| molecular cloning, sequence analysis and expression of a novel gene induced by near-uv light in bipolaris oryzae. | a cdna clone derived from a novel gene (uvi-1) that is inducible by near-uv light was isolated by a differential screening procedure from a cdna library of the fungus bipolaris oryzae and characterized further. sequence analysis of the clone revealed that uvi-1 encodes a protein with a putative molecular mass of 17 kda; the uvi-1 protein shows significant similarity to a putative protein encoded by a cdna which is expressed during appressorium formation in the rice blast fungus, magnaporthe gris ... | 2001 | 11589579 |
| cloning and overexpression of antifungal barley chitinase gene in escherichia coli. | plant chitinases are pathogenesis-related proteins, which are believed to be involved in plant defense responses to pathogen infection. in this study, chitinase gene from barley was cloned and overexpressed in escherichia coli. chitinase (35 kda) was isolated and purified. since the protein was produced as insoluble inclusion bodies, the protein was solubilized and refolded. purified chitinase exerted broad-spectrum antifungal activity against botrytis cinerea (blight of tobacco), pestalotia the ... | 2007 | 17029984 |
| rna-mediated gene silencing in the phytopathogenic fungus bipolaris oryzae. | the ascomycetous fungus bipolaris oryzae is the causal agent of brown leaf spot disease in rice and is a model for studying photomorphogenetic responses by near-uv radiation. targeted gene disruption (knockout) for functional analysis of photomorphogenesis-related genes in b. oryzae can be achieved by homologous recombination with low efficiency. here, the applicability of rna silencing (knockdown) as a tool for targeting endogenous genes in b. oryzae is reported. a polyketide synthase gene (pks ... | 2007 | 17227462 |
| characterization of the blr1 gene encoding a putative blue-light regulator in the phytopathogenic fungus bipolaris oryzae. | bipolaris oryzae is a filamentous ascomycetous fungus that causes brown leaf spot disease in rice. we isolated and characterized blr1, a gene that encodes a putative blue-light regulator similar to neurospora crassa white-collar 1 (wc-1). the deduced amino acid sequence of blr1 showed high degrees of similarity to other fungal blue-light regulator protein. disruption of the blr1 gene demonstrated that this gene is essential for conidial development after conidiophore formation and for near-uv ra ... | 2007 | 17233721 |
| suppression of phytopathogenic fungi by hexane extract of nepenthes ventricosa x maxima leaf. | the hexane extract of nepenthes ventricosa x maxima leaf exhibited antifungal activity against alternaria alternata, aspergillus niger, bipolaris oryzae, fusarium oxysporum, phytophthora capsici, rhizoctonia solani, rhizopus stolonifer var. stolonifer and sclerotinia sclerotiorum. | 2007 | 17573203 |
| cloning and characterization of the blr2, the homologue of the blue-light regulator of neurospora crassa wc-2, in the phytopathogenic fungus bipolaris oryzae. | bipolaris oryzae is a filamentous ascomycetous fungus that causes brown leaf spot disease in rice. we isolated and characterized blr2, a gene that encodes a putative blue-light regulator similar to neurospora crassa white collar-2 (wc-2). the deduced amino acid sequence of the blr2 showed significant homology to other fungal blue-light regulator proteins in the per-arnt-sim (pas) protein-protein interaction domain, nuclear localization signal, and gata zinc finger dna-binding domains. the blr2-s ... | 2008 | 18172720 |
| characterization of the bmr1 gene encoding a transcription factor for melanin biosynthesis genes in the phytopathogenic fungus bipolaris oryzae. | we isolated and characterized bipolaris melanin regulation 1 gene (bmr1) encoding a transcription factor for melanin biosynthesis genes in the phytopathogenic fungus bipolaris oryzae. sequence analysis showed that the bmr1 gene encodes a putative protein of 1012 amino acids that has 99% sequence similarity to transcription factor cmr1 of cochliobolus heterostrophus. the predicted b. oryzae bmr1 protein has two dna-binding motifs, two cys2his2 zinc finger domains, and a zn(ii)2cys6 binuclear clus ... | 2008 | 18312572 |
| characterization of a new antifungal lipid transfer protein from wheat. | lipid transfer proteins (ltps) are members of the family of pathogenesis-related proteins (pr-14) that are believed to be involved in plant defense responses. in this study, a novel gene ltp 3f1 encoding an antifungal protein from wheat (sumai 3) was subcloned, overexpressed in escherichia coli bl-21 (de3) and enriched using ammonium sulfate fractionation followed by gel permeation chromatography. molecular phylogeny analyses of wheat ltp 3f1 gene showed a strong identity to other plant ltps. pr ... | 2008 | 18595724 |
| defective active silicon uptake affects some components of rice resistance to brown spot. | rice is known to accumulate high amounts of silicon (si) in plant tissue, which helps to decrease the intensity of many economically important rice diseases. among these diseases, brown spot, caused by the fungus bipolaris oryzae, is one of the most devastating because it negatively affects yield and grain quality. this study aimed to evaluate the importance of active root si uptake in rice for controlling brown spot development. some components of host resistance were evaluated in a rice mutant ... | 2009 | 19055443 |
| cloning and expression analysis of two opsin-like genes in the phytopathogenic fungus bipolaris oryzae. | two opsin-like genes, ops1 and ops2, were identified from a subtracted cdna library for the identification of near-uv (nuv) radiation-enhanced genes using suppression subtractive hybridization methods in the brown leaf spot fungus bipolaris oryzae. the ops1 and ops2 genes encode predicted proteins of 306 and 304 amino acids, respectively. real-time pcr analysis showed that the ops1 transcript is expressed weakly in mycelia under dark conditions but shows enhanced expression after nuv irradiation ... | 2009 | 19456867 |
| disruption of srm1, a mitogen-activated protein kinase gene, affects sensitivity to osmotic and ultraviolet stressors in the phytopathogenic fungus bipolaris oryzae. | mitogen-activated protein kinases (mapks) play key roles in biological processes including differentiation, growth, proliferation, survival, and stress responses. we isolated and characterized the srm1 gene, which encodes an mapk related to yeast high-osmolarity glycerol 1 (hog1), from the rice leaf pathogen bipolaris oryzae. the deduced amino sequence of the srm1 gene showed significant homology with hog1-type mapk homologues from other phytopathogenic fungi and contained a tgy motif for phosph ... | 2006 | 16553861 |
| a map kinase gene, bmk1, is required for conidiation and pathogenicity in the rice leaf spot pathogen bipolaris oryzae. | we isolated and characterized bmk1, a gene encoding a mitogen-activated protein kinase (mapk), from the rice leaf spot pathogen bipolaris oryzae. the deduced amino acid sequence showed significant homology with fus3/kss1 mapk homologues from other phytopathogenic fungi. the bmk1 disruptants showed impaired hyphal growth, no conidial production, and loss of virulence against rice leaves, indicating that the bmk1 is essential for conidiation and pathogenicity in b. oryzae. | 2007 | 16546358 |
| antimicrobial and insecticidal protein isolated from seeds of clitoria ternatea, a tropical forage legume. | the tropical forage legume clitoria ternatea (l.) has important agronomic traits such as adaptation to a wide range of soil conditions and resistance to drought. it is resistant to a number of pathogens and pests. these important traits gave us reasons to look more closely at the plant. a highly basic small protein was purified from seeds of c. ternatea to homogeneity by using ultrafiltration with centricon-3 membrane tubes and preparative granulated-bed isoelectric focusing (ief). a single prot ... | 2004 | 15694280 |
| insertional mutagenesis and characterization of a polyketide synthase gene (pks1) required for melanin biosynthesis in bipolaris oryzae. | a polyketide synthase gene named pks1, involved in the melanin biosynthesis pathway of the phytopathogenic fungus bipolaris oryzae, was isolated using restriction enzyme-mediated integration. sequence analysis showed that the pks1 encodes a putative protein that has 2155 amino acids and significant similarity to other fungal polyketide synthases. targeted disruption of the pks1 gene showed that it is necessary for melanin biosynthesis in b. oryzae. northern blot analysis showed that pks1 transcr ... | 2004 | 15336395 |
| sheath rot of rice in iran. | sheath rot of rice occurs in most rice-growing regions of the world. it usually causes yield losses from 20 to 85%. sheath rot was reported from iran in 1993. year after year, the number of diseased plants increased in the northern iran. in summer of 2001, these symptoms were observed in most fields: lesions occur on the upper leaf sheaths, especially the flag leaf sheath. as the disease progresses, lesions enlarge and coalesce and may cover most of the leaf sheath. panicle may fail to completel ... | 2003 | 15151303 |
| cloning, functional characterization, and near-ultraviolet radiation-enhanced expression of a photolyase gene (phr1) from the phytopathogenic fungus bipolaris oryzae. | photolyase is a dna repair enzyme that can absorb blue/ultraviolet a light as energy and split a pyrimidine dimer induced by ultraviolet radiation. we isolated and characterized phr1, a gene encoding photolyase, from the phytopathogenic fungus bipolaris oryzae. sequence analysis showed that phr1 encodes a putative protein that has 634 amino acids, a molecular mass of 72.6 kda, and 51.3-55.5% sequence identity to other fungal photolyases. complementation of the photoreactivation-deficient escheri ... | 2004 | 15138697 |
| expression of thr1, a 1,3,8-trihydroxynaphthalene reductase gene involved in melanin biosynthesis in the phytopathogenic fungus bipolaris oryzae, is enhanced by near-ultraviolet radiation. | 1,3,8-trihydroxynaphthalene (1,3,8-thn) reductase is involved in the production of fungal dihydroxynaphthalene (dhn) melanin. we isolated and characterized thr1, a gene encoding 1,3,8-thn reductase, from the phytopathogenic fungus bipolaris oryzae. sequence analysis showed that thr1 encodes a putative protein of 267 amino acids having a molecular weight of 28.5 kda and 68-98% sequence identity to other fungal 1,3,8-thn reductases. targeted disruption of the thr1 gene showed that it is essential ... | 2004 | 14717841 |
| cloning, functional analysis and expression of a scytalone dehydratase gene ( scd1) involved in melanin biosynthesis of the phytopathogenic fungus bipolaris oryzae. | scytalone dehydratase is involved in the production of fungal dihydroxynaphthalene melanin. we isolated and characterized scd1, a gene encoding scytalone dehydratase, from the phytopathogenic fungus bipolaris oryzae. sequence analysis showed that scd1 encodes a putative protein that has 185 amino acids, a molecular weight of 21 kda and 51-75% sequence identity to other fungal scytalone dehydratases. targeted disruption of scd1 showed that this gene is necessary for melanin biosynthesis in b. ory ... | 2004 | 14716498 |
| the normal mycoflora of commodities from thailand. 2. beans, rice, small grains and other commodities. | part of a comprehensive study of fungi occurring in commodities in thailand, this paper reports results from 276 samples of mung beans, rice, sorghum and soybeans as well as other minor crops. samples for major commodities were taken from farmers' stocks, middlemen and retail outlets, while those for minor crops were mostly from retail. each sample was divided into two portions, one being examined in bangkok and the second at north ryde. mycological examinations were carried out by direct platin ... | 1994 | 7811571 |
| probing the role of tryptophan-derived secondary metabolism in defense responses against bipolaris oryzae infection in rice leaves by a suicide substrate of tryptophan decarboxylase. | tryptophan-derived secondary metabolites, including serotonin and its hydroxycinnamic acid amides, markedly accumulate in rice leaves in response to pathogen attack. these compounds have been implicated in the physical defense system against pathogen invasion by being deposited in cell walls. serotonin is biosynthesized from tryptophan via tryptamine, and tryptophan decarboxylase (tdc) catalyzes the first committed reaction. in this study, (s)-α-(fluoromethyl)tryptophan (s-αfmt) was utilized to ... | 2010 | 21112065 |
| deficiency in silicon uptake affects cytological, physiological, and biochemical events in the rice--bipolaris oryzae interaction. | this study investigated how a defect in the active uptake of silicon (si) affects rice resistance to brown spot. plants from a rice mutant (low silicon 1 [lsi1]) and its wild-type counterpart (cv. oochikara), growing in hydroponic culture with (+si; 2 mm) or without (-si) si, were inoculated with bipolaris oryzae. si concentration in leaf tissue of cv. oochikara and the lsi1 mutant increased by 381 and 263%, respectively, for the +si treatment compared with the -si treatment. the incubation peri ... | 2011 | 20879842 |
| disease-reducing effect of chromolaena odorata extract on sheath blight and other rice diseases. | sheath blight caused by rhizoctonia solani (teleomorph: thanatephorus cucumeris) is a major cause of crop loss in intensive rice production systems. no economically viable control methods have been developed. we screened aqueous extracts of common herbal plants that could reduce sheath blight lesions and found that foliar spraying and seed soaking application of extracts of either fresh or dried leaves of chromolaena odorata gave up to 68% reduction in sheath blight lesion lengths under controll ... | 2011 | 20839964 |
| identification and function of a polyketide synthase gene responsible for 1,8-dihydroxynaphthalene-melanin pigment biosynthesis in ascochyta rabiei. | ascochyta rabiei produces and accumulates one of the well-known fungal polyketides, 1,8-dihydroxynaphthalene-melanin pigment (dhn-melanin), in asexual and sexual fruiting bodies. degenerate pcr primers were used to isolate an arpks1 of a. rabiei encoding a polypeptide with high similarity to polyketide synthase (pks) involved in biosynthesis of dhn-melanin in other ascomycetous fungi. site-directed mutagenesis of arpks1 in a. rabiei generated melanin-deficient pycnidial mutants but caused no sig ... | 2010 | 20473673 |
| the inhibitory effect of the various seed coating substances against rice seed borne fungi and their shelf-life during storage. | presently, chemical seed treatments are in discussion due to their directly or indirectly impacts on human health or other living organisms. they may also negatively affect the ecosystem and the food chain. in rice seeds, chemicals may cause phytotoxic effects including seed degradation. eugenol is the main component of clove (eugenia caryophillis) oil, which was proved to act simultaneously as bactericide, virocide and especially fungicide. the in vitro study was aimed to compare the inhibitory ... | 2009 | 19899320 |
| [cloning and functional analysis of scytalone dehytratase gene in exserohilum turcicum]. | genemonic dna and cdna homologous fragments of the scd (scytalone dehydratase) gene were obtained by polymerase chain reaction (pcr) amplification from degenerated primer sets designed on the basis of the conserved amino acid regions of scytalone dehydratase and polyketide synthase domains from others fungis. the completed cdna sequence of scd in e. turcica was obtained by the method of smart-race and 3' race. there is one open reading frame composed of 181 codons and two deduced introns of 50 a ... | 2007 | 18271256 |
| the tryptophan pathway is involved in the defense responses of rice against pathogenic infection via serotonin production. | the upregulation of the tryptophan (trp) pathway in rice leaves infected by bipolaris oryzae was indicated by: (i) enhanced enzyme activity of anthranilate synthase (as), which regulates metabolic flux in the trp pathway; (ii) elevated levels of the as (oasa2, oasb1, and oasb2) transcripts; and (iii) increases in the contents of anthranilate, indole, and trp. the measurement of the contents of trp-derived metabolites by high-performance liquid chromatography coupled with tandem mass spectrometry ... | 2008 | 18266919 |
| characterizing and estimating rice brown spot disease severity using stepwise regression, principal component regression and partial least-square regression. | detecting plant health conditions plays a key role in farm pest management and crop protection. in this study, measurement of hyperspectral leaf reflectance in rice crop (oryzasativa l.) was conducted on groups of healthy and infected leaves by the fungus bipolaris oryzae (helminthosporium oryzae breda. de hann) through the wavelength range from 350 to 2,500 nm. the percentage of leaf surface lesions was estimated and defined as the disease severity. statistical methods like multiple stepwise re ... | 2007 | 17910117 |
| trichoderma harzianum: a biocontrol agent against bipolaris oryzae. | rice brown spot, caused by bipolaris oryzae, can be a serious disease causing a considerable yield loss. trichoderma harzianum is an effective biocontrol agent for a number of plant fungal diseases. thus, this research was carried out to investigate the mechanisms of action by which t. harzianum antagonizes bipolaris oryzae in vitro, and the efficacy of spray application of a spore suspension of t. harzianum for control of rice brown spot disease under field conditions. in vitro, the antagonisti ... | 2007 | 17592758 |
| co-expression of a modified maize ribosome-inactivating protein and a rice basic chitinase gene in transgenic rice plants confers enhanced resistance to sheath blight. | chitinases, beta-1,3-glucanases, and ribosome-inactivating proteins are reported to have antifungal activity in plants. with the aim of producing fungus-resistant transgenic plants, we co-expressed a modified maize ribosome-inactivating protein gene, mod1, and a rice basic chitinase gene, rch10, in transgenic rice plants. a construct containing mod1 and rch10 under the control of the rice rbcs and act1 promoters, respectively, was co-transformed with a plasmid containing the herbicide-resistance ... | 2003 | 12885168 |