oxidative and cell membrane stresses. Interestingly, both G protein alpha subunits were most probably involved in V. mali virulence. In infection assays using Malus domestica cv. ‘Fuji’ leaves and twigs, the size of lesions caused by deletion mutants △Gvm2, or △Gvm3 are significantly reduced. Furthermore, many genes encoding hydrolytic enzymes—important virulence factors in V. mali—are expressed at a lower level in these deletion mutants. Our results suggest that Gvm2 and Gvm3 play an important role in virulence probably by regulation of expression of cell wall degrading enzymes. △Gvm2, and △Gvm3 mutants were further analyzed with respect to their impact on the transcript levels of genes in the cAMP/PKA pathway. The expression of the genes encoding adenylate cyclase VmAC, protein kinase A (PKA) regulatory subunit VmPKR, and PKA catalytic subunit VmPKA1 are down-regulated in both mutants. Further analyses indicated that intracellular cAMP level and PKA activity are down-regulated in the △Gvm3 mutant, but are basically unchanged in the △Gvm2 mutant. Overall, our findings indicate that both Gvm2 and Gvm3 play diverse roles in the modulation of vegetative growth, asexual development, and virulence in V. mali. [ABSTRACT FROM AUTHOR]

The objective of this work was to study the underlying mechanisms of growth inhibition of Valsa mali var. mali , the causative pathogen of apple tree canker disease, by α-cembratrien-diol. The half maximal inhibitory concentration of α-cembratrien-diol against V. mali var. mali is 18.0 mg/L. Treatment of V. mali var. mali with α-cembratrien-diol resulted in various mycelial and cellular abnormalities, and the up- and down-regulation of 94 and 170 differentially expressed genes, respectively. Gene Ontology term enrichment analysis revealed that α-cembratrien-diol substantially altered the expression of genes involved in the redox process, tetrapyrrole binding, coenzyme binding, heme binding, and iron binding. Kyoto Encyclopedia of Genes and Genomes enrichment analysis also showed significant enrichment of specific metabolic pathways involving the set of differentially expressed genes. The present study will assist in the development of alternative α-cembratrien-diol-based biological control agents and ultimately facilitate organic apple production. [ABSTRACT FROM AUTHOR]

Composta por Radamés Gnattali (1906-1988) em 1956 para bandolim solista, conjunto de choro e orquestra de cordas, Retratos é uma suíte em quatro movimentos onde são homenageadas algumas das mais expressivas personalidades do cenário da música popular brasileira: Pixinguinha, Ernesto Nazareth, Anacleto de Medeiros e Chiquinha Gonzaga. O que dá forma e sustenta a narrativa da obra é a ideia de que os movimentos constituem retratos musicais destes compositores. Assim, a estrutura de cada movimento foi elaborada a partir de um modelo, ou seja, de cada compositor Gnattali escolheu uma peça que serviria de roteiro para o processo criativo dos retratos. Este estudo tem como foco o segundo movimento da suíte, a valsa, observando como está relacionado ao seu respectivo modelo, a valsa Expansiva de Ernesto Nazareth (1863-1934). Para ilustrar o paralelo será apresentada uma análise mais comparativa do que formal, procurando ampliar a visão do contexto histórico com evidências musicais, concentrando-se principalmente nos elementos comuns a ambas as peças.Written in 1956 by Brazilian composer Radamés Gnattali (1906-1988) for solo mandolin, choro ensemble and strings orchestra, Retratos (namely, Portraits in Portuguese) is a four movement suite that pays homage to some of the most significant personalities in the history of Brazilian popular music: Pixinguinha, Ernesto Nazareth, Anacleto de Medeiros and Chiquinha Gonzaga. What shapes and supports the suite's narrative is the idea that the movements represent musical portraits of these composers. As a result, each movement was structured after a model, that is, Gnattali has chosen a particular piece by each composer that would serve as a blueprint for the creative process of the portraits. The focus of this study is the suite's second movement, the waltz, observing how it is related to its respective model, the waltz Expansiva by Ernesto Nazareth (1863-1934). In order to illustrate this parallel, a more comparative than formal analysis will be provided, in an attempt to expand the view from the historical context to musical facts, drawing special attention to all cross-references present in the work.

Valsa pyri is a fatal pathogenic fungus that causes pear and apple canker disease. To date, its cellular development and pathogenicity have been poorly understood. In this study, a V . pyri Ca 2+ /calcineurin-dependent transcription factor CRZ1 (VpCRZ1) is identified and functionally characterized. The △VpCRZ1 mutant exhibits impaired pathogenicity and is no longer able to form fruiting body. Interestingly, this mutant also exhibits enhanced pigment deposition and increased resistance to cell wall perturbing agents including SDS, Congo red and calcofluor white (CFW). The expression levels of Congo red resistance genes ( VpRCR1 and VpRCR2 ) and chitin synthetase genes ( VpCHS2 and VpCHS6 ) are upregulated in the △VpCRZ1 mutant compared to the wild type. Furthermore, We show that a VpCRZ1: eGFP fusion protein localizes to the nucleus in a Ca 2+ -dependent manner similar to its homologs in other fungi, and that the VpFKS1 , VpPMC1 , VpPMC2 , VpPMR1 , and VpPMA1 genes are regulated by VpCRZ1 in response to Ca 2+ levels. Together, these results suggest that VpCRZ1 is a Ca 2+ -dependent transcription factor and required for regulating mycelial morphology, fruiting body formation, and virulence of this important pear and apple pathogen. [ABSTRACT FROM AUTHOR]

Valsa canker caused by the necrotrophic ascomycete Valsa mali is a destructive disease on apple in eastern Asia. To date, the disease still cannot be effectively controlled, mainly because V. mali extensively penetrates into the phloem and xylem and limited information about the resistance mechanism is available. In this study, we analyzed the transcriptome of V. mali -infected apple ( Malus x domestica ) to identify genes associated with V. mali induced resistance responses. Totally, 2713 apple genes were significantly up-regulated upon V. mali infection. Functional enrichment analysis showed that resistance responses were significantly over-represented in up-regulated genes, including chitin, hormone and cell death responses. Two chitin-elicitor receptors, MDP0000136494 and MDP0000169047, probably were the key chitin receptors responded to V. mali -infection. Jasmonic acid and salicylic acid signaling were revealed to be the primary phytohormone pathways of apple against V. mali. In addition, 11 cytochrome P450 genes likely to be involved in the xenobiotics biodegradation or phytoalexins biosynthesis were identified. This new information provides insights into the resistance responses against V. mali . Functional verification of these genes identified here will facilitate understanding the resistance mechanism of apple and establishing new effective disease arrangement strategies. [ABSTRACT FROM AUTHOR]

Apple valsa canker (AVC), caused by Valsa mali , is one of the most serious diseases of apple trees in eastern Asia, and the most important factor limiting apple production in China. This disease is difficult to control by chemical and agricultural measures, thus biocontrol may constitute a desirable alternative strategy. A Bacillus amyloliquefaciens strain denoted GB1 isolated from ageing cucumber stems, exhibited a strong antagonistic activity against V . mali , inhibiting significantly the germination of conidia and the growth of hyphae. GB1 conidial suspensions (above 10 6 CFU/ml) applied prior to wound inoculation of apple twigs with V. mali resulted in total inhibition of infection. Strain GB1 colonized xylem and phloem tissues surrounding the wounds made on apple twigs and formed biofilms over them. Results indicate that B. amyloliquefaciens GB1 may be a promising agent for the biocontrol of AVC, and provide new insights into the ability of B . amyloliquefaciens to colonize apple trees. [ABSTRACT FROM AUTHOR]

Genetic diversity of 40 isolates ofValsa malicolain Iran was investigated by MP-PCR. Isolates were obtained from different host plants in diverse regions during 2004–2010. Of the six microsatellite primers tested, only four primers; (ACTG)4, (GACA)4, (AC)8and (CGA)5,were able to amplify DNA fragments. With these four primers, 120 loci were identified; of which eight were monomorphic (6.7%) and 112 were polymorphic (93.3%). Approximate size of amplified DNA fragments ranged from 0.2 to 3 kb. Observed high genetic diversity in isolates ofV. malicolaindicates the eligibility of the marker to investigate ranks below the species level. The results of cluster analysis indicated that isolates are related to each other with 45.63% similarity and four groups (1, 2, 3 and 4) were identified in the dendrogram. Group 3 included 37 isolates that were obtained from different hosts and geographical regions and each of groups 1, 2 and 4 only had one isolate. Some correlations between identified groups and host origins or geographic distributions of the isolates were found. [ABSTRACT FROM AUTHOR]

Highlights: [•] The transcriptome of V. mali was sequenced and 13,046 genes were predicted. [•] Cell wall hydrolases and secondary metabolites were up-regulated during V. mali infection. [•] Five hundred and eighty three potential pathogenicity determinants of V. mali were predicted. [ABSTRACT FROM AUTHOR]

Valsa mali var. mali ( Vmm), which is the causative agent of Valsa canker of apple tree, causes heavy damage to apple production in eastern Asia. In this article, we report Agrobacterium tumefaciens-mediated transformation (ATMT) of Vmm and expression of gfp (green fluorescent protein) in this fungus. The transformation system was optimized to a transformation efficiency of approximately 150 transformants/10 conidia, and a library containing over 4,000 transformants was generated. The tested transformants were mitotically stable. One hundred percent hph (hygromycin B phosphotransferase) integration into Vmm was identified by PCR and five single-copy integration of T-DNA was detected in the eighteen transformants by Southern blot. To our knowledge, this is the first report of ATMT of Vmm. Furthermore, this library has been used to identify genes involved in the virulence of the pathogen, and the transformation system may also be useful to the transformation of other species of the genus Valsa. [ABSTRACT FROM AUTHOR]

Fungal diseases are posing tremendous threats to global economy and food safety. Among them, Valsa canker, caused by fungi of Valsa and their Cytospora anamorphs, has been a serious threat to fruit and forest trees and is one of the most destructive diseases of apple in East Asia, particularly. Accurate and robust delimitation of pathogen species is not only essential for the development of effective disease control programs, but also will advance our understanding of the emergence of plant diseases. However, species delimitation is especially difficult in Valsa because of the high variability of morphological traits and in many cases the lack of the teleomorph. In this study, we delimitated species boundary for pathogens causing apple Valsa canker with a multifaceted approach. Based on three independent loci, the internal transcribed spacer ( ITS), β-tubulin (Btu), and translation elongation factor-1 alpha ( EF1 α), we inferred gene trees with both maximum likelihood and Bayesian methods, estimated species tree with Bayesian multispecies coalescent approaches, and validated species tree with Bayesian species delimitation. Through divergence time estimation and ancestral host reconstruction, we tested the possible underlying mechanisms for fungal speciation and host-range change. Our results proved that two varieties of the former morphological species V. mali represented two distinct species, V. mali and V. pyri, which diverged about 5 million years ago, much later than the divergence of their preferred hosts, excluding a scenario of fungi-host co-speciation. The marked different thermal preferences and contrasting pathogenicity in cross-inoculation suggest ecological divergences between the two species. Apple was the most likely ancestral host for both V. mali and V. pyri. Host-range expansion led to the occurrence of V. pyri on both pear and apple. Our results also represent an example in which ITS data might underestimate species diversity. [ABSTRACT FROM AUTHOR]

Valsa mali var. mali (Vmm), the causal agent of apple tree canker disease, produces various toxic compounds, including protocatechuic acid, p-hydroxybenzoic acid, p-hydroxyacetophenone, 3-(p-hydroxyphenyl)propanoic acid and phloroglucinol. Here, we examined the relationship between toxin production and the pathogenicity of Vmm strains and determined their bioactivities in several assays, for further elucidating the pathogenesis mechanisms of Vmm and for developing new procedures to control this disease. The toxins were quantified with the high performance liquid chromatography (HPLC) method, and the results showed that the strain with attenuated virulence produced low levels of toxins with only three to four kinds of compounds being detectable. In contrast, higher amounts of toxins were produced by the more aggressive strain, and all five compounds were detected. This indicated a significant correlation between the pathogenicity of Vmm strains and their ability to produce toxins. However, this correlation only existed in planta, but not in vitro. During the infection of Vmm, protocatechuic acid was first detected at three days post inoculation (dpi), and the others at seven or 11 dpi. In addition, all compounds produced noticeable symptoms on host plants at concentrations of 2.5 to 40 mmol/L, with protocatechuic acid being the most effective compound, whereas 3-(p-hydroxyphenyl)propanoic acid or p-hydroxybenzoic acid were the most active compounds on non-host plants. [ABSTRACT FROM AUTHOR]

To study the induced resistance in apple against Valsa mali var. mali (Vmm), a Vmm-apple callus interaction system was developed to evaluate the induced resistance of an attenuated Vmm strain LXS081501 against further infection by a virulent Vmm strain LXS080601. The infection index was up to 97.32 for apple calli inoculated with LXS080601 alone at 15 days after inoculation whereas it was only 41.84 for calli pretreated with LXS081501 followed by LXS080601 inoculation. In addition, the maximum levels of free proline, soluble sugar, and protein in calli treated with LXS081501 plus LXS080601 were 2.14 to 3.47 times higher than controls and 1.42 to 1.75 times higher than LXS080601 treatment. The activities of defense-related enzymes such as phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), peroxidase (POD), and catalase (CAT) as well as β-1,3-glucanase and chitinase in apple calli inoculated with LXS080601 alone or LXS081501 plus LXS080601 increased significantly 24 hai and peaked from 48 to 120 hpi. However, in the latter treatment, the maximum enzyme activities were much higher and the activities always maintained much higher levels than control during the experimental period. These results suggested the roles of osmotic adjustment substances and defense-related enzymes in induced resistance. [ABSTRACT FROM AUTHOR]