Pseudomonas syringae pv. phaseolicola isolated from weeds in bean crop fields.

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Fernández-Sanz, A M; Rodicio, M R; González, A J

2016-04-01

Pseudomonas syringae pv. phaseolicola, the causative agent of halo blight in common bean (Phaseolus vulgaris L.), was isolated from weeds associated with bean crops in Spain. The bacterium was recovered from Fumaria sp, Mercurialis annua, Solanum nigrum and Sonchus oleraceus. Ps. s. pv. phaseolicola had previously been isolated from leguminous plants and S. nigrum, but to our knowledge, this is the first time it was recovered from the other three species. The isolates were phenotypically and genetically characterized, and they were compared with isolates recovered from common beans. Five different genotypic profiles were detected by PmeI-PFGE, two of them being of new description. Weed isolates were as pathogenic on bean plants as bean isolates, but they were not pathogenic on S. nigrum. Regarding the survival of the pathogen in weeds, Ps. s. pv. phaseolicola was isolated from So. oleraceus 11 weeks after the end of the bean crop. These results strongly support the idea of weeds as a potential source of inoculum for halo blight in bean. It has traditionally been considered that the main source of inoculum of Pseudomonas syringae pv. phaseolicola causing halo blight disease in Phaseolus vulgaris are the bean seeds, and that the host range of the bacterium is almost restricted to leguminous plants. In this study, the bacterium was recovered from four nonleguminous weed species collected in bean fields, and its permanence in weeds for at least 11 weeks after the harvesting of the beans was demonstrated. We have also proved that the strains isolated from weeds were pathogenic on bean plants. Accordingly, the host range of Ps. s. pv. phaseolicola could be broader than previously thought and weeds appear to be acting as a reservoir of the pathogen until the next crop. © 2016 The Society for Applied Microbiology.

BOX-PCR-based identification of bacterial species belonging to Pseudomonas syringae: P. viridiflava group

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Abi S.A. Marques

2008-01-01

Full Text Available The phenotypic characteristics and genetic fingerprints of a collection of 120 bacterial strains, belonging to Pseudomonas syringae sensu lato group, P. viridiflava and reference bacteria were evaluated, with the aim of species identification. The numerical analysis of 119 nutritional characteristics did not show patterns that would help with identification. Regarding the genetic fingerprinting, the results of the present study supported the observation that BOX-PCR seems to be able to identify bacterial strains at species level. After numerical analyses of the bar-codes, all pathovars belonging to each one of the nine described genomospecies were clustered together at a distance of 0.72, and could be separated at genomic species level. Two P. syringae strains of unknown pathovars (CFBP 3650 and CFBP 3662 and the three P. syringae pv. actinidiae strains were grouped in two extra clusters and might eventually constitute two new species. This genomic species clustering was particularly evident for genomospecies 4, which gathered P. syringae pvs. atropurpurea, coronafaciens, garçae, oryzae, porri, striafaciens, and zizaniae at a noticeably low distance.

Differentiation of Pseudomonas syringae Pathovars Originating from Stone Fruits

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Katarina Gašić

2012-01-01

Full Text Available Due to an overlapping host range, similar symptomatology and many common characteristics,Pseudomonas syringae pathovars originating from stone fruits can easily be misidentified.In order to select tests for rapid and efficient differentiation of P. s. pvs. syringae,morsprunorum and persicae, we studied the suitability and differentiating potential ofsome standard bacteriological and molecular methods. Differentiation of the strains wasperformed using LOPAT, GATTa and ice nucleation tests, nutrient sucrose broth growthand utilization of various carbon sources. PCR method enabled the detection of toxin-producinggenes: syrB and syrD in P. s. pv. syringae, and cfl gene in P. s. pv. morsprunorum race1. Syringomycin production by pv. syringae was confirmed in bioassay using Geotrichumcandidum, Saccharomyces cerevisiae and Rhodotorula pilimanae as indicator organisms.Pathogenicity test on lemon and immature nectarine fruits, as well as on string bean pods,showed different intensity of reaction of the inoculated material which could separate pv.syringae from the other two pathovars. PCR-based repetitive sequences, Rep-PCR withREP, ERIC and BOX primers revealed different genetic profiles within P. syringae pathovars.

Inhibition of apoptic cell death induced by Pseudomonas syringae pv. Tabaci and mycotoxin fumonisin B1

NARCIS (Netherlands)

Iakimova, E.T.; Batchvorova, R.; Kapchina, V.; Popov, T.; Atanassov, A.; Woltering, E.J.

2004-01-01

The impact of programmed cell death (PCD) inhibitors on lesion formation and biochemical events in transgenic (ttr line) and non-transgenic (Nevrokop 1164) tobacco infected with Pseudomonas syringae pv. tabaci was tested. Programmed cell death in tomato cell culture was induced by Fumonisin B1 (FUM)

Phenotypic and Genotypic Evaluation of Pseudomonas syringae pv. syringae Strains, Causing Citrus Blast in the West of Mazandaran and the East of Guilan

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S. Sameie-Shirkadeh

2017-01-01

Full Text Available Introduction: P. syringae pv. syringae (P.s.s, the causal agent of blast of citrus trees, is one of the most important plant pathogens in the world. P.s.s is unique among most P. syringae pathovars according to its ability to cause disease in over 180 species of plants in several unrelated genera. Traditionally, Strains of P.s.s are identified on the basis of biochemical and nutritional tests and symptom expression in host plants. Genomic fingerprinting methods based on the polymerase chain reaction (PCR have been applied for identification and classification of plant-associated bacteria to the subspecies level. The objectives of this study were the phenotypic and molecular evaluation of P.s. pv. syringae strains causing citrus blast in the West of Mazandaran and the East of Guilan, and study of genetic diversity of P.s.s isolates of citrus by using ERIC and REP-PCR markers. Materials and Methods: During 2011 to 2012, citrus infected tissues were sampled from different orchards in the West of Mazandaran and the East of Guilan. Bacterial phenotypes were studied based on standard physiological and biochemical tests. Gram reaction was determined by potassium hydroxide solubility test (KOH test. Strains were grown on King'B medium (KB and fluorescent pigment production was evaluated. Levan formation, oxidase reaction, potato soft rot, Arginine dihydrolase and induction of the hypersensitive reaction in tobacco leaves (LOPAT tests, were done as described by Schadd et al. The standard strains of P.s. pv. syringae form IVIA were used as reference strains in this study. Pathogenicity Test was done as described by Yessad et al. Citrus seedlings were maintained in a greenhouse at 20°C. In addition, a PCR-based method was used to confirm the genus and species of bacteria by using bacterial specific primer pair’s designed for a specific gene of syringomycin B. Genetic diversity among the strains, was studied by rep-PCR fingerprinting. Genomic

Characterization of five ECF sigma factors in the genome of Pseudomonas syringae pv. syringae B728a.

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Poulami Basu Thakur

Full Text Available Pseudomonas syringae pv. syringae B728a, a bacterial pathogen of bean, utilizes large surface populations and extracellular signaling to initiate a fundamental change from an epiphytic to a pathogenic lifestyle. Extracytoplasmic function (ECF sigma (σ factors serve as important regulatory factors in responding to various environmental signals. Bioinformatic analysis of the B728a genome revealed 10 ECF sigma factors. This study analyzed deletion mutants of five previously uncharacterized ECF sigma factor genes in B728a, including three FecI-type ECF sigma factors (ECF5, ECF6, and ECF7 and two ECF sigma factors placed in groups ECF11 and ECF18. Transcriptional profiling by qRT-PCR analysis of ECF sigma factor mutants was used to measure expression of their associated anti-sigma and outer membrane receptor proteins, and expression of genes associated with production of extracellular polysaccharides, fimbriae, glycine betaine and syringomycin. Notably, the B728aΔecf7 mutant displayed reduced swarming and had decreased expression of CupC fimbrial genes. Growth and pathogenicity assays, using a susceptible bean host, revealed that none of the tested sigma factor genes are required for in planta growth and lesion formation.

Assessment of strains of Pseudomonas syringae pv. tomato from Tanzania for resistance to copper and streptomycin

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Shenge, K.C.; Wydra, K.; Mabagala, M.B.

2008-01-01

Fifty-six strains of Pseudomonas syringae pv. tomato (P.s. pv. tomato) were collected from tomato-producing areas in Tanzania and assessed for resistance to copper and antibiotics. The collection was done from three tomato-producing regions (Morogoro, Arusha and Iringa), representing three...... different ecological conditions in the country. After isolation and identification, the P. s. pv. tomato strains were grown on King's medium B (KB) amended with 20% copper sulphate (w/v). The strains were also assessed for resistance to antibiotics. Results indicated that there was widespread resistance...... strains of the pathogen were moderately resistant to copper sulphate, such that 54.0% of them were able to grow on the KB medium amended with 20% (w/v) of the copper compound....

Pseudomonas syringae pv. actinidiae: a re-emerging, multi-faceted, pandemic pathogen.

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Scortichini, Marco; Marcelletti, Simone; Ferrante, Patrizia; Petriccione, Milena; Firrao, Giuseppe

2012-09-01

Pseudomonas syringae pv. actinidiae is the causal agent of bacterial canker of green-fleshed kiwifruit (Actinidia deliciosa) and yellow-fleshed kiwifruit (A. chinensis). A recent, sudden, re-emerging wave of this disease has occurred, almost contemporaneously, in all of the main areas of kiwifruit production in the world, suggesting that it can be considered as a pandemic disease. Recent in-depth genetic studies performed on P. syringae pv. actinidiae strains have revealed that this pathovar is composed of four genetically different populations which, to different extents, can infect crops of the genus Actinidia worldwide. Genome comparisons of these strains have revealed that this pathovar can gain and lose the phaseolotoxin gene cluster, as well as mobile genetic elements, such as plasmids and putative prophages, and that it can modify the repertoire of the effector gene arrays. In addition, the strains currently causing worldwide severe economic losses display an extensive set of genes related to the ecological fitness of the bacterium in planta, such as copper and antibiotic resistance genes, multiple siderophore genes and genes involved in the degradation of lignin derivatives and other phenolics. This pathogen can therefore easily colonize hosts throughout the year. Bacteria; Proteobacteria, gamma subdivision; Order Pseudomonadales; Family Pseudomonadaceae; Genus Pseudomonas; Pseudomonas syringae species complex, genomospecies 8; Pathovar actinidiae. Gram-negative, aerobic, motile, rod-shaped, polar flagella, oxidase-negative, arginine dihydrolase-negative, DNA 58.5-58.8 mol.% GC, elicits the hypersensitive response on tobacco leaves. Primarily studied as the causal agent of bacterial canker of green-fleshed kiwifruit (Actinidia deliciosa), it has also been isolated from yellow-fleshed kiwifruit (A. chinensis). In both species, it causes severe economic losses worldwide. It has also been isolated from wild A. arguta and A. kolomikta. In green-fleshed and

Isolation and sequence analysis of the Pseudomonas syringae pv. tomato gene encoding a 2,3-diphosphoglycerate-independent phosphoglyceromutase.

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Morris, V L; Jackson, D P; Grattan, M; Ainsworth, T; Cuppels, D A

1995-01-01

Pseudomonas syringae pv. tomato DC3481, a Tn5-induced mutant of the tomato pathogen DC3000, cannot grow and elicit disease symptoms on tomato seedlings. It also cannot grow on minimal medium containing malate, citrate, or succinate, three of the major organic acids found in tomatoes. We report here that this mutant also cannot use, as a sole carbon and/or energy source, a wide variety of hexoses and intermediates of hexose catabolism. Uptake studies have shown that DC3481 is not deficient in transport. A 3.8-kb EcoRI fragment of DC3000 DNA, which complements the Tn5 mutation, has been cloned and sequenced. The deduced amino acid sequences of two of the three open reading frames (ORFs) present on this fragment, ORF2 and ORF3, had no significant homology with sequences in the GenBank databases. However, the 510-amino-acid sequence of ORF1, the site of the Tn5 insertion, strongly resembled the deduced amino acid sequences of the Bacillus subtilis and Zea mays genes encoding 2,3-diphosphoglycerate (DPG)-independent phosphoglyceromutase (PGM) (52% identity and 72% similarity and 37% identity and 57% similarity, respectively). PGMs not requiring the cofactor DPG are usually found in plants and algae. Enzyme assays confirmed that P. syringae PGM activity required an intact ORF1. Not only is DC3481 the first PGM-deficient pseudomonad mutant to be described, but the P. syringae pgm gene is the first gram-negative bacterial gene identified that appears to code for a DPG-independent PGM. PGM activity appears essential for the growth and pathogenicity of P. syringae pv. tomato on its host plant. PMID:7896694

Isolation and sequence analysis of the Pseudomonas syringae pv. tomato gene encoding a 2,3-diphosphoglycerate-independent phosphoglyceromutase.

Science.gov (United States)

Morris, V L; Jackson, D P; Grattan, M; Ainsworth, T; Cuppels, D A

1995-04-01

Pseudomonas syringae pv. tomato DC3481, a Tn5-induced mutant of the tomato pathogen DC3000, cannot grow and elicit disease symptoms on tomato seedlings. It also cannot grow on minimal medium containing malate, citrate, or succinate, three of the major organic acids found in tomatoes. We report here that this mutant also cannot use, as a sole carbon and/or energy source, a wide variety of hexoses and intermediates of hexose catabolism. Uptake studies have shown that DC3481 is not deficient in transport. A 3.8-kb EcoRI fragment of DC3000 DNA, which complements the Tn5 mutation, has been cloned and sequenced. The deduced amino acid sequences of two of the three open reading frames (ORFs) present on this fragment, ORF2 and ORF3, had no significant homology with sequences in the GenBank databases. However, the 510-amino-acid sequence of ORF1, the site of the Tn5 insertion, strongly resembled the deduced amino acid sequences of the Bacillus subtilis and Zea mays genes encoding 2,3-diphosphoglycerate (DPG)-independent phosphoglyceromutase (PGM) (52% identity and 72% similarity and 37% identity and 57% similarity, respectively). PGMs not requiring the cofactor DPG are usually found in plants and algae. Enzyme assays confirmed that P. syringae PGM activity required an intact ORF1. Not only is DC3481 the first PGM-deficient pseudomonad mutant to be described, but the P. syringae pgm gene is the first gram-negative bacterial gene identified that appears to code for a DPG-independent PGM. PGM activity appears essential for the growth and pathogenicity of P. syringae pv. tomato on its host plant.

Screening of gamma radiation-induced pathogen resistance rice lines against Xanthomonas oryzae pv. oryzae

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Lim, Chan Ju; Lee, Ha Yeon; Kim, Woong Bom; Ahmad, Raza; Moon, Jae Sun; Kwon, Suk Yoon [Korea Research Institute of Beoscience and Biotechnology, Daejeon (Korea, Republic of); Kim, Dong Sub [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

2010-09-15

Bacterial blight is one of the most serious diseases of rice (Oryza sativa L.), and it has been known that Xanthomonas oryzae pv. oryzae (Xoo) causes this disease symptom. To develop resistance rice cultivars against Xoo, 3,000 lines of M{sub 3}, which were irradiated with gamma ray, were tested by 'scissor-dip method' primarily, and 191 putative resistant lines were selected. In M{sub 4} generation, these lines were screened again with various ways such as measuring of symptom of bacterial blight in leaf, number of tiller, fresh weight, and phenotypic segregation ratio in next generation. Finally, six resistance lines were selected. RT-PCR analysis revealed that these lines displayed high level of R-genes such as Xa21, Pi36, and Pi-ta. These results indicate that mutations by gamma ray cause disruptions of regulatory signal transduction systems of these R-genes. Furthermore, these selected mutants could be useful for the development of rice cultivar resistant to Xoo.

Virulence of the Phytopathogen Pseudomonas syringae pv. Maculicola Is rpoN Dependent

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Hendrickson, Erik L.; Guevera, Pablo; Peñaloza-Vàzquez, Alejandro; Shao, Jing; Bender, Carol; Ausubel, Frederick M.

2000-01-01

We cloned the rpoN (ntrA and glnF) gene encoding ς54 from the phytopathogen Pseudomonas syringae pv. maculicola strain ES4326. The P. syringae ES4326 rpoN gene complemented Pseudomonas aeruginosa, Escherichia coli, and Klebsiella aerogenes rpoN mutants for a variety of rpoN mutant phenotypes, including the inability to utilize nitrate as sole nitrogen source. DNA sequence analysis of the P. syringae ES4326 rpoN gene revealed that the deduced amino acid sequence was most similar (86% identity; 95% similarity) to the ς54 protein encoded by the Pseudomonas putida rpoN gene. A marker exchange protocol was used to construct an ES4326 rpoN insertional mutation, rpoN::Kmr. In contrast to wild-type ES4326, ES4326 rpoN::Kmr was nonmotile and could not utilize nitrate, urea, C4-dicarboxylic acids, several amino acids, or concentrations of ammonia below 2 mM as nitrogen sources. rpoN was essential for production of the phytotoxin coronatine and for expression of the structural genes encoding coronamic acid. In addition, ES4326 rpoN::Kmr did not multiply or elicit disease symptoms when infiltrated into Arabidopsis thaliana leaves, did not elicit the accumulation of several Arabidopsis defense-related mRNAs, and did not elicit a hypersensitive response (HR) when infiltrated into tobacco (Nicotiana tabacum) leaves. Furthermore, whereas P. syringae ES4326 carrying the avirulence gene avrRpt2 elicited an HR when infiltrated into Arabidopsis ecotype Columbia leaves, ES4326 rpoN::Kmr carrying avrRpt2 elicited no response. Constitutive expression of ES4326 hrpL in ES4326 rpoN::Kmr partially restored defense-related mRNA accumulation, showing a direct role for the hrp cluster in host defense gene induction in a compatible host-pathogen interaction. However, constitutive expression of hrpL in ES4326 rpoN::Kmr did not restore coronatine production, showing that coronatine biosynthesis requires factors other than hrpL. PMID:10852883

Identification of Pectin Degrading Enzymes Secreted by Xanthomonas oryzae pv. oryzae and Determination of Their Role in Virulence on Rice

OpenAIRE

Tayi, Lavanya; Maku, Roshan V.; Patel, Hitendra Kumar; Sonti, Ramesh V.

2016-01-01

Xanthomonas oryzae pv.oryzae (Xoo) causes the serious bacterial blight disease of rice. Xoo secretes a repertoire of plant cell wall degrading enzymes (CWDEs) like cellulases, xylanases, esterases etc., which act on various components of the rice cell wall. The major cellulases and xylanases secreted by Xoo have been identified and their role in virulence has been determined. In this study, we have identified some of the pectin degrading enzymes of Xoo and assessed their role in virulence. Bi...

First report of bacterial speck of tomato caused by Pseudomonas syringae pv. tomato race 1 in Portugal

OpenAIRE

Cruz, L.; Cruz, J.; Eloy, M.; Oliveira, Helena; Vaz, H.; Tenreiro, R.

2010-01-01

Protected and open field tomato crops are economically important for Portuguese agriculture. In 1983, Pseudomonas syringae pv. tomato (Okabe, 1933) Young, Dye & Wilkie, 1978 was first reported affecting protected crops (3) and then later under open field conditions (1). In the 2009 spring/summer season, several outbreaks of bacterial speck of tomato showing an unusual degree of severity were observed in open fields from the Tagus Valley Region

Expression, crystallization and preliminary X-ray crystallographic analysis of Xoo0352, d-alanine-d-alanine ligase A, from Xanthomonas oryzae pv. oryzae

International Nuclear Information System (INIS)

Doan, Thanh Thi Ngoc; Kim, Jin-Kwang; Kim, Hyesoon; Ahn, Yeh-Jin; Kim, Jeong-Gu; Lee, Byoung-Moo; Kang, Lin-Woo

2008-01-01

Xoo0352, which encodes d-alanine-d-alanine ligase A (DdlA), from X. oryzae pv. oryzae was cloned, purified and crystallized. Preliminary X-ray crystallographic analysis of DdlA crystals was performed. Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial blight (BB), which is one of the most devastating diseases of rice in most rice-growing countries. d-Alanine-d-alanine ligase A (DdlA), coded by the Xoo0352 gene, was expressed, purified and crystallized. DdlA is an enzyme that is involved in d-alanine metabolism and the biosynthesis of an essential bacterial peptidoglycan precursor, in which it catalyzes the formation of d-alanyl-d-alanine from two d-alanines, and is thus an attractive antibacterial drug target against Xoo. The DdlA crystals diffracted to 2.3 Å resolution and belonged to the primitive tetragonal space group P4 3 2 1 2, with unit-cell parameters a = b = 83.0, c = 97.6 Å. There is one molecule in the asymmetric unit, with a corresponding V M of 1.88 Å 3 Da −1 and a solvent content of 34.6%. The initial structure was determined by molecular replacement using d-alanine-d-alanine ligase from Staphylococcus aureus as a template model

Pseudomonas syringae pv. Tomato DC3000 Type III secretion effector polymutants reveal an interplay between hopAD1 and AvrPtoB

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The model pathogen Pseudomonas syringae pv. tomato DC3000 suppresses the two-tiered innate immune system of plants by injecting a complex repertoire of effector proteins into host cells via the type III secretion system. The model effector AvrPtoB has multiple domains and plant protein interactors i...

Pathotype profile of Xanthomonas oryzae pv. oryzae isolates from North Sumatera

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Noer, Z.; Hasanuddin; Lisnawita; Suryanto, D.

2018-02-01

The Bacterial blight disease caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most important diseases and has caused crop failure in rice crops. This pathogen infects the leaves in all plant growth phases. The purpose of this study is to investigation 10 Xoo isolates pathotype obtained from North Sumatra based on their interactions with 10 near-isogenic rice lines (NIL) of IRRI. The results showed that there are 6 pathotypes of virulence in North Sumatra, they are; pathotype I with incompatible interaction to all Xa genes, pathotype II with compatible interaction to Xa1 and Xa3 genes, while it has incompatible interaction to other genes, pathotype III with compatible interaction to Xa1, Xa5, Xa7, Xa8, Xa10 and Xa11 genes, but it has incompatible interaction to other genes, pathotype IV with compatible interaction to all Xa genes, pathotype V with compatible interaction to Xa1 gene and incompatible interaction to other genes, and pathotype VI with compatible interaction to Xa3 gene and incompatible interaction to other genes. Based on the resistant genes in each individual Xa2, Xa4, and Xa21 genes are the combination of Xa genes which are most suitable for use in the development of rice cultivars in North Sumatra.

Impact of Engineered Nanoparticles on Virulence of Xanthomonas oryzae pv oryzae and on Rice Sensitivity at its Infection

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Giuliano Degrassi

2014-12-01

Full Text Available The present work of nanocotoxicity wants to propose a new plant model starting from the rice plant. The model takes into consideration the impact of engineered nanoparticles (Ag, Co, Ni, CeO2, Fe3O4, TiO2 on rice plants that were weakened by infections of Xanthomonas oryzae pv oryzae bacteria. The results indicate that some NPs increase the rice sensitivity to the pathogen while others decrease the virulence of the pathogen towards rice. No-enrichment in component metal concentration is detected in above organs of rice, with exception of Ni-NPs treatment. An imbalance of major elements in infected rice crops treated with NPs was investigated.

Resistant and susceptible responses in alfalfa (Medicago sativa to bacterial stem blight caused by Pseudomonas syringae pv. syringae.

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Lev G Nemchinov

Full Text Available Bacterial stem blight caused by Pseudomonas syringae pv. syringae is a common disease of alfalfa (Medicago sativa L. Little is known about host-pathogen interactions and host defense mechanisms. Here, individual resistant and susceptible plants were selected from cultivars Maverick and ZG9830 and used for transcript profiling at 24 and 72 hours after inoculation (hai with the isolate PssALF3. Bioinformatic analysis revealed a number of differentially expressed genes (DEGs in resistant and susceptible genotypes. Although resistant plants from each cultivar produced a hypersensitive response, transcriptome analyses indicated that they respond differently at the molecular level. The number of DEGs was higher in resistant plants of ZG9830 at 24 hai than in Maverick, suggesting that ZG9830 plants had a more rapid effector triggered immune response. Unique up-regulated genes in resistant ZG9830 plants included genes encoding putative nematode resistance HSPRO2-like proteins, orthologs for the rice Xa21 and soybean Rpg1-b resistance genes, and TIR-containing R genes lacking both NBS and LRR domains. The suite of R genes up-regulated in resistant Maverick plants had an over-representation of R genes in the CC-NBS-LRR family including two genes for atypical CCR domains and a putative ortholog of the Arabidopsis RPM1 gene. Resistance in both cultivars appears to be mediated primarily by WRKY family transcription factors and expression of genes involved in protein phosphorylation, regulation of transcription, defense response including synthesis of isoflavonoids, and oxidation-reduction processes. These results will further the identification of mechanisms involved in resistance to facilitate selection of parent populations and development of commercial varieties.

Fungicidal activities and mechanisms of action of Pseudomonas syringae pv. syringae lipodepsipeptide syringopeptins 22A and 25A

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Mekki F. Bensaci

2011-10-01

Full Text Available The plant-associated bacterium Pseudomonas syringae pv. syringae simultaneously produces two classes of metabolites: the small cyclic lipodepsinonapeptides such as the syringomycins and the larger cyclic lipodepsipeptide syringopeptins SP22 or SP25. The syringomycins inhibit a broad spectrum of fungi (but particularly yeasts by lipid-dependent membrane interaction. The syringopeptins are phytotoxic and inhibitory to Gram positive bacteria. In this study, the fungicidal activities of two major syringopeptins, SP22A and SP25A, and their mechanisms of action were investigated and compared to those of syringomycin E. SP22A and SP25A were observed to inhibit the fungal yeasts Saccharomyces cerevisiae and Candida albicans although less effectively than syringomycin E. S. cerevisiae mutants defective in ergosterol and sphingolipid biosyntheses were less susceptible to SP22A and SP25A but the relative inhibitory capabilities of SRE vs. SP22A and SP25A were maintained. Similar differences were observed for capabilities to cause cellular K+ and Ca2+ fluxes in S. cerevisiae. Interestingly, in phospholipid bilayers the syringopeptins are found to induce larger macroscopic ionic conductances than syringomycin E but form single channels with similar properties. These findings suggest that the syringopeptins target the yeast plasma membrane, and, like syringomycin E, employ a lipid-dependent channel forming mechanism of action. The differing degrees of growth inhibition by these lipodepsipeptides may be explained by differences in their hydrophobicity. The more hydrophobic SP22A and SP25A might interact more strongly with the yeast cell wall that would create a selective barrier for their incorporation into the plasma membrane.

Characterization of Pseudomonas syringae pv. syringae, Causal Agent of Citrus Blast of Mandarin in Montenegro

OpenAIRE

Ivanovi?, ?arko; Perovi?, Tatjana; Popovi?, Tatjana; Blagojevi?, Jovana; Trkulja, Nenad; Hrn?i?, Snje?ana

2017-01-01

Citrus blast caused by bacterium Pseudomonas syringae is a very important disease of citrus occuring in many areas of the world, but with few data about genetic structure of the pathogen involved. Considering the above fact, this study reports genetic characterization of 43 P. syringae isolates obtained from plant tissue displaying citrus blast symptoms on mandarin (Citrus reticulata) in Montenegro, using multilocus sequence analysis of gyrB, rpoD, and gap1 gene sequences. Gene sequences from...

PATHOTYPE GROUPING OF Xanthomonas oryzae pv. oryzae ISOLATES FROM SOUTH SULAWESI AND SOUTHEAST SULAWESI

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Andi Khaeruni

2013-06-01

Full Text Available Bacterial leaf blight caused by Xanthomonas oryzae pv. oryzae (Xoo is an important rice disease, and has caused significant economic losses. This research aimed to determine the pathotype grouping and the distribution of Xoo isolates of South and Southeast Sulawesi. In order to obtain the information, 61 Xoo isolates of South Sulawesi and 29 isolates of Southeast Sulawesi were evaluated for their pathotype grouping against 5 diffential varieties. Research results showed that in South Sulawesi there were 2 pathotype groups, namely pathotype IV (32.79% and pathotype VIII(67.21%. Pathotype VIII was widely distributed over the Western and Central areas of South Sulawesi, whereas pathotype IV was widely distributed over the Southern area. In Southeast Sulawesi, it was found 5 pathotypes, namely pathotypes IV (27.58%, VI (10.34%, VIII (13.79%, IX (20.68%, and X (27.58%, with a limited and scattered distribution pattern on several areas. These results indicate that Xoo pathotype groups in South Sulawesi and Southeast Sulawesi are varied and tend to sift to more virulent pathotypes.

Integration Host Factor (IHF binds to the promoter region of the phtD operon involved in phaseolotoxin synthesis in P. syringae pv. phaseolicola NPS3121

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Álvarez-Morales Ariel

2011-05-01

Full Text Available Abstract Background Pseudomonas syringae pv. phaseolicola, the causal agent of halo blight disease in beans, produces a toxin known as phaseolotoxin, in whose synthesis participate a group of genes organized within the genome in a region known as the "Pht cluster". This region, which is thought to have been acquired by horizontal gene transfer, includes 5 transcriptional units, two monocistronic (argK, phtL and three polycistronic (phtA, phtD, phtM, whose expression is temperature dependent. So far, the regulatory mechanisms involved in phaseolotoxin synthesis have not been elucidated and the only well-established fact is the requirement of low temperatures for its synthesis. In this work, we searched for regulatory proteins that could be involved in phaseolotoxin synthesis, focusing on the regulation of the phtD operon. Results In this study we identified the global regulator IHF (Integration Host Factor, which binds to the promoter region of the phtD operon, exerting a negative effect on the expression of this operon. This is the first regulatory protein identified as part of the phaseolotoxin synthesis system. Our findings suggest that the Pht cluster was similarly regulated in the ancestral cluster by IHF or similar protein, and integrated into the global regulatory mechanism of P. syringae pv. phaseolicola, after the horizontal gene transfer event by using the host IHF protein. Conclusion This study identifies the IHF protein as one element involved in the regulation of phaseolotoxin synthesis in P. syringae pv. phaseolicola NPS3121 and provides new insights into the regulatory mechanisms involved in phaseolotoxin production.

A mutation in the aroE gene affects pigment production, virulence, and chemotaxis in Xanthomonas oryzae pv. oryzae.

Science.gov (United States)

Kim, Hong-Il; Noh, Tae-Hwan; Lee, Chang-Soo; Park, Young-Jin

2015-01-01

Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial blight (BB) in rice. To study its function, a random insertion mutation library of Xoo was constructed using the Tn5 transposon. A mutant strain with decreased virulence against the susceptible rice cultivar IR24 was isolated from the library (aroE mutant), which also had extremely low pigment production. Thermal asymmetric interlaced-polymerase chain reaction (TAIL-PCR) and sequence analysis of the mutant revealed that the transposon was inserted into the aroE gene (encoding shikimate dehydrogenase). To investigate gene expression changes in the pigment- and virulence-deficient mutant, DNA microarray analysis was performed, which showed downregulation of 20 genes involved in the chemotaxis of Xoo. Our findings reveal that mutation of the aroE gene affects virulence and pigment production, as well as expression of genes involved in Xoo chemotaxis. Copyright © 2014 Elsevier GmbH. All rights reserved.

Miniature transposable sequences are frequently mobilized in the bacterial plant pathogen Pseudomonas syringae pv. phaseolicola.

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Leire Bardaji

Full Text Available Mobile genetic elements are widespread in Pseudomonas syringae, and often associate with virulence genes. Genome reannotation of the model bean pathogen P. syringae pv. phaseolicola 1448A identified seventeen types of insertion sequences and two miniature inverted-repeat transposable elements (MITEs with a biased distribution, representing 2.8% of the chromosome, 25.8% of the 132-kb virulence plasmid and 2.7% of the 52-kb plasmid. Employing an entrapment vector containing sacB, we estimated that transposition frequency oscillated between 2.6×10(-5 and 1.1×10(-6, depending on the clone, although it was stable for each clone after consecutive transfers in culture media. Transposition frequency was similar for bacteria grown in rich or minimal media, and from cells recovered from compatible and incompatible plant hosts, indicating that growth conditions do not influence transposition in strain 1448A. Most of the entrapped insertions contained a full-length IS801 element, with the remaining insertions corresponding to sequences smaller than any transposable element identified in strain 1448A, and collectively identified as miniature sequences. From these, fragments of 229, 360 and 679-nt of the right end of IS801 ended in a consensus tetranucleotide and likely resulted from one-ended transposition of IS801. An average 0.7% of the insertions analyzed consisted of IS801 carrying a fragment of variable size from gene PSPPH_0008/PSPPH_0017, showing that IS801 can mobilize DNA in vivo. Retrospective analysis of complete plasmids and genomes of P. syringae suggests, however, that most fragments of IS801 are likely the result of reorganizations rather than one-ended transpositions, and that this element might preferentially contribute to genome flexibility by generating homologous regions of recombination. A further miniature sequence previously found to affect host range specificity and virulence, designated MITEPsy1 (100-nt, represented an average 2

Miniature transposable sequences are frequently mobilized in the bacterial plant pathogen Pseudomonas syringae pv. phaseolicola.

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Bardaji, Leire; Añorga, Maite; Jackson, Robert W; Martínez-Bilbao, Alejandro; Yanguas-Casás, Natalia; Murillo, Jesús

2011-01-01

Mobile genetic elements are widespread in Pseudomonas syringae, and often associate with virulence genes. Genome reannotation of the model bean pathogen P. syringae pv. phaseolicola 1448A identified seventeen types of insertion sequences and two miniature inverted-repeat transposable elements (MITEs) with a biased distribution, representing 2.8% of the chromosome, 25.8% of the 132-kb virulence plasmid and 2.7% of the 52-kb plasmid. Employing an entrapment vector containing sacB, we estimated that transposition frequency oscillated between 2.6×10(-5) and 1.1×10(-6), depending on the clone, although it was stable for each clone after consecutive transfers in culture media. Transposition frequency was similar for bacteria grown in rich or minimal media, and from cells recovered from compatible and incompatible plant hosts, indicating that growth conditions do not influence transposition in strain 1448A. Most of the entrapped insertions contained a full-length IS801 element, with the remaining insertions corresponding to sequences smaller than any transposable element identified in strain 1448A, and collectively identified as miniature sequences. From these, fragments of 229, 360 and 679-nt of the right end of IS801 ended in a consensus tetranucleotide and likely resulted from one-ended transposition of IS801. An average 0.7% of the insertions analyzed consisted of IS801 carrying a fragment of variable size from gene PSPPH_0008/PSPPH_0017, showing that IS801 can mobilize DNA in vivo. Retrospective analysis of complete plasmids and genomes of P. syringae suggests, however, that most fragments of IS801 are likely the result of reorganizations rather than one-ended transpositions, and that this element might preferentially contribute to genome flexibility by generating homologous regions of recombination. A further miniature sequence previously found to affect host range specificity and virulence, designated MITEPsy1 (100-nt), represented an average 2.4% of the total

Direct suppression of a rice bacterial blight (Xanthomonas oryzae pv. oryzae) by monoterpene (S)-limonene.

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Lee, Gun Woong; Chung, Moon-Soo; Kang, Mihyung; Chung, Byung Yeoup; Lee, Sungbeom

2016-05-01

Rice bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo), is a severe disease of rice plants. Upon pathogen infection, rice biosynthesizes phytoalexins, including diterpenoids such as momilactones, phytocassanes, and oryzalexins. However, information on headspace volatiles in response to Xoo infection is limited. We have examined headspace volatile terpenes, induced by the infection of Xoo, and investigated their biological roles in the rice plant. Monoterpenes α-thujene, α-pinene, sabinene, myrcene, α-terpene, and (S)-limonene and sesquiterpenes cyclosativene, α-copaene, and β-elemene were detected from 1-week-old Xoo-infected rice seedlings, by solid-phase microextraction-gas chromatography-mass spectrometry. All monoterpenes were constitutively released from rice seedlings before Xoo infection. However, (S)-limonene emission was further elicited after exposure of the seedlings to Xoo in coincidence with upregulation of limonene synthase gene (OsTPS20) transcripts. Only the stereospecific (S)-limonene [and not (R)-limonene or other monoterpenes] severely inhibited Xoo growth, as confirmed by disc diffusion and liquid culture assays. Rice seedlings showed suppressed pathogenic symptoms suggestive of resistance to Xoo infection after foliar treatment with (S)-limonene. Collectively, our findings suggest that (S)-limonene is a volatile phytoanticipin, which plays a significant role in suppressing Xoo growth in rice seedlings.

Anatomical changes on coffee leaves infected by Pseudomonas syringae pv. garcae

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Lucas Mateus Rivero Rodrigues

2015-12-01

Full Text Available ABSTRACTAlthough poorly studied, the bacterial halo blight is an important disease in the major coffee-producing states of Brazil. External damage and anatomical changes on leaves were measured in seedlings of Coffea arabica cv. Mundo Novo, susceptible to Pseudomonas syringae pv. garcae, by using histological sections obtained at 10 and 20 days after inoculation (DAI. The changes on the epidermis were smaller than the lesions measured in the mesophyll, irrespective of the evaluated colonization period, showing that the internal damage caused by the bacterium represent twice the damage observed externally. From the inoculation site, lysis occurred on the epidermal cells and on the palisade and spongy parenchyma cells, with strong staining of their cellular contents, as well as abnormal intercellular spaces in the palisade parenchyma, hypertrophy and hyperplasia of mesophyll cells and partial destruction of chloroplasts. Additionally, this study revealed the presence of inclusion bodies in epidermal and mesophyll cells. Bacterial masses were found in the apoplast between and within mesophyll cells. Bacteria were also observed in the bundle sheath and vascular bundles and were more pronounced at 20 DAI, not only near the inoculation site but also in distant areas, suggesting displacement through the vascular system. These results can be useful to understand this plant-pathogen interaction.

The mbo operon is specific and essential for biosynthesis of mangotoxin in Pseudomonas syringae.

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Carrión, Víctor J; Arrebola, Eva; Cazorla, Francisco M; Murillo, Jesús; de Vicente, Antonio

2012-01-01

Mangotoxin is an antimetabolite toxin produced by certain Pseudomonas syringae pv. syringae strains. This toxin is an oligopeptide that inhibits ornithine N-acetyl transferase, a key enzyme in the biosynthesis of ornithine and arginine. Previous studies have reported the involvement of the putative nonribosomal peptide synthetase MgoA in virulence and mangotoxin production. In this study, we analyse a new chromosomal region of P. syringae pv. syringae UMAF0158, which contains six coding sequences arranged as an operon (mbo operon). The mbo operon was detected in only mangotoxin-producing strains, and it was shown to be essential for the biosynthesis of this toxin. Mutants in each of the six ORFs of the mbo operon were partially or completely impaired in the production of the toxin. In addition, Pseudomonas spp. mangotoxin non-producer strains transformed with the mbo operon gained the ability to produce mangotoxin, indicating that this operon contains all the genetic information necessary for mangotoxin biosynthesis. The generation of a single transcript for the mbo operon was confirmed and supported by the allocation of a unique promoter and Rho-independent terminator. The phylogenetic analysis of the P. syringae strains harbouring the mbo operon revealed that these strains clustered together.

The rice XA21 ectodomain fused to the Arabidopsis EFR cytoplasmic domain confers resistance to Xanthomonas oryzae pv. oryzae.

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Thomas, Nicholas C; Oksenberg, Nir; Liu, Furong; Caddell, Daniel; Nalyvayko, Alina; Nguyen, Yen; Schwessinger, Benjamin; Ronald, Pamela C

2018-01-01

Rice ( Oryza sativa ) plants expressing the XA21 cell-surface receptor kinase are resistant to Xanthomonas oryzae pv. oryzae (Xoo) infection. We previously demonstrated that expressing a chimeric protein containing the ELONGATION FACTOR Tu RECEPTOR (EFR) ectodomain and the XA21 endodomain (EFR:XA21) in rice does not confer robust resistance to Xoo . To test if the XA21 ectodomain is required for Xoo resistance, we produced transgenic rice lines expressing a chimeric protein consisting of the XA21 ectodomain and EFR endodomain (XA21:EFR) and inoculated these lines with Xoo . We also tested if the XA21:EFR rice plants respond to a synthetic sulfated 21 amino acid derivative (RaxX21-sY) of the activator of XA21-mediated immunity, RaxX. We found that five independently transformed XA21:EFR rice lines displayed resistance to Xoo as measured by lesion length analysis, and showed that five lines share characteristic markers of the XA21 defense response (generation of reactive oxygen species and defense response gene expression) after treatment with RaxX21-sY. Our results indicate that expression of the XA21:EFR chimeric receptor in rice confers resistance to Xoo . These results suggest that the endodomain of the EFR and XA21 immune receptors are interchangeable and the XA21 ectodomain is the key determinant conferring robust resistance to Xoo .

Pathovars of Pseudomonas syringae Causing Bacterial Brown Spot and Halo Blight in Phaseolus vulgaris L. Are Distinguishable by Ribotyping

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González, Ana J.; Landeras, Elena; Mendoza, M. Carmen

2000-01-01

Ribotyping was evaluated as a method to differentiate between Pseudomonas syringae pv. phaseolicola and pv. syringae strains causing bacterial brown spot and halo blight diseases in Phaseolus vulgaris L. Ribotyping, with restriction enzymes BglI and SalI and using the Escherichia coli rrnB operon as the probe, differentiated 11 and 14 ribotypes, respectively, and a combination of data from both procedures yielded 19 combined ribotypes. Cluster analysis of the combined ribotypes differentiated the pathovars phaseolicola and syringae, as well as different clonal lineages within these pathovars. The potential of ribotyping to screen for correlations between lineages and factors such as geographical region and/or bean varieties is also reported. PMID:10653764

Using the concept of pseudo amino acid composition to predict resistance gene against Xanthomonas oryzae pv. oryzae in rice: an approach from chaos games representation.

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Jingbo, Xia; Silan, Zhang; Feng, Shi; Huijuan, Xiong; Xuehai, Hu; Xiaohui, Niu; Zhi, Li

2011-09-07

To evaluate the possibility of an unknown protein to be a resistant gene against Xanthomonas oryzae pv. oryzae, a different mode of pseudo amino acid composition (PseAAC) is proposed to formulate the protein samples by integrating the amino acid composition, as well as the Chaos games representation (CGR) method. Some numerical comparisons of triangle, quadrangle and 12-vertex polygon CGR are carried to evaluate the efficiency of using these fractal figures in classifiers. The numerical results show that among the three polygon methods, triangle method owns a good fractal visualization and performs the best in the classifier construction. By using triangle + 12-vertex polygon CGR as the mathematical feature, the classifier achieves 98.13% in Jackknife test and MCC achieves 0.8462. Copyright © 2011 Elsevier Ltd. All rights reserved.

Transcriptome analysis of WRKY gene family in Oryza officinalis Wall ex Watt and WRKY genes involved in responses to Xanthomonas oryzae pv. oryzae stress.

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Jiang, Chunmiao; Shen, Qingxi J; Wang, Bo; He, Bin; Xiao, Suqin; Chen, Ling; Yu, Tengqiong; Ke, Xue; Zhong, Qiaofang; Fu, Jian; Chen, Yue; Wang, Lingxian; Yin, Fuyou; Zhang, Dunyu; Ghidan, Walid; Huang, Xingqi; Cheng, Zaiquan

2017-01-01

Oryza officinalis Wall ex Watt, a very important and special wild rice species, shows abundant genetic diversity and disease resistance features, especially high resistance to bacterial blight. The molecular mechanisms of bacterial blight resistance in O. officinalis have not yet been elucidated. The WRKY transcription factor family is one of the largest gene families involved in plant growth, development and stress response. However, little is known about the numbers, structure, molecular phylogenetics, and expression of the WRKY genes under Xanthomonas oryzae pv. oryzae (Xoo) stress in O. officinalis due to lacking of O. officinalis genome. Therefore, based on the RNA-sequencing data of O. officinalis, we performed a comprehensive study of WRKY genes in O. officinalis and identified 89 OoWRKY genes. Then 89 OoWRKY genes were classified into three groups based on the WRKY domains and zinc finger motifs. Phylogenetic analysis strongly supported that the evolution of OoWRKY genes were consistent with previous studies of WRKYs, and subgroup IIc OoWRKY genes were the original ancestors of some group II and group III OoWRKYs. Among the 89 OoWRKY genes, eight OoWRKYs displayed significantly different expression (>2-fold, pWRKY family of transcription factors in O.officinalis. Insight was gained into the classification, evolution, and function of the OoWRKY genes, revealing the putative roles of eight significantly different expression OoWRKYs in Xoo strains PXO99 and C5 stress responses in O.officinalis. This study provided a better understanding of the evolution and functions of O. officinalis WRKY genes, and suggested that manipulating eight significantly different expression OoWRKYs would enhance resistance to bacterial blight.

Comparative Transcriptome Profiling of Rice Near-Isogenic Line Carrying Xa23 under Infection of Xanthomonas oryzae pv. oryzae.

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Tariq, Rezwan; Wang, Chunlian; Qin, Tengfei; Xu, Feifei; Tang, Yongchao; Gao, Ying; Ji, Zhiyuan; Zhao, Kaijun

2018-03-02

Bacterial blight, caused by Xanthomonas oryzae pv. oryzae ( Xoo ), is an overwhelming disease in rice-growing regions worldwide. Our previous studies revealed that the executor R gene Xa23 confers broad-spectrum disease resistance to all naturally occurring biotypes of Xoo . In this study, comparative transcriptomic profiling of two near-isogenic lines (NILs), CBB23 (harboring Xa23 ) and JG30 (without Xa23 ), before and after infection of the Xoo strain, PXO99 A , was done by RNA sequencing, to identify genes associated with the resistance. After high throughput sequencing, 1645 differentially expressed genes (DEGs) were identified between CBB23 and JG30 at different time points. Gene Ontlogy (GO) analysis categorized the DEGs into biological process, molecular function, and cellular component. KEGG analysis categorized the DEGs into different pathways, and phenylpropanoid biosynthesis was the most prominent pathway, followed by biosynthesis of plant hormones, flavonoid biosynthesis, and glycolysis/gluconeogenesis. Further analysis led to the identification of differentially expressed transcription factors (TFs) and different kinase responsive genes in CBB23, than that in JG30. Besides TFs and kinase responsive genes, DEGs related to ethylene, jasmonic acid, and secondary metabolites were also identified in both genotypes after PXO99 A infection. The data of DEGs are a precious resource for further clarifying the network of Xa23 -mediated resistance.

PENENTUAN PATOTIPE DAN KERAGAMAN GENETIK Xanthomonas oryzae pv. oryzae PADA TANAMAN PADI DI WILAYAH KARESIDENAN BANYUMAS

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Heru Adi Djatmiko

2011-11-01

Full Text Available One of the major diseases of rice paddy fields in Indonesia and the Asian countries is bacterial leaf blight or kresek caused by X. oryzae pv. oryzae (Xoo. Losses caused by the disease in Indonesia reached 70–80%, in India reached 74–81%, and Japan reached 20–50%, thus causing great losses in the economy. The objectives of that research were: 1 Characterize Xoo from Karesidenan Banyumas; 2 To study of the amount of damage and AUDPC (the area under disease progress curve of bacterial leaf blight disease at Karesidenan Banyumas; 3 To obtain of Xoo pathotype by using the test varieties; 4 To obtaining genetic diversity of Xoo that found in Banjarnegara, Purbalingga, Banyumas, Cilacap dan Kebumen region. Research was carried out in several stages: isolation and characterization of Xoo from Barlingmascakeb region, testing of Xoo with five varieties testing, assesment of disease intensity of bacterial leaf blight and AUDPC in the field, and testing the genetic diversity of Xoo. The results showed that pathogen of bacterial blight on rice is Xoo characterized yellow colour of colonies on SPA medium, negative gram reaction, catalase positive, oxidase negative, negative growth at 0.1% TZC, negative starch hydrolisis , and resistance to 0.001% Cu(NO32 positive. Xoo pathotype isolats found in Banjarnegara was pathotype X, Cilacap were pathotype I and II and Purbalingga was pathotype II. Eighteen of Xoo from Karesidenan Banyumas (Banjarnegara, Purbalingga, Banyumas, Cilacap and Kebumen of RAPD differ one from the others.

Variation in extragenic repetitive DNA sequences in Pseudomonas syringae and potential use of modified REP primers in the identification of closely related isolates

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Elif Çepni

2012-01-01

Full Text Available In this study, Pseudomonas syringe pathovars isolated from olive, tomato and bean were identified by species-specific PCR and their genetic diversity was assessed by repetitive extragenic palindromic (REP-PCR. Reverse universal primers for REP-PCR were designed by using the bases of A, T, G or C at the positions of 1, 4 and 11 to identify additional polymorphism in the banding patterns. Binding of the primers to different annealing sites in the genome revealed additional fingerprint patterns in eight isolates of P. savastanoi pv. savastanoi and two isolates of P. syringae pv. tomato. The use of four different bases in the primer sequences did not affect the PCR reproducibility and was very efficient in revealing intra-pathovar diversity, particularly in P. savastanoi pv. savastanoi. At the pathovar level, the primer BOX1AR yielded shared fragments, in addition to five bands that discriminated among the pathovars P. syringae pv. phaseolicola, P. savastanoi pv. savastanoi and P. syringae pv. tomato. REP-PCR with a modified primer containing C produced identical bands among the isolates in a pathovar but separated three pathovars more distinctly than four other primers. Although REP-and BOX-PCRs have been successfully used in the molecular identification of Pseudomonas isolates from Turkish flora, a PCR based on inter-enterobacterial repetitive intergenic concensus (ERIC sequences failed to produce clear banding patterns in this study.

Endophytic Streptomyces spp. as Biocontrol Agents of Rice Bacterial Leaf Blight Pathogen (Xanthomonas oryzae pv. oryzae

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RATIH DEWI HASTUTI

2012-12-01

Full Text Available Xanthomonas oryzae pv. oryzae (Xoo, a causal agent of bacterial leaf blight (BLB, is one of the most important pathogens of rice. The effectiveness of ten Streptomyces spp. isolates in suppressing Xoo disease was assessed in planta and in vitro. In planta experiments were carried out in a greenhouse and arranged in a randomized completely block design (RCBD with three replications. Twenty treatments were tested which included plants inoculated with both Streptomyces spp. and Xoo, and plants inoculated with only Streptomyces spp. Plants inoculated with Xoo and sprayed with a chemical bactericide, and plants inoculated with only Xoo served as positive controls, whereas plants not inoculated with either Streptomyces spp. or Xoo were used as negative controls. The results showed that the effect of endophytic Streptomyces spp. on BLB disease expressed as area under disease progress curve (AUDPC was not significantly different to that on control plants (P > 0.05. However, plants inoculated with endophytic Streptomyces spp. were significantly taller and produced higher tiller number than control plants (P < 0.05. Streptomyces spp. isolate AB131-1 gave the highest plant height. In vitro studies on biocontrol mechanisms of selected Streptomyces spp. isolates showed that isolate LBR02 gave the highest inhibition activity on Xoo growth, followed by AB131-1 and AB131-2. Two isolates (AB131-1 and LBR02 were able to produce chitinase, phosphatase, and siderophore which included biocontrol characteristics. Morphological and colonization studies under SEM and light microscopy confirmed that the three isolates were endophytic Streptomyces spp. from different species. These studies found that the paddy plant which was inoculated with endophytic Streptomyces spp. AB131-1 and infected by Xoo could increase the height of plant and number of tillers.

Natural variation for responsiveness to flg22, flgII-28, and csp22 and Pseudomonas syringae pv. tomato in heirloom tomatoes.

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Selvakumar Veluchamy

Full Text Available Tomato (Solanum lycopersicum L. is susceptible to many diseases including bacterial speck caused by Pseudomonas syringae pv. tomato. Bacterial speck disease is a serious problem worldwide in tomato production areas where moist conditions and cool temperatures occur. To enhance breeding of speck resistant fresh-market tomato cultivars we identified a race 0 field isolate, NC-C3, of P. s. pv. tomato in North Carolina and used it to screen a collection of heirloom tomato lines for speck resistance in the field. We observed statistically significant variation among the heirloom tomatoes for their response to P. s. pv. tomato NC-C3 with two lines showing resistance approaching a cultivar that expresses the Pto resistance gene, although none of the heirloom lines have Pto. Using an assay that measures microbe-associated molecular pattern (MAMP-induced production of reactive oxygen species (ROS, we investigated whether the heirloom lines showed differential responsiveness to three bacterial-derived peptide MAMPs: flg22 and flgII-28 (from flagellin and csp22 (from cold shock protein. Significant differences were observed for MAMP responsiveness among the lines, although these differences did not correlate strongly with resistance or susceptibility to bacterial speck disease. The identification of natural variation for MAMP responsiveness opens up the possibility of using a genetic approach to identify the underlying loci and to facilitate breeding of cultivars with enhanced disease resistance. Towards this goal, we discovered that responsiveness to csp22 segregates as a single locus in an F2 population of tomato.

Infection processes of xylem-colonizing pathogenic bacteria: possible explanations for the scarcity of qualitative disease resistance genes against them in crops.

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Bae, Chungyun; Han, Sang Wook; Song, Yu-Rim; Kim, Bo-Young; Lee, Hyung-Jin; Lee, Je-Min; Yeam, Inhwa; Heu, Sunggi; Oh, Chang-Sik

2015-07-01

Disease resistance against xylem-colonizing pathogenic bacteria in crops. Plant pathogenic bacteria cause destructive diseases in many commercially important crops. Among these bacteria, eight pathogens, Ralstonia solanacearum, Xanthomonas oryzae pv. oryzae, X. campestris pv. campestris, Erwinia amylovora, Pantoea stewartii subsp. stewartii, Clavibacter michiganensis subsp. michiganensis, Pseudomonas syringae pv. actinidiae, and Xylella fastidiosa, infect their host plants through different infection sites and paths and eventually colonize the xylem tissues of their host plants, resulting in wilting symptoms by blocking water flow or necrosis of xylem tissues. Noticeably, only a relatively small number of resistant cultivars in major crops against these vascular bacterial pathogens except X. oryzae pv. oryzae have been found or generated so far, although these pathogens threaten productivity of major crops. In this review, we summarize the lifestyles of major xylem-colonizing bacterial pathogens and then discuss the progress of current research on disease resistance controlled by qualitative disease resistance genes or quantitative trait loci against them. Finally, we propose infection processes of xylem-colonizing bacterial pathogens as one of possible reasons for why so few qualitative disease resistance genes against these pathogens have been developed or identified so far in crops.

Transcriptional Dynamics Driving MAMP-Triggered Immunity and Pathogen Effector-Mediated Immunosuppression in Arabidopsis Leaves Following Infection with Pseudomonas syringae pv tomato DC3000.

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Lewis, Laura A; Polanski, Krzysztof; de Torres-Zabala, Marta; Jayaraman, Siddharth; Bowden, Laura; Moore, Jonathan; Penfold, Christopher A; Jenkins, Dafyd J; Hill, Claire; Baxter, Laura; Kulasekaran, Satish; Truman, William; Littlejohn, George; Prusinska, Justyna; Mead, Andrew; Steinbrenner, Jens; Hickman, Richard; Rand, David; Wild, David L; Ott, Sascha; Buchanan-Wollaston, Vicky; Smirnoff, Nick; Beynon, Jim; Denby, Katherine; Grant, Murray

2015-11-01

Transcriptional reprogramming is integral to effective plant defense. Pathogen effectors act transcriptionally and posttranscriptionally to suppress defense responses. A major challenge to understanding disease and defense responses is discriminating between transcriptional reprogramming associated with microbial-associated molecular pattern (MAMP)-triggered immunity (MTI) and that orchestrated by effectors. A high-resolution time course of genome-wide expression changes following challenge with Pseudomonas syringae pv tomato DC3000 and the nonpathogenic mutant strain DC3000hrpA- allowed us to establish causal links between the activities of pathogen effectors and suppression of MTI and infer with high confidence a range of processes specifically targeted by effectors. Analysis of this information-rich data set with a range of computational tools provided insights into the earliest transcriptional events triggered by effector delivery, regulatory mechanisms recruited, and biological processes targeted. We show that the majority of genes contributing to disease or defense are induced within 6 h postinfection, significantly before pathogen multiplication. Suppression of chloroplast-associated genes is a rapid MAMP-triggered defense response, and suppression of genes involved in chromatin assembly and induction of ubiquitin-related genes coincide with pathogen-induced abscisic acid accumulation. Specific combinations of promoter motifs are engaged in fine-tuning the MTI response and active transcriptional suppression at specific promoter configurations by P. syringae. © 2015 American Society of Plant Biologists. All rights reserved.

A resistance locus in the American heirloom rice variety Carolina Gold Select is triggered by TAL effectors with diverse predicted targets and is effective against African strains of Xanthomonas oryzae pv. oryzicola.

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Triplett, Lindsay R; Cohen, Stephen P; Heffelfinger, Christopher; Schmidt, Clarice L; Huerta, Alejandra I; Tekete, Cheick; Verdier, Valerie; Bogdanove, Adam J; Leach, Jan E

2016-09-01

The rice pathogens Xanthomonas oryzae pathovar (pv.) oryzae and pv. oryzicola produce numerous transcription activator-like (TAL) effectors that increase bacterial virulence by activating expression of host susceptibility genes. Rice resistance mechanisms against TAL effectors include polymorphisms that prevent effector binding to susceptibility gene promoters, or that allow effector activation of resistance genes. This study identifies, in the heirloom variety Carolina Gold Select, a third mechanism of rice resistance involving TAL effectors. This resistance manifests through strong suppression of disease development in response to diverse TAL effectors from both X. oryzae pathovars. The resistance can be triggered by an effector with only 3.5 central repeats, is independent of the composition of the repeat variable di-residues that determine TAL effector binding specificity, and is independent of the transcriptional activation domain. We determined that the resistance is conferred by a single dominant locus, designated Xo1, that maps to a 1.09 Mbp fragment on chromosome 4. The Xo1 interval also confers complete resistance to the strains in the African clade of X. oryzae pv. oryzicola, representing the first dominant resistance locus against bacterial leaf streak in rice. The strong phenotypic similarity between the TAL effector-triggered resistance conferred by Xo1 and that conferred by the tomato resistance gene Bs4 suggests that monocots and dicots share an ancient or convergently evolved mechanism to recognize analogous TAL effector epitopes. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

A rapid seedling resistance assay identifies wild tomato lines that are resistant to Psuedomonas syringe pv. tomato race 1

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Bacterial speck caused by Pseudomonas syringae has historically been controlled by the Pto/Prf gene cluster. Emerging strains like P. syringae pv. tomato race 1 overcome resistance conferred by Pto/Prf, and can cause serious crop loss under appropriate environmental conditions. We developed a rapid ...

Overexpression of Rice Auxilin-Like Protein, XB21, Induces Necrotic Lesions, up-Regulates Endocytosis-Related Genes, and Confers Enhanced Resistance to Xanthomonas oryzae pv. oryzae.

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Park, Chang-Jin; Wei, Tong; Sharma, Rita; Ronald, Pamela C

2017-12-01

The rice immune receptor XA21 confers resistance to the bacterial pathogen, Xanthomonas oryzae pv. oryzae (Xoo). To elucidate the mechanism of XA21-mediated immunity, we previously performed a yeast two-hybrid screening for XA21 interactors and identified XA21 binding protein 21 (XB21). Here, we report that XB21 is an auxilin-like protein predicted to function in clathrin-mediated endocytosis. We demonstrate an XA21/XB21 in vivo interaction using co-immunoprecipitation in rice. Overexpression of XB21 in rice variety Kitaake and a Kitaake transgenic line expressing XA21 confers a necrotic lesion phenotype and enhances resistance to Xoo. RNA sequencing reveals that XB21 overexpression results in the differential expression of 8735 genes (4939 genes up- and 3846 genes down-regulated) (≥2-folds, FDR ≤0.01). The up-regulated genes include those predicted to be involved in 'cell death' and 'vesicle-mediated transport'. These results indicate that XB21 plays a role in the plant immune response and in regulation of cell death. The up-regulation of genes controlling 'vesicle-mediated transport' in XB21 overexpression lines is consistent with a functional role for XB21 as an auxilin.

Conductimetric detection of Pseudomonas syringae pathover pisi in pea seeds and soft rot Erwinia spp. on potato tubers

NARCIS (Netherlands)

Fraaije, B.

1996-01-01

Pea bacterial blight and potato blackleg are diseases caused by Pseudomonas syringae pv. pisi ( Psp ) and soft rot Erwinia spp., respectively. The primary source of inoculum for these bacteria is

Differential secretome analysis of Pseudomonas syringae pv tomato using gel-free MS proteomics

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Jörg eSchumacher

2014-07-01

Full Text Available The plant pathogen Pseudomonas syringae pv. tomato (DC3000 causes virulence by delivering effector proteins into host plant cells through its type three secretion system (T3SS. In response to the plant environment DC3000 expresses hypersensitive response and pathogenicity genes (hrp. Pathogenesis depends on the ability of the pathogen to manipulate the plant metabolism and to inhibit plant immunity, which depends to a large degree on the plant’s capacity to recognise both pathogen and microbial determinants (PAMP/MAMP-triggered immunity. We have developed and employed MS-based shotgun and targeted proteomics to (i elucidate the extracellular and secretome composition of DC3000 and (ii evaluate temporal features of the assembly of the T3SS and the secretion process together with its dependence of pH. The proteomic screen, under hrp inducing in vitro conditions, of extracellular and cytoplasmatic fractions indicated the segregated presence of not only T3SS implicated proteins such as HopK1, HrpK1, HrpA1 and Avrpto1, but also of proteins not usually associated with the T3SS or with pathogenicity. Using multiple reaction monitoring MS (MRM-MS to quantify HrpA1 and Avrpto1, we found that HrpA1 is rapidly expressed, at a strict pH-dependent rate and is post-translationally processed extracellularly. These features appear to not interfere with rapid Avrpto1 expression and secretion but may suggest some temporal post-translational regulatory mechanism of the T3SS assembly. The high specificity and sensitivity of the MRM-MS approach should provide a powerful tool to measure secretion and translocation in infected tissues.

Association and Expression of Virulence from Plasmids of the Group B Strain in Pseudomonas syringae pv. eriobotryae

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Tran Dang Khanh

2018-04-01

Full Text Available Pseudomonas syringae pv. eriobotryae causes serious stem canker in loquat (Eriobotrya japonica trees. This study was conducted to determine whether plasmids are involved with its virulence. The strain NAE89, which belonged to the B group, harbored two plasmids at approximately 6.2 and 50 Mdal that caused stem canker and halo leaf spots on loquat plants. Following digestion with BamHI and ligation into the BamHI cloning site of the broad range host cosmid pLAFR3, four DNA fragments at 3.8, 6.6, 12.3, and 22.8 kb were generated. Although the plasmid-encoded virulence gene psvA was undigested with the BamHI, the halo leaf spot gene may be adjacent to the psvA gene was digested. A pLAFR3 cosmid clone was introduced into the non-pathogenic PE0 and NAE89-1 strains by triparental matings and the pathogenicity was recovered. As a result, the pLAFR3 cosmid clone was introduced into the largest size DNA fragment of 22.8 kb and determined to be the causal agent of canker on the stem of the loquat. This study revealed that the psvA gene, previously found in the 50 Mdal plasmid, was also observed in the 22.8 kb DNA fragment.

Pseudomonas savastanoi pv. savastanoi: some like it knot.

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Ramos, Cayo; Matas, Isabel M; Bardaji, Leire; Aragón, Isabel M; Murillo, Jesús

2012-12-01

Pseudomonas savastanoi pv. savastanoi is the causal agent of olive (Olea europaea) knot disease and an unorthodox member of the P. syringae complex, causing aerial tumours instead of the foliar necroses and cankers characteristic of most members of this complex. Olive knot is present wherever olive is grown; although losses are difficult to assess, it is assumed that olive knot is one of the most important diseases of the olive crop. The last century witnessed a large number of scientific articles describing the biology, epidemiology and control of this pathogen. However, most P. savastanoi pv. savastanoi strains are highly recalcitrant to genetic manipulation, which has effectively prevented the pathogen from benefitting from the scientific progress in molecular biology that has elevated the foliar pathogens of the P. syringae complex to supermodels. A number of studies in recent years have made significant advances in the biology, ecology and genetics of P. savastanoi pv. savastanoi, paving the way for the molecular dissection of its interaction with other nonpathogenic bacteria and their woody hosts. The selection of a genetically pliable model strain was soon followed by the development of rapid methods for virulence assessment with micropropagated olive plants and the analysis of cellular interactions with the plant host. The generation of a draft genome of strain NCPPB 3335 and the closed sequence of its three native plasmids has allowed for functional and comparative genomic analyses for the identification of its pathogenicity gene complement. This includes 34 putative type III effector genes and genomic regions, shared with other pathogens of woody hosts, which encode metabolic pathways associated with the degradation of lignin-derived compounds. Now, the time is right to explore the molecular basis of the P. savastanoi pv. savastanoi-olive interaction and to obtain insights into why some pathovars like it necrotic and why some like it knot

Dissection of Resistance Genes to Pseudomonas syringae pv. phaseolicola in UI3 Common Bean Cultivar.

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González, Ana M; Godoy, Luís; Santalla, Marta

2017-11-23

Few quantitative trait loci have been mapped for resistance to Pseudomonas syringae pv. phaseolicola in common bean. Two F₂ populations were developed from the host differential UI3 cultivar. The objective of this study was to further characterize the resistance to races 1, 5, 7 and 9 of Psp included in UI3. Using a QTL mapping approach, 16 and 11 main-effect QTLs for pod and primary leaf resistance were located on LG10, explaining up to 90% and 26% of the phenotypic variation, respectively. The homologous genomic region corresponding to primary leaf resistance QTLs detected tested positive for the presence of resistance-associated gene cluster encoding nucleotide-binding and leucine-rich repeat (NL), Natural Resistance Associated Macrophage (NRAMP) and Pentatricopeptide Repeat family (PPR) proteins. It is worth noting that the main effect QTLs for resistance in pod were located inside a 3.5 Mb genomic region that included the Phvul.010G021200 gene, which encodes a protein that has the highest sequence similarity to the RIN4 gene of Arabidopsis, and can be considered an important candidate gene for the organ-specific QTLs identified here. These results support that resistance to Psp from UI3 might result from the immune response activated by combinations of R proteins, and suggest the guard model as an important mechanism in pod resistance to halo blight. The candidate genes identified here warrant functional studies that will help in characterizing the actual defense gene(s) in UI3 genotype.

The role of crop waste and soil in Pseudomonas syringae pathovar porri infection of leek (Allium porrum)

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Overbeek, van L.S.; Nijhuis, E.H.; Koenraadt, H.; Visser, J.H.M.

2010-01-01

Pseudomonas syringae pv. porri, the causal agent of bacterial blight of leek, is a current threat for leek (Allium porrum) production in the Netherlands. The roles of post-harvest crop waste and plant invasion from soil in leek plant infection was investigated with the purpose to gain better

HrcQ is necessary for Xanthomonas oryzae pv. oryzae HR-induction in non-host tobacco and pathogenicity in host rice

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Xiaoping Zhang

2013-12-01

Full Text Available Bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo, is one of the most destructive diseases of rice (Oryza sativa L. worldwide. The type III secretion system (T3SS of Xoo, encoded by the hrp (hypersensitive response and pathogenicity genes, plays critical roles in conferring pathogenicity in host rice and triggering a hypersensitive response (HR in non-host plants. To investigate the major genes conferring the pathogenicity and avirulence of Xoo, we previously constructed a random Tn5-insertion mutant library of Xoo strain PXO99A. We report here the isolation and characterization of a Tn5-insertion mutant PXM69. Tn5-insertion mutants were screened on indica rice JG30, which is highly susceptible to PXO99A, by leaf-cutting inoculation. Four mutants with reduced virulence were obtained after two rounds of screening. Among them, the mutant PXM69 had completely lost virulence to the rice host and ability to elicit HR in non-host tobacco. Southern blotting analysis showed a single copy of a Tn5-insertion in the genome of PXM69. PCR walking and sequencing analysis revealed that the Tn5 transposon was inserted at nucleotide position 70,192–70,201 in the genome of PXO99A, disrupting the type III hrc (hrp-conserved gene hrcQ, the first gene in the D operon of the hrp cluster in Xoo. To confirm the relationship between the Tn5-insertion and the avirulence phenotype of PXM69, we used the marker exchange mutagenesis to create a PXO99A mutant, ΔhrcQ::KAN, in which the hrcQ was disrupted by a kanamycin-encoding gene cassette at the same site as that of the Tn5-insertion. ΔhrcQ::KAN showed the same phenotype as mutant PXM69. Reintroduction of the wild-type hrcQ gene partially complemented the pathogenic function of PXM69. RT-PCR and cellulase secretion assays showed that the Tn5-disruption of hrcQ did not affect transcription of downstream genes in the D operon and function of the type II secretion system. Our results provide new insights into

HrcQ is necessary for Xanthomonas oryzae pv. oryzae HR-induction in non-host tobacco and pathogenicity in host rice

Institute of Scientific and Technical Information of China (English)

Xiaoping; Zhang; Chunlian; Wang; Chongke; Zheng; Jinying; Che; Yanqiang; Li; Kaijun; Zhao

2013-01-01

Bacterial blight, caused by Xanthomonas oryzae pv. oryzae(Xoo), is one of the most destructive diseases of rice(Oryza sativa L.) worldwide. The type III secretion system(T3SS) of Xoo, encoded by the hrp(hypersensitive response and pathogenicity) genes, plays critical roles in conferring pathogenicity in host rice and triggering a hypersensitive response(HR) in non-host plants. To investigate the major genes conferring the pathogenicity and avirulence of Xoo, we previously constructed a random Tn5-insertion mutant library of Xoo strain PXO99A. We report here the isolation and characterization of a Tn5-insertion mutant PXM69. Tn5-insertion mutants were screened on indica rice JG30, which is highly susceptible to PXO99A, by leaf-cutting inoculation.Four mutants with reduced virulence were obtained after two rounds of screening. Among them, the mutant PXM69 had completely lost virulence to the rice host and ability to elicit HR in non-host tobacco. Southern blotting analysis showed a single copy of a Tn5-insertion in the genome of PXM69. PCR walking and sequencing analysis revealed that the Tn5 transposon was inserted at nucleotide position 70,192–70,201 in the genome of PXO99A, disrupting the type III hrc(hrp-conserved) gene hrcQ, the first gene in the D operon of the hrp cluster in Xoo. To confirm the relationship between the Tn5-insertion and the avirulence phenotype of PXM69, we used the marker exchange mutagenesis to create a PXO99Amutant, ΔhrcQ::KAN, in which the hrcQ was disrupted by a kanamycin-encoding gene cassette at the same site as that of the Tn5-insertion. ΔhrcQ::KAN showed the same phenotype as mutant PXM69. Reintroduction of the wild-type hrcQ gene partially complemented the pathogenic function of PXM69. RT-PCR and cellulase secretion assays showed that the Tn5-disruption of hrcQ did not affect transcription of downstream genes in the D operon and function of the type II secretion system. Our results provide new insights into the pathogenic

OxyR-regulated catalase CatB promotes the virulence in rice via detoxifying hydrogen peroxide in Xanthomonas oryzae pv. oryzae.

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Yu, Chao; Wang, Nu; Wu, Maosen; Tian, Fang; Chen, Huamin; Yang, Fenghuan; Yuan, Xiaochen; Yang, Ching-Hong; He, Chenyang

2016-11-08

To facilitate infection, Xanthomonas oryzae pv. oryzae (Xoo), the bacterial blight pathogen of rice, needs to degrade hydrogen peroxide (H 2 O 2 ) generated by the host defense response via a mechanism that is mediated by the transcriptional regulator OxyR. The catalase (CAT) gene catB has previously been shown to belong to the OxyR regulon in Xoo. However, its expression patterns and function in H 2 O 2 detoxification and bacterial pathogenicity on rice remain to be elucidated. The catB gene encodes a putative catalase and is highly conserved in the sequenced strains of Xanthomonas spp. β-galactosidase analysis and electrophoretic mobility shift assays (EMSA) showed that OxyR positively regulated the transcription of catB by directly binding to its promoter region. The quantitative real-time PCR (qRT-PCR) assays revealed that the expression levels of catB and oxyR were significantly induced by H 2 O 2 . Deletion of catB or oxyR drastically impaired bacterial viability in the presence of extracellular H 2 O 2 and reduced CAT activity, demonstrating that CatB and OxyR contribute to H 2 O 2 detoxification in Xoo. In addition, ΔcatB and ΔoxyR displayed shorter bacterial blight lesions and reduced bacterial growth in rice compared to the wild-type stain, indicating that CatB and OxyR play essential roles in the virulence of Xoo. Transcription of catB is enhanced by OxyR in response to exogenous H 2 O 2 . CatB functions as an active catalase that is required for the full virulence of Xoo in rice.

Modular Study of the Type III Effector Repertoire in Pseudomonas syringae pv. tomato DC3000 Reveals a Matrix of Effector Interplay in Pathogenesis

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Hai-Lei Wei

2018-05-01

Full Text Available Summary: The bacterial pathogen Pseudomonas syringae pv. tomato DC3000 suppresses the two-tiered innate immune system of Nicotiana benthamiana and other plants by injecting a complex repertoire of type III secretion effector (T3E proteins. Effectorless polymutant DC3000D36E was used with a modularized system for native delivery of the 29 DC3000 T3Es singly and in pairs. Assays of the performance of this T3E library in N. benthamiana leaves revealed a matrix of T3E interplay, with six T3Es eliciting death and eight others variously suppressing the death activity of the six. The T3E library was also interrogated for effects on DC3000D36E elicitation of a reactive oxygen species burst, for growth in planta, and for T3Es that reversed these effects. Pseudomonas fluorescens and Agrobacterium tumefaciens heterologous delivery systems yielded notably different sets of death-T3Es. The DC3000D36E T3E library system highlights the importance of 13 T3Es and their interplay in interactions with N. benthamiana. : Wei et al. used a Pseudomonas syringae strain lacking all known type III effectors with a modularized library expressing the 29 active effectors in the strain’s native repertoire, individually and in pairs, to comprehensively determine effector actions and interplay in inducing and suppressing responses associated with plant pathogenesis and immunity. Keywords: effector-triggered-immunity, pattern-triggered-immunity, Hop proteins, plant immunity, mini-Tn7

Rice Snl6, a cinnamoyl-CoA reductase-like gene family member, is required for NH1-mediated immunity to Xanthomonas oryzae pv. oryzae.

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Rebecca S Bart

2010-09-01

Full Text Available Rice NH1 (NPR1 homolog 1 is a key mediator of innate immunity. In both plants and animals, the innate immune response is often accompanied by rapid cell death at the site of pathogen infection. Over-expression of NH1 in rice results in resistance to the bacterial pathogen, Xanthomonas oryzae pv. oryzae (Xoo, constitutive expression of defense related genes and enhanced benzothiadiazole (BTH- mediated cell death. Here we describe a forward genetic screen that identified a suppressor of NH1-mediated lesion formation and resistance, snl6. Comparative genome hybridization and fine mapping rapidly identified the genomic location of the Snl6 gene. Snl6 is a member of the cinnamoyl-CoA reductase (CCR-like gene family. We show that Snl6 is required for NH1-mediated resistance to Xoo. Further, we show that Snl6 is required for pathogenesis-related gene expression. In contrast to previously described CCR family members, disruption of Snl6 does not result in an obvious morphologic phenotype. Snl6 mutants have reduced lignin content and increased sugar extractability, an important trait for the production of cellulosic biofuels. These results suggest the existence of a conserved group of CCR-like genes involved in the defense response, and with the potential to alter lignin content without affecting development.

Response of tobacco to the Pseudomonas syringae pv. Tomato DC3000 is mainly dependent on salicylic acid signaling pathway.

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Liu, Yang; Wang, Li; Cai, Guohua; Jiang, Shanshan; Sun, Liping; Li, Dequan

2013-07-01

Pseudomonas syringae pv. Tomato DC3000 (Pst DC3000) was the first pathogen to be demonstrated to infect Arabidopsis and to cause disease symptoms in the laboratory setting. However, the defense response to Pst DC3000 was unclear in tobacco. In this report, the expression profiles of twelve defense response-related genes were analyzed after treatment with salicylic acid (SA), jasmonic acid (JA), and pathogen Pst DC3000 by qRT-PCR. According to our results, it could be presented that the genes primarily induced by SA were also induced to higher levels after Pst DC3000 infection. SA accumulation could be induced to a higher level than that of JA after Pst DC3000 infection. In addition, SA could result in hypersensitive response (HR), which did not completely depend on accumulation of reactive oxygen species. These results indicated that tobacco mainly depended on SA signaling pathway rather than on JA signaling pathway in response to Pst DC3000. Further study demonstrated that JA could significantly inhibit the accumulation of SA and the generation of the HR induced by Pst DC3000. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Dissection of Resistance Genes to Pseudomonas syringae pv. phaseolicola in UI3 Common Bean Cultivar

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Ana M. González

2017-11-01

Full Text Available Few quantitative trait loci have been mapped for resistance to Pseudomonas syringae pv. phaseolicola in common bean. Two F2 populations were developed from the host differential UI3 cultivar. The objective of this study was to further characterize the resistance to races 1, 5, 7 and 9 of Psp included in UI3. Using a QTL mapping approach, 16 and 11 main-effect QTLs for pod and primary leaf resistance were located on LG10, explaining up to 90% and 26% of the phenotypic variation, respectively. The homologous genomic region corresponding to primary leaf resistance QTLs detected tested positive for the presence of resistance-associated gene cluster encoding nucleotide-binding and leucine-rich repeat (NL, Natural Resistance Associated Macrophage (NRAMP and Pentatricopeptide Repeat family (PPR proteins. It is worth noting that the main effect QTLs for resistance in pod were located inside a 3.5 Mb genomic region that included the Phvul.010G021200 gene, which encodes a protein that has the highest sequence similarity to the RIN4 gene of Arabidopsis, and can be considered an important candidate gene for the organ-specific QTLs identified here. These results support that resistance to Psp from UI3 might result from the immune response activated by combinations of R proteins, and suggest the guard model as an important mechanism in pod resistance to halo blight. The candidate genes identified here warrant functional studies that will help in characterizing the actual defense gene(s in UI3 genotype.

Genome-wide DNA binding pattern of two-component system response regulator RhpR in Pseudomonas syringae

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Tianhong Zhou

2015-06-01

Full Text Available Although Pseudomonas syringae uses the two-component system RhpRS to modulate the expression of type III secretion system (T3SS genes and pathogenicity, the molecular mechanisms and the regulon of RhpRS have yet to be fully demonstrated. We have performed a genome-wide analysis of RhpR binding to DNA prepared from P. syringae pv. phaseolicola in order to identify candidate direct targets of RhpR-mediated transcriptional regulation, as described in our recent article [1]. The data are available from NCBI Gene Expression Omnibus (GEO with the accession number GSE58533. Here we describe the detailed methods and data analyses of our RhpR ChIP-seq dataset.

HOPM1 mediated disease resistance to Pseudomonas syringae in Arabidopsis

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He, Sheng Yang [Okemos, MI; Nomura, Kinya [East Lansing, MI

2011-11-15

The present invention relates to compositions and methods for enhancing plant defenses against pathogens. More particularly, the invention relates to enhancing plant immunity against bacterial pathogens, wherein HopM1.sub.1-300 mediated protection is enhanced, such as increased protection to Pseudomonas syringae pv. tomato DC3000 HopM1 and/or there is an increase in activity of an ATMIN associated plant protection protein, such as ATMIN7. Reagents of the present invention further provide a means of studying cellular trafficking while formulations of the present inventions provide increased pathogen resistance in plants.

Identification of Pectin Degrading Enzymes Secreted by Xanthomonas oryzae pv. oryzae and Determination of Their Role in Virulence on Rice.

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Lavanya Tayi

Full Text Available Xanthomonas oryzae pv.oryzae (Xoo causes the serious bacterial blight disease of rice. Xoo secretes a repertoire of plant cell wall degrading enzymes (CWDEs like cellulases, xylanases, esterases etc., which act on various components of the rice cell wall. The major cellulases and xylanases secreted by Xoo have been identified and their role in virulence has been determined. In this study, we have identified some of the pectin degrading enzymes of Xoo and assessed their role in virulence. Bioinformatics analysis indicated the presence of four pectin homogalacturonan (HG degrading genes in the genome of Xoo. The four HG degrading genes include one polygalacturonase (pglA, one pectin methyl esterase (pmt and two pectate lyases (pel and pelL. There was no difference in the expression of pglA, pmt and pel genes by laboratory wild type Xoo strain (BXO43 grown in either nutrient rich PS medium or in plant mimic XOM2 medium whereas the expression of pelL gene was induced in XOM2 medium as indicated by qRT-PCR experiments. Gene disruption mutations were generated in each of these four genes. The polygalacturonase mutant pglA- was completely deficient in degrading the substrate Na-polygalacturonicacid (PGA. Strains carrying mutations in the pmt, pel and pelL genes were as efficient as wild type Xoo (BXO43 in cleaving PGA. These observations clearly indicate that PglA is the major pectin degrading enzyme produced by Xoo. The pectin methyl esterase, Pmt, is the pectin de-esterifying enzyme secreted by Xoo as evident from the enzymatic activity assay performed using pectin as the substrate. Mutations in the pglA, pmt, pel and pelL genes have minimal effects on virulence. This suggests that, as compared to cellulases and xylanases, the HG degrading enzymes may not have a major role in the pathogenicity of Xoo.

Identification of Pectin Degrading Enzymes Secreted by Xanthomonas oryzae pv. oryzae and Determination of Their Role in Virulence on Rice.

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Tayi, Lavanya; Maku, Roshan V; Patel, Hitendra Kumar; Sonti, Ramesh V

2016-01-01

Xanthomonas oryzae pv.oryzae (Xoo) causes the serious bacterial blight disease of rice. Xoo secretes a repertoire of plant cell wall degrading enzymes (CWDEs) like cellulases, xylanases, esterases etc., which act on various components of the rice cell wall. The major cellulases and xylanases secreted by Xoo have been identified and their role in virulence has been determined. In this study, we have identified some of the pectin degrading enzymes of Xoo and assessed their role in virulence. Bioinformatics analysis indicated the presence of four pectin homogalacturonan (HG) degrading genes in the genome of Xoo. The four HG degrading genes include one polygalacturonase (pglA), one pectin methyl esterase (pmt) and two pectate lyases (pel and pelL). There was no difference in the expression of pglA, pmt and pel genes by laboratory wild type Xoo strain (BXO43) grown in either nutrient rich PS medium or in plant mimic XOM2 medium whereas the expression of pelL gene was induced in XOM2 medium as indicated by qRT-PCR experiments. Gene disruption mutations were generated in each of these four genes. The polygalacturonase mutant pglA- was completely deficient in degrading the substrate Na-polygalacturonicacid (PGA). Strains carrying mutations in the pmt, pel and pelL genes were as efficient as wild type Xoo (BXO43) in cleaving PGA. These observations clearly indicate that PglA is the major pectin degrading enzyme produced by Xoo. The pectin methyl esterase, Pmt, is the pectin de-esterifying enzyme secreted by Xoo as evident from the enzymatic activity assay performed using pectin as the substrate. Mutations in the pglA, pmt, pel and pelL genes have minimal effects on virulence. This suggests that, as compared to cellulases and xylanases, the HG degrading enzymes may not have a major role in the pathogenicity of Xoo.

AtMIN7 mediated disease resistance to Pseudomonas syringae in Arabidopsis

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He, Sheng Yang [Okemos, MI; Nomura, Kinya [East Lansing, MI

2011-07-26

The present invention relates to compositions and methods for enhancing plant defenses against pathogens. More particularly, the invention relates to enhancing plant immunity against bacterial pathogens, wherein AtMIN7 mediated protection is enhanced and/or there is a decrease in activity of an AtMIN7 associated virulence protein such as a Pseudomonas syringae pv. tomato DC3000 HopM1. Reagents of the present invention provide a means of studying cellular trafficking while formulations of the present inventions provide increased pathogen resistance in plants.

Atmospheric CO2 Alters Resistance of Arabidopsis to Pseudomonas syringae by Affecting Abscisic Acid Accumulation and Stomatal Responsiveness to Coronatine

NARCIS (Netherlands)

Zhou, Y.; Vroegop-Vos, I.; Schuurink, R.C.; Pieterse, C.M.J.; Van Wees, S.C.M.

Atmospheric CO2 influences plant growth and stomatal aperture. Effects of high or low CO2 levels on plant disease resistance are less well understood. Here, resistance of Arabidopsis thaliana against the foliar pathogen Pseudomonas syringae pv. tomato DC3000 (Pst) was investigated at three different

Xanthomonas oryzae pv. oryzae TALE proteins recruit OsTFIIAγ1 to compensate for the absence of OsTFIIAγ5 in bacterial blight in rice.

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Ma, Wenxiu; Zou, Lifang; Ji, Zhiyuan; Xu, Xiameng; Xu, Zhengyin; Yang, Yangyang; Alfano, James R; Chen, Gongyou

2018-04-28

Xanthomonas oryzae pv. oryzae (Xoo), causal agent of bacterial blight (BB) of rice, uses transcription activator-like effectors (TALEs) to interact with the basal transcription factor gama subunit OsTFIIAγ5 (Xa5) and activates transcription of host genes. However, how OsTFIIAγ1, the other OsTFIIAγ protein, functions in the presence of TALEs remains unclear. In this study, we show that OsTFIIAγ1 plays a compensatory role in the absence of Xa5. The expression of OsTFIIAγ1, which is activated by TALE PthXo7, increased the expression of host genes targeted by avirulent and virulent TALEs. Defective OsTFIIAγ1 rice lines showed reduced expression of the TALE-targeted susceptibility (S) genes, OsSWEET11 and OsSWEET14, which resulted in increased BB resistance. Selected TALEs (PthXo1, AvrXa7, and AvrXa27) were evaluated for interactions with OsTFIIAγ1, Xa5 and xa5 (naturally-occurring mutant form of Xa5) using biomolecular fluorescence complementation (BiFC) and microscale thermophoresis (MST). BiFC and MST demonstrated that the three TALEs bind Xa5 and OsTFIIAγ1 with a stronger affinity than xa5. These results provide insight into the complex roles of OsTFIIAγ1 and OsTFIIAγ5 in TALE-mediated host gene transcription. This article is protected by copyright. All rights reserved. © 2018 BSPP and John Wiley & Sons Ltd.

Rice bacterial blight pathogen Xanthomonas oryzae pv. oryzae produces multiple DSF-family signals in regulation of virulence factor production

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Cha Jae-Soon

2010-07-01

Full Text Available Abstract Background Xanthomonas oryzae pv. oryzae (Xoo is the causal agent of rice bacterial blight disease. Xoo produces a range of virulence factors, including EPS, extracellular enzyme, iron-chelating siderophores, and type III-secretion dependent effectors, which are collectively essential for virulence. Genetic and genomics evidence suggest that Xoo might use the diffusible signal factor (DSF type quorum sensing (QS system to regulate the virulence factor production. However, little is known about the chemical structure of the DSF-like signal(s produced by Xoo and the factors influencing the signal production. Results Xoo genome harbours an rpf cluster comprising rpfB, rpfF, rpfC and rpfG. The proteins encoded by these genes are highly homologous to their counterparts in X. campestris pv. campestris (Xcc, suggesting that Xcc and Xoo might use similar mechanisms for DSF biosynthesis and autoregulation. Consistent with in silico analysis, the rpfF mutant was DSF-deficient and the rpfC mutant produced about 25 times higher DSF-like activity than the wild type Xoo strain KACC10331. From the supernatants of rpfC mutant, we purified three compounds showing strong DSF-like activity. Mass spectrometry and NMR analysis revealed that two of them were the previously characterized DSF and BDSF; the third one was a novel unsaturated fatty acid with 2 double bonds and was designated as CDSF in this study. Further analysis showed that all the three DSF-family signals were synthesized via the enzyme RpfF encoded by Xoo2868. DSF and BDSF at a final concentration of 3 μM to the rpfF mutant could fully restore its extracellular xylanase activity and EPS production to the wild type level, but CDSF was less active than DSF and BDSF in induction of EPS and xylanase. DSF and CDSF shared a similar cell density-dependent production time course with the maximum production being detected at 42 h after inoculation, whereas the maximum production of BDSF was observed

Plant innate immunity induced by flagellin suppresses the hypersensitive response in non-host plants elicited by Pseudomonas syringae pv. averrhoi.

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Chia-Fong Wei

Full Text Available A new pathogen, Pseudomonas syringae pv. averrhoi (Pav, which causes bacterial spot disease on carambola was identified in Taiwan in 1997. Many strains of this pathovar have been isolated from different locations and several varieties of hosts. Some of these strains, such as HL1, are nonmotile and elicit a strong hypersensitive response (HR in nonhost tobacco leaves, while other strains, such as PA5, are motile and elicit a weak HR. Based on the image from a transmission electron microscope, the results showed that HL1 is flagellum-deficient and PA5 has normal flagella. Here we cloned and analyzed the fliC gene and glycosylation island from Pav HL1 and PA5. The amino acid sequences of FliC from HL1 and PA5 are identical to P. s. pvs. tabaci (Pta, glycinea and phaseolicola and share very high similarity with other pathovars of P. syringae. In contrast to the flagellin mutant PtaΔfliC, PA5ΔfliC grows as well as wild type in the host plant, but it elicits stronger HR than wild type does in non-host plants. Furthermore, the purified Pav flagellin, but not the divergent flagellin from Agrobacterium tumefaciens, is able to impair the HR induced by PA5ΔfliC. PA5Δfgt1 possessing nonglycosylated flagella behaved as its wild type in both bacterial growth in host and HR elicitation. Flagellin was infiltrated into tobacco leaves either simultaneously with flagellum-deficient HL1 or prior to the inoculation of wild type HL1, and both treatments impaired the HR induced by HL1. Moreover, the HR elicited by PA5 and PA5ΔfliC was enhanced by the addition of cycloheximide, suggesting that the flagellin is one of the PAMPs (pathogen-associated molecular patterns contributed to induce the PAMP-triggered immunity (PTI. Taken together, the results shown in this study reveal that flagellin in Pav is capable of suppressing HR via PTI induction during an incompatible interaction.

Plant Innate Immunity Induced by Flagellin Suppresses the Hypersensitive Response in Non-Host Plants Elicited by Pseudomonas syringae pv. averrhoi

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Wei, Chia-Fong; Hsu, Shih-Tien; Deng, Wen-Ling; Wen, Yu-Der; Huang, Hsiou-Chen

2012-01-01

A new pathogen, Pseudomonas syringae pv. averrhoi (Pav), which causes bacterial spot disease on carambola was identified in Taiwan in 1997. Many strains of this pathovar have been isolated from different locations and several varieties of hosts. Some of these strains, such as HL1, are nonmotile and elicit a strong hypersensitive response (HR) in nonhost tobacco leaves, while other strains, such as PA5, are motile and elicit a weak HR. Based on the image from a transmission electron microscope, the results showed that HL1 is flagellum-deficient and PA5 has normal flagella. Here we cloned and analyzed the fliC gene and glycosylation island from Pav HL1 and PA5. The amino acid sequences of FliC from HL1 and PA5 are identical to P. s. pvs. tabaci (Pta), glycinea and phaseolicola and share very high similarity with other pathovars of P. syringae. In contrast to the flagellin mutant PtaΔfliC, PA5ΔfliC grows as well as wild type in the host plant, but it elicits stronger HR than wild type does in non-host plants. Furthermore, the purified Pav flagellin, but not the divergent flagellin from Agrobacterium tumefaciens, is able to impair the HR induced by PA5ΔfliC. PA5Δfgt1 possessing nonglycosylated flagella behaved as its wild type in both bacterial growth in host and HR elicitation. Flagellin was infiltrated into tobacco leaves either simultaneously with flagellum-deficient HL1 or prior to the inoculation of wild type HL1, and both treatments impaired the HR induced by HL1. Moreover, the HR elicited by PA5 and PA5ΔfliC was enhanced by the addition of cycloheximide, suggesting that the flagellin is one of the PAMPs (pathogen-associated molecular patterns) contributed to induce the PAMP-triggered immunity (PTI). Taken together, the results shown in this study reveal that flagellin in Pav is capable of suppressing HR via PTI induction during an incompatible interaction. PMID:22911741

The mangotoxin biosynthetic operon (mbo) is specifically distributed within Pseudomonas syringae genomospecies 1 and was acquired only once during evolution.

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Carrión, Víctor J; Gutiérrez-Barranquero, José A; Arrebola, Eva; Bardaji, Leire; Codina, Juan C; de Vicente, Antonio; Cazorla, Francisco M; Murillo, Jesús

2013-02-01

Mangotoxin production was first described in Pseudomonas syringae pv. syringae strains. A phenotypic characterization of 94 P. syringae strains was carried out to determine the genetic evolution of the mangotoxin biosynthetic operon (mbo). We designed a PCR primer pair specific for the mbo operon to examine its distribution within the P. syringae complex. These primers amplified a 692-bp DNA fragment from 52 mangotoxin-producing strains and from 7 non-mangotoxin-producing strains that harbor the mbo operon, whereas 35 non-mangotoxin-producing strains did not yield any amplification. This, together with the analysis of draft genomes, allowed the identification of the mbo operon in five pathovars (pathovars aptata, avellanae, japonica, pisi, and syringae), all of which belong to genomospecies 1, suggesting a limited distribution of the mbo genes in the P. syringae complex. Phylogenetic analyses using partial sequences from housekeeping genes differentiated three groups within genomospecies 1. All of the strains containing the mbo operon clustered in groups I and II, whereas those lacking the operon clustered in group III; however, the relative branching order of these three groups is dependent on the genes used to construct the phylogeny. The mbo operon maintains synteny and is inserted in the same genomic location, with high sequence conservation around the insertion point, for all the strains in groups I and II. These data support the idea that the mbo operon was acquired horizontally and only once by the ancestor of groups I and II from genomospecies 1 within the P. syringae complex.

Genomic Structural Variations Affecting Virulence During Clonal Expansion of Pseudomonas syringae pv. actinidiae Biovar 3 in Europe.

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Firrao, Giuseppe; Torelli, Emanuela; Polano, Cesare; Ferrante, Patrizia; Ferrini, Francesca; Martini, Marta; Marcelletti, Simone; Scortichini, Marco; Ermacora, Paolo

2018-01-01

Pseudomonas syringae pv. actinidiae (Psa) biovar 3 caused pandemic bacterial canker of Actinidia chinensis and Actinidia deliciosa since 2008. In Europe, the disease spread rapidly in the kiwifruit cultivation areas from a single introduction. In this study, we investigated the genomic diversity of Psa biovar 3 strains during the primary clonal expansion in Europe using single molecule real-time (SMRT), Illumina and Sanger sequencing technologies. We recorded evidences of frequent mobilization and loss of transposon Tn6212, large chromosome inversions, and ectopic integration of IS sequences (remarkably ISPsy31, ISPsy36, and ISPsy37). While no phenotype change associated with Tn6212 mobilization could be detected, strains CRAFRU 12.29 and CRAFRU 12.50 did not elicit the hypersensitivity response (HR) on tobacco and eggplant leaves and were limited in their growth in kiwifruit leaves due to insertion of ISPsy31 and ISPsy36 in the hrpS and hrpR genes, respectively, interrupting the hrp cluster. Both strains had been isolated from symptomatic plants, suggesting coexistence of variant strains with reduced virulence together with virulent strains in mixed populations. The structural differences caused by rearrangements of self-genetic elements within European and New Zealand strains were comparable in number and type to those occurring among the European strains, in contrast with the significant difference in terms of nucleotide polymorphisms. We hypothesize a relaxation, during clonal expansion, of the selection limiting the accumulation of deleterious mutations associated with genome structural variation due to transposition of mobile elements. This consideration may be relevant when evaluating strategies to be adopted for epidemics management.

Pseudomonas syringae evades host Immunity by degrading flagellin monomers with alkaline protease AprA

OpenAIRE

Pel, M.J.C.; Van Dijken, A.J.H.; Bardoel, B.W.; Seidl, M.F; Van der Ent, S.; Van Strijp, J.A.G.

2014-01-01

Bacterial flagellin molecules are strong inducers of innate immune responses in both mammals and plants. The opportunistic pathogen Pseudomonas aeruginosa secretes an alkaline protease called AprA that degrades flagellin monomers. Here, we show that AprA is widespread among a wide variety of bacterial species. In addition, we investigated the role of AprA in virulence of the bacterial plant athogen P. syringae pv. tomato DC3000. The AprA-deficient DC3000 ΔaprA knockout mutant was significantl...

Virulence of Pseudomonas syringae pv. tomato DC3000 is modulated through the Catabolite Repression Control protein Crc

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Pseudomonas syringae (P.s.) infects diverse plant species and several P.s. pathovars have been used in the study of molecular events that occur during plant-microbe interactions. Although the relationship between bacterial metabolism, nutrient acquisition and virulence has attracted increasing atten...

Isolation and characterisation of EfeM, a periplasmic component of the putative EfeUOBM iron transporter of Pseudomonas syringae pv. syringae

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Rajasekaran, Mohan B [School of Biological Sciences Harborne Building, Whiteknights Campus, Reading, RG6 6AS (United Kingdom); Structural Biology Unit at The BioCentre, University of Reading, Harborne Building, Whiteknights Campus, Reading, RG6 6AS (United Kingdom); Mitchell, Sue A; Gibson, Trevor M [Structural Biology Unit at The BioCentre, University of Reading, Harborne Building, Whiteknights Campus, Reading, RG6 6AS (United Kingdom); Hussain, Rohanah; Siligardi, Giuliano [Circular Dichroism Group, Diamond Light Source, Chiltern, Oxfordshire,OX11 0DE (United Kingdom); Andrews, Simon C [School of Biological Sciences Harborne Building, Whiteknights Campus, Reading, RG6 6AS (United Kingdom); Watson, Kimberly A, E-mail: k.a.watson@reading.ac.uk [School of Biological Sciences Harborne Building, Whiteknights Campus, Reading, RG6 6AS (United Kingdom); Structural Biology Unit at The BioCentre, University of Reading, Harborne Building, Whiteknights Campus, Reading, RG6 6AS (United Kingdom)

2010-07-30

Research highlights: {yields} Bioinformatic analysis reveals EfeM is a metallopeptidase with conserved HXXE motif. {yields} Mass spectrometry confirms EfeM consists of 251 residues, molecular weight 27,772Da. {yields} SRCD spectroscopy shows an {alpha}-helical secondary structure. {yields} Single crystals of EfeM are orthorhombic and diffract to 1.6A resolution. {yields} Space group is P22{sub 1}2{sub 1} with cell dimensions a = 46.74, b = 95.17 and c = 152.61 A. -- Abstract: The EfeM protein is a component of the putative EfeUOBM iron-transporter of Pseudomonas syringae pathovar syringae and is thought to act as a periplasmic, ferrous-iron binding protein. It contains a signal peptide of 34 amino acid residues and a C-terminal 'Peptidase{sub M}75' domain of 251 residues. The C-terminal domain contains a highly conserved 'HXXE' motif thought to act as part of a divalent cation-binding site. In this work, the gene (efeM or 'Psyr{sub 3}370') encoding EfeM was cloned and over-expressed in Escherichia coli, and the mature protein was purified from the periplasm. Mass spectrometry confirmed the identity of the protein (M{sub W} 27,772 Da). Circular dichroism spectroscopy of EfeM indicated a mainly {alpha}-helical structure, consistent with bioinformatic predictions. Purified EfeM was crystallised by hanging-drop vapor diffusion to give needle-shaped crystals that diffracted to a resolution of 1.6 A. This is the first molecular study of a peptidase M75 domain with a presumed iron transport role.

Modular Study of the Type III Effector Repertoire in Pseudomonas syringae pv. tomato DC3000 Reveals a Matrix of Effector Interplay in Pathogenesis.

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Wei, Hai-Lei; Zhang, Wei; Collmer, Alan

2018-05-08

The bacterial pathogen Pseudomonas syringae pv. tomato DC3000 suppresses the two-tiered innate immune system of Nicotiana benthamiana and other plants by injecting a complex repertoire of type III secretion effector (T3E) proteins. Effectorless polymutant DC3000D36E was used with a modularized system for native delivery of the 29 DC3000 T3Es singly and in pairs. Assays of the performance of this T3E library in N. benthamiana leaves revealed a matrix of T3E interplay, with six T3Es eliciting death and eight others variously suppressing the death activity of the six. The T3E library was also interrogated for effects on DC3000D36E elicitation of a reactive oxygen species burst, for growth in planta, and for T3Es that reversed these effects. Pseudomonas fluorescens and Agrobacterium tumefaciens heterologous delivery systems yielded notably different sets of death-T3Es. The DC3000D36E T3E library system highlights the importance of 13 T3Es and their interplay in interactions with N. benthamiana. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

The Identification of Genes Important in Pseudomonas syringae pv. phaseolicola Plant Colonisation Using In Vitro Screening of Transposon Libraries.

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Bharani Manoharan

Full Text Available The bacterial plant pathogen Pseudomonas syringae pv. phaseolicola (Pph colonises the surface of common bean plants before moving into the interior of plant tissue, via wounds and stomata. In the intercellular spaces the pathogen proliferates in the apoplastic fluid and forms microcolonies (biofilms around plant cells. If the pathogen can suppress the plant's natural resistance response, it will cause halo blight disease. The process of resistance suppression is fairly well understood, but the mechanisms used by the pathogen in colonisation are less clear. We hypothesised that we could apply in vitro genetic screens to look for changes in motility, colony formation, and adhesion, which are proxies for infection, microcolony formation and cell adhesion. We made transposon (Tn mutant libraries of Pph strains 1448A and 1302A and found 106/1920 mutants exhibited alterations in colony morphology, motility and biofilm formation. Identification of the insertion point of the Tn identified within the genome highlighted, as expected, a number of altered motility mutants bearing mutations in genes encoding various parts of the flagellum. Genes involved in nutrient biosynthesis, membrane associated proteins, and a number of conserved hypothetical protein (CHP genes were also identified. A mutation of one CHP gene caused a positive increase in in planta bacterial growth. This rapid and inexpensive screening method allows the discovery of genes important for in vitro traits that can be correlated to roles in the plant interaction.

An operon for production of bioactive gibberellin A4 phytohormone with wide distribution in the bacterial rice leaf streak pathogen Xanthomonas oryzae pv. oryzicola.

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Nagel, Raimund; Turrini, Paula C G; Nett, Ryan S; Leach, Jan E; Verdier, Valérie; Van Sluys, Marie-Anne; Peters, Reuben J

2017-05-01

Phytopathogens have developed elaborate mechanisms to attenuate the defense response of their host plants, including convergent evolution of complex pathways for production of the GA phytohormones, which were actually first isolated from the rice fungal pathogen Gibberella fujikuroi. The rice bacterial pathogen Xanthomonas oryzae pv. oryzicola (Xoc) has been demonstrated to contain a biosynthetic operon with cyclases capable of producing the universal GA precursor ent-kaurene. Genetic (knock-out) studies indicate that the derived diterpenoid serves as a virulence factor for this rice leaf streak pathogen, serving to reduce the jasmonic acid-mediated defense response. Here the functions of the remaining genes in the Xoc operon are elucidated and the distribution of the operon in X. oryzae is investigated in over 100 isolates. The Xoc operon leads to production of the bioactive GA 4 , an additional step beyond production of the penultimate precursor GA 9 mediated by the homologous operons recently characterized from rhizobia. Moreover, this GA biosynthetic operon was found to be widespread in Xoc (> 90%), but absent in the other major X. oryzae pathovar. These results indicate selective pressure for production of GA 4 in the distinct lifestyle of Xoc, and the importance of GA to both fungal and bacterial pathogens of rice. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Pollen as a possible pathway for the dissemination of Pseudomonas syringae pv. actinide and bacterial canker of kiwifruit

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Rodanthi TONTOU

2014-09-01

Full Text Available Pollen collected in a kiwifruit orchard with symptoms of bacterial canker and naturally contaminated by Pseudomonas syringae pv. actinidiae (Psa, was used to pollinate an experimental orchard, in order to confirm its role, under commercial orchard conditions, in disseminating the pathogen and, possibly, contributing to disease spread. A pollen lot, certified free from Psa, was used with the same methods as a control. Two pollination techniques were used: dusting (dry pollen and spraying (pollen suspension in water. The orchard was monitored during 2 years from experimental pollination, with regular sampling of flowers, fruits, leaves, and vines, to check for Psa as an epiphyte or endophyte, and for bacterial canker symptoms. Psa was recovered from flowers, fruitlets and leaves during the first season, mainly in plots where contaminated pollen had been sprayed in water suspension. From early August until harvesting time (mid-October, Psa detection was possible only on leaves. No symptoms developed during the first season after pollination. No endophytic Psa was detected in pruned vines in the following winter. During the second season, detection and isolation of Psa was erratic, but direct isolation was achieved from four plots. During the second season after pollination, typical leaf symptoms were observed on a few vines, and Psa was isolated and identified. Our results suggest that Psa could be disseminated via contaminated kiwifruit pollen as a pathway for spread of bacterial canker. However, further pollination experiments are needed to establish, beyond any doubt, whether contaminated pollen may contribute to possible disease outbreaks.

In planta gene expression analysis of Xanthomonas oryzae pathovar oryzae, African strain MAI1

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Verdier Valérie

2010-06-01

Full Text Available Abstract Background Bacterial leaf blight causes significant yield losses in rice crops throughout Asia and Africa. Although both the Asian and African strains of the pathogen, Xanthomonas oryzae pv. oryzae (Xoo, induce similar symptoms, they are nevertheless genetically different, with the African strains being more closely related to the Asian X. oryzae pv. oryzicola (Xoc. Results Changes in gene expression of the African Xoo strain MAI1 in the susceptible rice cultivar Nipponbare were profiled, using an SSH Xoo DNA microarray. Microarray hybridization was performed comparing bacteria recovered from plant tissues at 1, 3, and 6 days after inoculation (dai with bacteria grown in vitro. A total of 710 bacterial genes were found to be differentially expressed, with 407 up-regulated and 303 down-regulated. Expression profiling indicated that less than 20% of the 710 bacterial transcripts were induced in the first 24 h after inoculation, whereas 63% were differentially expressed at 6 dai. The 710 differentially expressed genes were one-end sequenced. 535 sequences were obtained from which 147 non-redundant sequences were identified. Differentially expressed genes were related to metabolism, secretion and transport, pathogen adherence to plant tissues, plant cell-wall degradation, IS elements, and virulence. In addition, various other genes encoding proteins with unknown function or showing no similarity to other proteins were also induced. The Xoo MAI1 non-redundant set of sequences was compared against several X. oryzae genomes, revealing a specific group of genes that was present only in MAI1. Numerous IS elements were also found to be differentially expressed. Quantitative real-time PCR confirmed 86% of the identified profile on a set of 14 genes selected according to the microarray analysis. Conclusions This is the first report to compare the expression of Xoo genes in planta across different time points during infection. This work shows that

Studies on the physiological changes in the rice plants infected with Xanthomonas campestris pv. oryzae, (3)

International Nuclear Information System (INIS)

Watanabe, Minoru; Samejima, Shin-ichi; Hosokawa, Daijiro

1980-01-01

Accumulation of 14 C-photosynthetic assimilates in rice leaves infected with Xanthomonas campestris pv. oryzae was studied by using autoradiography for the purpose of elucidating the movement of nutrients from healthy tissues to the infected parts. When rice plants were exposed to 14 CO 2 immediately after inoculation, 14 C-photosynthetic assimilates did not accumulate in and around the inoculated spots of leaves until the lesions became visible, i.e., approximately 7 days after inoculation. When the leaves were exposed to 14 CO 2 before visible lesions appeared, 2 and 5 days after inoculation, the assimilates did not accumulate in the inoculated areas, but apparently accumulated in the lesions 24 hr later on from the exposure of leaves with visible lesions. In the newly formed lesions, accumulation site corresponded to the yellow streak parts of lesions along leaf veins. In the large and old lesions, assimilates hardly any accumulated in the center of lesions, grayish-white in color, but accumulated in the border parts of lesions adjacent to healthy tissues which are developing and yellow streak in symptoms. (author)

A possible role for acetylated intermediates in diaminopimelate and tabtoxinine-beta-lactam biosynthesis in Pseudomonas syringae pv. tabaci BR2.024.

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Liu, L; Shaw, P D

1997-01-01

The deduced product of an open reading frame (ORF3) located in the tabtoxinine-beta-lactam (T beta L) biosynthetic region of Pseudomonas syringae pv. tabaci BR2.024 (BR2.024) has significant sequence homology to the dapD products of other bacteria. dapD encodes L-2,3,4,5-tetrahydrodipicolinate succinyl coenzyme A succinyltransferase (THDPA-ST), an enzyme in the diaminopimelate (DAP) and lysine biosynthetic pathway. Complementation studies, in vitro transcription-translation experiments, and enzymatic assays indicated that ORF3 encodes a product with THDPA-ST activity in Escherichia coli dapD mutant beta 274. However, a BR2.024 mutant with an insert in ORF3 was prototrophic, and only basal THDPA-ST activity was detected in extracts of both parent and mutant. This finding suggested that ORF3 was not required for DAP biosynthesis and that it did not encode a product with THDPA-ST activity. The results of enzymatic studies, indicating that BR2.024 uses acetylated intermediates for DAP biosynthesis, are consistent with the hypothesis that BR2.024 does not need THDPA-ST for DAP biosynthesis. The ORF3 mutant produced reduced levels of tabtoxin, indicating that ORF3 may have a role in T beta L biosynthesis. We have named the gene tabB and have proposed a possible function for the gene product. PMID:9294453

The Arabidopsis thaliana cysteine-rich receptor-like kinase CRK20 modulates host responses to Pseudomonas syringae pv. tomato DC3000 infection.

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Ederli, Luisa; Madeo, Laura; Calderini, Ornella; Gehring, Chris; Moretti, Chiaraluce; Buonaurio, Roberto; Paolocci, Francesco; Pasqualini, Stefania

2011-10-15

In plants, the cysteine-rich repeat kinases (CRKs) are a sub-family of receptor-like protein kinases that contain the DUF26 motif in their extracellular domains. It has been shown that in Arabidopsis thaliana, CRK20 is transcriptionally induced by pathogens, salicylic acid and ozone (O(3)). However, its role in responses to biotic and abiotic stress remains to be elucidated. To determine the function of CRK20 in such responses, two CRK20 loss-of-function mutants, crk20-1 and crk20-2, were isolated from public collections of Arabidopsis T-DNA tagged lines and examined for responses to O(3) and Pseudomonas syringae pv. tomato (Pst) DC3000. crk20-1 and crk20-2 showed similar O(3) sensitivities and no differences in the expression of defense genes when compared with the wild-type. However, pathogen growth was significantly reduced, while there were no differences in the induction of salicylic acid related defense genes or salicylic acid accumulation. Furthermore, correlation analysis of CRK20 gene expression suggests that it has a role in the control of H(2)O and/or nutrient transport. We therefore propose that CRK20 promotes conditions that are favorable for Pst DC3000 growth in Arabidopsis, possibly through the regulation of apoplastic homeostasis, and consequently, of the environment of this biotrophic pathogen. Copyright © 2011 Elsevier GmbH. All rights reserved.

The Arabidopsis thaliana cysteine-rich receptor-like kinase CRK20 modulates host responses to Pseudomonas syringae pv. tomato DC3000 infection

KAUST Repository

Ederli, Luisa

2011-10-01

In plants, the cysteine-rich repeat kinases (CRKs) are a sub-family of receptor-like protein kinases that contain the DUF26 motif in their extracellular domains. It has been shown that in Arabidopsis thaliana, CRK20 is transcriptionally induced by pathogens, salicylic acid and ozone (O3). However, its role in responses to biotic and abiotic stress remains to be elucidated. To determine the function of CRK20 in such responses, two CRK20 loss-of-function mutants, crk20-1 and crk20-2, were isolated from public collections of Arabidopsis T-DNA tagged lines and examined for responses to O3 and Pseudomonas syringae pv. tomato (Pst) DC3000. crk20-1 and crk20-2 showed similar O3 sensitivities and no differences in the expression of defense genes when compared with the wild-type. However, pathogen growth was significantly reduced, while there were no differences in the induction of salicylic acid related defense genes or salicylic acid accumulation. Furthermore, correlation analysis of CRK20 gene expression suggests that it has a role in the control of H2O and/or nutrient transport. We therefore propose that CRK20 promotes conditions that are favorable for Pst DC3000 growth in Arabidopsis, possibly through the regulation of apoplastic homeostasis, and consequently, of the environment of this biotrophic pathogen. © 2011 Elsevier GmbH.

Arabidopsis AtERF15 positively regulates immunity against Pseudomonas syringae pv. tomato DC3000 and Botrytis cinerea

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Huijuan eZhang

2015-09-01

Full Text Available Upon pathogen infection, activation of immune response requires effective transcriptional reprogramming that regulates inducible expression of a large set of defense genes. A number of ethylene-responsive factor transcription factors have been shown to play critical roles in regulating immune responses in plants. In the present study, we explored the functions of Arabidopsis AtERF15 in immune responses against Pseudomonas syringae pv. tomato (Pst DC3000, a (hemibiotrophic bacterial pathogen, and Botrytis cinerea, a necrotrophic fungal pathogen. Expression of AtERF15 was induced by infection of Pst DC3000 and B. cinerea and by treatments with salicylic acid (SA and methyl jasmonate. Biochemical assays demonstrated that AtERF15 is a nucleus-localized transcription activator. The AtERF15-overexpressing (AtERF15-OE plants displayed enhanced resistance while the AtERF15-RNAi plants exhibited decreased resistance against Pst DC3000 and B. cinerea. Meanwhile, Pst DC3000- or B. cinerea-induced expression of defense genes was upregulated in AtERF15-OE plants but downregulated in AtERF15-RNAi plants, as compared to the expression in wild type plants. In response to infection with B. cinerea, the AtERF15-OE plants accumulated less reactive oxygen species (ROS while the AtERF15-RNAi plants accumulated more ROS. The flg22- and chitin-induced oxidative burst was abolished and expression levels of the pattern-triggered immunity-responsive genes AtFRK1 and AtWRKY53 were suppressed in AtER15-RNAi plants upon treatment with flg22 or chitin. Furthermore, SA-induced defense response was also partially impaired in the AtERF15-RNAi plants. These data demonstrate that AtERF15 is a positive regulator of multiple layers of the immune responses in Arabidopsis.

The plant pathogen Pseudomonas syringae pv. tomato is genetically monomorphic and under strong selection to evade tomato immunity.

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Rongman Cai

2011-08-01

Full Text Available Recently, genome sequencing of many isolates of genetically monomorphic bacterial human pathogens has given new insights into pathogen microevolution and phylogeography. Here, we report a genome-based micro-evolutionary study of a bacterial plant pathogen, Pseudomonas syringae pv. tomato. Only 267 mutations were identified between five sequenced isolates in 3,543,009 nt of analyzed genome sequence, which suggests a recent evolutionary origin of this pathogen. Further analysis with genome-derived markers of 89 world-wide isolates showed that several genotypes exist in North America and in Europe indicating frequent pathogen movement between these world regions. Genome-derived markers and molecular analyses of key pathogen loci important for virulence and motility both suggest ongoing adaptation to the tomato host. A mutational hotspot was found in the type III-secreted effector gene hopM1. These mutations abolish the cell death triggering activity of the full-length protein indicating strong selection for loss of function of this effector, which was previously considered a virulence factor. Two non-synonymous mutations in the flagellin-encoding gene fliC allowed identifying a new microbe associated molecular pattern (MAMP in a region distinct from the known MAMP flg22. Interestingly, the ancestral allele of this MAMP induces a stronger tomato immune response than the derived alleles. The ancestral allele has largely disappeared from today's Pto populations suggesting that flagellin-triggered immunity limits pathogen fitness even in highly virulent pathogens. An additional non-synonymous mutation was identified in flg22 in South American isolates. Therefore, MAMPs are more variable than expected differing even between otherwise almost identical isolates of the same pathogen strain.

Immunocytochemical localization of HrpA and HrpZ supports a role for the Hrp pilus in the transfer of effector proteins from Pseudomonas syringae pv. tomato across the host plant cell wall.

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Brown, I R; Mansfield, J W; Taira, S; Roine, E; Romantschuk, M

2001-03-01

The Hrp pilus, composed of HrpA subunits, is an essential component of the type III secretion system in Pseudomonas syringae. We used electron microscopy (EM) and immunocytochemistry to examine production of the pilus in vitro from P. syringae pv. tomato strain DC3000 grown under hrp-inducing conditions on EM grids. Pili, when labeled with antibodies to HrpA, developed rapidly in a nonpolar manner shortly after the detection of the hrpA transcript and extended up to 5 microm into surrounding media. Structures at the base of the pilus were clearly differentiated from the basal bodies of flagella. The HrpZ protein, also secreted via the type III system, was found by immunogold labeling to be associated with the pilus in vitro. Accumulation and secretion of HrpA and HrpZ were also examined quantitatively after the inoculation of wild-type DC3000 and hrpA and hrpZ mutants into leaves of Arabidopsis thaliana. The functional pilus crossed the plant cell wall to generate tracks of immunogold labeling for HrpA and HrpZ. Mutants that produced HrpA but did not assemble pili were nonpathogenic, did not secrete HrpA protein, and were compromised for the accumulation of HrpZ. A model is proposed in which the rapidly elongating Hrp pilus acts as a moving conveyor, facilitating transfer of effector proteins from bacteria to the plant cytoplasm across the formidable barrier of the plant cell wall.

Comparative genome analysis provides insights into the evolution and adaptation of Pseudomonas syringae pv. aesculi on Aesculus hippocastanum.

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Sarah Green

Full Text Available A recently emerging bleeding canker disease, caused by Pseudomonas syringae pathovar aesculi (Pae, is threatening European horse chestnut in northwest Europe. Very little is known about the origin and biology of this new disease. We used the nucleotide sequences of seven commonly used marker genes to investigate the phylogeny of three strains isolated recently from bleeding stem cankers on European horse chestnut in Britain (E-Pae. On the basis of these sequences alone, the E-Pae strains were identical to the Pae type-strain (I-Pae, isolated from leaf spots on Indian horse chestnut in India in 1969. The phylogenetic analyses also showed that Pae belongs to a distinct clade of P. syringae pathovars adapted to woody hosts. We generated genome-wide Illumina sequence data from the three E-Pae strains and one strain of I-Pae. Comparative genomic analyses revealed pathovar-specific genomic regions in Pae potentially implicated in virulence on a tree host, including genes for the catabolism of plant-derived aromatic compounds and enterobactin synthesis. Several gene clusters displayed intra-pathovar variation, including those encoding type IV secretion, a novel fatty acid biosynthesis pathway and a sucrose uptake pathway. Rates of single nucleotide polymorphisms in the four Pae genomes indicate that the three E-Pae strains diverged from each other much more recently than they diverged from I-Pae. The very low genetic diversity among the three geographically distinct E-Pae strains suggests that they originate from a single, recent introduction into Britain, thus highlighting the serious environmental risks posed by the spread of an exotic plant pathogenic bacterium to a new geographic location. The genomic regions in Pae that are absent from other P. syringae pathovars that infect herbaceous hosts may represent candidate genetic adaptations to infection of the woody parts of the tree.

Expression of Vitis amurensis VaERF20 in Arabidopsis thaliana Improves Resistance to Botrytis cinerea and Pseudomonas syringae pv. Tomato DC3000

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Mengnan Wang

2018-03-01

Full Text Available Ethylene response factor (ERF transcription factors play important roles in regulating immune responses in plants. In our study, we characterized a member of the ERF transcription factor family, VaERF20, from the Chinese wild Vitis genotype, V. amurensis Rupr “Shuangyou”. Phylogenetic analysis indicated that VaERF20 belongs to group IXc of the ERF family, in which many members are known to contribute to fighting pathogen infection. Consistent with this, expression of VaERF20 was induced by treatment with the necrotrophic fungal pathogen Botrytis cinerea (B. cinerea in “Shuangyou” and V. vinifera “Red Globe”. Arabidopsis thaliana plants over-expressing VaERF20 displayed enhanced resistance to B. cinerea and the bacterium Pseudomonas syringae pv. tomato (Pst DC3000. Patterns of pathogen-induced reactive oxygen species (ROS accumulation were entirely distinct in B. cinerea and PstDC3000 inoculated plants. Examples of both salicylic acid (SA and jasmonic acid/ethylene (JA/ET responsive defense genes were up-regulated after B. cinerea and PstDC3000 inoculation of the VaERF20-overexpressing transgenic A. thaliana plants. Evidence of pattern-triggered immunity (PTI, callose accumulation and stomatal defense, together with increased expression of PTI genes, was also greater in the transgenic lines. These data indicate that VaERF20 participates in various signal transduction pathways and acts as an inducer of immune responses.

Characterization of dapB, a gene required by Pseudomonas syringae pv. tabaci BR2.024 for lysine and tabtoxinine-beta-lactam biosynthesis.

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Liu, L; Shaw, P D

1997-01-01

The dapB gene, which encodes L-2,3-dihydrodipicolinate reductase, the second enzyme of the lysine branch of the aspartic amino acid family, was cloned and sequenced from a tabtoxin-producing bacterium, Pseudomonas syringae pv. tabaci BR2.024. The deduced amino acid sequence shared 60 to 90% identity to known dapB gene products from gram-negative bacteria and 19 to 21% identity to the dapB products from gram-positive bacteria. The consensus sequence for the NAD(P)H binding site [(V/I)(A/G)(V/I)XGXXGXXG)] and the proposed substrate binding site (HHRHK) were conserved in the polypeptide. A BR2.024 dapB mutant is a diaminopimelate auxotroph and tabtoxin negative. The addition of a mixture of L-,L-, D,D-, and meso-diaminopimelate to defined media restored growth but not tabtoxin production. Cloned DNA fragments containing the parental dapB gene restored the ability to grow in defined media and tabtoxin production to the dapB mutant. These results indicate that the dapB gene is required for both lysine and tabtoxin biosynthesis, thus providing the first genetic evidence that the biosynthesis of tabtoxin proceeds in part along the lysine biosynthetic pathway. These data also suggest that L-2,3,4,5-tetrahydrodipicolinate is a common intermediate for both lysine and tabtoxin biosynthesis. PMID:8990304

The Ca2+ induced two-component system, CvsSR regulates the Type III secretion system and the extracytoplasmic function sigma-factor AlgU in Pseudomonas syringae pv. tomato DC3000.

Science.gov (United States)

Fishman, Maxwell R; Zhang, Johnson; Bronstein, Philip A; Stodghill, Paul; Filiatrault, Melanie J

2017-12-20

Two-component systems (TCSs) of bacteria regulate many different aspects of the bacterial life cycle including pathogenesis. Most TCSs remain uncharacterized with no information about the signal(s) or regulatory targets and/or role in bacterial pathogenesis. Here, we characterized a TCS in the plant-pathogenic bacterium Pseudomonas syringae pv. tomato DC3000 ( Pto ) composed of the histidine kinase, CvsS, and the response regulator, CvsR. CvsSR is necessary for virulence of Pto , since ΔcvsS and ΔcvsR strains produced fewer symptoms and demonstrated reduced growth on multiple hosts as compared to WT. We discovered that expression of cvsSR is induced by Ca 2+ concentrations found in leaf apoplastic fluid. Thus, Ca 2+ can be added to the list of signals that promote pathogenesis of Pto during host colonization. Through chromatin immunoprecipitation followed by next generation sequencing (ChIP-seq) and global transcriptome analysis (RNA-seq) we discerned the CvsR regulon. CvsR directly activated expression of the type III secretion system regulators, hrpR and hrpS , that regulates Pto virulence in a type III secretion system dependent manner. CvsR also indirectly repressed transcription of the extracytoplasmic sigma factor algU and production of alginate. Phenotypic analysis determined that CvsSR inversely regulated biofilm formation, swarming motility, and cellulose production in a Ca 2+ -dependent manner. Overall, our results show that CvsSR is a key regulatory hub critical for interaction with host plants. Importance Pathogenic bacteria must be able to react and respond to the surrounding environment, make use of available resources, and avert or counter host immune responses. Often, these abilities rely on two-component systems (TCSs) composed of interacting proteins that modulate gene expression. We identified a TCS in the plant-pathogenic bacterium Pseudomonas syringae that responds to the presence of calcium, which is an important signal during the plant

Constitutive activation of jasmonate signaling in an Arabidopsis mutant correlates with enhanced resistance to Erysiphe cichoracearum, Pseudomonas syringae, and Myzus persicae.

Science.gov (United States)

Ellis, Christine; Karafyllidis, Ioannis; Turner, John G

2002-10-01

In Arabidopsis spp., the jasmonate (JA) response pathway generally is required for defenses against necrotrophic pathogens and chewing insects, while the salicylic acid (SA) response pathway is generally required for specific, resistance (R) gene-mediated defenses against both biotrophic and necrotrophic pathogens. For example, SA-dependent defenses are required for resistance to the biotrophic fungal pathogen Erysiphe cichoracearum UCSC1 and the bacterial pathogen Pseudomonas syringae pv. maculicola, and also are expressed during response to the green peach aphid Myzus persicae. However, recent evidence indicates that the expression of JA-dependent defenses also may confer resistance to E. cichoracearum. To confirm and to extend this observation, we have compared the disease and pest resistance of wild-type Arabidopsis plants with that of the mutants coil, which is insensitive to JA, and cev1, which has constitutive JA signaling. Measurements of the colonization of these plants by E. cichoracearum, P. syringae pv. maculicola, and M. persicae indicated that activation of the JA signal pathway enhanced resistance, and was associated with the activation of JA-dependent defense genes and the suppression of SA-dependent defense genes. We conclude that JA and SA induce alternative defense pathways that can confer resistance to the same pathogens and pests.

Modeling and mapping the current and future distribution of Pseudomonas syringae pv. actinidiae under climate change in China.

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Rulin Wang

Full Text Available Bacterial canker of kiwifruit caused by Pseudomonas syringae pv. actinidiae (Psa is a major threat to the kiwifruit industry throughout the world and accounts for substantial economic losses in China. The aim of the present study was to test and explore the possibility of using MaxEnt (maximum entropy models to predict and analyze the future large-scale distribution of Psa in China.Based on the current environmental factors, three future climate scenarios, which were suggested by the fifth IPCC report, and the current distribution sites of Psa, MaxEnt combined with ArcGIS was applied to predict the potential suitable areas and the changing trend of Psa in China. The jackknife test and correlation analysis were used to choose dominant climatic factors. The receiver operating characteristic curve (ROC drawn by MaxEnt was used to evaluate the accuracy of the simulation.The results showed that under current climatic conditions, the area from latitude 25° to 36°N and from longitude 101° to 122°E is the primary potential suitable area of Psa in China. The highly suitable area (with suitability between 66 and 100 was mainly concentrated in Northeast Sichuan, South Shaanxi, most of Chongqing, West Hubei and Southwest Gansu and occupied 4.94% of land in China. Under different future emission scenarios, both the areas and the centers of the suitable areas all showed differences compared with the current situation. Four climatic variables, i.e., maximum April temperature (19%, mean temperature of the coldest quarter (14%, precipitation in May (11.5% and minimum temperature in October (10.8%, had the largest impact on the distribution of Psa.The MaxEnt model is potentially useful for forecasting the future adaptive distribution of Psa under climate change, and it provides important guidance for comprehensive management.

Modeling and mapping the current and future distribution of Pseudomonas syringae pv. actinidiae under climate change in China.

Science.gov (United States)

Wang, Rulin; Li, Qing; He, Shisong; Liu, Yuan; Wang, Mingtian; Jiang, Gan

2018-01-01

Bacterial canker of kiwifruit caused by Pseudomonas syringae pv. actinidiae (Psa) is a major threat to the kiwifruit industry throughout the world and accounts for substantial economic losses in China. The aim of the present study was to test and explore the possibility of using MaxEnt (maximum entropy models) to predict and analyze the future large-scale distribution of Psa in China. Based on the current environmental factors, three future climate scenarios, which were suggested by the fifth IPCC report, and the current distribution sites of Psa, MaxEnt combined with ArcGIS was applied to predict the potential suitable areas and the changing trend of Psa in China. The jackknife test and correlation analysis were used to choose dominant climatic factors. The receiver operating characteristic curve (ROC) drawn by MaxEnt was used to evaluate the accuracy of the simulation. The results showed that under current climatic conditions, the area from latitude 25° to 36°N and from longitude 101° to 122°E is the primary potential suitable area of Psa in China. The highly suitable area (with suitability between 66 and 100) was mainly concentrated in Northeast Sichuan, South Shaanxi, most of Chongqing, West Hubei and Southwest Gansu and occupied 4.94% of land in China. Under different future emission scenarios, both the areas and the centers of the suitable areas all showed differences compared with the current situation. Four climatic variables, i.e., maximum April temperature (19%), mean temperature of the coldest quarter (14%), precipitation in May (11.5%) and minimum temperature in October (10.8%), had the largest impact on the distribution of Psa. The MaxEnt model is potentially useful for forecasting the future adaptive distribution of Psa under climate change, and it provides important guidance for comprehensive management.

Bacterial canker on kiwifruit in Italy: Anatomical changes in the wood and in the primary infection sites

NARCIS (Netherlands)

Renzi, M.; Copini, P.; Taddei, A.R.; Rossetti, A.; Gallipoli, L.; Mazzaglia, A.; Balestra, G.M.

2012-01-01

The bacterial canker of kiwifruit caused by Pseudomonas syringae pv. actinidiae is a severe threat to kiwifruit production worldwide. Many aspects of P. syringae pv. actinidiae biology and epidemiology still require in-depth investigation. The infection by and spread of P. syringae pv. actinidiae in

Virulence of Pseudomonas syringae pv. tomato DC3000 Is Influenced by the Catabolite Repression Control Protein Crc.

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Chakravarthy, Suma; Butcher, Bronwyn G; Liu, Yingyu; D'Amico, Katherine; Coster, Matthew; Filiatrault, Melanie J

2017-04-01

Pseudomonas syringae infects diverse plant species and is widely used as a model system in the study of effector function and the molecular basis of plant diseases. Although the relationship between bacterial metabolism, nutrient acquisition, and virulence has attracted increasing attention in bacterial pathology, it is largely unexplored in P. syringae. The Crc (catabolite repression control) protein is a putative RNA-binding protein that regulates carbon metabolism as well as a number of other factors in the pseudomonads. Here, we show that deletion of crc increased bacterial swarming motility and biofilm formation. The crc mutant showed reduced growth and symptoms in Arabidopsis and tomato when compared with the wild-type strain. We have evidence that the crc mutant shows delayed hypersensitive response (HR) when infiltrated into Nicotiana benthamiana and tobacco. Interestingly, the crc mutant was more susceptible to hydrogen peroxide, suggesting that, in planta, the mutant may be sensitive to reactive oxygen species generated during pathogen-associated molecular pattern-triggered immunity (PTI). Indeed, HR was further delayed when PTI-induced tissues were challenged with the crc mutant. The crc mutant did not elicit an altered PTI response in plants compared with the wild-type strain. We conclude that Crc plays an important role in growth and survival during infection.

Pseudomonas syringae pv. actinidiae (PSA) Isolates from Recent Bacterial Canker of Kiwifruit Outbreaks Belong to the Same Genetic Lineage

Science.gov (United States)

Taratufolo, Maria C.; Cai, Rongman; Almeida, Nalvo F.; Goodman, Tokia; Guttman, David S.; Vinatzer, Boris A.; Balestra, Giorgio M.

2012-01-01

Intercontinental spread of emerging plant diseases is one of the most serious threats to world agriculture. One emerging disease is bacterial canker of kiwi fruit (Actinidia deliciosa and A. chinensis) caused by Pseudomonas syringae pv. actinidiae (PSA). The disease first occurred in China and Japan in the 1980s and in Korea and Italy in the 1990s. A more severe form of the disease broke out in Italy in 2008 and in additional countries in 2010 and 2011 threatening the viability of the global kiwi fruit industry. To start investigating the source and routes of international transmission of PSA, genomes of strains from China (the country of origin of the genus Actinidia), Japan, Korea, Italy and Portugal have been sequenced. Strains from China, Italy, and Portugal have been found to belong to the same clonal lineage with only 6 single nucleotide polymorphisms (SNPs) in 3,453,192 bp and one genomic island distinguishing the Chinese strains from the European strains. Not more than two SNPs distinguish each of the Italian and Portuguese strains from each other. The Japanese and Korean strains belong to a separate genetic lineage as previously reported. Analysis of additional European isolates and of New Zealand isolates exploiting genome-derived markers showed that these strains belong to the same lineage as the Italian and Chinese strains. Interestingly, the analyzed New Zealand strains are identical to European strains at the tested SNP loci but test positive for the genomic island present in the sequenced Chinese strains and negative for the genomic island present in the European strains. Results are interpreted in regard to the possible direction of movement of the pathogen between countries and suggest a possible Chinese origin of the European and New Zealand outbreaks. PMID:22590555

The Arabidopsis lectin receptor kinase LecRK-V.5 represses stomatal immunity induced by Pseudomonas syringae pv. tomato DC3000.

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Marie Desclos-Theveniau

2012-02-01

Full Text Available Stomata play an important role in plant innate immunity by limiting pathogen entry into leaves but molecular mechanisms regulating stomatal closure upon pathogen perception are not well understood. Here we show that the Arabidopsis thaliana L-type lectin receptor kinase-V.5 (LecRK-V.5 negatively regulates stomatal immunity. Loss of LecRK-V.5 function increased resistance to surface inoculation with virulent bacteria Pseudomonas syringae pv tomato DC3000. Levels of resistance were not affected after infiltration-inoculation, suggesting that LecRK-V.5 functions at an early defense stage. By contrast, lines overexpressing LecRK-V.5 were more susceptible to Pst DC3000. Enhanced resistance in lecrk-V.5 mutants was correlated with constitutive stomatal closure, while increased susceptibility phenotypes in overexpression lines were associated with early stomatal reopening. Lines overexpressing LecRK-V.5 also demonstrated a defective stomatal closure after pathogen-associated molecular pattern (PAMP treatments. LecRK-V.5 is rapidly expressed in stomatal guard cells after bacterial inoculation or treatment with the bacterial PAMP flagellin. In addition, lecrk-V.5 mutants guard cells exhibited constitutive accumulation of reactive oxygen species (ROS and inhibition of ROS production opened stomata of lecrk-V.5. LecRK-V.5 is also shown to interfere with abscisic acid-mediated stomatal closure signaling upstream of ROS production. These results provide genetic evidences that LecRK-V.5 negatively regulates stomatal immunity upstream of ROS biosynthesis. Our data reveal that plants have evolved mechanisms to reverse bacteria-mediated stomatal closure to prevent long-term effect on CO(2 uptake and photosynthesis.

Identification of molecular markers linked to rice bacterial blight resistance genes from Oryza meyeriana

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Jing WANG,Chen CHENG,Yanru ZHOU,Yong YANG,Qiong MEI,Junmin LI,Ye CHENG,Chengqi YAN,Jianping CHEN

2015-09-01

Full Text Available Y73 is a progeny of asymmetric somatic hybridization between Oryza sativa cv. Dalixiang and the wild rice species Oryza meyeriana. Inoculation with a range of strains of Xanthomonas oryzae pv. oryzae showed that Y73 had inherited a high level of resistance to rice bacterial blight (BB from its wild parent. An F2 population of 7125 individuals was constructed from the cross between Y73 and a BB-susceptible cultivar IR24. After testing 615 SSR and STS markers covering the 12 rice chromosomes, 186 markers were selected that showed polymorphism between Y73 and IR24. Molecular markers linked to the BB resistance genes in Y73 were scanned using the F2 population and the polymorphic markers. The SSR marker RM128 on chromosome 1, the STS marker R03D159 on chromosome 3 and the STS marker R05D104 on chromosome 5 were found to be linked to the rice BB resistance genes in Y73.

XocR, a LuxR solo required for virulence in Xanthomonas oryzae pv. oryzicola.

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Xu, Huiyong; Zhao, Yancun; Qian, Guoliang; Liu, Fengquan

2015-01-01

Xanthomonas oryzae pv. oryzicola (Xoc) causes bacterial leaf streak (BLS) in rice, a serious bacterial disease of rice in Asia and parts of Africa. The virulence mechanisms of Xoc are not entirely clear and control measures for BLS are poorly developed. The solo LuxR proteins are widespread and shown to be involved in virulence in some plant associated bacteria (PAB). Here, we have cloned and characterized a PAB LuxR solo from Xoc, named as XocR. Mutation of xocR almost completely impaired the virulence ability of Xoc on host rice, but did not alter the ability to trigger HR (hypersensitive response, a programmed cell death) on non-host (plant) tobacco, suggesting the diversity of function of xocR in host and non-host plants. We also provide evidence to show that xocR is involved in the regulation of growth-independent cell motility in response to a yet-to-be-identified rice signal, as mutation of xocR impaired cell swimming motility of wild-type Rs105 in the presence but not absence of rice macerate. We further found that xocR regulated the transcription of two characterized virulence-associated genes (recN and trpE) in the presence of rice macerate. The promoter regions of recN and trpE possessed a potential binding motif (an imperfect pip box-like element) of XocR, raising the possibility that XocR might directly bind the promoter regions of these two genes to regulate their transcriptional activity. Our studies add a new member of PAB LuxR solos and also provide new insights into the role of PAB LuxR solo in the virulence of Xanthomonas species.

Gaseous 3-pentanol primes plant immunity against a bacterial speck pathogen, Pseudomonas syringae pv. tomato via salicylic acid and jasmonic acid-dependent signaling pathways in Arabidopsis.

Science.gov (United States)

Song, Geun C; Choi, Hye K; Ryu, Choong-Min

2015-01-01

3-Pentanol is an active organic compound produced by plants and is a component of emitted insect sex pheromones. A previous study reported that drench application of 3-pentanol elicited plant immunity against microbial pathogens and an insect pest in crop plants. Here, we evaluated whether 3-pentanol and the derivatives 1-pentanol and 2-pentanol induced plant systemic resistance using the in vitro I-plate system. Exposure of Arabidopsis seedlings to 10 μM and 100 nM 3-pentanol evaporate elicited an immune response to Pseudomonas syringae pv. tomato DC3000. We performed quantitative real-time PCR to investigate the 3-pentanol-mediated Arabidopsis immune responses by determining Pathogenesis-Related (PR) gene expression levels associated with defense signaling through salicylic acid (SA), jasmonic acid (JA), and ethylene signaling pathways. The results show that exposure to 3-pentanol and subsequent pathogen challenge upregulated PDF1.2 and PR1 expression. Selected Arabidopsis mutants confirmed that the 3-pentanol-mediated immune response involved SA and JA signaling pathways and the NPR1 gene. Taken together, this study indicates that gaseous 3-pentanol triggers induced resistance in Arabidopsis by priming SA and JA signaling pathways. To our knowledge, this is the first report that a volatile compound of an insect sex pheromone triggers plant systemic resistance against a bacterial pathogen.

Gaseous 3-pentanol primes plant immunity against a bacterial speck pathogen, Pseudomonas syringae pv. tomato via salicylic acid and jasmonic acid-dependent signaling pathways in Arabidopsis

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Geun Cheol eSong

2015-10-01

Full Text Available 3-Pentanol is an active organic compound produced by plants and is a component of emitted insect sex pheromones. A previous study reported that drench application of 3-pentanol elicited plant immunity against microbial pathogens and an insect pest in crop plants. Here, we evaluated whether 3-pentanol and the derivatives 1-pentanol and 2-pentanol induced plant systemic resistance using the in vitro I-plate system. Exposure of Arabidopsis seedlings to 10 M and 100 nM 3-pentanol evaporate elicited an immune response to Pseudomonas syringae pv. tomato DC3000. We performed quantitative real-time PCR to investigate the 3-pentanol-mediated Arabidopsis immune responses by determining Pathogenesis-Related (PR gene expression levels associated with defense signaling through SA, JA, and ethylene signaling pathways. The results show that exposure to 3-pentanol and subsequent pathogen challenge upregulated PDF1.2 and PR1 expression. Selected Arabidopsis mutants confirmed that the 3-pentanol-mediated immune response involved salicylic acid (SA and jasmonic acid (JA signaling pathways and the NPR1 gene. Taken together, this study indicates that gaseous 3-pentanol triggers induced resistance in Arabidopsis by priming SA and JA signaling pathways. To our knowledge, this is the first report that a volatile compound of an insect sex pheromone triggers plant systemic resistance against a bacterial pathogen.

Studies on the physiological changes in the rice plants infected with Xanthomonas campestris pv. of oryzae, (4)

International Nuclear Information System (INIS)

Watanabe, Minoru; Samejima, Shin-ichi; Hayashi, Nobuo; Hosokawa, Daijiro

1980-01-01

The translocation and accumulation of 14 C-photosynthetic assimilates in rice plants infected with Xanthomonas campestris pv. oryzae were investigated. Approximately the same quantities of assimilates were detected in healthy and infected leaves 1 day after photosynthesis, but 1.7 times as much as healthy leaves assimilates were still remained in infected leaves 7 days after photosynthesis. Much more 14 C-photosynthetic assimilates were generally detected in leaf blade than in leaf sheath or in root within 1 day after photosynthesis, but detected in leaf sheath than in leaf blade later than 2 days after photosynthesis. The rates of translocation of 14 C-assimilates from leaf blade to leaf sheath were lower in inoculated rice plants than in healthy ones. In both healthy and inoculated leaves of susceptible and resistant cultivars, there was a tendency that 14 C-sugar contents decreased, but 14 C-organic acid and -amino acid contents increased gradually after photosynthesis. Incorporation of 14 C-photosynthetic assimilates into invading bacterial cells which were separated from leaf tissues by the methods of leakage and Millipore filtration was not detected immediately after photosynthesis, but became apparent 5 days after photosynthesis. The leakage of 14 C-photosynthetic assimilates from leaf tissues into bathing solution was about 4 times higher in infected leaves than in healthy ones 5 days after photosynthesis, suggesting that the permeability in infected leaf tissues would increase. (author)

Suppression of Plant Immune Responses by the Pseudomonas savastanoi pv. savastanoi NCPPB 3335 Type III Effector Tyrosine Phosphatases HopAO1 and HopAO2

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María Pilar Castañeda-Ojeda

2017-05-01

Full Text Available The effector repertoire of the olive pathogen P. savastanoi pv. savastanoi NCPPB 3335 includes two members of the HopAO effector family, one of the most diverse T3E families of the P. syringae complex. The study described here explores the phylogeny of these dissimilar members, HopAO1 and HopAO2, among the complex and reveals their activities as immune defense suppressors. Although HopAO1 is predominantly encoded by phylogroup 3 strains isolated from woody organs of woody hosts, both HopAO1 and HopAO2 are phylogenetically clustered according to the woody/herbaceous nature of their host of isolation, suggesting host specialization of the HopAO family across the P. syringae complex. HopAO1 and HopAO2 translocate into plant cells and show hrpL-dependent expression, which allows their classification as actively deployed type III effectors. Our data also show that HopAO1 and HopAO2 possess phosphatase activity, a hallmark of the members of this family. Both of them exert an inhibitory effect on early plant defense responses, such as ROS production and callose deposition, and are able to suppress ETI responses induced by the effectorless polymutant of P. syringae pv. tomato DC3000 (DC3000D28E in Nicotiana. Moreover, we demonstrate that a ΔhopAO1 mutant of P. savastanoi NCPBB 3335 exhibits a reduced fitness and virulence in olive plants, which supports the relevance of this effector during the interaction of this strain with its host plants. This work contributes to the field with the first report regarding functional analysis of HopAO homologs encoded by P. syringae or P. savastanoi strains isolated from woody hosts.

Suppression of Plant Immune Responses by the Pseudomonas savastanoi pv. savastanoi NCPPB 3335 Type III Effector Tyrosine Phosphatases HopAO1 and HopAO2

Science.gov (United States)

Castañeda-Ojeda, María Pilar; Moreno-Pérez, Alba; Ramos, Cayo; López-Solanilla, Emilia

2017-01-01

The effector repertoire of the olive pathogen P. savastanoi pv. savastanoi NCPPB 3335 includes two members of the HopAO effector family, one of the most diverse T3E families of the P. syringae complex. The study described here explores the phylogeny of these dissimilar members, HopAO1 and HopAO2, among the complex and reveals their activities as immune defense suppressors. Although HopAO1 is predominantly encoded by phylogroup 3 strains isolated from woody organs of woody hosts, both HopAO1 and HopAO2 are phylogenetically clustered according to the woody/herbaceous nature of their host of isolation, suggesting host specialization of the HopAO family across the P. syringae complex. HopAO1 and HopAO2 translocate into plant cells and show hrpL-dependent expression, which allows their classification as actively deployed type III effectors. Our data also show that HopAO1 and HopAO2 possess phosphatase activity, a hallmark of the members of this family. Both of them exert an inhibitory effect on early plant defense responses, such as ROS production and callose deposition, and are able to suppress ETI responses induced by the effectorless polymutant of P. syringae pv. tomato DC3000 (DC3000D28E) in Nicotiana. Moreover, we demonstrate that a ΔhopAO1 mutant of P. savastanoi NCPBB 3335 exhibits a reduced fitness and virulence in olive plants, which supports the relevance of this effector during the interaction of this strain with its host plants. This work contributes to the field with the first report regarding functional analysis of HopAO homologs encoded by P. syringae or P. savastanoi strains isolated from woody hosts. PMID:28529516

Co-silencing of tomato S-adenosylhomocysteine hydrolase genes confers increased immunity against Pseudomonas syringae pv. tomato DC3000 and enhanced tolerance to drought stress

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Li Xiao Hui

2015-09-01

Full Text Available S-adenosylhomocysteine hydrolase (SAHH, catalyzing the reversible hydrolysis of S-adenosylhomocysteine to adenosine and homocysteine, is a key enzyme that maintain the cellular methylation potential in all organisms. We report here the biological functions of tomato SlSAHHs in stress response. The tomato genome contains three SlSAHH genes that encode SlSAHH proteins with high level of sequence identity. qRT-PCR analysis revealed that SlSAHHs responded with distinct expression induction patterns to Pseudomonas syringae pv. tomato (Pst DC3000 and Botrytis cinerea as well as to defense signaling hormones such as salicylic acid, jasmonic acid and a precursor of ethylene. Virus-induced gene silencing-based knockdown of individual SlSAHH gene did not affect the growth performance and the response to Pst DC3000. However, co-silencing of three SlSAHH genes using a conserved sequence led to significant inhibition of vegetable growth. The SlSAHH-co-silenced plants displayed increased resistance to Pst DC3000 but did not alter the resistance to B. cinerea. Co-silencing of SlSAHHs resulted in constitutively activated defense responses including elevated SA level, upregulated expression of defense-related and PAMP-triggered immunity marker genes and increased callose deposition and H2O2 accumulation. Furthermore, the SlSAHH-co-silenced plants also exhibited enhanced drought stress tolerance although they had relatively small roots. These data demonstrate that, in addition to the functions in growth and development, SAHHs also play important roles in regulating biotic and abiotic stress responses in plants.

Soil mixture composition alters Arabidopsis susceptibility to Pseudomonas syringae infection

Science.gov (United States)

Pseudomonas syringae is a Gram-negative bacterial pathogen that causes disease on more than 100 different plant species, including the model plant Arabidopsis thaliana. Dissection of the Arabidopsis thaliana-Pseudomonas syringae pathosystem has identified many factors that contribute to successful ...

Transfer of bacterial blight resistance from Oryza meyeriana to O.Sativa L.by asymmetric somatic hybridization

Institute of Scientific and Technical Information of China (English)

ZHU Yongsheng; CHEN Baotang; YU Shunwu; ZHANG Duanpin; ZHANG Xueqin; YAN Qiusheng

2004-01-01

Asymmetric somatic hybrid plants were produced between cultivated rice (Oryza sativa L.) and wild species [O. Meyeriana (Zoll. etMor, exSteud.)] with high resistance to rice bacterial blight. X-ray-irradiated protoplasts of the wild species were used as donor and chemically fused with iodoacetamide-inactivated protoplasts of rice cv. 02428to produce hybrids. Seventy-two plants were regenerated from 623 calli based on metabolic complementation. The morphological characters of the plants closely resembled that of the rice. Simple sequence repeats were employed to identify their hybridity. Cytological analysis of root-tips revealed that their chromosome number varied in the range of 27-38. The somatic hybrids were inoculated with strains of Xanthamonas oryzae pv. Oryzae at adult growth stage and demonstrated the resistance to bacterial blight introgression from the O. Meyeriana.

Defining essential processes in plant pathogenesis with Pseudomonas syringae pv. tomato DC3000 disarmed polymutants and a subset of key type III effectors.

Science.gov (United States)

Wei, Hai-Lei; Collmer, Alan

2017-12-25

Pseudomonas syringae pv. tomato DC3000 and its derivatives cause disease in tomato, Arabidopsis and Nicotiana benthamiana. The primary virulence factors include a repertoire of 29 effector proteins injected into plant cells by the type III secretion system and the phytotoxin coronatine. The complete repertoire of effector genes and key coronatine biosynthesis genes have been progressively deleted and minimally reassembled to reconstitute basic pathogenic ability in N. benthamiana, and in Arabidopsis plants that have mutations in target genes that mimic effector actions. This approach and molecular studies of effector activities and plant immune system targets have highlighted a small subset of effectors that contribute to essential processes in pathogenesis. Most notably, HopM1 and AvrE1 redundantly promote an aqueous apoplastic environment, and AvrPtoB and AvrPto redundantly block early immune responses, two conditions that are sufficient for substantial bacterial growth in planta. In addition, disarmed DC3000 polymutants have been used to identify the individual effectors responsible for specific activities of the complete repertoire and to more effectively study effector domains, effector interplay and effector actions on host targets. Such work has revealed that AvrPtoB suppresses cell death elicitation in N. benthamiana that is triggered by another effector in the DC3000 repertoire, highlighting an important aspect of effector interplay in native repertoires. Disarmed DC3000 polymutants support the natural delivery of test effectors and infection readouts that more accurately reveal effector functions in key pathogenesis processes, and enable the identification of effectors with similar activities from a broad range of other pathogens that also defeat plants with cytoplasmic effectors. © 2017 BSPP AND JOHN WILEY & SONS LTD.

40 CFR 180.1145 - Pseudomonas syringae; exemption from the requirement of a tolerance.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Pseudomonas syringae; exemption from... FOOD Exemptions From Tolerances § 180.1145 Pseudomonas syringae; exemption from the requirement of a tolerance. Pseudomonas syringae is exempted from the requirement of a tolerance on all raw agricultural...

Genomic analysis of the Kiwifruit pathogen Pseudomonas syringae pv. actinidiae provides insight into the origins of an emergent plant disease.

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Honour C McCann

Full Text Available The origins of crop diseases are linked to domestication of plants. Most crops were domesticated centuries--even millennia--ago, thus limiting opportunity to understand the concomitant emergence of disease. Kiwifruit (Actinidia spp. is an exception: domestication began in the 1930s with outbreaks of canker disease caused by P. syringae pv. actinidiae (Psa first recorded in the 1980s. Based on SNP analyses of two circularized and 34 draft genomes, we show that Psa is comprised of distinct clades exhibiting negligible within-clade diversity, consistent with disease arising by independent samplings from a source population. Three clades correspond to their geographical source of isolation; a fourth, encompassing the Psa-V lineage responsible for the 2008 outbreak, is now globally distributed. Psa has an overall clonal population structure, however, genomes carry a marked signature of within-pathovar recombination. SNP analysis of Psa-V reveals hundreds of polymorphisms; however, most reside within PPHGI-1-like conjugative elements whose evolution is unlinked to the core genome. Removal of SNPs due to recombination yields an uninformative (star-like phylogeny consistent with diversification of Psa-V from a single clone within the last ten years. Growth assays provide evidence of cultivar specificity, with rapid systemic movement of Psa-V in Actinidia chinensis. Genomic comparisons show a dynamic genome with evidence of positive selection on type III effectors and other candidate virulence genes. Each clade has highly varied complements of accessory genes encoding effectors and toxins with evidence of gain and loss via multiple genetic routes. Genes with orthologs in vascular pathogens were found exclusively within Psa-V. Our analyses capture a pathogen in the early stages of emergence from a predicted source population associated with wild Actinidia species. In addition to candidate genes as targets for resistance breeding programs, our findings

Pseudomnas syringae – a Pathogen of Fruit Trees in Serbia

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Veljko Gavrilović

2009-01-01

Full Text Available Data about symptomatology, pathogenicity and bacteriological characteristics of Pseudomonas syringae, and PCR methods for fast and reliable detection of the pathogen are given in this paper. P. syringae has been experimentaly proved as a pathogen of pear, apple, apricot, plum cherry, and raspberry, and pathogen strains have also been isolated from necrotic peach buds. Two pathogen varieties, syringae and morsprunorum, were found in our research in Serbia, the former being dominant on fruit trees.The most reliable method for detection of this bacteria is PCR, using BOX and REP primers. This method has also revealed significant differences among the strains originating from fruit trees in Serbia. Thus, it was proved that the population of P. syringae in Serbia is heterogeneous, which is very important for future epidemiologocal studies. Control of this pathogen includes mechanical, cultural and chemical measures, but integrated approach is very important for sustainable control.

Bacterial canker on kiwifruit in Italy: anatomical changes in the wood and in the primary infection sites.

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Renzi, Marsilio; Copini, Paul; Taddei, Anna R; Rossetti, Antonio; Gallipoli, Lorenzo; Mazzaglia, Angelo; Balestra, Giorgio M

2012-09-01

The bacterial canker of kiwifruit caused by Pseudomonas syringae pv. actinidiae is a severe threat to kiwifruit production worldwide. Many aspects of P. syringae pv. actinidiae biology and epidemiology still require in-depth investigation. The infection by and spread of P. syringae pv. actinidiae in xylem and phloem was investigated by carrying out artificial inoculation experiments with histological and dendrochronological analyses of naturally diseased plants in Italy. We found that the bacterium can infect host plants by entering natural openings and lesions. In naturally infected kiwifruit plants, P. syringae pv. actinidiae is present in the lenticels as well as in the dead phloem tissue beneath the lenticels, surrounded by a lesion in the periderm which appears to indicate the importance of lenticels to kiwifruit infection. Biofilm formation was observed outside and inside plants. In cases of advanced stages of P. syringae pv. actinidiae infection, neuroses of the phloem occur, which are followed by cambial dieback and most likely by infection of the xylem. Anatomical changes in wood such as reduced ring width, a drastic reduction in vessel size, and the presence of tyloses were observed within several infected sites. In the field, these changes occur only a year after the first leaf symptoms are observed suggesting a significant time lapse between primary and secondary symptoms. It was possible to study the temporal development of P. syringae pv. actinidiae-induced cambial dieback by applying dendrochronology methods which revealed that cambial dieback occurs only during the growing season.

Pseudomonas syringae enhances herbivory by suppressing the reactive oxygen burst in Arabidopsis.

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Groen, Simon C; Humphrey, Parris T; Chevasco, Daniela; Ausubel, Frederick M; Pierce, Naomi E; Whiteman, Noah K

2016-01-01

Plant-herbivore interactions have evolved in the presence of plant-colonizing microbes. These microbes can have important third-party effects on herbivore ecology, as exemplified by drosophilid flies that evolved from ancestors feeding on plant-associated microbes. Leaf-mining flies in the genus Scaptomyza, which is nested within the paraphyletic genus Drosophila, show strong associations with bacteria in the genus Pseudomonas, including Pseudomonas syringae. Adult females are capable of vectoring these bacteria between plants and larvae show a preference for feeding on P. syringae-infected leaves. Here we show that Scaptomyza flava larvae can also vector P. syringae to and from feeding sites, and that they not only feed more, but also develop faster on plants previously infected with P. syringae. Our genetic and physiological data show that P. syringae enhances S. flava feeding on infected plants at least in part by suppressing anti-herbivore defenses mediated by reactive oxygen species. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bacterial Leaf Spot of Parsley: Characterization of a New Disease

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Since 2002, a severe leaf spot disease on parsley has occurred throughout central coastal California and particularly in Monterey County. Two different bacterial pathogens (Pseudomonas syringae pv. apii, and P. syringae pv. coriandricola) have been associated these outbreaks on parsley. Our research...

Show us your spots! Researchers need samples of bacterial leaf spots on celery, cilantro, parsley, and other crops.

Science.gov (United States)

Since 2002, a severe leaf spot disease on parsley has occurred throughout central coastal California and particularly in Monterey County. Three different bacterial pathogens (Pseudomonas syringae pv. apii, P. syringae pv. coriandricola and an organism very closely related to P. viridiflava) have bee...

Transgenic tomato plants overexpressing tyramine N-hydroxycinnamoyltransferase exhibit elevated hydroxycinnamic acid amide levels and enhanced resistance to Pseudomonas syringae.

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Campos, Laura; Lisón, Purificación; López-Gresa, María Pilar; Rodrigo, Ismael; Zacarés, Laura; Conejero, Vicente; Bellés, José María

2014-10-01

Hydroxycinnamic acid amides (HCAA) are secondary metabolites involved in plant development and defense that have been widely reported throughout the plant kingdom. These phenolics show antioxidant, antiviral, antibacterial, and antifungal activities. Hydroxycinnamoyl-CoA:tyramine N-hydroxycinnamoyl transferase (THT) is the key enzyme in HCAA synthesis and is induced in response to pathogen infection, wounding, or elicitor treatments, preceding HCAA accumulation. We have engineered transgenic tomato plants overexpressing tomato THT. These plants displayed an enhanced THT gene expression in leaves as compared with wild type (WT) plants. Consequently, leaves of THT-overexpressing plants showed a higher constitutive accumulation of the amide coumaroyltyramine (CT). Similar results were found in flowers and fruits. Moreover, feruloyltyramine (FT) also accumulated in these tissues, being present at higher levels in transgenic plants. Accumulation of CT, FT and octopamine, and noradrenaline HCAA in response to Pseudomonas syringae pv. tomato infection was higher in transgenic plants than in the WT plants. Transgenic plants showed an enhanced resistance to the bacterial infection. In addition, this HCAA accumulation was accompanied by an increase in salicylic acid levels and pathogenesis-related gene induction. Taken together, these results suggest that HCAA may play an important role in the defense of tomato plants against P. syringae infection.

Early Arabidopsis root hair growth stimulation by pathogenic strains of Pseudomonas syringae.

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Pecenková, Tamara; Janda, Martin; Ortmannová, Jitka; Hajná, Vladimíra; Stehlíková, Zuzana; Žárský, Viktor

2017-09-01

Selected beneficial Pseudomonas spp. strains have the ability to influence root architecture in Arabidopsis thaliana by inhibiting primary root elongation and promoting lateral root and root hair formation. A crucial role for auxin in this long-term (1week), long-distance plant-microbe interaction has been demonstrated. Arabidopsis seedlings were cultivated in vitro on vertical plates and inoculated with pathogenic strains Pseudomonas syringae pv. maculicola (Psm) and P. syringae pv. tomato DC3000 (Pst), as well as Agrobacterium tumefaciens (Atu) and Escherichia coli (Eco). Root hair lengths were measured after 24 and 48h of direct exposure to each bacterial strain. Several Arabidopsis mutants with impaired responses to pathogens, impaired ethylene perception and defects in the exocyst vesicle tethering complex that is involved in secretion were also analysed. Arabidopsis seedling roots infected with Psm or Pst responded similarly to when infected with plant growth-promoting rhizobacteria; root hair growth was stimulated and primary root growth was inhibited. Other plant- and soil-adapted bacteria induced similar root hair responses. The most compromised root hair growth stimulation response was found for the knockout mutants exo70A1 and ein2. The single immune pathways dependent on salicylic acid, jasmonic acid and PAD4 are not directly involved in root hair growth stimulation; however, in the mutual cross-talk with ethylene, they indirectly modify the extent of the stimulation of root hair growth. The Flg22 peptide does not initiate root hair stimulation as intact bacteria do, but pretreatment with Flg22 prior to Psm inoculation abolished root hair growth stimulation in an FLS2 receptor kinase-dependent manner. These early response phenomena are not associated with changes in auxin levels, as monitored with the pDR5::GUS auxin reporter. Early stimulation of root hair growth is an effect of an unidentified component of living plant pathogenic bacteria. The root

Differential modulation of plant immune responses by diverse members of the Pseudomonas savastanoi pv. savastanoi HopAF type III effector family.

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Castañeda-Ojeda, M Pilar; López-Solanilla, Emilia; Ramos, Cayo

2017-06-01

The Pseudomonas savastanoi pv. savastanoi NCPPB 3335 type III secretion system (T3SS) effector repertoire includes 33 candidates, seven of which translocate into host cells and interfere with plant defences. The present study was performed to investigate the co-existence of both plasmid- and chromosomal-encoded members of the HopAF effector family, HopAF1-1 and HopAF1-2, respectively, in the genome of NCPPB 3335. Here, we show that the HopAF1 paralogues are widely distributed in the Pseudomonas syringae complex, where HopAF1-1 is most similar to the homologues encoded by other P. syringae pathovars infecting woody hosts that belong to phylogroups 1 and 3. We show that the expression of both HopAF1-1 and HopAF-2 is transcriptionally dependent on HrpL and demonstrate their delivery into Nicotiana tabacum leaves. Although the heterologous delivery of either HopAF1-1 or HopAF1-2 significantly suppressed the production of defence-associated reactive oxygen species levels, only HopAF1-2 reduced the levels of callose deposition. Moreover, the expression of HopAF1-2 by functionally effectorless P. syringae pv. tomato DC3000D28E completely inhibited the hypersensitive response in tobacco and significantly increased the competitiveness of the strain in Nicotiana benthamiana. Despite their functional differences, subcellular localization studies reveal that green fluorescent protein (GFP) fusions to either HopAF1-1 or HopAF1-2 are targeted to the plasma membrane when they are expressed in plant cells, a process that is completely dependent on the integrity of their N-myristoylation motif. Our results further support the notion that highly similar T3SS effectors might differentially interact with diverse plant targets, even when they co-localize in the same cell compartment. © 2016 BSPP AND JOHN WILEY & SONS LTD.

Hexanoic acid is a resistance inducer that protects tomato plants against Pseudomonas syringae by priming the jasmonic acid and salicylic acid pathways.

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Scalschi, Loredana; Vicedo, Begonya; Camañes, Gemma; Fernandez-Crespo, Emma; Lapeña, Leonor; González-Bosch, Carmen; García-Agustín, Pilar

2013-05-01

Hexanoic acid-induced resistance (Hx-IR) is effective against several pathogens in tomato plants. Our study of the mechanisms implicated in Hx-IR against Pseudomonas syringae pv. tomato DC3000 suggests that hexanoic acid (Hx) treatment counteracts the negative effect of coronatine (COR) and jasmonyl-isoleucine (JA-Ile) on the salicylic acid (SA) pathway. In Hx-treated plants, an increase in the expression of jasmonic acid carboxyl methyltransferase (JMT) and the SA marker genes PR1 and PR5 indicates a boost in this signalling pathway at the expense of a decrease in JA-Ile. Moreover, Hx treatment potentiates 12-oxo-phytodienoic acid accumulation, which suggests that this molecule might play a role per se in Hx-IR. These results support a positive relationship between the SA and JA pathways in Hx-primed plants. Furthermore, one of the mechanisms of virulence mediated by COR is stomatal re-opening on infection with P. syringae. In this work, we observed that Hx seems to inhibit stomatal opening in planta in the presence of COR, which suggests that, on infection in tomato, this treatment suppresses effector action to prevent bacterial entry into the mesophyll. © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

PENGARUH RHIZOPUS ORYZAE DAN ASPERGILLUS ORYZAE TERHADAP KUALITAS KECAP

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Dewi Sabita Slamet

2012-11-01

Full Text Available Telah diteliti pengganti fermentasi mikroorganisme Aspergillus oryzae Rhyzopus oryzae dan campuran Aspergillus dan Rhyzopus oryzae, dengan perendaman dalam larutan garam 20% dalam waktu yang berbeda terhadap kualitas kecap.Lamanya perendaman dalam larutan garam 20% yang berbeda menghasilkan kadar protein kecap yang berbeda. Aspergillus oryzae lebih baik dalam menghasilkan enzima protease dari pada Rhyzopus oryzae.Uji organoleptik menunjukkan perbedaan tidak bermakna dalam hal rasa maupun aroma antar kecap yang dibuat dengan strain jamur yang berlainan serta waktu perendaman yang berbeda. Untuk membuat kecap, sebaiknya dilakukan perendaman dalam larutan garam 20% selama 14 hari.

Diversity and Abundance of Ice Nucleating Strains of Pseudomonas syringae in a Freshwater Lake in Virginia, USA.

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Pietsch, Renée B; Vinatzer, Boris A; Schmale, David G

2017-01-01

The bacterium Pseudomonas syringae is found in a variety of terrestrial and aquatic environments. Some strains of P. syringae express an ice nucleation protein (hereafter referred to as Ice+) allowing them to catalyze the heterogeneous freezing of water. Though P. syringae has been sampled intensively from freshwater sources in France, little is known about the genetic diversity of P. syringae in natural aquatic habitats in North America. We collected samples of freshwater from three different depths in Claytor Lake, Virginia, USA between November 2015 and June 2016. Samples were plated on non-selective medium (TSA) and on medium selective for Pseudomonas (KBC) and closely related species to estimate the total number of culturable bacteria and of Pseudomonas , respectively. A droplet freezing assay was used to screen colonies for the Ice+ phenotype. Ice+ colonies were then molecularly identified based on the cts (citrate synthase) gene and the 16S rDNA gene. Phylogenetic analysis of cts sequences showed a surprising diversity of phylogenetic subgroups of P. syringae . Frequencies of Ice+ isolates on P. syringae selective medium ranged from 0 to 15% per sample with the highest frequency being found in spring. Our work shows that freshwater lakes can be a significant reservoir of Ice+ P. syringae . Future work is needed to determine the contribution of P. syringae from freshwater lakes to the P. syringae populations present in the atmosphere and on plants and, in particular, if freshwater lakes could be an inoculum source of P. syringae -caused plant disease outbreaks.

E-2-hexenal promotes susceptibility to Pseudomonas syringae by activating jasmonic acid pathways in Arabidopsis

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Alessandra eScala

2013-04-01

Full Text Available Green Leaf Volatiles (GLVs are C6-molecules - alcohols, aldehydes and esters - produced by plants upon herbivory or during pathogen infection. Exposure to this blend of volatiles induces defence-related responses in neighboring undamaged plants, thus assigning a role to GLVs in regulating plant defences. Here we compared Arabidopsis thaliana ecotype Ler with a hydroperoxide lyase line, hpl1, unable to synthesize GLVs, for susceptibility to Pseudomonas syringae pv. tomato (DC3000. We found that the growth of DC3000 was significantly reduced in the hpl1 mutant. This phenomenon correlated with lower jasmonic acid (JA levels and higher salicylic acid (SA levels in the hpl1 mutant. Furthermore, upon infection, the JA-responsive genes VSP2 and LEC were only slightly or not induced, respectively, in hpl1. This suggests that the reduced growth of DC3000 in hpl1 plants is due to the constraint of JA-dependent responses. Treatment of hpl1 plants with E-2-hexenal, one of the more reactive GLVs, prior to infection with DC3000, resulted in increased growth of DC3000 in hpl1, thus complementing this mutant. Interestingly, the growth of DC3000 also increased in Ler plants treated with E-2-hexenal. This stronger growth was not dependent on the JA-signaling component MYC2, but on ORA59, an integrator of JA and ethylene signaling pathways, and on the production of coronatine by DC3000. GLVs may have multiple effects on plant-pathogen interactions, in this case reducing resistance to P. syringae via JA and ORA59.

The Pseudomonas syringae type III effector HopG1 targets mitochondria, alters plant development, and suppresses plant innate immunity

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Block, Anna; Guo, Ming; Li, Guangyong; Elowsky, Christian; Clemente, Thomas E.; Alfano, James R.

2009-01-01

Summary The bacterial plant pathogen Pseudomonas syringae uses a type III protein secretion system to inject type III effectors into plant cells. Primary targets of these effectors appear to be effector-triggered immunity (ETI) and pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI). The type III effector HopG1 is a suppressor of ETI that is broadly conserved in bacterial plant pathogens. Here we show that HopG1 from P. syringae pv. tomato DC3000 also suppresses PTI. Interestingly, HopG1 localizes to plant mitochondria, suggesting that its suppression of innate immunity may be linked to a perturbation of mitochondrial function. While HopG1 possesses no obvious mitochondrial signal peptide, its N-terminal two-thirds was sufficient for mitochondrial localization. A HopG1-GFP fusion lacking HopG1’s N-terminal 13 amino acids was not localized to the mitochondria reflecting the importance of the N-terminus for targeting. Constitutive expression of HopG1 in Arabidopsis thaliana, Nicotiana tabacum (tobacco) and Lycopersicon esculentum (tomato) dramatically alters plant development resulting in dwarfism, increased branching and infertility. Constitutive expression of HopG1 in planta leads to reduced respiration rates and an increased basal level of reactive oxygen species. These findings suggest that HopG1’s target is mitochondrial and that effector/target interaction promotes disease by disrupting mitochondrial functions. PMID:19863557

Development of a Multiple Loci Variable Number of Tandem Repeats Analysis (MLVA) to Unravel the Intra-Pathovar Structure of Pseudomonas syringae pv. actinidiae Populations Worldwide

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Ciarroni, Serena; Gallipoli, Lorenzo; Taratufolo, Maria C.; Butler, Margi I.; Poulter, Russell T. M.; Pourcel, Christine; Vergnaud, Gilles; Balestra, Giorgio M.; Mazzaglia, Angelo

2015-01-01

The bacterial canker of kiwifruit by Pseudomonas syringae pv. actinidiae is an emblematic example of a catastrophic disease of fruit crops. In 2008 a new, extremely virulent form of the pathogen emerged and rapidly devastated many Actinidia spp. orchards all over the world. In order to understand differences in populations within this pathovar and to elucidate their diffusion and movements on world scale, it is necessary to be able to quickly and on a routine basis compare new isolates with previous records. In this report a worldwide collection of 142 strains was analyzed by MLVA, chosen as investigative technique for its efficacy, reproducibility, simplicity and low cost. A panel of 13 Variable Number of Tandem Repeats (VNTR) loci was identified and used to describe the pathogen population. The MLVA clustering is highly congruent with the population structure as previously established by other molecular approaches including whole genome sequencing and correlates with geographic origin, time of isolation and virulence. For convenience, we divided the VNTR loci in two panels. Panel 1 assay, using six loci, recognizes 23 different haplotypes, clustered into ten complexes with highest congruence with previous classifications. Panel 2, with seven VNTR loci, provides discriminatory power. Using the total set of 13 VNTR loci, 58 haplotypes can be distinguished. The recent hypervirulent type shows very limited diversity and includes, beside the strains from Europe, New Zealand and Chile, a few strains from Shaanxi, China. A broad genetic variability is observed in China, but different types are also retrievable in Japan and Korea. The low virulent strains cluster together and are very different from the other MLVA genotypes. Data were used to generate a public database in MLVAbank. MLVA represents a very promising first-line assay for large-scale routine genotyping, prior to whole genome sequencing of only the most relevant samples. PMID:26262683

The Facultative Symbiont Rickettsia Protects an Invasive Whitefly against Entomopathogenic Pseudomonas syringae Strains.

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Hendry, Tory A; Hunter, Martha S; Baltrus, David A

2014-12-01

Facultative endosymbionts can benefit insect hosts in a variety of ways, including context-dependent roles, such as providing defense against pathogens. The role of some symbionts in defense may be overlooked, however, when pathogen infection is transient, sporadic, or asymptomatic. The facultative endosymbiont Rickettsia increases the fitness of the sweet potato whitefly (Bemisia tabaci) in some populations through mechanisms that are not yet understood. In this study, we investigated the role of Rickettsia in mediating the interaction between the sweet potato whitefly and Pseudomonas syringae, a common environmental bacterium, some strains of which are pathogenic to aphids. Our results show that P. syringae multiplies within whiteflies, leading to host death, and that whiteflies infected with Rickettsia show a decreased rate of death due to P. syringae. Experiments using plants coated with P. syringae confirmed that whiteflies can acquire the bacteria at a low rate while feeding, leading to increased mortality, particularly when the whiteflies are not infected with Rickettsia. These results suggest that P. syringae may affect whitefly populations in nature and that Rickettsia can ameliorate this effect. This study highlights the possible importance of interactions among opportunistic environmental pathogens and endosymbionts of insects. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

ORF Alignment: NC_004578 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available nas syringae ... pv. syringae B728a] ... Length = 133 ... Query: 313 ETCSLFFVEAIHAAEERVWITSPYFIPD...EAVSAALTLAVLRGVDVRLLLPSRPDHYVVYA 372 ... ETCSLFFVEAIHAAEERVWITSPYFIPDEAV+A...ALTLAVLRGVDVRLLLPSRPDHYVVYA Sbjct: 1 ... ETCSLFFVEAIHAAEERVWITSPYFIPDEAVTAALTLAVLRGVDVRLLLPSRPDHYVVYA 60 ... Quer

Flagellar motility confers epiphytic fitness advantages upon Pseudomonas syringae

International Nuclear Information System (INIS)

Haefele, D.M.; Lindow, S.E.

1987-01-01

The role of flagellar motility in determining the epiphytic fitness of an ice-nucleation-active strain of Pseudomonas syringae was examined. The loss of flagellar motility reduced the epiphytic fitness of a normally motile P. syringae strain as measured by its growth, survival, and competitive ability on bean leaf surfaces. Equal population sizes of motile parental or nonmotile mutant P. syringae strains were maintained on bean plants for at least 5 days following the inoculation of fully expanded primary leaves. However, when bean seedlings were inoculated before the primary leaves had expanded and bacterial populations on these leaves were quantified at full expansion, the population size of the nonmotile derivative strain reached only 0.9% that of either the motile parental or revertant strain. When fully expanded bean primary leaves were coinoculated with equal numbers of motile and nonmotile cells, the population size of a nonmotile derivative strain was one-third of that of the motile parental or revertant strain after 8 days. Motile and nonmotile cells were exposed in vitro and on plants to UV radiation and desiccating conditions. The motile and nonmotile strains exhibited equal resistance to both stresses in vitro. However, the population size of a nonmotile strain on leaves was less than 20% that of a motile revertant strain when sampled immediately after UV irradiation. Epiphytic populations of both motile and nonmotile P. syringae declined under desiccating conditions on plants, and after 8 days, the population size of a nonmotile strain was less than one-third that of the motile parental or revertant strain

Coronatine Facilitates Pseudomonas syringae Infection of Arabidopsis Leaves at Night

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Panchal, Shweta; Roy, Debanjana; Chitrakar, Reejana; Price, Lenore; Breitbach, Zachary S.; Armstrong, Daniel W.; Melotto, Maeli

2016-01-01

In many land plants, the stomatal pore opens during the day and closes during the night. Thus, periods of darkness could be effective in decreasing pathogen penetration into leaves through stomata, the primary sites for infection by many pathogens. Pseudomonas syringae pv. tomato (Pst) DC3000 produces coronatine (COR) and opens stomata, raising an intriguing question as to whether this is a virulence strategy to facilitate bacterial infection at night. In fact, we found that (a) biological concentration of COR is effective in opening dark-closed stomata of Arabidopsis thaliana leaves, (b) the COR defective mutant Pst DC3118 is less effective in infecting Arabidopsis in the dark than under light and this difference in infection is reduced with the wild type bacterium Pst DC3000, and (c) cma, a COR biosynthesis gene, is induced only when the bacterium is in contact with the leaf surface independent of the light conditions. These findings suggest that Pst DC3000 activates virulence factors at the pre-invasive phase of its life cycle to infect plants even when environmental conditions (such as darkness) favor stomatal immunity. This functional attribute of COR may provide epidemiological advantages for COR-producing bacteria on the leaf surface. PMID:27446113

Coronatine Facilitates Pseudomonas syringae Infection of Arabidopsis Leaves at Night.

Science.gov (United States)

Panchal, Shweta; Roy, Debanjana; Chitrakar, Reejana; Price, Lenore; Breitbach, Zachary S; Armstrong, Daniel W; Melotto, Maeli

2016-01-01

In many land plants, the stomatal pore opens during the day and closes during the night. Thus, periods of darkness could be effective in decreasing pathogen penetration into leaves through stomata, the primary sites for infection by many pathogens. Pseudomonas syringae pv. tomato (Pst) DC3000 produces coronatine (COR) and opens stomata, raising an intriguing question as to whether this is a virulence strategy to facilitate bacterial infection at night. In fact, we found that (a) biological concentration of COR is effective in opening dark-closed stomata of Arabidopsis thaliana leaves, (b) the COR defective mutant Pst DC3118 is less effective in infecting Arabidopsis in the dark than under light and this difference in infection is reduced with the wild type bacterium Pst DC3000, and (c) cma, a COR biosynthesis gene, is induced only when the bacterium is in contact with the leaf surface independent of the light conditions. These findings suggest that Pst DC3000 activates virulence factors at the pre-invasive phase of its life cycle to infect plants even when environmental conditions (such as darkness) favor stomatal immunity. This functional attribute of COR may provide epidemiological advantages for COR-producing bacteria on the leaf surface.

An insight into the photodynamic approach versus copper formulations in the control of Pseudomonas syringae pv. actinidiae in kiwi plants.

Science.gov (United States)

Jesus, Vânia; Martins, Diana; Branco, Tatiana; Valério, Nádia; Neves, Maria G P M S; Faustino, Maria A F; Reis, Luís; Barreal, Esther; Gallego, Pedro P; Almeida, Adelaide

2018-02-14

In the last decade, the worldwide production of kiwi fruit has been highly affected by Pseudomonas syringae pv. actinidiae (Psa), a phytopathogenic bacterium; this has led to severe economic losses that are seriously affecting the kiwi fruit trade. The available treatments for this disease are still scarce, with the most common involving frequently spraying the orchards with copper derivatives, in particular cuprous oxide (Cu 2 O). However, these copper formulations should be avoided due to their high toxicity; therefore, it is essential to search for new approaches for controlling Psa. Antimicrobial photodynamic therapy (aPDT) may be an alternative approach to inactivate Psa. aPDT consists in the use of a photosensitizer molecule (PS) that absorbs light and by transference of the excess of energy or electrons to molecular oxygen forms highly reactive oxygen species (ROS) that can affect different molecular targets, thus being very unlikely to lead to the development of microbe resistance. The aim of the present study was to evaluate the effectiveness of aPDT to photoinactivate Psa, using the porphyrin Tetra-Py + -Me and different light intensities. The degree of inactivation of Psa was assessed using the PS at 5.0 μM under low irradiance (4.0 mW cm -2 ). Afterward, ex vivo experiments, using artificially contaminated kiwi leaves, were conducted with a PS at 50 μM under 150 mW cm -2 and sunlight irradiation. A reduction of 6 log in the in vitro assays after 90 min of irradiation was observed. In the ex vivo tests, the decrease was lower, approximately 1.8 log reduction at an irradiance of 150 mW cm -2 , 1.2 log at 4.0 mW cm -2 , and 1.5 log under solar radiation. However, after three successive cycles of treatment under 150 mW cm -2 , a 4 log inactivation was achieved. No negative effects were observed on leaves after treatment. Assays using Cu 2 O were also performed at the recommended concentration by law (50 g h L -1 ) and at concentrations 10 times

EVALUACIÓN DE LA CONCENTRACIÓN DE LOS ÁCIDOS ACÉTICO, BUTÍRICO Y PROPIÓNICO EN EL CO-CULTIVO: ASPERGILLUS ORYZAE-BUTYRIVIBRIO FIBRISOLVENS. EVALUATION OF THE CONCENTRATION OF THE ACETIC, BUTYRIC AND PROPIONIC ACIDS IN THE CO-CULTURE: ASPERGILLUS ORYZAE-BUTYRIVIBRIO FIBRISOLVENS

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C. LARA MANTILLA

2008-12-01

Full Text Available Se realizó un estudio en co-cultivo entre el hongo Aspergillus oryzae y la bacteria ruminal celulolítica Butyrivibrio fibrisolvens, cuyo objetivo fue determinar "in vitro" el efecto del hongo sobre la producción de los ácidos acético, propiónico y butírico por parte de la bacteria. El medio de cultivo se preparó utilizando líquido ruminal filtrado, centrifugado, autoclavado y diluído al 40% con agua, y 0,05 p/v de pastos Angleton (Dichamthium aristatum (Córdoba, Colombia. Las condiciones de cultivo fueron en anaerobiosis, y el tiempo de incubación de 24 horas. A partir del sobrenadante fueron determinadas las concentraciones de los ácidos grasos volátiles por cromatografía de gases. Se estudiaron dos relaciones bacteria-hongo: 1:1 y 1:3. Como resultado se observó un efecto negativo de Aspergillus oryzae sobre Butyrivibrio fibrisolvens, que se reflejó en la disminución en la producción de ácidos grasos volátiles.A study in co-culture between Aspergillus oryzae with the cellulolytic ruminal bacteria Butyrivibrio fibrisolvens was carried out aiming the "in vitro" determination of the effect of the fungi on the production of acetic, propionic and butyric acids by the bacteria. The culture medium was prepared using filtered, centrifuged, autoclaved and ruminal liquid diluted to 40% with water, and 0,05 % p/v of Angleton grass [;Dichamthium aristatum]; [;Córdoba, Colombia];. Culture was performed in anaerobic conditions for 24 hours. The concentrations of volatile fatty acids in the supernatant were determined by gas chromatography. Two bacteria-fungi relations were studied: 1:1 and 1:3. The results showed a negative effect of Aspergillus oryzae on Butyrivibrio fibrisolvens which was reflected in a decrease in the production of volatile fatty acids.

NCBI nr-aa BLAST: CBRC-TNIG-22-0185 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-TNIG-22-0185 ref|YP_451103.1| manganese transport protein [Xanthomonas oryzae ...pv. oryzae MAFF 311018] dbj|BAE68829.1| manganese transport protein [Xanthomonas oryzae pv. oryzae MAFF 311018] YP_451103.1 0.030 28% ...

Redox proteomics of tomato in response to Pseudomonas syringae infection

Science.gov (United States)

Balmant, Kelly Mayrink; Parker, Jennifer; Yoo, Mi-Jeong; Zhu, Ning; Dufresne, Craig; Chen, Sixue

2015-01-01

Unlike mammals with adaptive immunity, plants rely on their innate immunity based on pattern-triggered immunity (PTI) and effector-triggered immunity (ETI) for pathogen defense. Reactive oxygen species, known to play crucial roles in PTI and ETI, can perturb cellular redox homeostasis and lead to changes of redox-sensitive proteins through modification of cysteine sulfhydryl groups. Although redox regulation of protein functions has emerged as an important mechanism in several biological processes, little is known about redox proteins and how they function in PTI and ETI. In this study, cysTMT proteomics technology was used to identify similarities and differences of protein redox modifications in tomato resistant (PtoR) and susceptible (prf3) genotypes in response to Pseudomonas syringae pv tomato (Pst) infection. In addition, the results of the redox changes were compared and corrected with the protein level changes. A total of 90 potential redox-regulated proteins were identified with functions in carbohydrate and energy metabolism, biosynthesis of cysteine, sucrose and brassinosteroid, cell wall biogenesis, polysaccharide/starch biosynthesis, cuticle development, lipid metabolism, proteolysis, tricarboxylic acid cycle, protein targeting to vacuole, and oxidation–reduction. This inventory of previously unknown protein redox switches in tomato pathogen defense lays a foundation for future research toward understanding the biological significance of protein redox modifications in plant defense responses. PMID:26504582

NCBI nr-aa BLAST: CBRC-PMAR-01-0384 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-PMAR-01-0384 ref|YP_200844.1| putative manganese transport protein MntH [Xanth...omonas oryzae pv. oryzae KACC10331] gb|AAW75459.1| manganese transport protein [Xanthomonas oryzae pv. oryzae KACC10331] YP_200844.1 1.7 33% ...

NCBI nr-aa BLAST: CBRC-TNIG-22-0185 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-TNIG-22-0185 ref|YP_200844.1| putative manganese transport protein MntH [Xanth...omonas oryzae pv. oryzae KACC10331] gb|AAW75459.1| manganese transport protein [Xanthomonas oryzae pv. oryzae KACC10331] YP_200844.1 0.030 28% ...

Building Integrated PV and PV/Hybrid Products - The PV:BONUS Experience: Preprint

Energy Technology Data Exchange (ETDEWEB)

Thomas, H.; Pierce, L. K.

2001-10-01

Presented at the 2001 NCPV Program Review Meeting: Successes and lessons learned from PV:BONUS (Building Opportunities in the United States in PV). This program has funded the development of PV or PV/hybrid products for building applications.

Pseudomonas syringae Catalases Are Collectively Required for Plant Pathogenesis

Science.gov (United States)

Guo, Ming; Block, Anna; Bryan, Crystal D.; Becker, Donald F.

2012-01-01

The bacterial pathogen Pseudomonas syringae pv. tomato DC3000 must detoxify plant-produced hydrogen peroxide (H2O2) in order to survive in its host plant. Candidate enzymes for this detoxification include the monofunctional catalases KatB and KatE and the bifunctional catalase-peroxidase KatG of DC3000. This study shows that KatG is the major housekeeping catalase of DC3000 and provides protection against menadione-generated endogenous H2O2. In contrast, KatB rapidly and substantially accumulates in response to exogenous H2O2. Furthermore, KatB and KatG have nonredundant roles in detoxifying exogenous H2O2 and are required for full virulence of DC3000 in Arabidopsis thaliana. Therefore, the nonredundant ability of KatB and KatG to detoxify plant-produced H2O2 is essential for the bacteria to survive in plants. Indeed, a DC3000 catalase triple mutant is severely compromised in its ability to grow in planta, and its growth can be partially rescued by the expression of katB, katE, or katG. Interestingly, our data demonstrate that although KatB and KatG are the major catalases involved in the virulence of DC3000, KatE can also provide some protection in planta. Thus, our results indicate that these catalases are virulence factors for DC3000 and are collectively required for pathogenesis. PMID:22797762

OryzaGenome: Genome Diversity Database of Wild Oryza Species

KAUST Repository

Ohyanagi, Hajime

2015-11-18

The species in the genus Oryza, encompassing nine genome types and 23 species, are a rich genetic resource and may have applications in deeper genomic analyses aiming to understand the evolution of plant genomes. With the advancement of next-generation sequencing (NGS) technology, a flood of Oryza species reference genomes and genomic variation information has become available in recent years. This genomic information, combined with the comprehensive phenotypic information that we are accumulating in our Oryzabase, can serve as an excellent genotype-phenotype association resource for analyzing rice functional and structural evolution, and the associated diversity of the Oryza genus. Here we integrate our previous and future phenotypic/habitat information and newly determined genotype information into a united repository, named OryzaGenome, providing the variant information with hyperlinks to Oryzabase. The current version of OryzaGenome includes genotype information of 446 O. rufipogon accessions derived by imputation and of 17 accessions derived by imputation-free deep sequencing. Two variant viewers are implemented: SNP Viewer as a conventional genome browser interface and Variant Table as a textbased browser for precise inspection of each variant one by one. Portable VCF (variant call format) file or tabdelimited file download is also available. Following these SNP (single nucleotide polymorphism) data, reference pseudomolecules/ scaffolds/contigs and genome-wide variation information for almost all of the closely and distantly related wild Oryza species from the NIG Wild Rice Collection will be available in future releases. All of the resources can be accessed through http://viewer.shigen.info/oryzagenome/.

Dual Effect of the Cubic Ag₃PO₄ Crystal on Pseudomonas syringae Growth and Plant Immunity

Directory of Open Access Journals (Sweden)

Mi Kyung Kim

2016-04-01

Full Text Available We previously found that the antibacterial activity of silver phosphate crystals on Escherichia coli depends on their structure. We here show that the cubic form of silver phosphate crystal (SPC can also be applied to inhibit the growth of a plant-pathogenic Pseudomonas syringae bacterium. SPC pretreatment resulted in reduced in planta multiplication of P. syringae. Induced expression of a plant defense marker gene PR1 by SPC alone is suggestive of its additional plant immunity-stimulating activity. Since SPC can simultaneously inhibit P. syringae growth and induce plant defense responses, it might be used as a more effective plant disease-controlling agent.

ORF Alignment: NC_006834 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available NC_006834 gi|58582167 >1iwlA 2 180 70 254 2e-49 ... ref|YP_201183.1| outer-membrane lipoproteins... ... outer-membrane lipoproteins carrier protein precursor ... [Xanthomonas oryzae pv. oryzae KAC... carrier protein precursor [Xanthomonas ... oryzae pv. oryzae KACC10331] gb|AAW75798.1| ...

PV-CAD: an integrated tool for designing PV facades; PV-CAD - Ein integriertes Werkzeug zur Auslegung von PV-Fassaden

Energy Technology Data Exchange (ETDEWEB)

Giese, H.; Viotto, M. [Inst. fuer Solare Energieversorgungstechnik (ISET) e.V., Kassel (Germany); Esser, M.; Pukrop, D. [Univ. Oldenburg (Germany). Abt. Energie- und Halbleiterforschung; Stellbogen, D. [Zentrum fuer Sonnenergie- und Wasserstoff-Forschung, Stuttgart (Germany)

1997-12-31

PV-CAD provides PV system planners with a practice-oriented tool for an efficient design of PV facades. Being compatible with the standard programmes of the architects` and electrical engineering sectors it can be used on already existing systems and allows the user to draw on previously acquired knowedge. Its open interfaces permit the integration of further design tools. PV CAD works under Microsoft Windows for which it has the necessary graphic user interface. Its compliance to PC standards opens up a wide range of applications and permits its use also on inexpensive computers. Thanks to its promotion by the Federal Ministry for Education, Science, Research, and Technology under the research project ``Computer programmes for the design of photovoltaic facades`` PV-CAD is available at a moderate price. PV-CAD permits an efficient planning of solar facades and therefore has the potential to stimulate the use of PV on buildings. (orig.) [Deutsch] Mit PV-CAD steht dem Anlagenplaner ein anwendungsorientiertes Werkzeug zur Verfuegung, das eine rationelle Auslegung von PV-Fassaden ermoeglicht. Die Kompatibilitaet zu Standardprogrammen aus dem Architektur- und Elektrosektor erlaubt die Nutzung bereits vorhandener Systeme und damit erworbener Kenntnisse. Offene Schnittstellen gestatten die Einbindung weiterer Entwurfswerkzeuge. PV-CAD arbeitet unter Microsoft-Windows und verfuegt ueber die entsprechende grafische Benutzerschnittstelle. Die Kompatibilitaet zum PC-Standard eroeffnet eine sehr breite Anwenderbasis und ermoeglicht den Einsatz des Programms auch auf preiswerten Rechnern. Aufgrund der Foerderung durch das Bundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie im Rahmen des Forschungsprojekts `Rechnerprogramm zur Auslegung von Photovoltaik-Fassaden` steht PV-CAD preiswert zur Verfuegung. PV-CAD ermoeglicht eine effiziente Planung von Solarfassaden und kann daher dem PV-Einsatz in Gebaeuden weitere Impulse geben. (orig.)

PV-WEB: internet-based PV information tool

International Nuclear Information System (INIS)

Cowley, P.

2003-01-01

This report gives details of a project to create a web-based information system on photovoltaic (PV) systems for the British PV Association (PV-UK) for use by decision makers in government, the utilities, and the housing and construction sectors. The project, which aims to provide an easily accessible tool for UK companies, promote PV technology, increase competitiveness, and identify market opportunities, is described. The design of the web site and its implementation and the evolution are discussed, along with the maintenance of the site by PV-UK and the opportunities offered to PV-UK Members

PV-WEB: internet-based PV information tool

Energy Technology Data Exchange (ETDEWEB)

Cowley, P

2003-07-01

This report gives details of a project to create a web-based information system on photovoltaic (PV) systems for the British PV Association (PV-UK) for use by decision makers in government, the utilities, and the housing and construction sectors. The project, which aims to provide an easily accessible tool for UK companies, promote PV technology, increase competitiveness, and identify market opportunities, is described. The design of the web site and its implementation and the evolution are discussed, along with the maintenance of the site by PV-UK and the opportunities offered to PV-UK Members.

Thermo-Regulation of Genes Mediating Motility and Plant Interactions in Pseudomonas syringae

Science.gov (United States)

Hockett, Kevin L.; Burch, Adrien Y.; Lindow, Steven E.

2013-01-01

Pseudomonas syringae is an important phyllosphere colonist that utilizes flagellum-mediated motility both as a means to explore leaf surfaces, as well as to invade into leaf interiors, where it survives as a pathogen. We found that multiple forms of flagellum-mediated motility are thermo-suppressed, including swarming and swimming motility. Suppression of swarming motility occurs between 28° and 30°C, which coincides with the optimal growth temperature of P. syringae. Both fliC (encoding flagellin) and syfA (encoding a non-ribosomal peptide synthetase involved in syringafactin biosynthesis) were suppressed with increasing temperature. RNA-seq revealed 1440 genes of the P. syringae genome are temperature sensitive in expression. Genes involved in polysaccharide synthesis and regulation, phage and IS elements, type VI secretion, chemosensing and chemotaxis, translation, flagellar synthesis and motility, and phytotoxin synthesis and transport were generally repressed at 30°C, while genes involved in transcriptional regulation, quaternary ammonium compound metabolism and transport, chaperone/heat shock proteins, and hypothetical genes were generally induced at 30°C. Deletion of flgM, a key regulator in the transition from class III to class IV gene expression, led to elevated and constitutive expression of fliC regardless of temperature, but did not affect thermo-regulation of syfA. This work highlights the importance of temperature in the biology of P. syringae, as many genes encoding traits important for plant-microbe interactions were thermo-regulated. PMID:23527276

The PIN1 family gene PvPIN1 is involved in auxin-dependent root emergence and tillering in switchgrass

Directory of Open Access Journals (Sweden)

Kaijie Xu

2016-03-01

Full Text Available Abstract Switchgrass (Panicum virgatum L.; family Poaceae is a warm-season C4 perennial grass. Tillering plays an important role in determining the morphology of aboveground parts and the final biomass yield of switchgrass. Auxin distribution in plants can affect a variety of important growth and developmental processes, including the regulation of shoot and root branching, plant resistance and biological yield. Auxin transport and gradients in plants are mediated by influx and efflux carriers. PvPIN1, a switchgrass PIN1-like gene that is involved in regulating polar transport, is a putative auxin efflux carrier. Neighbor-joining analysis using sequences deposited in NCBI databases showed that the PvPIN1gene belongs to the PIN1 family and is evolutionarily closer to the Oryza sativa japonica group. Tiller emergence and development was significantly promoted in plants subjected toPvPIN1 RNA interference (RNAi, which yielded a phenotype similar to that of wild-type plants treated with the auxin transport inhibitor TIBA (2,3,5-triiodobenzoic acid. A transgenic approach that inducedPvPIN1 gene overexpression or suppression altered tiller number and the shoot/root ratio. These data suggest that PvPIN1plays an important role in auxin-dependent adventitious root emergence and tillering.

Characterization of Pseudomonas pathovars isolated from rosaceous fruit trees in East Algeria.

Science.gov (United States)

Harzallah, D; Sadallah, S; Larous, L

2004-01-01

A survey of bacterial diseases due to Pseudomonas on rosaceous fruit trees was conducted. In forty two orchards located in the Constantine region ( East Algeria). Pseudomonas isolates were identified on the bases of their cultural and biochemical characteristics . A total of fifty nine phytopathogenic bacteria were isolated from diseased pome and stone fruit trees. Thirty one strains comparable to Pseudomonas syringae pv. syringae were isolated from cherry (Prunus avium L.), plum (P. domestica L.), apricot (P. armeniaca L.), almond (P. dulcis L.) and pear trees (Pirus communis L.); sixteen strains comparable to Pseudomonas syringae pv. morsprunorum were obtained from samples of cherry and plum. Twelve strains of Pseudomonas viridiflava were isolated from cherry, apricot and peach (Prunus persica L.).

New strategies for genetic engineering Pseudomonas syringae using recombination

Science.gov (United States)

Here we report that DNA oligonucleotides (oligos) introduced directly into bacteria by electroporation can recombine with the bacterial chromosome. This phenomenon was identified in Pseudomonas syringae and we subsequently found that Escherichia coli, Salmonella typhimurium and Shigella flexneri are...

2018-03-13T08:12:57Z https://www.ajol.info/index.php/all/oai oai:ojs ...

African Journals Online (AJOL)

Acidovorax avenae subsp. avenae ainsi que Xanthomonas oryzae pv. oryzae ont été chacune détectées dans 50 % des échantillons et Burkholderia Glumae dans 16,66 %. 52 % des bactéries identifiées se rapportent à Acidovorax avenae subsp. avenae, 35 % à Xanthomonas oryzae pv. oryzae et 13 % à Burkholderia ...

40 CFR 180.1114 - Pseudomonas fluorescens A506, Pseudomonas fluorescens 1629RS, and Pseudomonas syringae 742RS...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Pseudomonas fluorescens A506, Pseudomonas fluorescens 1629RS, and Pseudomonas syringae 742RS; exemptions from the requirement of a tolerance... Tolerances § 180.1114 Pseudomonas fluorescens A506, Pseudomonas fluorescens 1629RS, and Pseudomonas syringae...

Entomopathogenicity to Two Hemipteran Insects Is Common but Variable across Epiphytic Pseudomonas syringae Strains.

Science.gov (United States)

Smee, Melanie R; Baltrus, David A; Hendry, Tory A

2017-01-01

Strains of the well-studied plant pathogen Pseudomonas syringae show large differences in their ability to colonize plants epiphytically and to inflict damage to hosts. Additionally, P. syringae can infect some sap-sucking insects and at least one P. syringae strain is highly virulent to insects, causing death to most individuals within as few as 4 days and growing to high population densities within insect hosts. The likelihood of agricultural pest insects coming into contact with transient populations of P. syringae while feeding on plants is high, yet the ecological implications of these interactions are currently not well understood as virulence has not been tested across a wide range of strains. To investigate virulence differences across strains we exposed the sweet potato whitefly, Bemisia tabaci , and the pea aphid, Acyrthosiphon pisum , both of which are cosmopolitan agricultural pests, to 12 P. syringae strains. We used oral inoculations with bacteria suspended in artificial diet in order to assay virulence while controlling for other variables such as differences in epiphytic growth ability. Generally, patterns of pathogenicity remain consistent across the two species of hemipteran insects, with bacterial strains from phylogroup II, or genomospecies 1, causing the highest rate of mortality with up to 86% of individuals dead after 72 h post infection. The rate of mortality is highly variable across strains, some significantly different from negative control treatments and others showing no discernable difference. Interestingly, one of the most pathogenic strains to both aphids and whiteflies (Cit7) is thought to be non-pathogenic on plants. We also found Cit7 to establish the highest epiphytic population after 48 h on fava beans. Between the nine P. syringae strains tested for epiphytic ability there is also much variation, but epiphytic ability was positively correlated with pathogenicity to insects, suggesting that the two traits may be linked and that

Entomopathogenicity to Two Hemipteran Insects Is Common but Variable across Epiphytic Pseudomonas syringae Strains

Directory of Open Access Journals (Sweden)

Melanie R. Smee

2017-12-01

Full Text Available Strains of the well-studied plant pathogen Pseudomonas syringae show large differences in their ability to colonize plants epiphytically and to inflict damage to hosts. Additionally, P. syringae can infect some sap-sucking insects and at least one P. syringae strain is highly virulent to insects, causing death to most individuals within as few as 4 days and growing to high population densities within insect hosts. The likelihood of agricultural pest insects coming into contact with transient populations of P. syringae while feeding on plants is high, yet the ecological implications of these interactions are currently not well understood as virulence has not been tested across a wide range of strains. To investigate virulence differences across strains we exposed the sweet potato whitefly, Bemisia tabaci, and the pea aphid, Acyrthosiphon pisum, both of which are cosmopolitan agricultural pests, to 12 P. syringae strains. We used oral inoculations with bacteria suspended in artificial diet in order to assay virulence while controlling for other variables such as differences in epiphytic growth ability. Generally, patterns of pathogenicity remain consistent across the two species of hemipteran insects, with bacterial strains from phylogroup II, or genomospecies 1, causing the highest rate of mortality with up to 86% of individuals dead after 72 h post infection. The rate of mortality is highly variable across strains, some significantly different from negative control treatments and others showing no discernable difference. Interestingly, one of the most pathogenic strains to both aphids and whiteflies (Cit7 is thought to be non-pathogenic on plants. We also found Cit7 to establish the highest epiphytic population after 48 h on fava beans. Between the nine P. syringae strains tested for epiphytic ability there is also much variation, but epiphytic ability was positively correlated with pathogenicity to insects, suggesting that the two traits may be

PV and PV/hybrid products for buildings

Energy Technology Data Exchange (ETDEWEB)

Thomas, H. P.; Hayter, S. J.; Martin, R. L., Pierce, L. K.

2000-05-15

Residential, commercial, and industrial buildings combined are the largest consumers of electricity in the United States and represent a significant opportunity for photovoltaic (PV) and PV/hybrid systems. The U.S. Department of Energy (DOE) is conducting a phased research and product development program, Building Opportunities in the United States for Photovoltaics (PV:BONUS), focused on this market sector. The purpose of the program is to develop technologies and foster business arrangements integrating cost-effective PV or hybrid products into buildings. The first phase was completed in 1996 and a second solicitation, PV:BONUS2, was initiated during 1997. These projects are resulting in a variety of building-integrated products. This paper summarizes the recent progress of the seven firms and collaborative teams currently participating in PV:BONUS2 and outlines planned work for the final phase of their work.

A rare sugar, d-allose, confers resistance to rice bacterial blight with upregulation of defense-related genes in Oryza sativa.

Science.gov (United States)

Kano, Akihito; Gomi, Kenji; Yamasaki-Kokudo, Yumiko; Satoh, Masaru; Fukumoto, Takeshi; Ohtani, Kouhei; Tajima, Shigeyuki; Izumori, Ken; Tanaka, Keiji; Ishida, Yutaka; Tada, Yasuomi; Nishizawa, Yoko; Akimitsu, Kazuya

2010-01-01

We investigated responses of rice plant to three rare sugars, d-altrose, d-sorbose, and d-allose, due to establishment of mass production methods for these rare sugars. Root growth and shoot growth were significantly inhibited by d-allose but not by the other rare sugars. A large-scale gene expression analysis using a rice microarray revealed that d-allose treatment causes a high upregulation of many defense-related, pathogenesis-related (PR) protein genes in rice. The PR protein genes were not upregulated by other rare sugars. Furthermore, d-allose treatment of rice plants conferred limited resistance of the rice against the pathogen Xanthomonas oryzae pv. oryzae but the other tested sugars did not. These results indicate that d-allose has a growth inhibitory effect but might prove to be a candidate elicitor for reducing disease development in rice.

Virulence determinants of Pseudomonas syringae strains isolated from grasses in the context of a small type III effector repertoire

DEFF Research Database (Denmark)

Dudnik, Alexey; Dudler, Robert

2014-01-01

derivative that inhibits the eukaryotic proteasome. In strains colonizing dicotyledonous plants, the compound was demonstrated to suppress the salicylic-acid-dependent defense pathway. Here, we analyze virulence factors of three strains colonizing wheat (Triticum aestivum): P. syringae pathovar syringae (Psy...

Tryptophan-Containing Cyclic Decapeptides with Activity against Plant Pathogenic Bacteria

Directory of Open Access Journals (Sweden)

Cristina Camó

2017-10-01

Full Text Available A library of 66 cyclic decapeptides incorporating a Trp residue was synthesized on solid phase and screened against the phytopathogenic bacteria Pseudomonas syringae pv. syringae, Xanthomonas axonopodis pv. vesicatoria, and Erwinia amylovora. The hemolytic activity of these peptides was also evaluated. The results obtained were compared with those of a collection of Phe analogues previously reported. The analysis of the data showed that the presence of the Trp improved the antibacterial activity against these three pathogens. In particular, 40 to 46 Trp analogues displayed lower minimum inhibitory concentration (MIC values than their corresponding Phe counterparts. Interestingly, 26 Trp-containing sequences exhibited MIC of 0.8 to 3.1 μM against X. axonopodis pv. vesicatoria, 21 peptides MIC of 1.6 to 6.2 μM against P. syringae pv. syringae and six peptides MIC of 6.2 to 12.5 μM against E. amylovora. Regarding the hemolysis, in general, Trp derivatives displayed a percentage of hemolysis comparable to that of their Phe analogues. Notably, 49 Trp-containing cyclic peptides showed a hemolysis ≤ 20% at 125 μM. The peptides with the best biological activity profile were c(LKKKLWKKLQ (BPC086W and c(LKKKKWLLKQ (BPC108W, which displayed MIC values ranging from 0.8 to 12.5 μM and a hemolysis ≤ 8% at 125 μM. Therefore, it is evident that these Trp sequences constitute promising candidates for the development of new agents for use in plant protection.

Impacts of PV Array Sizing on PV Inverter Lifetime and Reliability

DEFF Research Database (Denmark)

Sangwongwanich, Ariya; Yang, Yongheng; Sera, Dezso

2017-01-01

. However, oversizing the PV array will increase the loading of PV inverters, which may have undesired influence on the PV inverter lifetime and reliability. In that case, it may result in a negative impact on the overall PV energy cost, due to the increased maintenance for the PV inverters. This paper...... evaluates the lifetime of PV inverters considering the PV array sizing and installation sites, e.g., Denmark and Arizona. The results reveal that the PV array sizing has a considerable impact on the PV inverter lifetime and reliability, especially in Denmark, where the average solar irradiance level...

Impacts of PV Array Sizing on PV Inverter Lifetime and Reliability

OpenAIRE

Sangwongwanich, Ariya; Yang, Yongheng; Sera, Dezso; Blaabjerg, Frede

2017-01-01

In order to enable a more wide-scale utilization of PV systems, the cost of PV energy has to be comparable with other energy sources. Oversizing the PV array is one common approach to reduce the cost of PV energy, since it increases the PV energy yield during low solar irradiance conditions. However, oversizing the PV array will increase the loading of PV inverters, which may have undesired influence on the PV inverter lifetime and reliability. In that case, it may result in a negative impact...

Simultaneous Detection of Three Bacterial Seed-Borne Diseases in Rice Using Multiplex Polymerase Chain Reaction

Directory of Open Access Journals (Sweden)

In Jeong Kang

2016-12-01

Full Text Available Burkholderia glumae (bacterial grain rot, Xanthomonas oryzae pv. oryzae (bacterial leaf blight, and Acidovorax avenae subsp. avenae (bacterial brown stripe are major seedborne pathogens of rice. Based on the 16S and 23S rDNA sequences for A. avenae subsp. avenae and B. glumae, and transposase A gene sequence for X. oryzae pv. oryzae, three sets of primers had been designed to produce 402 bp for B. glumae, 490 bp for X. oryzae, and 290 bp for A. avenae subsp. avenae with the 63°C as an optimum annealing temperature. Samples collected from naturally infected fields were detected with two bacteria, B. glumae and A. avenae subsp. avenae but X. oryzae pv. oryzae was not detected. This assay can be used to identify pathogens directly from infected seeds, and will be an effective tool for the identification of the three pathogens in rice plants.

Simultaneous Detection of Three Bacterial Seed-Borne Diseases in Rice Using Multiplex Polymerase Chain Reaction.

Science.gov (United States)

Kang, In Jeong; Kang, Mi-Hyung; Noh, Tae-Hwan; Shim, Hyeong Kwon; Shin, Dong Bum; Heu, Suggi

2016-12-01

Burkholderia glumae (bacterial grain rot), Xanthomonas oryzae pv. oryzae (bacterial leaf blight), and Acidovorax avenae subsp. avenae (bacterial brown stripe) are major seedborne pathogens of rice. Based on the 16S and 23S rDNA sequences for A. avenae subsp. avenae and B. glumae , and transposase A gene sequence for X. oryzae pv. oryzae , three sets of primers had been designed to produce 402 bp for B. glumae , 490 bp for X. oryzae , and 290 bp for A. avenae subsp. avenae with the 63°C as an optimum annealing temperature. Samples collected from naturally infected fields were detected with two bacteria, B. glumae and A. avenae subsp. avenae but X. oryzae pv. oryzae was not detected. This assay can be used to identify pathogens directly from infected seeds, and will be an effective tool for the identification of the three pathogens in rice plants.

Ortholog Alleles at Xa3/Xa26 Locus Confer Conserved Race-Specific Resistance against Xanthomonas oryzae in Rice

Institute of Scientific and Technical Information of China (English)

Hong-Jing Li; Xiang-Hua Li; Jing-Hua Xiao; Rod A. Wing; Shi-Ping Wang

2012-01-01

The rice disease resistance (R) gene Xa3/Xa26 (having also been named Xa3 and Xa26) against Xanthomonas oryzae pv.oryzae (Xoo),which causes bacterial blight disease,belongs to a multiple gene family clustered in chromosome 11 and is from an AA genome rice cultivar (Oryza sativa L.).This family encodes leucine-rich repeat (LRR) receptor kinasetype proteins.Here,we show that the orthologs (alleles) of Xa3/Xa26,Xa3/Xa26-2,and Xa3/Xa26-3,from wild Oryza species O.officinalis (CC genome) and O.minuta (BBCC genome),respectively,were also R genes against Xoo.Xa3/Xa26-2 and Xa3/Xa26-3 conferred resistance to 16 of the 18 Xoo strains examined.Comparative sequence analysis of the Xa3/Xa26 families in the two wild Oryza species showed that Xa3/Xa26-3 appeared to have originated from the CC genome of O.minuta.The predicted proteins encoded by Xa3/Xa26,Xa3/Xa26-2,and Xa3/Xa26-3 share 91-99％ sequence identity and 94-99％ sequence similarity.Transgenic plants carrying a single copy of Xa3/Xa26,Xa3/Xa26-2,or Xa3/Xa26-3,in the same genetic background,showed a similar resistance spectrum to a set of Xoo strains,although plants carrying Xa3/Xa26-2 or Xa3/Xa26-3 showed lower resistance levels than the plants carrying Xa3/Xa26.These results suggest that the Xa3/Xa26 locus predates the speciation of A and C genome,which is approximately 7.5 million years ago.Thus,the resistance specificity of this locus has been conserved for a long time.

Inhibitory effect of Thymus vulgaris and Origanum vulgare essential oils on virulence factors of phytopathogenic Pseudomonas syringae strains.

Science.gov (United States)

Carezzano, M E; Sotelo, J P; Primo, E; Reinoso, E B; Paletti Rovey, M F; Demo, M S; Giordano, W F; Oliva, M de Las M

2017-07-01

Pseudomonas syringae is a phytopathogenic bacterium that causes lesions in leaves during the colonisation process. The damage is associated with production of many virulence factors, such as biofilm and phytotoxins. The essential oils of Thymus vulgaris (thyme) and Origanum vulgare (oregano) have been demonstrated to inhibit P. syringae. The aim of this study was to investigate the effects of T. vulgaris and O. vulgare essential oils on production of virulence factors of phytopathogenic P. syringae strains, including anti-biofilm and anti-toxins activities. The broth microdilution method was used for determination of MIC and biofilm inhibition assays. Coronatine, syringomycin and tabtoxin were pheno- and genotypically evaluated. Both oils showed good inhibitory activity against P. syringae, with MIC values from 1.43 to 11.5 mg·ml -1 for thyme and 5.8 to 11.6 mg·ml -1 for oregano. Biofilm formation, production of coronatine, syringomycin and tabtoxin were inhibited by thyme and oregano essential oil in most strains. The results presented here are promising, demonstrating the bactericidal activity and reduction of virulence factor production after treatment with thyme and oregano oil, providing insight into how they exert their antibacterial activity. These natural products could be considered in the future for the control of diseases caused by P. syringae. © 2017 German Botanical Society and The Royal Botanical Society of the Netherlands.

Arabidopsis seedling flood-inoculation technique: a rapid and reliable assay for studying plant-bacterial interactions

Directory of Open Access Journals (Sweden)

Uppalapati Srinivasa R

2011-10-01

Full Text Available Abstract Background The Arabidopsis thaliana-Pseudomonas syringae model pathosystem is one of the most widely used systems to understand the mechanisms of microbial pathogenesis and plant innate immunity. Several inoculation methods have been used to study plant-pathogen interactions in this model system. However, none of the methods reported to date are similar to those occurring in nature and amicable to large-scale mutant screens. Results In this study, we developed a rapid and reliable seedling flood-inoculation method based on young Arabidopsis seedlings grown on MS medium. This method has several advantages over conventional soil-grown plant inoculation assays, including a shorter growth and incubation period, ease of inoculation and handling, uniform infection and disease development, requires less growth chamber space and is suitable for high-throughput screens. In this study we demonstrated the efficacy of the Arabidopsis seedling assay to study 1 the virulence factors of P. syringae pv. tomato DC3000, including type III protein secretion system (TTSS and phytotoxin coronatine (COR; 2 the effector-triggered immunity; and 3 Arabidopsis mutants affected in salicylic acid (SA- and pathogen-associated molecular pattern (PAMPs-mediated pathways. Furthermore, we applied this technique to study nonhost resistance (NHR responses in Arabidopsis using nonhost pathogens, such as P. syringae pv. tabaci, pv. glycinea and pv. tomato T1, and confirmed the functional role of FLAGELLIN-SENSING 2 (FLS2 in NHR. Conclusions The Arabidopsis seedling flood-inoculation assay provides a rapid, efficient and economical method for studying Arabidopsis-Pseudomonas interactions with minimal growth chamber space and time. This assay could also provide an excellent system for investigating the virulence mechanisms of P. syringae. Using this method, we demonstrated that FLS2 plays a critical role in conferring NHR against nonhost pathovars of P. syringae, but not to

EVALUATION OF THE CONCENTRATION OF THE ACETIC, BUTYRIC AND PROPIONIC ACIDS IN THE CO-CULTURE: ASPERGILLUS ORYZAE-BUTYRIVIBRIO FIBRISOLVENS

OpenAIRE

LARA MANTILLA, C.

2008-01-01

Se realizó un estudio en co-cultivo entre el hongo Aspergillus oryzae y la bacteria ruminal celulolítica Butyrivibrio fibrisolvens, cuyo objetivo fue determinar "in vitro" el efecto del hongo sobre la producción de los ácidos acético, propiónico y butírico por parte de la bacteria. El medio de cultivo se preparó utilizando líquido ruminal filtrado, centrifugado, autoclavado y diluído al 40% con agua, y 0,05 p/v de pastos Angleton (Dichamthium aristatum) (Córdoba, Colombia). Las condiciones de...

Analysis of nucleotide diversity among alleles of the major bacterial blight resistance gene Xa27 in cultivars of rice (Oryza sativa) and its wild relatives.

Science.gov (United States)

Bimolata, Waikhom; Kumar, Anirudh; Sundaram, Raman Meenakshi; Laha, Gouri Shankar; Qureshi, Insaf Ahmed; Reddy, Gajjala Ashok; Ghazi, Irfan Ahmad

2013-08-01

Xa27 is one of the important R-genes, effective against bacterial blight disease of rice caused by Xanthomonas oryzae pv. oryzae (Xoo). Using natural population of Oryza, we analyzed the sequence variation in the functionally important domains of Xa27 across the Oryza species. DNA sequences of Xa27 alleles from 27 rice accessions revealed higher nucleotide diversity among the reported R-genes of rice. Sequence polymorphism analysis revealed synonymous and non-synonymous mutations in addition to a number of InDels in non-coding regions of the gene. High sequence variation was observed in the promoter region including the 5'UTR with 'π' value 0.00916 and 'θ w ' = 0.01785. Comparative analysis of the identified Xa27 alleles with that of IRBB27 and IR24 indicated the operation of both positive selection (Ka/Ks > 1) and neutral selection (Ka/Ks ≈ 0). The genetic distances of alleles of the gene from Oryza nivara were nearer to IRBB27 as compared to IR24. We also found the presence of conserved and null UPT (upregulated by transcriptional activator) box in the isolated alleles. Considerable amino acid polymorphism was localized in the trans-membrane domain for which the functional significance is yet to be elucidated. However, the absence of functional UPT box in all the alleles except IRBB27 suggests the maintenance of single resistant allele throughout the natural population.

PV potential and potential PV rent in European regions

DEFF Research Database (Denmark)

Hansen, Anders Chr.; Thorn, Paul

2013-01-01

The paper provides a GIS based model for assessing the potentials of photovoltaic electricity in Europe by NUTS 2 regions. The location specific energy potential per PV-­‐panel area is estimated based on observations of solar irradiation, conversion efficiency, levelised costs and the social value...... of PV-­‐electricity. Combined with the potential density of PV-­‐panel area based on land cover and environental restrictions, the PV energy potential and the potential PV ressource rent is calculated. These calculations enbable the model to estimate the regional patterns at NUTS 2 level...

Characterisation of bacterial brown spot pathogen from dry bean ...

African Journals Online (AJOL)

Pseudomonas syringae pv. syringae (Pss) causes bacterial brown spot (BBS) of beans (Phaseolus vulgaris L.), with yield losses of up to 55% in South Africa. Pss has a wide host range and for many of these, the pathogen has been biochemically and genetically characterised. However, few studies have been conducted on ...

Simultaneous Detection of Three Bacterial Seed-Borne Diseases in Rice Using Multiplex Polymerase Chain Reaction

OpenAIRE

Kang, In Jeong; Kang, Mi-Hyung; Noh, Tae-Hwan; Shim, Hyeong Kwon; Shin, Dong Bum; Heu, Suggi

2016-01-01

Burkholderia glumae (bacterial grain rot), Xanthomonas oryzae pv. oryzae (bacterial leaf blight), and Acidovorax avenae subsp. avenae (bacterial brown stripe) are major seedborne pathogens of rice. Based on the 16S and 23S rDNA sequences for A. avenae subsp. avenae and B. glumae, and transposase A gene sequence for X. oryzae pv. oryzae, three sets of primers had been designed to produce 402 bp for B. glumae, 490 bp for X. oryzae, and 290 bp for A. avenae subsp. avenae with the 63°C as an opti...

Coexistence between neighbours

DEFF Research Database (Denmark)

Shenge, K.C.; Mabagala, R.B.; Mortensen, C A Nieves Paulino

2008-01-01

Experiments were conducted under laboratory and screenhouse conditions to study the coexistence between Pseudomonas syringae pv. tomato and Xanthomonas campestris pv. vesicatoria, incitants of bacterial speck and bacterial spot diseases of tomato. Results of in vitro studies showed that when mixe...

A cell wall-degrading esterase of Xanthomonas oryzae requires a unique substrate recognition module for pathogenesis on rice.

Science.gov (United States)

Aparna, Gudlur; Chatterjee, Avradip; Sonti, Ramesh V; Sankaranarayanan, Rajan

2009-06-01

Xanthomonas oryzae pv oryzae (Xoo) causes bacterial blight, a serious disease of rice (Oryza sativa). LipA is a secretory virulence factor of Xoo, implicated in degradation of rice cell walls and the concomitant elicitation of innate immune responses, such as callose deposition and programmed cell death. Here, we present the high-resolution structural characterization of LipA that reveals an all-helical ligand binding module as a distinct functional attachment to the canonical hydrolase catalytic domain. We demonstrate that the enzyme binds to a glycoside ligand through a rigid pocket comprising distinct carbohydrate-specific and acyl chain recognition sites where the catalytic triad is situated 15 A from the anchored carbohydrate. Point mutations disrupting the carbohydrate anchor site or blocking the pocket, even at a considerable distance from the enzyme active site, can abrogate in planta LipA function, exemplified by loss of both virulence and the ability to elicit host defense responses. A high conservation of the module across genus Xanthomonas emphasizes the significance of this unique plant cell wall-degrading function for this important group of plant pathogenic bacteria. A comparison with the related structural families illustrates how a typical lipase is recruited to act on plant cell walls to promote virulence, thus providing a remarkable example of the emergence of novel functions around existing scaffolds for increased proficiency of pathogenesis during pathogen-plant coevolution.

Contribution of alginate and levan production to biofilm formation by Pseudomonas syringae

DEFF Research Database (Denmark)

Laue, H.; Schenk, A.; Li, H.

2006-01-01

formation, biofilms of Pseudomonas syringae strains with different EPS patterns were compared. The mucoid strain PG4180.muc, which produces levan and alginate, and its levan- and/or alginate-deficient derivatives all formed biofilms in the wells of microtitre plates and in flow chambers. Confocal laser...... by binding of the lectin from Naja mossambica to a fibrous structure in biofilms of all P. syringae derivatives. Production of the as yet uncharacterized additional EPS might be more important for biofilm formation than the syntheses of levan and alginate.......Exopolysaccharides (EPSs) play important roles in the attachment of bacterial cells to a surface and/or in building and maintaining the three-dimensional, complex structure of bacterial biofilms. To elucidate the spatial distribution and function of the EPSs levan and alginate during biofilm...

Interband cascade (IC) photovoltaic (PV) architecture for PV devices

Science.gov (United States)

Yang, Rui Q.; Tian, Zhaobing; Mishima, Tetsuya D.; Santos, Michael B.; Johnson, Matthew B.; Klem, John F.

2015-10-20

A photovoltaic (PV) device, comprising a PV interband cascade (IC) stage, wherein the IC PV stage comprises an absorption region with a band gap, the absorption region configured to absorb photons, an intraband transport region configured to act as a hole barrier, and an interband tunneling region configured to act as an electron barrier. An IC PV architecture for a photovoltaic device, the IC PV architecture comprising an absorption region, an intraband transport region coupled to the absorption region, and an interband tunneling region coupled to the intraband transport region and to the adjacent absorption region, wherein the absorption region, the intraband transport region, and the interband tunneling region are positioned such that electrons will flow from the absorption region to the intraband transport region to the interband tunneling region.

An Analysis of Open World PvP in LOTRO's PvMP as a Case Study for PvP Games

Directory of Open Access Journals (Sweden)

Toh Weimin

2014-11-01

Full Text Available This article focuses on the analysis of emergent gameplay, based on a case study of the author's subjective gameplay experience of Player versus Monster Player (PvMP in The Lord of the Rings Online (LOTRO. The argument presented here is that although there is a core system of Player versus Player (PvP which LOTRO shares with other online games, each type of online game has a specific kind of PvP system which attracts players to engage in the gameplay. For instance, the open world sandbox type of PvP attracts certain players to play in LOTRO's PvMP. One of the main aims of this study is thus to investigate some of the core systems of PvP gameplay in open world sandbox PvP. In this article, LOTRO is shown to offer unique opportunities for studying emergent gameplay in open world games, with particular relevance to PvP studies. Two of the core systems of PvP discussed include the design of the simple gameplay rules to support emergent gameplay, and the community's attitudes towards player's behaviours. The types of emergent gameplay discussed include free play versus negotiated fair play, the players' utilisation of strategies in open world PvP to support collaborative and competitive gameplay, and the changing dynamics of open ended gameplay. It is hoped that the analysis provided in this article would form the­ basis of future work on a more general framework for understanding PvP in other online games.

Fire resistant PV shingle assembly

Science.gov (United States)

Lenox, Carl J.

2012-10-02

A fire resistant PV shingle assembly includes a PV assembly, including PV body, a fire shield and a connection member connecting the fire shield below the PV body, and a support and inter-engagement assembly. The support and inter-engagement assembly is mounted to the PV assembly and comprises a vertical support element, supporting the PV assembly above a support surface, an upper interlock element, positioned towards the upper PV edge, and a lower interlock element, positioned towards the lower PV edge. The upper interlock element of one PV shingle assembly is inter-engageable with the lower interlock element of an adjacent PV shingle assembly. In some embodiments the PV shingle assembly may comprise a ventilation path below the PV body. The PV body may be slidably mounted to the connection member to facilitate removal of the PV body.

PV/T slates - Laboratory measurements; PV/T-Schiefer. Labormessungen

Energy Technology Data Exchange (ETDEWEB)

Kropf, S.

2003-07-01

This comprehensive, illustrated report for the Swiss Federal Office of Energy (SFOE) is one a series of five reports dealing with increasing the overall efficiency of photovoltaic (PV) installations by also using the heat collected by the dark-coloured PV panels. The work reported on addresses open questions on the use of the heat and its optimal use. This report deals with an experimental outdoor set-up and reviews in-situ measurements made on a prototype of a ventilated PV-tile system (PV/T-Slates). The report describes the configuration and construction of the experimental PV-tiled roof and the measurement system used to measure its electrical and thermal performance. The results of the measurements made are presented in detail in graphical form. The influence of various factors such as air-slit width and mounting angle are discussed.

Virus-induced Gene Silencing-based Functional Analyses Revealed the Involvement of Several Putative Trehalose-6-Phosphate Synthase/Phosphatase Genes in Disease Resistance against Botrytis cinerea and Pseudomonas syringae pv. tomato DC3000 in Tomato

Directory of Open Access Journals (Sweden)

Huijuan Zhang

2016-08-01

Full Text Available Trehalose and its metabolism have been demonstrated to play important roles in control of plant growth, development and stress responses. However, direct genetic evidence supporting the functions of trehalose and its metabolism in defense response against pathogens is lacking. In the present study, genome-wide characterization of putative trehalose-related genes identified 11 SlTPSs for trehalose-6-phosphate synthase, 8 SlTPPs for trehalose-6-phosphate phosphatase and one SlTRE1 for trehalase in tomato genome. Nine SlTPSs, 4 SlTPPs and SlTRE1 were selected for functional analyses to explore their involvement in tomato disease resistance. Some selected SlTPSs, SlTPPs and SlTRE1 responded with distinct expression induction patterns to Botrytis cinerea and Pseudomonas syringae pv. tomato (Pst DC3000 as well as to defense signaling hormones (e.g. salicylic acid, jasmonic acid and a precursor of ethylene. Virus-induced gene silencing-mediated silencing of SlTPS3, SlTPS4 or SlTPS7 led to deregulation of ROS accumulation and attenuated the expression of defense-related genes upon pathogen infection and thus deteriorated the resistance against B. cinerea or Pst DC3000. By contrast, silencing of SlTPS5 or SlTPP2 led to an increased expression of the defense-related genes upon pathogen infection and conferred an increased resistance against Pst DC3000. Silencing of SlTPS3, SlTPS4, SlTPS5, SlTPS7 or SlTPP2 affected trehalose level in tomato plants with or without infection of B. cinerea or Pst DC3000. These results demonstrate that SlTPS3, SlTPS4, SlTPS5, SlTPS7 and SlTPP2 play roles in resistance against B. cinerea and Pst DC3000, implying the importance of trehalose and tis metabolism in regulation of defense response against pathogens in tomato.

Plasmodium vivax Tryptophan Rich Antigen PvTRAg36.6 Interacts with PvETRAMP and PvTRAg56.6 Interacts with PvMSP7 during Erythrocytic Stages of the Parasite.

Directory of Open Access Journals (Sweden)

Kriti Tyagi

Full Text Available Plasmodium vivax is most wide spread and a neglected malaria parasite. There is a lack of information on parasite biology of this species. Genome of this parasite encodes for the largest number of tryptophan-rich proteins belonging to 'Pv-fam-a' family and some of them are potential drug/vaccine targets but their functional role(s largely remains unexplored. Using bacterial and yeast two hybrid systems, we have identified the interacting partners for two of the P. vivax tryptophan-rich antigens called PvTRAg36.6 and PvTRAg56.2. The PvTRAg36.6 interacts with early transcribed membrane protein (ETRAMP of P.vivax. It is apically localized in merozoites but in early stages it is seen in parasite periphery suggesting its likely involvement in parasitophorous vacuole membrane (PVM development or maintenance. On the other hand, PvTRAg56.2 interacts with P.vivax merozoite surface protein7 (PvMSP7 and is localized on merozoite surface. Co-localization of PvTRAg56.2 with PvMSP1 and its molecular interaction with PvMSP7 probably suggest that, PvTRAg56.2 is part of MSP-complex, and might assist or stabilize the protein complex at the merozoite surface. In conclusion, the PvTRAg proteins have different sub cellular localizations and specific associated functions during intra-erythrocytic developmental cycle.

Plasmodium vivax Tryptophan Rich Antigen PvTRAg36.6 Interacts with PvETRAMP and PvTRAg56.6 Interacts with PvMSP7 during Erythrocytic Stages of the Parasite

Science.gov (United States)

Tyagi, Kriti; Hossain, Mohammad Enayet; Thakur, Vandana; Aggarwal, Praveen; Malhotra, Pawan; Mohmmed, Asif; Sharma, Yagya Dutta

2016-01-01

Plasmodium vivax is most wide spread and a neglected malaria parasite. There is a lack of information on parasite biology of this species. Genome of this parasite encodes for the largest number of tryptophan-rich proteins belonging to ‘Pv-fam-a’ family and some of them are potential drug/vaccine targets but their functional role(s) largely remains unexplored. Using bacterial and yeast two hybrid systems, we have identified the interacting partners for two of the P. vivax tryptophan-rich antigens called PvTRAg36.6 and PvTRAg56.2. The PvTRAg36.6 interacts with early transcribed membrane protein (ETRAMP) of P.vivax. It is apically localized in merozoites but in early stages it is seen in parasite periphery suggesting its likely involvement in parasitophorous vacuole membrane (PVM) development or maintenance. On the other hand, PvTRAg56.2 interacts with P.vivax merozoite surface protein7 (PvMSP7) and is localized on merozoite surface. Co-localization of PvTRAg56.2 with PvMSP1 and its molecular interaction with PvMSP7 probably suggest that, PvTRAg56.2 is part of MSP-complex, and might assist or stabilize the protein complex at the merozoite surface. In conclusion, the PvTRAg proteins have different sub cellular localizations and specific associated functions during intra-erythrocytic developmental cycle. PMID:26954579

ORF Alignment: NC_004578 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available ... [Pseudomonas syringae pv. tomato str. DC3000] ... Length = 157 ... Query: 238 GHGIPLSIHDAHGLDKTLEHVVSEIQRVHPSRLIRSN...IGALELIRCDHERIAQLLSNLVS 297 ... GHGIPLSIHDAHGLDKTLEHVVSEIQRVHPSRLIRSN...IGALELIRCDHERIAQLLSNLVS Sbjct: 1 ... GHGIPLSIHDAHGLDKTLEHVVSEIQRVHPSRLIRSNIGALELIRCDHERIAQLLSNLV

Genetic variation and population structure in Oryza ...

Indian Academy of Sciences (India)

Oryza malampuzhaensis Krish. et Chand. ( 2 n = 4 x = 48 ; Poaceae, Oryza) is endemic to Western Ghats, South India, and shows a highly localized distribution over a small geographical area in this region. This is the most poorly understood taxon in genus Oryza and is often misidentified as O. officinalis owing to their close ...

The PV market

International Nuclear Information System (INIS)

Hammond, B.

1992-01-01

This paper forecasts the photovoltaic (PV) market growth for the 1990s. Ten years of PV history are reviewed and used to establish market trends in terms of average selling price (ASP) and kilowatts shipped by market segment. The market is segmented into indoor consumer, stand-alone, and grid-connected applications. Indoor consumer presently represents a saturated market and is fairly predictable. The stand-alone market (i.e. not connected to the utility grid) is fairly stable and predictable. The utility PV market however is highly dependent on a number of market factors such as the cost of conventional energy the cost of PV systems utility acceptance of PV and regulatory controls. Government and institutional regulations, environmental issues, and OPEC and Middle East politics will have the greatest impact on the cost of conventional fuels. Private and federal investment in PV technology development could have a significant impact on the cost of PV systems. Forecasts are provided through the year 2000 for indoor consumer stand-alone and utility markets

Role of hydroperoxide lyase in white-backed planthopper (Sogatella furcifera Horváth)-induced resistance to bacterial blight in rice, Oryza sativa L.

Science.gov (United States)

Gomi, Kenji; Satoh, Masaru; Ozawa, Rika; Shinonaga, Yumi; Sanada, Sachiyo; Sasaki, Katsutomo; Matsumura, Masaya; Ohashi, Yuko; Kanno, Hiroo; Akimitsu, Kazuya; Takabayashi, Junji

2010-01-01

A pre-infestation of the white-backed planthopper (WBPH), Sogatella furcifera Horváth, conferred resistance to bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo) in rice (Oryza sativa L.) under both laboratory and field conditions. The infestation of another planthopper species, the brown planthopper (BPH) Nilaparvata lugens Stål, did not significantly reduce the incidence of bacterial blight symptoms. A large-scale screening using a rice DNA microarray and quantitative RT-PCR revealed that WBPH infestation caused the upregulation of more defence-related genes than did BPH infestation. Hydroperoxide lyase 2 (OsHPL2), an enzyme for producing C(6) volatiles, was upregulated by WBPH infestation, but not by BPH infestation. One C(6) volatile, (E)-2-hexenal, accumulated in rice after WBPH infestation, but not after BPH infestation. A direct application of (E)-2-hexenal to a liquid culture of Xoo inhibited the growth of the bacterium. Furthermore, a vapour treatment of rice plants with (E)-2-hexenal induced resistance to bacterial blight. OsHPL2-overexpressing transgenic rice plants exhibited increased resistance to bacterial blight. Based on these data, we conclude that OsHPL2 and its derived (E)-2-hexenal play some role in WBPH-induced resistance in rice.

Features of air masses associated with the deposition of Pseudomonas syringae and Botrytis cinerea by rain and snowfall.

Science.gov (United States)

Monteil, Caroline L; Bardin, Marc; Morris, Cindy E

2014-11-01

Clarifying the role of precipitation in microbial dissemination is essential for elucidating the processes involved in disease emergence and spread. The ecology of Pseudomonas syringae and its presence throughout the water cycle makes it an excellent model to address this issue. In this study, 90 samples of freshly fallen rain and snow collected from 2005-2011 in France were analyzed for microbiological composition. The conditions favorable for dissemination of P. syringae by this precipitation were investigated by (i) estimating the physical properties and backward trajectories of the air masses associated with each precipitation event and by (ii) characterizing precipitation chemistry, and genetic and phenotypic structures of populations. A parallel study with the fungus Botrytis cinerea was also performed for comparison. Results showed that (i) the relationship of P. syringae to precipitation as a dissemination vector is not the same for snowfall and rainfall, whereas it is the same for B. cinerea and (ii) the occurrence of P. syringae in precipitation can be linked to electrical conductivity and pH of water, the trajectory of the air mass associated with the precipitation and certain physical conditions of the air mass (i.e. temperature, solar radiation exposure, distance traveled), whereas these predictions are different for B. cinerea. These results are pertinent to understanding microbial survival, emission sources and atmospheric processes and how they influence microbial dissemination.

ORF Alignment: NC_004578 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available s syringae ... pv. tomato str. DC3000] ... Length = 151 ... Query: 151 ALAAKNRLLHYLVFECDGRNFCIDASVVTELVDGPEI...TASDFASDCCFGVTSVRGTKVPA 210 ... ALAAKNRLLHYLVFECDGRNFCIDASVVTELVDGPEI...TASDFASDCCFGVTSVRGTKVPA Sbjct: 1 ... ALAAKNRLLHYLVFECDGRNFCIDASVVTELVDGPEITASDFASDCCFGVTSVRGTKVPA 60 ... Qu

Transgenic expression of the rice Xa21 pattern-recognition receptor in banana (Musa sp.) confers resistance to Xanthomonas campestris pv. musacearum.

Science.gov (United States)

Tripathi, Jaindra N; Lorenzen, Jim; Bahar, Ofir; Ronald, Pamela; Tripathi, Leena

2014-08-01

Banana Xanthomonas wilt (BXW), caused by the bacterium Xanthomonas campestris pv. musacearum (Xcm), is the most devastating disease of banana in east and central Africa. The spread of BXW threatens the livelihood of millions of African farmers who depend on banana for food security and income. There are no commercial chemicals, biocontrol agents or resistant cultivars available to control BXW. Here, we take advantage of the robust resistance conferred by the rice pattern-recognition receptor (PRR), XA21, to the rice pathogen Xanthomonas oryzae pv. oryzae (Xoo). We identified a set of genes required for activation of Xa21-mediated immunity (rax) that were conserved in both Xoo and Xcm. Based on the conservation, we hypothesized that intergeneric transfer of Xa21 would confer resistance to Xcm. We evaluated 25 transgenic lines of the banana cultivar 'Gonja manjaya' (AAB) using a rapid bioassay and 12 transgenic lines in the glasshouse for resistance against Xcm. About 50% of the transgenic lines showed complete resistance to Xcm in both assays. In contrast, all of the nontransgenic control plants showed severe symptoms that progressed to complete wilting. These results indicate that the constitutive expression of the rice Xa21 gene in banana results in enhanced resistance against Xcm. Furthermore, this work demonstrates the feasibility of PRR gene transfer between monocotyledonous species and provides a valuable new tool for controlling the BXW pandemic of banana, a staple food for 100 million people in east Africa. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Elusive Origins of the Extra Genes in Aspergillus oryzae

Science.gov (United States)

Khaldi, Nora; Wolfe, Kenneth H.

2008-01-01

The genome sequence of Aspergillus oryzae revealed unexpectedly that this species has approximately 20% more genes than its congeneric species A. nidulans and A. fumigatus. Where did these extra genes come from? Here, we evaluate several possible causes of the elevated gene number. Many gene families are expanded in A. oryzae relative to A. nidulans and A. fumigatus, but we find no evidence of ancient whole-genome duplication or other segmental duplications, either in A. oryzae or in the common ancestor of the genus Aspergillus. We show that the presence of divergent pairs of paralogs is a feature peculiar to A. oryzae and is not shared with A. nidulans or A. fumigatus. In phylogenetic trees that include paralog pairs from A. oryzae, we frequently find that one of the genes in a pair from A. oryzae has the expected orthologous relationship with A. nidulans, A. fumigatus and other species in the subphylum Eurotiomycetes, whereas the other A. oryzae gene falls outside this clade but still within the Ascomycota. We identified 456 such gene pairs in A. oryzae. Further phylogenetic analysis did not however indicate a single consistent evolutionary origin for the divergent members of these pairs. Approximately one-third of them showed phylogenies that are suggestive of horizontal gene transfer (HGT) from Sordariomycete species, and these genes are closer together in the A. oryzae genome than expected by chance, but no unique Sordariomycete donor species was identifiable. The postulated HGTs from Sordariomycetes still leave the majority of extra A. oryzae genes unaccounted for. One possible explanation for our observations is that A. oryzae might have been the recipient of many separate HGT events from diverse donors. PMID:18725939

Elusive origins of the extra genes in Aspergillus oryzae.

Directory of Open Access Journals (Sweden)

Nora Khaldi

Full Text Available The genome sequence of Aspergillus oryzae revealed unexpectedly that this species has approximately 20% more genes than its congeneric species A. nidulans and A. fumigatus. Where did these extra genes come from? Here, we evaluate several possible causes of the elevated gene number. Many gene families are expanded in A. oryzae relative to A. nidulans and A. fumigatus, but we find no evidence of ancient whole-genome duplication or other segmental duplications, either in A. oryzae or in the common ancestor of the genus Aspergillus. We show that the presence of divergent pairs of paralogs is a feature peculiar to A. oryzae and is not shared with A. nidulans or A. fumigatus. In phylogenetic trees that include paralog pairs from A. oryzae, we frequently find that one of the genes in a pair from A. oryzae has the expected orthologous relationship with A. nidulans, A. fumigatus and other species in the subphylum Eurotiomycetes, whereas the other A. oryzae gene falls outside this clade but still within the Ascomycota. We identified 456 such gene pairs in A. oryzae. Further phylogenetic analysis did not however indicate a single consistent evolutionary origin for the divergent members of these pairs. Approximately one-third of them showed phylogenies that are suggestive of horizontal gene transfer (HGT from Sordariomycete species, and these genes are closer together in the A. oryzae genome than expected by chance, but no unique Sordariomycete donor species was identifiable. The postulated HGTs from Sordariomycetes still leave the majority of extra A. oryzae genes unaccounted for. One possible explanation for our observations is that A. oryzae might have been the recipient of many separate HGT events from diverse donors.

Dynamic Evolution of Pathogenicity Revealed by Sequencing and Comparative Genomics of 19 Pseudomonas syringae Isolates

Science.gov (United States)

Romanchuk, Artur; Chang, Jeff H.; Mukhtar, M. Shahid; Cherkis, Karen; Roach, Jeff; Grant, Sarah R.; Jones, Corbin D.; Dangl, Jeffery L.

2011-01-01

Closely related pathogens may differ dramatically in host range, but the molecular, genetic, and evolutionary basis for these differences remains unclear. In many Gram- negative bacteria, including the phytopathogen Pseudomonas syringae, type III effectors (TTEs) are essential for pathogenicity, instrumental in structuring host range, and exhibit wide diversity between strains. To capture the dynamic nature of virulence gene repertoires across P. syringae, we screened 11 diverse strains for novel TTE families and coupled this nearly saturating screen with the sequencing and assembly of 14 phylogenetically diverse isolates from a broad collection of diseased host plants. TTE repertoires vary dramatically in size and content across all P. syringae clades; surprisingly few TTEs are conserved and present in all strains. Those that are likely provide basal requirements for pathogenicity. We demonstrate that functional divergence within one conserved locus, hopM1, leads to dramatic differences in pathogenicity, and we demonstrate that phylogenetics-informed mutagenesis can be used to identify functionally critical residues of TTEs. The dynamism of the TTE repertoire is mirrored by diversity in pathways affecting the synthesis of secreted phytotoxins, highlighting the likely role of both types of virulence factors in determination of host range. We used these 14 draft genome sequences, plus five additional genome sequences previously reported, to identify the core genome for P. syringae and we compared this core to that of two closely related non-pathogenic pseudomonad species. These data revealed the recent acquisition of a 1 Mb megaplasmid by a sub-clade of cucumber pathogens. This megaplasmid encodes a type IV secretion system and a diverse set of unknown proteins, which dramatically increases both the genomic content of these strains and the pan-genome of the species. PMID:21799664

Defence responses of arabidopsis thaliana to infection by pseudomonas syringae are regulated by the circadian clock

KAUST Repository

Bhardwaj, Vaibhav

2011-10-31

The circadian clock allows plants to anticipate predictable daily changes in abiotic stimuli, such as light; however, whether the clock similarly allows plants to anticipate interactions with other organisms is unknown. Here we show that Arabidopsis thaliana (Arabidopsis) has circadian clock-mediated variation in resistance to the virulent bacterial pathogen Pseudomonas syringae pv. tomato DC3000 (Pst DC3000), with plants being least susceptible to infection in the subjective morning. We suggest that the increased resistance to Pst DC3000 observed in the morning in Col-0 plants results from clock-mediated modulation of pathogen associated molecular pattern (PAMP)-triggered immunity. Analysis of publicly available microarray data revealed that a large number of Arabidopsis defence-related genes showed both diurnal- and circadian-regulation, including genes involved in the perception of the PAMP flagellin which exhibit a peak in expression in the morning. Accordingly, we observed that PAMP-triggered callose deposition was significantly higher in wild-type plants inoculated with Pst DC3000 hrpA in the subjective morning than in the evening, while no such temporal difference was evident in arrhythmic plants. Our results suggest that PAMP-triggered immune responses are modulated by the circadian clock and that temporal regulation allows plants to anticipate and respond more effectively to pathogen challenges in the daytime. © 2011 Bhardwaj et al.

Building brighter PV business

International Nuclear Information System (INIS)

Hacker, R.

2002-01-01

The current status and future prospects of the UK market for solar photovoltaic (PV) electricity are briefly discussed. Through the Department of Trade and Industry (DTI), the UK Government has supported research and development (R and D) into PV for a number of years. This programme has now been extended to demonstrating PV systems on houses. Phase 2 - the domestic field trial programme - aims to monitor the performance of individual systems and the impact on a cluster of systems on the electricity network. New funding had allowed a trebling of the size of this programme, which involves both private developers and housing associations. The DTI is also working to promote PV on commercial buildings, eg the installation of BP Solar PV systems at BP petrol stations. The PV industry in the UK is technically strong and is working to overcome the barriers in the UK to greater uptake of the technology (including cost, conservatism, legal requirements and metering practices). Improvements are expected in a number of recent initiatives in the electricity industry to boost PV use and the PV industry is lobbying for PV to be included in the Enhanced Capital Allowances (ECA) scheme

The life history of Pseudomonas syringae: linking agriculture to earth system processes.

Science.gov (United States)

Morris, Cindy E; Monteil, Caroline L; Berge, Odile

2013-01-01

The description of the ecology of Pseudomonas syringae is moving away from that of a ubiquitous epiphytic plant pathogen to one of a multifaceted bacterium sans frontières in fresh water and other ecosystems linked to the water cycle. Discovery of the aquatic facet of its ecology has led to a vision of its life history that integrates spatial and temporal scales spanning billions of years and traversing catchment basins, continents, and the planet and that confronts the implication of roles that are potentially conflicting for agriculture (as a plant pathogen and as an actor in processes leading to rain and snowfall). This new ecological perspective has also yielded insight into epidemiological phenomena linked to disease emergence. Overall, it sets the stage for the integration of more comprehensive contexts of ecology and evolutionary history into comparative genomic analyses to elucidate how P. syringae subverts the attack and defense responses of the cohabitants of the diverse environments it occupies.

CBL-interacting protein kinase 6 negatively regulates immune response to Pseudomonas syringae in Arabidopsis.

Science.gov (United States)

Sardar, Atish; Nandi, Ashis Kumar; Chattopadhyay, Debasis

2017-06-15

Cytosolic calcium ion (Ca2+) is an essential mediator of the plant innate immune response. Here, we report that a calcium-regulated protein kinase Calcineurin B-like protein (CBL)-interacting protein kinase 6 (CIPK6) functions as a negative regulator of immunity against the bacterial pathogen Pseudomonas syringae in Arabidopsis thaliana. Arabidopsis lines with compromised expression of CIPK6 exhibited enhanced disease resistance to the bacterial pathogen and to P. syringae harboring certain but not all avirulent effectors, while restoration of CIPK6 expression resulted in abolition of resistance. Plants overexpressing CIPK6 were more susceptible to P. syringae. Enhanced resistance in the absence of CIPK6 was accompanied by increased accumulation of salicylic acid and elevated expression of defense marker genes. Salicylic acid accumulation was essential for improved immunity in the absence of CIPK6. CIPK6 negatively regulated the oxidative burst associated with perception of pathogen-associated microbial patterns (PAMPs) and bacterial effectors. Accelerated and enhanced activation of the mitogen-activated protein kinase cascade in response to bacterial and fungal elicitors was observed in the absence of CIPK6. The results of this study suggested that CIPK6 negatively regulates effector-triggered and PAMP-triggered immunity in Arabidopsis. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

A genetic screen reveals Arabidopsis stomatal and/or apoplastic defenses against Pseudomonas syringae pv. tomato DC3000.

Directory of Open Access Journals (Sweden)

Weiqing Zeng

2011-10-01

Full Text Available Bacterial infection of plants often begins with colonization of the plant surface, followed by entry into the plant through wounds and natural openings (such as stomata, multiplication in the intercellular space (apoplast of the infected tissues, and dissemination of bacteria to other plants. Historically, most studies assess bacterial infection based on final outcomes of disease and/or pathogen growth using whole infected tissues; few studies have genetically distinguished the contribution of different host cell types in response to an infection. The phytotoxin coronatine (COR is produced by several pathovars of Pseudomonas syringae. COR-deficient mutants of P. s. tomato (Pst DC3000 are severely compromised in virulence, especially when inoculated onto the plant surface. We report here a genetic screen to identify Arabidopsis mutants that could rescue the virulence of COR-deficient mutant bacteria. Among the susceptible to coronatine-deficient Pst DC3000 (scord mutants were two that were defective in stomatal closure response, two that were defective in apoplast defense, and four that were defective in both stomatal and apoplast defense. Isolation of these three classes of mutants suggests that stomatal and apoplastic defenses are integrated in plants, but are genetically separable, and that COR is important for Pst DC3000 to overcome both stomatal guard cell- and apoplastic mesophyll cell-based defenses. Of the six mutants defective in bacterium-triggered stomatal closure, three are defective in salicylic acid (SA-induced stomatal closure, but exhibit normal stomatal closure in response to abscisic acid (ABA, and scord7 is compromised in both SA- and ABA-induced stomatal closure. We have cloned SCORD3, which is required for salicylic acid (SA biosynthesis, and SCORD5, which encodes an ATP-binding cassette (ABC protein, AtGCN20/AtABCF3, predicted to be involved in stress-associated protein translation control. Identification of SCORD5 begins to

Building opportunities in the U.S. for PV (PV:BONUS): A progress report

International Nuclear Information System (INIS)

Taylor, R.W.

1994-01-01

Five contract teams are developing photovoltaic (PV) products that will have a significant impact on building-integrated PV systems. The product lines that these teams are pursuing include roofing materials, building facade materials, PV integrated into modular homes, ac-PV modules, and utility-dispatchable PV systems. The objective of these efforts is to develop product and market opportunities that can provide for the introduction of PV into the buildings market sector at higher allowable installed systems costs than conventional ground- or roof-mounted systems. Each of the teams has a unique approach, and synergistic opportunities among teams are beginning to emerge. This paper reviews the product and market development efforts of these teams and describes the links between the product efforts and parallel analytical work to develop PV as a demand-side management option

Induction of Xa10-like Genes in Rice Cultivar Nipponbare Confers Disease Resistance to Rice Bacterial Blight.

Science.gov (United States)

Wang, Jun; Tian, Dongsheng; Gu, Keyu; Yang, Xiaobei; Wang, Lanlan; Zeng, Xuan; Yin, Zhongchao

2017-06-01

Bacterial blight of rice, caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive bacterial diseases throughout the major rice-growing regions in the world. The rice disease resistance (R) gene Xa10 confers race-specific disease resistance to X. oryzae pv. oryzae strains that deliver the corresponding transcription activator-like (TAL) effector AvrXa10. Upon bacterial infection, AvrXa10 binds specifically to the effector binding element in the promoter of the R gene and activates its expression. Xa10 encodes an executor R protein that triggers hypersensitive response and activates disease resistance. 'Nipponbare' rice carries two Xa10-like genes in its genome, of which one is the susceptible allele of the Xa23 gene, a Xa10-like TAL effector-dependent executor R gene isolated recently from 'CBB23' rice. However, the function of the two Xa10-like genes in disease resistance to X. oryzae pv. oryzae strains has not been investigated. Here, we designated the two Xa10-like genes as Xa10-Ni and Xa23-Ni and characterized their function for disease resistance to rice bacterial blight. Both Xa10-Ni and Xa23-Ni provided disease resistance to X. oryzae pv. oryzae strains that deliver the matching artificially designed TAL effectors (dTALE). Transgenic rice plants containing Xa10-Ni and Xa23-Ni under the Xa10 promoter provided specific disease resistance to X. oryzae pv. oryzae strains that deliver AvrXa10. Xa10-Ni and Xa23-Ni knock-out mutants abolished dTALE-dependent disease resistance to X. oryzae pv. oryzae. Heterologous expression of Xa10-Ni and Xa23-Ni in Nicotiana benthamiana triggered cell death. The 19-amino-acid residues at the N-terminal regions of XA10 or XA10-Ni are dispensable for their function in inducing cell death in N. benthamiana and the C-terminal regions of XA10, XA10-Ni, and XA23-Ni are interchangeable among each other without affecting their function. Like XA10, both XA10-Ni and XA23-Ni locate to the endoplasmic reticulum (ER) membrane

Biosynthesis and regulation of coronatine, a non-host-specific phytotoxin produced by Pseudomonas syringae.

Science.gov (United States)

Bender, C L; Palmer, D A; Peñaloza-Vázquez, A; Rangaswamy, V; Ullrich, M

1998-01-01

Many P. syringae pathovars are known to produce low-molecular-weight, diffusible toxins in infected host plants. These phytotoxins reproduce some of the symptoms of the relevant bacterial disease and are effective at very low concentrations. Phytotoxins generally enhance the virulence of the P. syringae pathovar which produces them, but are not required for pathogenesis. Genes encoding phytotoxin production have been identified and cloned from several P. syringae pathovars. With the exception of coronatine, toxin biosynthetic gene clusters are generally chromosomally encoded. In several pathovars, the toxin biosynthetic gene cluster also contains a resistance gene which functions to protect the producing strain from the biocidal effects of the toxin. In the case of phaseolotoxin, a resistance gene (argK) has been utilized to engineer phaseolotoxin-resistant tobacco plants. Although P. syringae phytotoxins can induce very similar effects in plants (chlorosis and necrosis), their biosynthesis and mode of action can be quite different. Knowledge of the biosynthetic pathways to these toxins and the cloning of the structural genes for their biosynthesis has relevance to the development of new bioactive compounds with altered specificity. For example, polyketides constitute a huge family of structurally diverse natural products including antibiotics, chemotherapeutic compounds, and antiparasitics. Most of the research on polyketide synthesis in bacteria has focused on compounds synthesized by Streptomyces or other actinomycetes. It is also important to note that it is now possible to utilize a genetic rather than synthetic approach to biosynthesize novel polyketides with altered biological properties (Hutchinson and Fujii, 1995; Kao et al., 1994; Donadio et al., 1993; Katz and Donadio, 1993). Most of the reprogramming or engineering of novel polyketides has been done using actinomycete PKSs, but much of this technology could also be applied to polyketides synthesized by

Disruption of the ammonium transporter AMT1.1 alters basal defences generating resistance against Pseudomonas syringae and Plectosphaerella cucumerina

Directory of Open Access Journals (Sweden)

Victoria ePastor

2014-05-01

Full Text Available Disruption of the high-affinity nitrate transporter NRT2.1 activates the priming defence against Pseudomonas syringae, resulting in enhanced resistance. In this study, it is demonstrated that the high-affinity ammonium transporter AMT1.1 is a negative regulator of Arabidopsis defence responses. The T-DNA knockout mutant amt1.1 displays enhanced resistance against Plectosphaerella cucumerina and reduced susceptibility to P. syringae. The impairment of AMT1.1 induces significant metabolic changes in the absence of challenge, suggesting that amt1.1 retains constitutive defence responses. Interestingly, amt1.1 combats pathogens differently depending on the lifestyle of the pathogen. In addition, N starvation enhances the susceptibility of wild type plants and the mutant amt1.1 to P. syringae whereas it has no effect on P. cucumerina resistance. The metabolic changes of amt1.1 against P. syringae are subtler and are restricted to the phenylpropanoid pathway, which correlates with its reduced susceptibility. By contrast, the amt1.1 mutant responds by activating higher levels of camalexin and callose against P. cucumerina. In addition, amt1.1 shows altered levels of aliphatic and indolic glucosinolates and other Trp-related compounds following infection by the necrotroph. These observations indicate that AMT1.1 may play additional roles that affect N uptake and plant immune responses.

Improved annotation through genome-scale metabolic modeling of Aspergillus oryzae

DEFF Research Database (Denmark)

Vongsangnak, Wanwipa; Olsen, Peter; Hansen, Kim

2008-01-01

Background: Since ancient times the filamentous fungus Aspergillus oryzae has been used in the fermentation industry for the production of fermented sauces and the production of industrial enzymes. Recently, the genome sequence of A. oryzae with 12,074 annotated genes was released but the number...... to a genome scale metabolic model of A. oryzae. Results: Our assembled EST sequences we identified 1,046 newly predicted genes in the A. oryzae genome. Furthermore, it was possible to assign putative protein functions to 398 of the newly predicted genes. Noteworthy, our annotation strategy resulted...... model was validated and shown to correctly describe the phenotypic behavior of A. oryzae grown on different carbon sources. Conclusion: A much enhanced annotation of the A. oryzae genome was performed and a genomescale metabolic model of A. oryzae was reconstructed. The model accurately predicted...

SH1 leaf rust and bacterial halo blight coffee resistances are genetically independent

Directory of Open Access Journals (Sweden)

Lucas Mateus Rivero Rodrigues

Full Text Available ABSTRACT Coffee resistance to Pseudomonas syringae pv. garcae has been associated to pleiotropic effect of SH1 allele, present in coffee plants resistant to certain races of Hemileia vastatrix, the causal agent of leaf rust, or genetic linkage between resistance alleles to both pathogens. To validate this hypothesis, 63 coffee plants in F2 generation were evaluated for resistance to 2 isolates of H. vastatrix carriers of alleles, respectively, v2, v5 (isolate I/2015 and v1; v2; v5 (isolate II/2015 with the objective to confirm presence of SH1 allele in resistant plants to isolate I/2015. The same coffee plants were evaluated for resistance to a mixture of P. syringae pv. garcae strains highly pathogenic to coffee. Results showed that, among F2 coffee allele SH1 carriers, resistant to isolate I/2015, resistant and susceptible plants to bacterial halo blight were found; the same segregation occurs between F2 homozygous for SH1 allele, susceptible to the same isolate (I/2015 of H. vastatrix. Results also indicate that there is no pleiotropic effect of gene or allele SH1 connection between genes conferring resistance to leaf rust caused by H. vastatrix and bacterial halo blight caused by P. syringae pv. garcae.

PV ready roofing systems

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

The integration of PV technology into roofs of houses has become very popular in the United States, Japan, Germany and The Netherlands. There could be a considerable market in the UK for these systems, given the large number of houses that are projected to be built in the next 10 years, and taking account of increased awareness of energy issues. A significant proportion of the market share of annual installed PV is for solar PV systems installed into homes (currently 15%), this is expected to rise to 23% (900MW) by 2010. The grid connected roof and building mounted facade systems represent the fastest growing market for PV systems in Europe. In conclusion, therefore, innovative approached for fixing PV technology onto roofs have been identified for both domestic roofs and for the commercial sector. With reference to production methodologies within the roofing industry, both approaches should be capable of being designed with PV-ready connections suitable for fixing PV modules at a later date. This will help overcome the key barriers of cost of installation, skills required and the lack of retrofit potential. Based on the results of this project, Sustainable Energy together with PV Systems are keen to take forward the full research and development of PV-ready systems for both the domestic and commercial sectors.

Sensorless PV Array Diagnostic Method for Residential PV Systems

DEFF Research Database (Denmark)

Sera, Dezso; Spataru, Sergiu; Mathe, Laszlo

2011-01-01

This work proposes a temperature and irradiance sensorless diagnostic method suitable for small residential PV installations, focusing on detection of partial shadows. The method works by detection of failures in crystalline silicone PV arrays by concomitant monitoring of some of their key...

ORF Alignment: NC_006834 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available ... transferase [Xanthomonas oryzae pv. oryzae KACC10331] ... Length = 196 ... Query: 163 HLVVQAMDFASDQFSRDAFARC...AMACPPGIVRSVRKRQAEYFFGRLAARHALHQQGLVVH 222 ... HLVVQAMDFASDQFSRDAFARC...AMACPPGIVRSVRKRQAEYFFGRLAARHALHQQGLVVH Sbjct: 1 ... HLVVQAMDFASDQFSRDAFARCAMACPPGIVRSVRKRQAEYFFGRLAARHA

City and County Solar PV Training Program, Module 2: Screening and Identifying PV Projects

Energy Technology Data Exchange (ETDEWEB)

Elgqvist, Emma M [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-04-09

When screening and identifying PV projects, cities and counties should understand the different factors that impact the technical and economic potential of a PV project, the steps of the PV screening process, and how to use REopt Lite to screen a site for PV and storage project potential.

Pyramiding of blast and bacterial leaf blight resistance genes into ...

African Journals Online (AJOL)

Blast caused by the fungus Magnaporthe oryzae (Hebert) Barr. and bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) are two major diseases of rice (Oryza sativa). The use of varietal resistance is the most appropriate strategy for controlling the diseases, and molecular assisted selection can ...

Syringa oblata Lindl var. alba as a source of oleuropein and related compounds

NARCIS (Netherlands)

Nenadis, N.; Vervoort, J.J.M.; Boeren, J.A.; Tsimidou, M.Z.

2007-01-01

The leaf methanol extract of Syringa oblata Lindl var. alba was investigated as a source of oleuropein and related compounds. The extract had a high total phenol content and a radical scavenging activity similar to that of the respective extract from Olea europaea leaves. HPLC-DAD characterisation

PV power plants

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-07-01

Within the international seminar of the Ostbayerisches Technologie-Transfer-Institut e.V. (OTTI) at 11th June, 2012 in Munich (Federal Republic of Germany), the following lectures were held: (1) Technical due diligence (Dietmar Obst); (2) Certification / rating system for large PV plants (Robert Pfatischer); (3) O and M requirements (Lars Rulf); (4) IR photography for large scale systems (Bernhard Weinreich); (5) New market models for PV systems - direct marketing and sales of PV electricity (Martin Schneider); (6) Needs and benefits for plant certification for grid connection and operation (Christoph Luetke-Lengerich); (7) Lare volume module testing / Screening in the field and workshop (Semir Merzoug); (8) Dismantling costs of large scale PV plants (Siegfried Schimpf).

Cell biology of the Koji mold Aspergillus oryzae.

Science.gov (United States)

Kitamoto, Katsuhiko

2015-01-01

Koji mold, Aspergillus oryzae, has been used for the production of sake, miso, and soy sauce for more than one thousand years in Japan. Due to the importance, A. oryzae has been designated as the national micro-organism of Japan (Koku-kin). A. oryzae has been intensively studied in the past century, with most investigations focusing on breeding techniques and developing methods for Koji making for sake brewing. However, the understanding of fundamental biology of A. oryzae remains relatively limited compared with the yeast Saccharomyces cerevisiae. Therefore, we have focused on studying the cell biology including live cell imaging of organelles, protein vesicular trafficking, autophagy, and Woronin body functions using the available genomic information. In this review, I describe essential findings of cell biology of A. oryzae obtained in our study for a quarter of century. Understanding of the basic biology will be critical for not its biotechnological application, but also for an understanding of the fundamental biology of other filamentous fungi.

PV Obelisk - Information system with photovoltaics; PV-Obelisk Orientierungssystem mit Photovoltaik

Energy Technology Data Exchange (ETDEWEB)

Ruoss, D.; Rasmussen, J.

2004-07-01

This final report for the Swiss Federal Office of Energy (SFOE) describes the development of an information system powered by a photovoltaic (PV) array. As an innovative approach, the 'PV-Obelisk' project is the combination of PV with a multi-functional pillar made of natural stone in an aesthetic way. The PV modules serve both as a power supply and as a design element. Two initial prototypes led the way to a third, optimised consumer configuration that was planned to guarantee maximum user frequency. Test operation in front of the 'Heidiland' motor way restaurant confirmed the market analyses made and delivered the expected results. The product, whose three LCD displays are updated via a mobile telephony-based text-message system, proved its technical reliability and showed a high user frequency. Because of the high overall energy consumption, PV power can only partially contribute to the energy supply needed. Various compromises in the technical and aesthetic areas are discussed that were made for the sake of product acceptance in the market. The range of application areas for such a 'PV Obelisk' are discussed and the need for early co-ordination with urban planners is stressed.

Elicitation of Induced Resistance against Pectobacterium carotovorum and Pseudomonas syringae by Specific Individual Compounds Derived from Native Korean Plant Species

Directory of Open Access Journals (Sweden)

Choong-Min Ryu

2013-10-01

Full Text Available Plants have developed general and specific defense mechanisms for protection against various enemies. Among the general defenses, induced resistance has distinct characteristics, such as broad-spectrum resistance and long-lasting effectiveness. This study evaluated over 500 specific chemical compounds derived from native Korean plant species to determine whether they triggered induced resistance against Pectobacterium carotovorum supsp. carotovorum (Pcc in tobacco (Nicotiana tabacum and Pseudomonas syringae pv. tomato (Pst in Arabidopsis thaliana. To select target compound(s with direct and indirect (volatile effects, a new Petri-dish-based in vitro disease assay system with four compartments was developed. The screening assay showed that capsaicin, fisetin hydrate, jaceosidin, and farnesiferol A reduced the disease severity significantly in tobacco. Of these four compounds, capsaicin and jaceosidin induced resistance against Pcc and Pst, which depended on both salicylic acid (SA and jasmonic acid (JA signaling, using Arabidopsis transgenic and mutant lines, including npr1 and NahG for SA signaling and jar1 for JA signaling. The upregulation of the PR2 and PDF1.2 genes after Pst challenge with capsaicin pre-treatment indicated that SA and JA signaling were primed. These results demonstrate that capsaicin and jaceosidin can be effective triggers of strong induced resistance against both necrotrophic and biotrophic plant pathogens.

Novel Methods to Determine Feeder Locational PV Hosting Capacity and PV Impact Signatures

Energy Technology Data Exchange (ETDEWEB)

Reno, Matthew J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Coogan, Kyle [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Seuss, John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Broderick, Robert Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-05-01

Often PV hosting capacity analysis is performed for a limited number of distribution feeders. For medium - voltage distribution feeders, previous results generally analyze less than 20 feeders, and then the results are extrapolated out to similar types of feeders. Previous hosting capacity research has often focused on determining a single value for the hosting capacity for the entire feeder, whereas this research expands previous hosting capacity work to investigate all the regions of the feeder that may allow many different hosting capacity values wit h an idea called locational hosting capacity (LHC)to determine the largest PV size that can be interconnected at different locations (buses) on the study feeders. This report discusses novel methods for analyzing PV interconnections with advanced simulati on methods. The focus is feeder and location - specific impacts of PV that determine the locational PV hosting capacity. Feeder PV impact signature are used to more precisely determine the local maximum hosting capacity of individual areas of the feeder. T he feeder signature provides improved interconnection screening with certain zones that show the risk of impact to the distribution feeder from PV interconnections.

Energy balance of the global photovoltaic (PV) industry--is the PV industry a net electricity producer?

Science.gov (United States)

Dale, Michael; Benson, Sally M

2013-04-02

A combination of declining costs and policy measures motivated by greenhouse gas (GHG) emissions reduction and energy security have driven rapid growth in the global installed capacity of solar photovoltaics (PV). This paper develops a number of unique data sets, namely the following: calculation of distribution of global capacity factor for PV deployment; meta-analysis of energy consumption in PV system manufacture and deployment; and documentation of reduction in energetic costs of PV system production. These data are used as input into a new net energy analysis of the global PV industry, as opposed to device level analysis. In addition, the paper introduces a new concept: a model tracking energetic costs of manufacturing and installing PV systems, including balance of system (BOS) components. The model is used to forecast electrical energy requirements to scale up the PV industry and determine the electricity balance of the global PV industry to 2020. Results suggest that the industry was a net consumer of electricity as recently as 2010. However, there is a >50% that in 2012 the PV industry is a net electricity provider and will "pay back" the electrical energy required for its early growth before 2020. Further reducing energetic costs of PV deployment will enable more rapid growth of the PV industry. There is also great potential to increase the capacity factor of PV deployment. These conclusions have a number of implications for R&D and deployment, including the following: monitoring of the energy embodied within PV systems; designing more efficient and durable systems; and deploying PV systems in locations that will achieve high capacity factors.

Multilayered Regulation of Ethylene Induction Plays a Positive Role in Arabidopsis Resistance against Pseudomonas syringae.

Science.gov (United States)

Guan, Rongxia; Su, Jianbin; Meng, Xiangzong; Li, Sen; Liu, Yidong; Xu, Juan; Zhang, Shuqun

2015-09-01

Ethylene, a key phytohormone involved in plant-pathogen interaction, plays a positive role in plant resistance against fungal pathogens. However, its function in plant bacterial resistance remains unclear. Here, we report a detailed analysis of ethylene induction in Arabidopsis (Arabidopsis thaliana) in response to Pseudomonas syringae pv tomato DC3000 (Pst). Ethylene biosynthesis is highly induced in both pathogen/microbe-associated molecular pattern (PAMP)-triggered immunity and effector-triggered immunity (ETI), and the induction is potentiated by salicylic acid (SA) pretreatment. In addition, Pst actively suppresses PAMP-triggered ethylene induction in a type III secretion system-dependent manner. SA potentiation of ethylene induction is dependent mostly on MITOGEN-ACTIVATED PROTEIN KINASE6 (MPK6) and MPK3 and their downstream ACS2 and ACS6, two type I isoforms of 1-aminocyclopropane-1-carboxylic acid synthases (ACSs). ACS7, a type III ACS whose expression is enhanced by SA pretreatment, is also involved. Pst expressing the avrRpt2 effector gene (Pst-avrRpt2), which is capable of triggering ETI, induces a higher level of ethylene production, and the elevated portion is dependent on SALICYLIC ACID INDUCTION DEFICIENT2 and NONEXPRESSER OF PATHOGENESIS-RELATED GENE1, two key players in SA biosynthesis and signaling. High-order ACS mutants with reduced ethylene induction are more susceptible to both Pst and Pst-avrRpt2, demonstrating a positive role of ethylene in plant bacterial resistance mediated by both PAMP-triggered immunity and ETI. © 2015 American Society of Plant Biologists. All Rights Reserved.

JPRS Report, Science & Technology, USSR: Life Sciences.

Science.gov (United States)

1987-06-29

MEDITSINSKAYA BIOTEKHNOLOGIYA, No 11, Nov 85) 20 Xanthomonas Campestris Pv. Oryzae, Rice Seed Bacteriosis Pathogen in the Ukraine (I.B, Koroleva...ethylene, and are active in a series of bioassays on auxins, gibberellins and cytokinins. Nevertheless, according to the character of their biological...CAMPESTRIS PV. ORYZAE, RICE SEED BACTERIOSIS PATHOGEN IN THE UKRAINE Kiev MIKROBIOLOGICHESKIY ZHURNAL in Russian Vol 47, No 6, Nov-Dec 85 (manuscript

NpPDR1, a Pleiotropic Drug Resistance-Type ATP-Binding Cassette Transporter from Nicotiana plumbaginifolia, Plays a Major Role in Plant Pathogen Defense1

Science.gov (United States)

Stukkens, Yvan; Bultreys, Alain; Grec, Sébastien; Trombik, Tomasz; Vanham, Delphine; Boutry, Marc

2005-01-01

Nicotiana plumbaginifolia NpPDR1, a plasma membrane pleiotropic drug resistance-type ATP-binding cassette transporter formerly named NpABC1, has been suggested to transport the diterpene sclareol, an antifungal compound. However, direct evidence for a role of pleiotropic drug resistance transporters in the plant defense is still lacking. In situ immunolocalization and histochemical analysis using the gusA reporter gene showed that NpPDR1 was constitutively expressed in the whole root, in the leaf glandular trichomes, and in the flower petals. However, NpPDR1 expression was induced in the whole leaf following infection with the fungus Botrytis cinerea, and the bacteria Pseudomonas syringae pv tabaci, Pseudomonas fluorescens, and Pseudomonas marginalis pv marginalis, which do not induce a hypersensitive response in N. plumbaginifolia, whereas a weaker response was observed using P. syringae pv syringae, which does induce a hypersensitive response. Induced NpPDR1 expression was more associated with the jasmonic acid than the salicylic acid signaling pathway. These data suggest that NpPDR1 is involved in both constitutive and jasmonic acid-dependent induced defense. Transgenic plants in which NpPDR1 expression was prevented by RNA interference showed increased sensitivity to sclareol and reduced resistance to B. cinerea. These data show that NpPDR1 is involved in pathogen resistance and thus demonstrate a new role for the ATP-binding cassette transporter family. PMID:16126865

NpPDR1, a pleiotropic drug resistance-type ATP-binding cassette transporter from Nicotiana plumbaginifolia, plays a major role in plant pathogen defense.

Science.gov (United States)

Stukkens, Yvan; Bultreys, Alain; Grec, Sébastien; Trombik, Tomasz; Vanham, Delphine; Boutry, Marc

2005-09-01

Nicotiana plumbaginifolia NpPDR1, a plasma membrane pleiotropic drug resistance-type ATP-binding cassette transporter formerly named NpABC1, has been suggested to transport the diterpene sclareol, an antifungal compound. However, direct evidence for a role of pleiotropic drug resistance transporters in the plant defense is still lacking. In situ immunolocalization and histochemical analysis using the gusA reporter gene showed that NpPDR1 was constitutively expressed in the whole root, in the leaf glandular trichomes, and in the flower petals. However, NpPDR1 expression was induced in the whole leaf following infection with the fungus Botrytis cinerea, and the bacteria Pseudomonas syringae pv tabaci, Pseudomonas fluorescens, and Pseudomonas marginalis pv marginalis, which do not induce a hypersensitive response in N. plumbaginifolia, whereas a weaker response was observed using P. syringae pv syringae, which does induce a hypersensitive response. Induced NpPDR1 expression was more associated with the jasmonic acid than the salicylic acid signaling pathway. These data suggest that NpPDR1 is involved in both constitutive and jasmonic acid-dependent induced defense. Transgenic plants in which NpPDR1 expression was prevented by RNA interference showed increased sensitivity to sclareol and reduced resistance to B. cinerea. These data show that NpPDR1 is involved in pathogen resistance and thus demonstrate a new role for the ATP-binding cassette transporter family.

PV Thermal systems: PV panels supplying renewable electricity and heat

NARCIS (Netherlands)

Helden, van W.G.J.; Zolingen, van R.J.C.; Zondag, H.A.

2004-01-01

With PV Thermal panels sunlight is converted into electricity and heat simultaneously. Per unit area the total efficiency of a PVT panel is higher than the sum of the efficiencies of separate PV panels and solar thermal collectors. During the last 20 years research into PVT techniques and concepts

Top 10 plant pathogenic bacteria in molecular plant pathology.

Science.gov (United States)

Mansfield, John; Genin, Stephane; Magori, Shimpei; Citovsky, Vitaly; Sriariyanum, Malinee; Ronald, Pamela; Dow, Max; Verdier, Valérie; Beer, Steven V; Machado, Marcos A; Toth, Ian; Salmond, George; Foster, Gary D

2012-08-01

Many plant bacteriologists, if not all, feel that their particular microbe should appear in any list of the most important bacterial plant pathogens. However, to our knowledge, no such list exists. The aim of this review was to survey all bacterial pathologists with an association with the journal Molecular Plant Pathology and ask them to nominate the bacterial pathogens they would place in a 'Top 10' based on scientific/economic importance. The survey generated 458 votes from the international community, and allowed the construction of a Top 10 bacterial plant pathogen list. The list includes, in rank order: (1) Pseudomonas syringae pathovars; (2) Ralstonia solanacearum; (3) Agrobacterium tumefaciens; (4) Xanthomonas oryzae pv. oryzae; (5) Xanthomonas campestris pathovars; (6) Xanthomonas axonopodis pathovars; (7) Erwinia amylovora; (8) Xylella fastidiosa; (9) Dickeya (dadantii and solani); (10) Pectobacterium carotovorum (and Pectobacterium atrosepticum). Bacteria garnering honourable mentions for just missing out on the Top 10 include Clavibacter michiganensis (michiganensis and sepedonicus), Pseudomonas savastanoi and Candidatus Liberibacter asiaticus. This review article presents a short section on each bacterium in the Top 10 list and its importance, with the intention of initiating discussion and debate amongst the plant bacteriology community, as well as laying down a benchmark. It will be interesting to see, in future years, how perceptions change and which bacterial pathogens enter and leave the Top 10. © 2012 The Authors. Molecular Plant Pathology © 2012 BSPP and Blackwell Publishing Ltd.

Comparison of three different methods of perturbing the potential vorticity field in mesoscale forecasts of Mediterranean heavy precipitation events: PV-gradient, PV-adjoint and PV-satellite

Science.gov (United States)

Vich, M.; Romero, R.; Richard, E.; Arbogast, P.; Maynard, K.

2010-09-01

Heavy precipitation events occur regularly in the western Mediterranean region. These events often have a high impact on the society due to economic and personal losses. The improvement of the mesoscale numerical forecasts of these events can be used to prevent or minimize their impact on the society. In previous studies, two ensemble prediction systems (EPSs) based on perturbing the model initial and boundary conditions were developed and tested for a collection of high-impact MEDEX cyclonic episodes. These EPSs perturb the initial and boundary potential vorticity (PV) field through a PV inversion algorithm. This technique ensures modifications of all the meteorological fields without compromising the mass-wind balance. One EPS introduces the perturbations along the zones of the three-dimensional PV structure presenting the local most intense values and gradients of the field (a semi-objective choice, PV-gradient), while the other perturbs the PV field over the MM5 adjoint model calculated sensitivity zones (an objective method, PV-adjoint). The PV perturbations are set from a PV error climatology (PVEC) that characterizes typical PV errors in the ECMWF forecasts, both in intensity and displacement. This intensity and displacement perturbation of the PV field is chosen randomly, while its location is given by the perturbation zones defined in each ensemble generation method. Encouraged by the good results obtained by these two EPSs that perturb the PV field, a new approach based on a manual perturbation of the PV field has been tested and compared with the previous results. This technique uses the satellite water vapor (WV) observations to guide the correction of initial PV structures. The correction of the PV field intents to improve the match between the PV distribution and the WV image, taking advantage of the relation between dark and bright features of WV images and PV anomalies, under some assumptions. Afterwards, the PV inversion algorithm is applied to run

Multilayered Regulation of Ethylene Induction Plays a Positive Role in Arabidopsis Resistance against Pseudomonas syringae1[OPEN

Science.gov (United States)

Guan, Rongxia; Su, Jianbin; Meng, Xiangzong; Li, Sen; Liu, Yidong; Xu, Juan; Zhang, Shuqun

2015-01-01

Ethylene, a key phytohormone involved in plant-pathogen interaction, plays a positive role in plant resistance against fungal pathogens. However, its function in plant bacterial resistance remains unclear. Here, we report a detailed analysis of ethylene induction in Arabidopsis (Arabidopsis thaliana) in response to Pseudomonas syringae pv tomato DC3000 (Pst). Ethylene biosynthesis is highly induced in both pathogen/microbe-associated molecular pattern (PAMP)-triggered immunity and effector-triggered immunity (ETI), and the induction is potentiated by salicylic acid (SA) pretreatment. In addition, Pst actively suppresses PAMP-triggered ethylene induction in a type III secretion system-dependent manner. SA potentiation of ethylene induction is dependent mostly on MITOGEN-ACTIVATED PROTEIN KINASE6 (MPK6) and MPK3 and their downstream ACS2 and ACS6, two type I isoforms of 1-aminocyclopropane-1-carboxylic acid synthases (ACSs). ACS7, a type III ACS whose expression is enhanced by SA pretreatment, is also involved. Pst expressing the avrRpt2 effector gene (Pst-avrRpt2), which is capable of triggering ETI, induces a higher level of ethylene production, and the elevated portion is dependent on SALICYLIC ACID INDUCTION DEFICIENT2 and NONEXPRESSER OF PATHOGENESIS-RELATED GENE1, two key players in SA biosynthesis and signaling. High-order ACS mutants with reduced ethylene induction are more susceptible to both Pst and Pst-avrRpt2, demonstrating a positive role of ethylene in plant bacterial resistance mediated by both PAMP-triggered immunity and ETI. PMID:26265775

Photovoltaics for Buildings Cutting-Edge PV

International Nuclear Information System (INIS)

Hayter, S. J.; Martin, R. L.

1998-01-01

Photovoltaic (PV) technology development for building-integrated applications (commonly called PV for Buildings) is one of the fastest growing areas in the PV industry. Buildings represent a huge potential market for photovoltaics because they consume approximately two-thirds of the electricity consumed in the US. The PV and buildings industries are beginning to work together to address issues including building codes and standards, integration, after-market servicing, education, and building energy efficiency. One of the most notable programs to encourage development of new PV-for-buildings products is the PV:BONUS program, supported by the US Department of Energy. Demand for these products from building designers has escalated since the program was initiated in 1993. This paper presents a range of PV-for-buildings issues and products that are currently influencing today's PV and buildings markets

Global PV Market Development

International Nuclear Information System (INIS)

Schmidt, F.

2009-01-01

The dawn of 2009 saw several events which caused major turbulence in the global photovoltaic industry. In 2008 the Spanish PV market grew beyond all expectations and even outranked Germany as the world's number one market. However, the promotion scheme was modified and a market cap was introduced in 2009, cutting back the maximum capacity to be installed to about the level of 2007. In addition, the industry is facing an oversupply of PV modules and a harsh recession which is significantly affecting the traditionally strong PV markets. International photovoltaic companies are challenged by a changing market situation: all of a sudden, competition has increased significantly, pushing the customer to the fore. As a result, a consolidation process is expected within the PV industry worldwide. However, the story is not all negative. In the U.S., the election of Barack Obama may be seen as the starting signal for a massive expansion in PV, likely to bring the country to first place globally within the next five years. Furthermore, different markets and market segments are being opened up - especially in Europe - thanks to the gradual arrival of generation parity and new PV support mechanisms. EuPD Research has observed and studied international PV markets since its foundation. The information included in the presentation is based on a wide range of quantitative and qualitative studies that EuPD Research has conducted in the key markets since 2002. Florian Schmidt, EuPD Research's Head of Product Management, will give an overview of the global PV market and how it is developing in this crucial year 2009. Aspects such as technology development, production capacities and the demand side will be included, with a special emphasis on the European PV markets. So far Chinese PV companies have often benefited from the booming PV markets in Europe, above all Germany and Spain. Due to the lack of domestic market, the Chinese industry strongly depends on the export and is

Evaluation of Oryza sativa x O. glaberrima derived progenies for ...

African Journals Online (AJOL)

USER

2010-06-28

Jun 28, 2010 ... The genus Oryza has two cultivated species, Asian rice (Oryza sativa L.) and African rice (Oryza glaberrima Steud.) and 22 wild species. O. glaberrima is low yielding but has useful genes for resistance to biotic and abiotic stresses. Introgression lines derived from backcrossing of O. sativa x O. glaberrima,.

The defense-responsive genes showing enhanced and repressed expression after pathogen infection in rice (Oryza sativa L.)

Institute of Scientific and Technical Information of China (English)

ZHOU; Bin(周斌); PENG; Kaiman(彭开蔓); CHU; Zhaohui(储昭晖); WANG; Shiping(王石平); ZHANG; Qifa(张启发)

2002-01-01

Despite large numbers of studies about defense response, processes involved in the resistance of plants to incompatible pathogens are still largely uncharacterized. The objective of this study was to identify genes involved in defense response by cDNA array analysis and to gain knowledge about the functions of the genes involved in defense response. Approximately 20000 rice cDNA clones were arrayed on nylon filters. RNA samples isolated from different rice lines after infection with incompatible strains or isolates of Xanthomonas oryzae pv. oryzae or Pyricularia grisea, respectively, were used to synthesize cDNA as probes for screening the cDNA arrays. A total of 100 differentially expressed unique sequences were identified from 5 pathogen-host combinations. Fifty-three sequences were detected as showing enhanced expression and 47 sequences were detected as showing repressed expression after pathogen infection. Sequence analysis revealed that most of the 100 sequences had various degrees of homology with genes in databases which encode or putatively encode transcription regulating proteins, translation regulating proteins, transport proteins, kinases, metabolic enzymes, and proteins involved in other functions. Most of the genes have not been previously reported as being involved in the disease resistance response in rice. The results from cDNA arrays, reverse transcription-polymerase chain reaction, and RNA gel blot analysis suggest that activation or repression of most of these genes might occur commonly in the defense response.

Genome Sequences of Oryza Species

KAUST Repository

Kumagai, Masahiko

2018-02-14

This chapter summarizes recent data obtained from genome sequencing, annotation projects, and studies on the genome diversity of Oryza sativa and related Oryza species. O. sativa, commonly known as Asian rice, is the first monocot species whose complete genome sequence was deciphered based on physical mapping by an international collaborative effort. This genome, along with its accurate and comprehensive annotation, has become an indispensable foundation for crop genomics and breeding. With the development of innovative sequencing technologies, genomic studies of O. sativa have dramatically increased; in particular, a large number of cultivars and wild accessions have been sequenced and compared with the reference rice genome. Since de novo genome sequencing has become cost-effective, the genome of African cultivated rice, O. glaberrima, has also been determined. Comparative genomic studies have highlighted the independent domestication processes of different rice species, but it also turned out that Asian and African rice share a common gene set that has experienced similar artificial selection. An international project aimed at constructing reference genomes and examining the genome diversity of wild Oryza species is currently underway, and the genomes of some species are publicly available. This project provides a platform for investigations such as the evolution, development, polyploidization, and improvement of crops. Studies on the genomic diversity of Oryza species, including wild species, should provide new insights to solve the problem of growing food demands in the face of rapid climatic changes.

Genome Sequences of Oryza Species

KAUST Repository

Kumagai, Masahiko; Tanaka, Tsuyoshi; Ohyanagi, Hajime; Hsing, Yue-Ie C.; Itoh, Takeshi

2018-01-01

This chapter summarizes recent data obtained from genome sequencing, annotation projects, and studies on the genome diversity of Oryza sativa and related Oryza species. O. sativa, commonly known as Asian rice, is the first monocot species whose complete genome sequence was deciphered based on physical mapping by an international collaborative effort. This genome, along with its accurate and comprehensive annotation, has become an indispensable foundation for crop genomics and breeding. With the development of innovative sequencing technologies, genomic studies of O. sativa have dramatically increased; in particular, a large number of cultivars and wild accessions have been sequenced and compared with the reference rice genome. Since de novo genome sequencing has become cost-effective, the genome of African cultivated rice, O. glaberrima, has also been determined. Comparative genomic studies have highlighted the independent domestication processes of different rice species, but it also turned out that Asian and African rice share a common gene set that has experienced similar artificial selection. An international project aimed at constructing reference genomes and examining the genome diversity of wild Oryza species is currently underway, and the genomes of some species are publicly available. This project provides a platform for investigations such as the evolution, development, polyploidization, and improvement of crops. Studies on the genomic diversity of Oryza species, including wild species, should provide new insights to solve the problem of growing food demands in the face of rapid climatic changes.

Apoplastic peroxidases are required for salicylic acid-mediated defense against Pseudomonas syringae.

Science.gov (United States)

Mammarella, Nicole D; Cheng, Zhenyu; Fu, Zheng Qing; Daudi, Arsalan; Bolwell, G Paul; Dong, Xinnian; Ausubel, Frederick M

2015-04-01

Reactive oxygen species (ROS) generated by NADPH oxidases or apoplastic peroxidases play an important role in the plant defense response. Diminished expression of at least two Arabidopsis thaliana peroxidase encoding genes, PRX33 (At3g49110) and PRX34 (At3g49120), as a consequence of anti-sense expression of a heterologous French bean peroxidase gene (asFBP1.1), were previously shown to result in reduced levels of ROS following pathogen attack, enhanced susceptibility to a variety of bacterial and fungal pathogens, and reduced levels of callose production and defense-related gene expression in response to the microbe associated molecular pattern (MAMP) molecules flg22 and elf26. These data demonstrated that the peroxidase-dependent oxidative burst plays an important role in the elicitation of pattern-triggered immunity (PTI). Further work reported in this paper, however, shows that asFBP1.1 antisense plants are not impaired in all PTI-associated responses. For example, some but not all flg22-elicited genes are induced to lower levels by flg22 in asFPB1.1, and callose deposition in asFPB1.1 is similar to wild-type following infiltration with a Pseudomonas syringae hrcC mutant or with non-host P. syringae pathovars. Moreover, asFPB1.1 plants did not exhibit any apparent defect in their ability to mount a hypersensitive response (HR). On the other hand, salicylic acid (SA)-mediated activation of PR1 was dramatically impaired in asFPB1.1 plants. In addition, P. syringae-elicited expression of many genes known to be SA-dependent was significantly reduced in asFBP1.1 plants. Consistent with this latter result, in asFBP1.1 plants the key regulator of SA-mediated responses, NPR1, showed both dramatically decreased total protein abundance and a failure to monomerize, which is required for its translocation into the nucleus. Copyright © 2014 Elsevier Ltd. All rights reserved.

PV-hybrid and mini-grid

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

Within the 5th European PV-hybrid and mini-grid conference 29th and 30th April, 2010 in Tarragona (Spain) the following lectures were held: (1) Overview of IEA PVPS Task 11 PV-hybrid systems within mini grids; (2) Photovoltaic revolution for deployment in developing countries; (3) Legal and financial conditions for the sustainable operation of mini-grids; (4) EU instruments to promote renewable energies in developing countries; (5) PV hybridization of diesel electricity generators: Conditions of profitability and examples in differential power and storage size ranges; (6) Education suit of designing PV hybrid systems; (7) Sustainable renewable energy projects for intelligent rural electrification in Laos, Cambodia and Vietnam; (8) Techno-economic feasibility of energy supply of remote villages in Palestine by PV systems, diesel generators and electric grid (Case studies: Emnazeil and Atouf villages); (9) Technical, economical and sustainability considerations of a solar PV mini grid as a tool for rural electrification in Uganda; (10) Can we rate inverters for rural electrification on the basis of energy efficiency?; (11) Test procedures for MPPT charge controllers characterization; (12) Energy storage for mini-grid stabilization; (13) Redox flow batteries - Already an alternative storage solution for hybrid PV mini-grids?; (14) Control methods for PV hybrid mini-grids; (15) Partial AC-coupling in mini-grids; (15) Normative issues of small wind turbines in PV hybrid systems; (16) Communication solutions for PV hybrid systems; (17) Towards flexible control and communication of mini-grids; (18) PV/methanol fuel cell hybrid system for powering a highway security variable message board; (19) Polygeneration smartgrids: A solution for the supply of electricity, potable water and hydrogen as fuel for transportation in remote Areas; (20) Implementation of the Bronsbergen micro grid using FACDS; (21) A revisited approach for the design of PV wind hybrid systems; (22

SunShot 2030 for Photovoltaics (PV): Envisioning a Low-Cost PV Future

Energy Technology Data Exchange (ETDEWEB)

Cole, Wesley J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Frew, Bethany A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gagnon, Pieter J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Richards, James [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sun, Yinong [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zuboy, Jarrett; Woodhouse, Michael A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Margolis, Robert M [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-10-01

This presentation summarizes the findings from the report 'SunShot 2030 for Photovoltaics (PV): Envisioning a Low-cost PV Future.' This presentation was given as a webinar on September 26, 2017.

Economic PV - a shift in thinking

International Nuclear Information System (INIS)

Maycock, P.

1999-01-01

This article argues that photovoltaic (PV) technology is already economically viable contrary to current opinion. A table of world PV module shipments for 1990 to 1998 by market sector is presented, and use of PV modules in consumer electronics such as calculators, battery trickle chargers, and garden lights; in communications and signals (eg. microwave repeaters, cellular communication); and in the residential sector in fluorescent lights, radios etc. are discussed. The early adopters of PV technology, and the value placed on PV devices by consumers are considered. Details of PV manufacturing costs for 1997, and forecasts for 2000 and 2010 are tabulated

Biological Activity of Essential Oils from Leaves and Fruits of Pepper Tree (Schinus molle L. to Control Rice Weevil (Sitophilus oryzae L. Bioactividad de aceites esenciales de hojas y frutos del aguaribay (Schinus molle L. en el gorgojo del arroz (Sitophilus oryzae L.

Directory of Open Access Journals (Sweden)

Verónica Benzi

2009-06-01

impregnación de trigo entero; y para los índices nutricionales y la actividad antialimentaria impregnación de discos de harina de trigo. El aceite esencial de hojas mostró efectos repelentes a ambas concentraciones (0,04 y 0,4% p/v, mientras que el de frutos no produjo repelencia. Ambos aceites alteraron la fisiología nutricional de S. oryzae. El aceite de frutos produjo un efecto antialimentario fuerte (62% y el de hojas leve (40,6%. No se observó actividad fumigante.

ORF Alignment: NC_006834 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available monas ... oryzae pv. oryzae KACC10331] ... Length = 130 ... Query: 158 PDGLRIQIVDKQNRPMFDIGRDQLKPYTVAILHELSNFINQVPNHIS...ITGHTDTTAYSSD 217 ... PDGLRIQIVDKQNRPMFDIGRDQLKPYTVAILHELSNFINQVPNHIS...ITGHTDTTAYSSD Sbjct: 1 ... PDGLRIQIVDKQNRPMFDIGRDQLKPYTVAILHELSNFINQVPNHISITGHTDTTAYSSD 60 ... Query: 278 TQDAES 283 ... TQDAES Sbjct: 121 TQDAES 126

Genetic analysis of conidiation regulatory pathways in koji-mold Aspergillus oryzae.

Science.gov (United States)

Ogawa, Masahiro; Tokuoka, Masafumi; Jin, Feng Jie; Takahashi, Tadashi; Koyama, Yasuji

2010-01-01

Conidia of koji-mold Aspergillus oryzae are often used as starters in the fermented food industry. However, little is known about conidiation regulation in A. oryzae. To improve the productivity of conidia in A. oryzae, it is necessary to understand conidiation regulation in the strain. Therefore, we analyzed the conidiation regulatory system in A. oryzae using 10 kinds of conidiation regulatory gene disruptants. The phenotypes of AorfluG, AorflbA, AorflbB, AorflbC, AorflbD, AorflbE, AorbrlA, AorabaA, AorwetA, and AorfadA mutants are almost identical to those of the corresponding mutants in Aspergillus nidulans. The results indicated that the functions of conidiation regulatory genes are almost conserved between A. oryzae and A. nidulans. However, the severely reduced conidiation phenotype of the AorfluG disruptant in A. oryzae differs from the phenotype of the corresponding mutant in Aspergillus fumigatus in air-exposed culture conditions. These results suggest that A. oryzae, A. nidulans, and A. fumigatus have a G-protein signaling pathway and brlA orthologs in common, and only A. fumigatus has particular brlA activation pathways that are independent of the fluG ortholog. Furthermore, the analyses of AorflbA disruptant and AorfadA dominant-active mutants implicated that AorFadA-mediated G-protein signaling suppresses vegetative growth of A. oryzae.

PV module mounting method and mounting assembly

Science.gov (United States)

Lenox, Carl J.S.; Johnson, Kurt M.

2013-04-23

A method for mounting PV modules to a deck includes selecting PV module layout pattern so that adjacent PV module edges are spaced apart. PV mounting and support assemblies are secured to the deck according to the layout pattern using fasteners extending into the deck. The PV modules are placed on the PV mounting and support assemblies. Retaining elements are located over and secured against the upper peripheral edge surfaces of the PV modules so to secure them to the deck with the peripheral edges of the PV modules spaced apart from the deck. In some examples a PV module mounting assembly, for use on a shingled deck, comprises flashing, a base mountable on the flashing, a deck-penetrating fastener engageable with the base and securable to the deck so to secure the flashing and the base to the shingled deck, and PV module mounting hardware securable to the base.

Numerical study of PV/T-SAHP system

Institute of Scientific and Technical Information of China (English)

Gang PEI; Jie JI; Ke-liang LIU; Han-feng HE; Ai-guo JIANG

2008-01-01

In order to utilize solar energy effectively and to achieve a higher electrical efficiency by limiting the operating temperature of the photovoltaic (PV) panel, a novel photovoltaic/thermal solar-assisted heat pump (PV/T-SAHP) system was proposed and constructed. The hybrid solar system generates electricity and thermal energy simultaneously. A distributed parameters model of the PV/T-SAHP system was developed and applied to analyze the system dynamic performance in terms of PV action, photothermal action and Rankine cycle processes. The simulation results indicated that the coefficient of performance (COP) of the proposed PV/T-SAHP can be much better than that of the conventional heat pump. Both PV-efficiency and photothermic efficiency have been improved considerably. The results also showed that the performance of this PV/T-SAHP system was strongly influenced by the evaporator area, tube pitch and tilt angle of the PV/T evaporator, which are the key factors in PV/T-SAHP system optimization and PV/T evaporator design.

Incorporation of Bacterial Blight Resistance Genes Into Lowland Rice Cultivar Through Marker-Assisted Backcross Breeding.

Science.gov (United States)

Pradhan, Sharat Kumar; Nayak, Deepak Kumar; Pandit, Elssa; Behera, Lambodar; Anandan, Annamalai; Mukherjee, Arup Kumar; Lenka, Srikanta; Barik, Durga Prasad

2016-07-01

Bacterial blight (BB) of rice caused by Xanthomonas oryzae pv. oryzae is a major disease of rice in many rice growing countries. Pyramided lines carrying two BB resistance gene combinations (Xa21+xa13 and Xa21+xa5) were developed in a lowland cultivar Jalmagna background through backcross breeding by integrating molecular markers. In each backcross generation, markers closely linked to the disease resistance genes were used to select plants possessing the target genes. Background selection was continued in those plants carrying resistant genes until BC(3) generation. Plants having the maximum contribution from the recurrent parent genome were selected in each generation and hybridized with the recipient parent. The BB-pyramided line having the maximum recipient parent genome recovery of 95% was selected among BC3F1 plants and selfed to isolate homozygous BC(3)F(2) plants with different combinations of BB resistance genes. Twenty pyramided lines with two resistance gene combinations exhibited high levels of tolerance against the BB pathogen. In order to confirm the resistance, the pyramided lines were inoculated with different X. oryzae pv. oryzae strains of Odisha for bioassay. The genotypes with combination of two BB resistance genes conferred high levels of resistance to the predominant X. oryzae pv. oryzae isolates prevalent in the region. The pyramided lines showed similarity with the recipient parent with respect to major agro-morphologic traits.

Design optimization of grid-connected PV inverters

DEFF Research Database (Denmark)

Koutroulis, Eftichios; Blaabjerg, Frede

2011-01-01

The DC/AC inverters are the key elements in grid-connected PV energy production systems. In this paper, new design optimization techniques focused on transformerless (very high efficiency) PV inverters are proposed. They have been developed based on an analysis of the deficiencies of the current......, state-of-the-art PV inverters design technology, which limits the amount of PV energy supplied into the electric grid. The influences of the electric grid regulations and standards and the PV array operational characteristics on the design of grid-connected PV inverters have also been considered....... The simulation results verify that the proposed optimization techniques enable the maximization of the PV energy injected into the electric grid by the optimized PV installation....

A case study of utility PV economics

International Nuclear Information System (INIS)

Wenger, H.; Hoff, T.; Osborn, D.E.

1997-01-01

This paper presents selected results from a detailed study of grid-connected photovoltaic (PV) applications within the service area of the Sacramento Municipal Utility District. The intent is to better understand the economics and markets for grid-connected PV systems in a utility setting. Research results include: Benefits calculations for utility-owned PV systems at transmission and distribution voltages; How the QuickScreen software package can help utilities investigate the viability of distributed PV; Energy production and capacity credit estimates for fixed and tracking PV systems; Economics and rate impacts of net metering residential PV systems; Market potential estimates for residential rooftop PV systems; and Viability and timing of grid-connected PV commercialization paths

Solar PV. Innovators talking; Zon PV. Innovators aan het woord

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-02-15

Qualitative studies have been conducted of the results of completed projects focused on energy innovation, spread over the seven themes of the top sector Energy: Energy saving in industry, Energy conservation in the built environment, Gas, Bio-energy, Smart grids, Offshore Wind, Solar PV. This provides insight into the follow-up activities and lessons of some EOS (Energy Research Subsidy) completed projects with the aim to inspire, connect and strengthen the TKIs (Topconsortia for Knowledge and Innovation) and individual companies and researchers working on energy innovation. This report concerns the research on solar PV [Dutch] Er is een kwalitatief onderzoek uitgevoerd naar de resultaten van afgeronde projecten gericht op energie-innovatie, verdeeld over de zeven thema's van de topsector Energie: Energiebesparing in de industrie; Energiebesparing in de gebouwde omgeving; Gas; Bio-energie; Smart grids; Wind op zee; Zon-pv. Daarmee wordt inzicht gegeven in de vervolgactiviteiten en lessen van een aantal afgesloten EOS-projecten (Energie Onderzoek Subsidie) met het oog op het inspireren, verbinden en versterken van de TKI's (Topconsortia voor Kennis en Innovatie) en individuele bedrijven en onderzoekers die werken aan energie-innovatie. Dit rapport betreft het onderzoek naar zon PV.

Solar PV. Innovators talking; Zon PV. Innovators aan het woord

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-02-15

Qualitative studies have been conducted of the results of completed projects focused on energy innovation, spread over the seven themes of the top sector Energy: Energy saving in industry, Energy conservation in the built environment, Gas, Bio-energy, Smart grids, Offshore Wind, Solar PV. This provides insight into the follow-up activities and lessons of some EOS (Energy Research Subsidy) completed projects with the aim to inspire, connect and strengthen the TKIs (Topconsortia for Knowledge and Innovation) and individual companies and researchers working on energy innovation. This report concerns the research on solar PV [Dutch] Er is een kwalitatief onderzoek uitgevoerd naar de resultaten van afgeronde projecten gericht op energie-innovatie, verdeeld over de zeven thema's van de topsector Energie: Energiebesparing in de industrie; Energiebesparing in de gebouwde omgeving; Gas; Bio-energie; Smart grids; Wind op zee; Zon-pv. Daarmee wordt inzicht gegeven in de vervolgactiviteiten en lessen van een aantal afgesloten EOS-projecten (Energie Onderzoek Subsidie) met het oog op het inspireren, verbinden en versterken van de TKI's (Topconsortia voor Kennis en Innovatie) en individuele bedrijven en onderzoekers die werken aan energie-innovatie. Dit rapport betreft het onderzoek naar zon PV.

Firefighter Safety for PV Systems

DEFF Research Database (Denmark)

Mathe, Laszlo; Sera, Dezso; Spataru, Sergiu

2015-01-01

An important and highly discussed safety issue for photovoltaic (PV) systems is that as long as the PV panels are illuminated, a high voltage is present at the PV string terminals and cables between the string and inverters that is independent of the state of the inverter's dc disconnection switch...

Dynamics of sugar content in vegetative organs of Syringa Genus representatives introduced into Steppe Zone

Directory of Open Access Journals (Sweden)

L. G. Dolgova

2005-12-01

Full Text Available Quantitative and qualitative contents of sugars in phases of growth and development in overground organs of species of Syringa L. genus were determined. It is shown a cryoprotective role of sugars in plants. Conclusions on resistance of plants under conditions of a steppe zone are made.

Grid integrated distributed PV (GridPV).

Energy Technology Data Exchange (ETDEWEB)

Reno, Matthew J.; Coogan, Kyle

2013-08-01

This manual provides the documentation of the MATLAB toolbox of functions for using OpenDSS to simulate the impact of solar energy on the distribution system. The majority of the functions are useful for interfacing OpenDSS and MATLAB, and they are of generic use for commanding OpenDSS from MATLAB and retrieving information from simulations. A set of functions is also included for modeling PV plant output and setting up the PV plant in the OpenDSS simulation. The toolbox contains functions for modeling the OpenDSS distribution feeder on satellite images with GPS coordinates. Finally, example simulations functions are included to show potential uses of the toolbox functions. Each function in the toolbox is documented with the function use syntax, full description, function input list, function output list, example use, and example output.

PV/T slates - Pilot project in Steinhausen; PV/T-Schiefer. Pilotprojekt Steinhausen

Energy Technology Data Exchange (ETDEWEB)

Kropf, S.

2003-07-01

This comprehensive, illustrated report for the Swiss Federal Office of Energy (SFOE) is one a series of five reports dealing with increasing the overall efficiency of photovoltaic (PV) installations by also using the heat collected by the dark-coloured PV panels. The work reported on addresses open questions on the use of the heat and its optimal use. This report deals with a ventilated PV-tile system (PV/T-Slates) mounted on a garden shed in Steinhausen, Switzerland. The installation provides power and heat to the main house. The report describes the construction and operation of this pilot project and the results of measurements made on its electrical and thermal performance. The results of measurements made are presented in detail in graphical form and compared with the results of simulation. Suggestions are made for the optimisation of the system. Figures are presented on energy production and energy flows in graphical form.

Photovoltaics: PV takes off the UK

International Nuclear Information System (INIS)

Noble, Ray; Gregory, Jenny

2000-01-01

Despite historical ups and downs, there is still ambition to bring increasingly efficient photovoltaic (PV) systems to the market. PV for major remote telecommunications systems is now an established part of the market, many mobile phone systems are powered by PV and there is potential for increased use of home solar systems, especially in developing countries. Over the past few years, building-integrated PV (BIPV) has been on the increase. In 1999, global production from PV exceeded 200 MW and the UK installed capacity was greater than 1 MW. BIPV is a fast growing market and its characteristics and advantages are discussed. PV installations at Nottingham University, Greenwich Pavilion, BP Amoco Sunbury, Baglan Bay, BP filling stations, and Sainsbury's are described

Bioconversion of Capsaicin by Aspergillus oryzae.

Science.gov (United States)

Lee, Minji; Cho, Jeong-Yong; Lee, Yu Geon; Lee, Hyoung Jae; Lim, Seong-Il; Park, So-Lim; Moon, Jae-Hak

2015-07-08

This study identified metabolites of capsaicin bioconverted by Aspergillus oryzae, which is generally used for mass production of gochujang prepared by fermenting red pepper powder in Korea. A. oryzae was incubated with capsaicin in potato dextrose broth. Capsaicin decreased depending on the incubation period, but new metabolites increased. Five capsaicin metabolites purified from the ethyl acetate fraction of the capsaicin culture were identified as N-vanillylcarbamoylbutyric acid, N-vanillyl-9-hydroxy-8-methyloctanamide, ω-hydroxycapsaicin, 8-methyl-N-vanillylcarbamoyl-6(E)-octenoic acid, and 2-methyl-N-vanillylcarbamoyl-6(Z)-octenoic acid by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The capsaicin metabolites in gochujang were confirmed and quantitated by selective multiple reaction monitoring detection after liquid chromatography electrospray ionization MS using the isolated compounds as external standards. On the basis of the structures of the capsaicin metabolites, it is proposed that capsaicin metabolites were converted by A. oryzae by ω-hydroxylation, alcohol oxidation, hydrogenation, isomerization, and α- and/or β-oxidation.

PV-BUK: Operating and maintenance costs of photovoltaic installations; PV-BUK - Betriebs- und Unterhaltskosten von PV-Anlagen - Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Stettler, S.; Toggweiler, P. [Enecolo AG, Moenchaltorf (Switzerland); Ruoss, D.; Schudel, P. [Envision, Lucerne (Switzerland); Kottmann, A.; Steinle, F. [BE Netz AG, Lucerne (Switzerland)

2008-03-15

This final report elaborated for the Swiss Federal Office of Energy (SFOE) takes a look at the results of a project carried out to determine the costs for facility management, to estimate future cost development and to propose activities for the further reduction of the operation and maintenance costs of photovoltaic systems. Information on the cost situation was collected by literature study, as well as in interviews and surveys with photovoltaic (PV) experts and the owners of PV installations. The discussion of the results at a workshop with about 20 Swiss PV experts is noted. The results are presented and discussed. These show that operating costs per kWh decrease with the size of the PV system. Figures are quoted. The major part of the costs are quoted as being those for spare parts, especially for the inverter. The authors are of the opinion that, in future, costs for facility management will further decrease, as they are partly linked to capital and insurance costs. Potential for optimisation is said to exist in several areas of facility management such as, for example, in system monitoring and fast reaction in the case of malfunctions.

Morphological and molecular characterization of fungal pathogen, Magnaphorthe oryzae

International Nuclear Information System (INIS)

Hasan, Nor’Aishah; Rafii, Mohd Y.; Rahim, Harun A.; Ali, Nusaibah Syd; Mazlan, Norida; Abdullah, Shamsiah

2016-01-01

Rice is arguably the most crucial food crops supplying quarter of calories intake. Fungal pathogen, Magnaphorthe oryzae promotes blast disease unconditionally to gramineous host including rice species. This disease spurred an outbreaks and constant threat to cereal production. Global rice yield declining almost 10-30% including Malaysia. As Magnaphorthe oryzae and its host is model in disease plant study, the rice blast pathosystem has been the subject of intense interest to overcome the importance of the disease to world agriculture. Therefore, in this study, our prime objective was to isolate samples of Magnaphorthe oryzae from diseased leaf obtained from MARDI Seberang Perai, Penang, Malaysia. Molecular identification was performed by sequences analysis from internal transcribed spacer (ITS) region of nuclear ribosomal RNA genes. Phylogenetic affiliation of the isolated samples were analyzed by comparing the ITS sequences with those deposited in the GenBank database. The sequence of the isolate demonstrated at least 99% nucleotide identity with the corresponding sequence in GenBank for Magnaphorthe oryzae. Morphological observed under microscope demonstrated that the structure of conidia followed similar characteristic as M. oryzae. Finding in this study provide useful information for breeding programs, epidemiology studies and improved disease management

Morphological and molecular characterization of fungal pathogen, Magnaphorthe oryzae

Science.gov (United States)

Hasan, Nor'Aishah; Rafii, Mohd Y.; Rahim, Harun A.; Ali, Nusaibah Syd; Mazlan, Norida; Abdullah, Shamsiah

2016-02-01

Rice is arguably the most crucial food crops supplying quarter of calories intake. Fungal pathogen, Magnaphorthe oryzae promotes blast disease unconditionally to gramineous host including rice species. This disease spurred an outbreaks and constant threat to cereal production. Global rice yield declining almost 10-30% including Malaysia. As Magnaphorthe oryzae and its host is model in disease plant study, the rice blast pathosystem has been the subject of intense interest to overcome the importance of the disease to world agriculture. Therefore, in this study, our prime objective was to isolate samples of Magnaphorthe oryzae from diseased leaf obtained from MARDI Seberang Perai, Penang, Malaysia. Molecular identification was performed by sequences analysis from internal transcribed spacer (ITS) region of nuclear ribosomal RNA genes. Phylogenetic affiliation of the isolated samples were analyzed by comparing the ITS sequences with those deposited in the GenBank database. The sequence of the isolate demonstrated at least 99% nucleotide identity with the corresponding sequence in GenBank for Magnaphorthe oryzae. Morphological observed under microscope demonstrated that the structure of conidia followed similar characteristic as M. oryzae. Finding in this study provide useful information for breeding programs, epidemiology studies and improved disease management.

Pseudomonas syringae evades host immunity by degrading flagellin monomers with alkaline protease AprA.

Science.gov (United States)

Pel, Michiel J C; van Dijken, Anja J H; Bardoel, Bart W; Seidl, Michael F; van der Ent, Sjoerd; van Strijp, Jos A G; Pieterse, Corné M J

2014-07-01

Bacterial flagellin molecules are strong inducers of innate immune responses in both mammals and plants. The opportunistic pathogen Pseudomonas aeruginosa secretes an alkaline protease called AprA that degrades flagellin monomers. Here, we show that AprA is widespread among a wide variety of bacterial species. In addition, we investigated the role of AprA in virulence of the bacterial plant pathogen P. syringae pv. tomato DC3000. The AprA-deficient DC3000 ΔaprA knockout mutant was significantly less virulent on both tomato and Arabidopsis thaliana. Moreover, infiltration of A. thaliana Col-0 leaves with DC3000 ΔaprA evoked a significantly higher level of expression of the defense-related genes FRK1 and PR-1 than did wild-type DC3000. In the flagellin receptor mutant fls2, pathogen virulence and defense-related gene activation did not differ between DC3000 and DC3000 ΔaprA. Together, these results suggest that AprA of DC3000 is important for evasion of recognition by the FLS2 receptor, allowing wild-type DC3000 to be more virulent on its host plant than AprA-deficient DC3000 ΔaprA. To provide further evidence for the role of DC3000 AprA in host immune evasion, we overexpressed the AprA inhibitory peptide AprI of DC3000 in A. thaliana to counteract the immune evasive capacity of DC3000 AprA. Ectopic expression of aprI in A. thaliana resulted in an enhanced level of resistance against wild-type DC3000, while the already elevated level of resistance against DC3000 ΔaprA remained unchanged. Together, these results indicate that evasion of host immunity by the alkaline protease AprA is important for full virulence of strain DC3000 and likely acts by preventing flagellin monomers from being recognized by its cognate immune receptor.

NH4+ protects tomato plants against Pseudomonas syringae by activation of systemic acquired acclimation.

Science.gov (United States)

Fernández-Crespo, Emma; Scalschi, Loredana; Llorens, Eugenio; García-Agustín, Pilar; Camañes, Gemma

2015-11-01

NH4 (+) nutrition provokes mild toxicity by enhancing H2O2 accumulation, which acts as a signal activating systemic acquired acclimation (SAA). Until now, induced resistance mechanisms in response to an abiotic stimulus and related to SAA were only reported for exposure to a subsequent abiotic stress. Herein, the first evidence is provided that this acclimation to an abiotic stimulus induces resistance to later pathogen infection, since NH4 (+) nutrition (N-NH4 (+))-induced resistance (NH4 (+)-IR) against Pseudomonas syringae pv tomato DC3000 (Pst) in tomato plants was demonstrated. N-NH4 (+) plants displayed basal H2O2, abscisic acid (ABA), and putrescine (Put) accumulation. H2O2 accumulation acted as a signal to induce ABA-dependent signalling pathways required to prevent NH4 (+) toxicity. This acclimatory event provoked an increase in resistance against later pathogen infection. N-NH4 (+) plants displayed basal stomatal closure produced by H2O2 derived from enhanced CuAO and rboh1 activity that may reduce the entry of bacteria into the mesophyll, diminishing the disease symptoms as well as strongly inducing the oxidative burst upon Pst infection, favouring NH4 (+)-IR. Experiments with inhibitors of Put accumulation and the ABA-deficient mutant flacca demonstrated that Put and ABA downstream signalling pathways are required to complete NH4 (+)-IR. The metabolic profile revealed that infected N-NH4 (+) plants showed greater ferulic acid accumulation compared with control plants. Although classical salicylic acid (SA)-dependent responses against biotrophic pathogens were not found, the important role of Put in the resistance of tomato against Pst was demonstrated. Moreover, this work revealed the cross-talk between abiotic stress acclimation (NH4 (+) nutrition) and resistance to subsequent Pst infection. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Transposable element distribution, abundance and role in genome size variation in the genus Oryza.

Science.gov (United States)

Zuccolo, Andrea; Sebastian, Aswathy; Talag, Jayson; Yu, Yeisoo; Kim, HyeRan; Collura, Kristi; Kudrna, Dave; Wing, Rod A

2007-08-29

The genus Oryza is composed of 10 distinct genome types, 6 diploid and 4 polyploid, and includes the world's most important food crop - rice (Oryza sativa [AA]). Genome size variation in the Oryza is more than 3-fold and ranges from 357 Mbp in Oryza glaberrima [AA] to 1283 Mbp in the polyploid Oryza ridleyi [HHJJ]. Because repetitive elements are known to play a significant role in genome size variation, we constructed random sheared small insert genomic libraries from 12 representative Oryza species and conducted a comprehensive study of the repetitive element composition, distribution and phylogeny in this genus. Particular attention was paid to the role played by the most important classes of transposable elements (Long Terminal Repeats Retrotransposons, Long interspersed Nuclear Elements, helitrons, DNA transposable elements) in shaping these genomes and in their contributing to genome size variation. We identified the elements primarily responsible for the most strikingly genome size variation in Oryza. We demonstrated how Long Terminal Repeat retrotransposons belonging to the same families have proliferated to very different extents in various species. We also showed that the pool of Long Terminal Repeat Retrotransposons is substantially conserved and ubiquitous throughout the Oryza and so its origin is ancient and its existence predates the speciation events that originated the genus. Finally we described the peculiar behavior of repeats in the species Oryza coarctata [HHKK] whose placement in the Oryza genus is controversial. Long Terminal Repeat retrotransposons are the major component of the Oryza genomes analyzed and, along with polyploidization, are the most important contributors to the genome size variation across the Oryza genus. Two families of Ty3-gypsy elements (RIRE2 and Atlantys) account for a significant portion of the genome size variations present in the Oryza genus.

ORF Alignment: NC_004578 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available NC_004578 gi|28871348 >1dlwA 1 114 25 138 3e-25 ... ref|NP_793967.1| protozoan/cyanob...acterial globin family protein [Pseudomonas ... syringae pv. tomato str. DC3000] gb|AAO57662.1| ... protozoa

Optimization of PV-based energy production by dynamic PV-panel/inverter configuration

DEFF Research Database (Denmark)

Paasch, Kasper; Nymand, Morten; Haase, Frerk

This paper investigates the possible increase in annual energy production of a PV system with more than one MPPT (maximum power point tracker) input channels under Nordic illumination conditions, in case a concept of dynamic switching of the PV panels is used at the inputs of the inverters....

Browse Title Index

African Journals Online (AJOL)

Items 451 - 500 of 11090 ... Vol 10, No 78 (2011), A study on reverse osmosis permeating treatment ... of resistance to streptomycin in Xanthomonas oryzae pv. oryzae, Abstract PDF ... suitable for Medicago truncatula leaf proteome, Abstract PDF.

The levels of nitrite and nitrate, proline and protein profiles in tomato plants infected with pseudomonas syringae

International Nuclear Information System (INIS)

Berber, I.; Onlu, H.

2012-01-01

In this study, the contents of nitrite-nitrate and free L-proline, and pathogenesis-related (PR) proteins in tomato plants following inoculation with Pseudomonas syringae pv. tomato strain were examined. The results of the nitrite and nitrate indicated that there was a reduction in the levels of nitrate in the infected tomato plants through 1-8 study days, compared with the healthy plants. On the other hands, when the nitrite amounts increased in the first and second days, the nitrite concentrations reduced in infected plants at subsequent time periods, compared with uninfected plants. The accumulation of free proline increased in the infected plants, according to control plants. The whole-cell protein profiles displayed that the levels of the protein bands of molecular masses 204.6 kDa and 69.9 kDa significantly increased in infected and uninfected plants during 2-10 study days. In additionally, in the quantities of the protein bands of molecular weights 90.3 and 79.4 kDa were observed an increase in the infected and healthy plants after the fourth day. However, the protein band of molecular weight 54.3 kDa was visible only in uninfected plants for the fourth and eighth days. Finally, the study suggest that there were the sophisticate relationships among the proline accumulation, the conversion of nitrate to nitrite and the induction of PR protein genes in the regulation of defense mechanisms toward microbial invaders. Our results also indicated that the increases in nitrite and proline contents might be useful indicator for the response toward pathogen attacks. (author)

PV integration into a CSP plant

Science.gov (United States)

Carvajal, Javier López; Barea, Jose M.; Barragan, Jose; Ortega, Carlos

2017-06-01

This paper describes a preliminary techno-economic analysis of the integration of a PV plant into an optimized Parabolic Trough Plant in order to reduce the online consumptions and thus, increase the net electricity injected into the grid. The idea is to assess the feasibility of such project and see what configuration would be the optimal. An extra effort has been made in terms of modelling as the analysis has to be done to the integrated CSP + PV plant instead of analyzing them independently. Two different technologies have been considered for the PV plant, fix and one-axis tracking. Additionally three different scenarios have been considered for the CSP plant auxiliary consumptions as they are essential for determining the optimal PV plant (the higher the auxiliary consumption the higher the optimal PV plant). As could be expected, the results for all cases with PV show an improvement in terms of electricity generation and also in terms of LCOE with respect to the CSP plant. Such improvement is slightly higher with tracking technology for this specific study. Although this exercise has been done to an already designed CSP plant (so only the PV plant had to be optimized), the methodology could be applied for the optimization of an integrated CSP + PV plant during the design phase.

Projecting of PV facades in consideration of PV-specific operating conditions; Besonderheiten bei der Projektierung von Photovoltaik-Fassadenanlagen

Energy Technology Data Exchange (ETDEWEB)

Decker, B.; Grimmig, B.; Mencke, D. [Institut fuer Solarenergieforschung GmbH Hameln/Emmerthal (ISFH), Emmerthal (Germany). Gruppe Photovoltaik-Systeme; Stellbogen, D. [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Stuttgart (Germany). Fachgebiet Photovoltaische Anlagentechnik

1998-02-01

PV facades can provide several additional functions such as weather protection, thermal insulation, daylighting or sun protection. On the other hand, specific operating conditions for PV facades must be taken into account when selecting components and designing the system. Depending on ventilation conditions, there is a large range of maximum module temperatures. South-oriented PV facades receive about 30% less yearly irradiation than an optimally inclined PV generator, hence reflection losses are approximately 4% higher. The maximum of yearly irradiation lies only in the 400-600 W/m{sup 2} range. Surrounding buildings and/or vegetation can impair performance of the PV-facades. For a south-oriented PV facade an annual yield in the range of 470-560 kwh/kW{sub p}.a has been prodicted which was verified by operating results of eight PV facades. (orig.) [Deutsch] Photovoltaik (PV) Fassaden ermoeglichen neben der Stromerzeugung zusaetzliche Funktionen wie Wetterschutz bzw. Waermedaemmung des Gebaeudes oder Tageslichtnutzung bzw. Sonnenschutz der Innenraeume. Allerdings muessen fassadenspezifische Betriebsbedingungen, bei der Komponentenauswahl und Systemauslegung beruecksichtigt werden. Unterschiedliche Hinterlueftungsbedingungen fuehren zu einer grossen Bandbreite der maximalen Modultemperatur. PV-Suedfassaden empfangen etwa 30% weniger Jahreseinstrahlung als ein optimal geneigter PV-Generator. Die Haelfte der jaehrlichen Einstrahlung trifft mit Einfallswinkeln groesser 50 auf die vertikal angeordneten Module wodurch die Reflexionsverluste um ca. 4% hoeher sind. Das Maximum der Jahreseinstrahlung liegt nur um 400-600 W/m{sup 2} und erreicht selten Werte ueber 800 W/m{sup 2}. Umliegende Gebaeude oder Vegetation koennen zu Teilabschattungen des Generators fuehren. Fuer eine vertikale PV-Suedfassade wird ein Jahresenergieertrag in Hoehe von 470-560 kWh/kW{sub p}.a prognostiziert, der anhand der Betriebsergebnisse von acht PV-Fassadenanlagen verifiziert werden konnte

Interaction between Pyricularia oryzae, four Helminthosporium species and Curvularia lunata in rice leaves

Directory of Open Access Journals (Sweden)

M. Bahous

2003-08-01

Full Text Available The interaction between six fungal parasites of rice: Pyricularia oryzae, Helminthosporium oryzae, H. sativum, H. spiciferum, H. australiensis and Curvularia lunata was studied quantitatively by a modified plant ecology technique known as the de Wit replacement series. Each fungus was inoculated alone or in combination with one of the other five fungi in various proportions into rice plants under experimental conditions. Leaves developing lesions were harvested and incubated in a moist chamber. The yield of each fungus was its conidial production on the rice leaves. The artificial inoculations indicated that interactions between the pathogens in the mixture could be beneficial, antagonistic, or null. Interspecific interaction (i.e. antagonism occurred in the majority of paired combinations (H. oryzae + P. oryzae; H. sativum + H. spiciferum, H. australiensis, C. lunata or P. oryzae; H. australiensis + H. spiciferum, C. lunata or P. oryzae; and P. oryzae + C. lunata. The relative yield total (RYT lines were significantly lower than the expected value, which is 1. The RYT lines were concave upward, revealing a beneficial effect of one or both pathogens on the other, when H. oryzae was in mixture with H. sativum or H. spiciferum. A null effect between fungi occurred in four combinations (H. oryzae + H. australiensis or C. lunata; H. spiciferum + C. lunata; and P. oryzae + H. spiciferum showing that with these combinations inter- and intraspecific competitions were equal in intensity. Thus, the de Wit replacement series technique indicated that it was possible to quantify the interaction between all the pathogenic fungi tested.

A Mathematical model to investigate quorum sensing regulation and its heterogenecity in pseudomonas syringae on leaves

Science.gov (United States)

The bacterium Pseudomonas syringae is a plant-pathogen, which through quorum sensing (QS), controls virulence. In this paper, by means of mathematical modeling, we investigate QS of this bacterium when living on leaf surfaces. We extend an existing stochastic model for the formation of Pseudomonas s...

The case for better PV forecasting

DEFF Research Database (Denmark)

Alet, Pierre-Jean; Efthymiou, Venizelos; Graditi, Giorgio

2016-01-01

Rising levels of PV penetration mean increasingly sophisticated forecasting technologies are needed to maintain grid stability and maximise the economic value of PV systems. The Grid Integration working group of the European Technology and Innovation Platform – Photovoltaics (ETIP PV) shares the ...

Development of a GIS Tool for High Precision PV Degradation Monitoring and Supervision: Feasibility Analysis in Large and Small PV Plants

Directory of Open Access Journals (Sweden)

Miguel de Simón-Martín

2017-06-01

Full Text Available It is well known that working photovoltaic (PV plants show several maintenance needs due to wiring and module degradation, mismatches, dust, and PV cell defects and faults. There are a wide range of theoretical studies as well as some laboratory tests that show how these circumstances may affect the PV production. Thus, it is mandatory to evaluate the whole PV plant performance and, then, its payback time, profitability, and environmental impact or carbon footprint. However, very few studies include a systematic procedure to quantify and supervise the real degradation effects and fault impacts on the field. In this paper, the authors first conducted a brief review of the most frequent PV faults and the degradation that can be found under real conditions of operation of PV plants. Then, they proposed and developed an innovative Geographic Information System (GIS application to locate and supervise them. The designed tool was applied to both a large PV plant of 108 kWp and a small PV plant of 9 kWp installed on a home rooftop. For the large PV plant, 24 strings of PV modules were modelized and introduced into the GIS application and every module in the power plant was studied including voltage, current, power, series and parallel resistances, fill factor, normalized PV curve to standard test conditions (STC, thermography and visual analysis. For the small PV installation three strings of PV panels were studied identically. It must be noted that PV modules in this case included power optimizers. The precision of the study enabled the researchers to locate and supervise up to a third part of every PV cell in the system, which can be adequately georeferenced. The developed tool allows both the researchers and the investors to increase control of the PV plant performance, to lead to better planning of maintenance actuations, and to evaluate several PV module replacement strategies in a preventive maintenance program. The PV faults found include hot

Adiabatic Rearrangement of Hollow PV Towers

Directory of Open Access Journals (Sweden)

Eric A Hendricks

2010-10-01

Full Text Available Diabatic heating from deep moist convection in the hurricane eyewall produces a towering annular structure of elevated potential vorticity (PV. This structure has been referred to as a hollow PV tower. The sign reversal of the radial gradient of PV satisfies the Charney-Stern necessary condition for combined barotropic-baroclinic instability. For thin enough annular structures, small perturbations grow exponentially, extract energy from the mean flow, and lead to hollow tower breakdown, with significant vortex structural and intensity change. The three-dimensional adiabatic rearrangements of two prototypical hurricane-like hollow PV towers (one thick and one thin are examined in an idealized framework. For both hollow towers, dynamic instability causes air parcels with high PV to be mixed into the eye preferentially at lower levels, where unstable PV wave growth rates are the largest. Little or no mixing is found to occur at upper levels. The mixing at lower and middle levels is most rapid for the breakdown of the thin hollow tower, consistent with previous barotropic results. For both hollow towers, this advective rearrangement of PV affects the tropical cyclone structure and intensity in a number of ways. First, the minimum central pressure and maximum azimuthal mean velocity simultaneously decrease, consistent with previous barotropic results. Secondly, isosurfaces of absolute angular momentum preferentially shift inward at low levels, implying an adiabatic mechanism by which hurricane eyewall tilt can form. Thirdly, a PV bridge, similar to that previously found in full-physics hurricane simulations, develops as a result of mixing at the isentropic levels where unstable PV waves grow most rapidly. Finally, the balanced mass field resulting from the PV rearrangement is warmer in the eye between 900 and 700 hPa. The location of this warming is consistent with observed warm anomalies in the eye, indicating that in certain instances the hurricane

Secretome of Aspergillus oryzae in Shaoxing rice wine koji.

Science.gov (United States)

Zhang, Bo; Guan, Zheng-Bing; Cao, Yu; Xie, Guang-Fa; Lu, Jian

2012-04-16

Shaoxing rice wine is the most famous and representative Chinese rice wine. Aspergillus oryzae SU16 is used in the manufacture of koji, the Shaoxing rice wine starter culture. In the current study, a comprehensive analysis of the secretome profile of A. oryzae SU16 in Shaoxing rice wine koji was performed for the first time. The proteomic analysis for the identification of the secretory proteins was done using two-dimensional electrophoresis combined with matrix-assisted laser desorption/ionization-tandem time of flight mass spectrometry based on the annotated A. oryzae genome sequence. A total of 41 unique proteins were identified from the secretome. These proteins included 17 extracellular proteins following the classical secretory pathway, and 10 extracellular proteins putatively secreted by the non-classical secretory pathway. The present secretome profile greatly differed from previous reports on A. oryzae growing in other solid-state nutrient sources. Several new secretory or putative secretory proteins were also found. These proteomic data will significantly aid the advancement of research on the secretome of A. oryzae, especially in solid-state cultures, and in elucidating the production process mechanism of Shaoxing rice wine koji. The findings may promote the technological development and innovation of the Shaoxing rice wine industry. Copyright © 2012 Elsevier B.V. All rights reserved.

Parallel experimental study of a novel super-thin thermal absorber based photovoltaic/thermal (PV/T system against conventional photovoltaic (PV system

Directory of Open Access Journals (Sweden)

Peng Xu

2015-11-01

Full Text Available Photovoltaic (PV semiconductor degrades in performance due to temperature rise. A super thin-conductive thermal absorber is therefore developed to regulate the PV working temperature by retrofitting the existing PV panel into the photovoltaic/thermal (PV/T panel. This article presented the parallel comparative investigation of the two different systems through both laboratory and field experiments. The laboratory evaluation consisted of one PV panel and one PV/T panel respectively while the overall field system involved 15 stand-alone PV panels and 15 retrofitted PV/T panels. The laboratory testing results demonstrated the PV/T panel could achieve the electrical efficiency of about 16.8% (relatively 5% improvement comparing with the stand-alone PV panel, and yield an extra amount of heat with thermal efficiency of nearly 65%. The field testing results indicated that the hybrid PV/T panel could enhance the electrical return of PV panels by nearly 3.5%, and increase the overall energy output by nearly 324.3%. Further opportunities and challenges were then discussed from aspects of different PV/T stakeholders to accelerate the development. It is expected that such technology could become a significant solution to yield more electricity, offset heating load freely and reduce carbon footprint in contemporary energy environment.

Chitin nanofiber elucidates the elicitor activity of polymeric chitin in plants

Directory of Open Access Journals (Sweden)

Mayumi eEgusa

2015-12-01

Full Text Available Chitin, an N-acetyl-D-glucosamine polymer, is a component of fungal cell walls and a microbe/pathogen-associated molecular pattern that elicits plant defense responses. As polymeric chitin is difficult to handle due to its insolubility in water, many studies on chitin-induced immune responses have used water-soluble low-molecular weight chitin instead. Thus, it is unclear if polymeric chitin can induce resistance. Here, we examined the elicitor activity of chitin nanofiber (CNF of submicron thickness prepared from polymeric chitin. CNF showed a high dispersing ability in water and induced both reactive oxygen species (ROS production and chitin-induced defense-related gene expression in Arabidopsis thaliana seedlings. The Arabidopsis chitin elicitor receptor kinase 1 (Atcerk1 mutant, which is impaired in chitin perception, also failed to respond to CNF. CNF exposure triggered ROS generation in suspension-cultured cells from Oryza sativa. Furthermore, pre-treatment of Arabidopsis leaves with CNF effectively reduced pathogen infection by both the fungus Alternaria brassicicola and the bacterium Pseudomonas syringae pv. tomato DC3000. These results demonstrate that CNF has elicitor activity and will help define the role of polymeric chitin in plant immune responses.

Clarification of Taxonomic Status within the Pseudomonas syringae Species Group Based on a Phylogenomic Analysis

Directory of Open Access Journals (Sweden)

Margarita Gomila

2017-12-01

Full Text Available The Pseudomonas syringae phylogenetic group comprises 15 recognized bacterial species and more than 60 pathovars. The classification and identification of strains is relevant for practical reasons but also for understanding the epidemiology and ecology of this group of plant pathogenic bacteria. Genome-based taxonomic analyses have been introduced recently to clarify the taxonomy of the whole genus. A set of 139 draft and complete genome sequences of strains belonging to all species of the P. syringae group available in public databases were analyzed, together with the genomes of closely related species used as outgroups. Comparative genomics based on the genome sequences of the species type strains in the group allowed the delineation of phylogenomic species and demonstrated that a high proportion of strains included in the study are misclassified. Furthermore, representatives of at least 7 putative novel species were detected. It was also confirmed that P. ficuserectae, P. meliae, and P. savastanoi are later synonyms of P. amygdali and that “P. coronafaciens” should be revived as a nomenspecies.

Role of N-terminal 28-amino-acid region of Rhizopus oryzae lipase in directing proteins to secretory pathway of Aspergillus oryzae.

Science.gov (United States)

Hama, Shinji; Tamalampudi, Sriappareddy; Shindo, Naoki; Numata, Takao; Yamaji, Hideki; Fukuda, Hideki; Kondo, Akihiko

2008-07-01

To develop a new approach for improving heterologous protein production in Aspergillus oryzae, we focused on the functional role of the N-terminal region of Rhizopus oryzae lipase (ROL). Several N-terminal deletion variants of ROL were expressed in A. oryzae. Interestingly, a segment of 28 amino acids from the C-terminal region of the propeptide (N28) was found to be critical for secretion of ROL into the culture medium. To further investigate the role of N28, the ROL secretory process was visualized in vivo using ROL-green fluorescent protein (GFP) fusion proteins. In cells producing ROL with N28, fluorescence observations showed that the fusion proteins are transported through endoplasmic reticulum (ER), Golgi, and cell wall, which is one of the typical secretory processes in a eukaryotic cell. Because the expression of the mature ROL-GFP fusion protein induced fluorescence accumulation without its translocation into the ER, N28 is considered to play a crucial role in protein transport. When N28 was inserted between the secretion signal and GFP, fluorescence observations showed that GFP, which is originally a cytoplasmic protein, was efficiently translocated into the ER of A. oryzae, resulting in an enhanced secretion of mature GFP after proteolytic cleavage of N28. These findings suggest that N28 facilitates protein translocation into ER and can be a promising candidate for improving heterologous protein production in A. oryzae.

The market for photovoltaic (PV) technology

International Nuclear Information System (INIS)

Frantzis, L.; Vejtasa, K.M.

1993-01-01

This paper describes a study that was intended to provide the Electric Power Research Institute (EPRI) with a market analysis for photovoltaic (PV) technologies under development by EPRI and others. The analysis was to focus on markets and factors leading to significant incremental growth for PV demand, large enough to support more efficient scale PV manufacturing capacity. EPRI anticipates that PV ultimately could provide grid-connected power, however, the 1995--2010 market dynamics are uncertain. The specific objectives of this study, therefore, were to: determine what major future domestic US markets for PV technologies will emerge and provide enough volume to support significant improvements in manufacturing costs through manufacturing economies of scale; provide insight on what is needed to gain acceptance of PV technologies for electric power generation in those major markets; provide insight on when investments in demonstration and manufacturing facilities should be made and what is needed to be successful in each element of the business that these markets could support (e.g., technology development, manufacturing, sales, installation, and service); and provide key insights on the requirements for commercial success of PV in the utility sector

Antibiotic effective against Saccharomyces produced by Aspergillus oryzae

Energy Technology Data Exchange (ETDEWEB)

Nakata, H.; Sakai, T.; Takeda, M.; Tsukahara, T.

1980-01-01

Production of an antibiotic effective against Saccharomyces cerevisiae was investigated in 85 strains of Aspergillus oryzae, isolated from commercial koji molds. The antibiotic was produced by 50 strains. A. oryzae was cultivated at 30 degrees for 15-20 days in koji extract. The crude preparation was obtained by precipitation from the culture filtrate with EtOH, MeOH, or Me/sub 2/CO.

Production of the natural iron chelator deferriferrichrysin from Aspergillus oryzae and evaluation as a novel food-grade antioxidant.

Science.gov (United States)

Todokoro, Takehiko; Fukuda, Katsuharu; Matsumura, Kengo; Irie, Motoko; Hata, Yoji

2016-07-01

Deferriferrichrysin (Dfcy) is a siderophore found in foods fermented by Aspergillus oryzae and is a promising candidate for an antioxidant food additive because of its high binding constant toward iron. However, the Dfcy concentration is typically low in foods and cultures. We optimised culture conditions to improve Dfcy production to 2800 mg L(-1) from 22.5 mg L(-1) under typical conditions. Then, we evaluated the potential of Dfcy as a food additive by measuring its safety, stability, and antioxidant activity. Dfcy was sufficiently stable that over 90% remained after pasteurisation at 63 °C for 30 min at pH 3-11, or after sterilisation at 120 °C for 4 min at pH 4-6. Dfcy showed high antioxidant activity in an oil-in-water model, where inhibition of lipid oxidation was measured by peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) assays. Dfcy decreased PV and TBARS by 83% and 75%, respectively. Antioxidant activity of Dfcy was equal to or higher than that of the synthetic chelator EDTA. Our study provides the first practical method for production of Dfcy. Dfcy can be a novel food-grade antioxidant and the first natural alternative to the synthesised iron chelator EDTA. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Antagonism of rice phylloplane fungi against Cercospora oryzae

Science.gov (United States)

Mardani, A.; Hadiwiyono

2018-03-01

Narrow brown leaf spot (NBLS) caused by Cercospora oryzae Miyake is one of the important obstacle in rice cultivation that can decrease the productivity up to 40%. It has been known well that some phylloplane fungi are antagonistic to some leaf diseases. Phylloplane fungi of rice however haven’t been studied much and poorly understood as biological control agent of rice pathogen such C. oryzae. The research aimed to study the antagonism of some phylloplane fungi of rice against C. oryzae. At least 14 isolates of phylloplane fungi were collected which consisted of six pathogenic and eight nonpathogenic variants. All of nonpathogenic isolates were antagonistic against C. oryzae both in vitro and only one isolate could not inhibit the infection of the pathogen in vivo. Some isolates were identified as Aspergillus, Mucor, Penicillium, Fusarium, and Trichoderma. The isolate of Mucor and Fusarium could inhibit the highest growth of pathogen on potato dextrose medium that were at 36.0% and 35.5% respectively. Whereas on artificial inoculation on rice, some isolates such Penicillium and Fusarium could inhibit most effectively and were significantly different to Mencozeb application with dosage 5g L-1.

Reduction of hexavalent chromium by Rhizopus Oryzae | Sukumar ...

African Journals Online (AJOL)

The ability of Rhizopus oryzae to reduce Cr6+ was evaluated in batch microcosms. The optimum pH of R. oryzae growth was between 6.0 and 7.0. The maximum chromium reduction efficiency of 91.15% and biomass growth was achieved at a pH of 7, temperature of 37°C, with an initial Cr6+ concentration of 400 ppm and ...

First report of wheat blast caused by magnaporthe oryzae pathotype triticum in Bangladesh

Science.gov (United States)

Wheat blast or ‘brusone’, caused by the ascomycetous fungus Magnaporthe oryzae B.C. Couch (synonym Pyricularia oryzae Cavara), was first identified in 1985 in Brazil. M. oryzae is composed of a range of morphologically identical but genetically different host-specific pathotypes that are specialized...

Global transcriptional responses of Pseudomonas syringae DC3000 to changes in iron bioavailability in vitro

Directory of Open Access Journals (Sweden)

Rutzke Michael

2008-12-01

Full Text Available Abstract Background Pseudomonas syringae pv tomato DC3000 (DC3000 is a Gram-negative model plant pathogen that is found in a wide variety of environments. To survive in these diverse conditions it must sense and respond to various environmental cues. One micronutrient required for most forms of life is iron. Bioavailable iron has been shown to be an important global regulator for many bacteria where it not only regulates a wide variety of genes involved in general cell physiology but also virulence determinants. In this study we used microarrays to study differential gene regulation in DC3000 in response to changes in levels of cell-associated iron. Results DC3000 cultures were grown under highly controlled conditions and analyzed after the addition of iron citrate or sodium citrate to the media. In the cultures supplemented with iron, we found that cell-associated iron increased rapidly while culture densities were not significantly different over 4 hours when compared to cultures with sodium citrate added. Microarray analysis of samples taken from before and after the addition of either sodium citrate or iron citrate identified 386 differentially regulated genes with high statistical confidence. Differentially regulated genes were clustered based on expression patterns observed between comparison of samples taken at different time points and with different supplements. This analysis grouped genes associated with the same regulatory motifs and/or had similar putative or known function. Conclusion This study shows iron is rapidly taken up from the medium by iron-depleted DC3000 cultures and that bioavailable iron is a global cue for the expression of iron transport, storage, and known virulence factors in DC3000. Furthermore approximately 34% of the differentially regulated genes are associated with one of four regulatory motifs for Fur, PvdS, HrpL, or RpoD.

Rice (Oryza) hemoglobins

Science.gov (United States)

Hemoglobins (Hbs) corresponding to non-symbiotic (nsHb) and truncated (tHb) Hbs have been identified in rice (Oryza). This review discusses the major findings from the current studies on rice Hbs. At the molecular level, a family of the nshb genes, consisting of hb1, hb2, hb3, hb4 and hb5, and a sin...

Experimental investigation of PV modules recycling; PV module recycle no jikkenteki kento

Energy Technology Data Exchange (ETDEWEB)

Unagida, H; Kurokawa, K [Tokyo University of Agriculture and Technology, Tokyo (Japan); Sakuta, K; Otani, K; Murata, K [Electrotechnical Laboratory, Tsukuba (Japan)

1997-11-25

Recycling, cost/energy analysis and recovery experiment were made on crystalline silicon PV modules with EVA(ethylene vinyl acetate)-laminated structure. The life of modules is dependent not on performance deterioration of PV cells themselves but on yellowing or poor transmittance of EVA caused by ultraviolet ray, and disconnection between cells by thermal stress. Recovery is carried out in 3 stages of cell, wafer and material. Recovery in the stages of cell and wafer results in considerable reduction of energy and cost. The recovery experiment was carried out using PV module samples prepared by cutting the modules into 25times15mm pieces after removing Al frames from the used modules, peeling back sheets and cutting off EVA. Since a nitric acid process at 70-80degC can dissolve EVA effectively, it is promising for reuse of surface glass and PV cells as they are. This process is also carried out under a condition around room temperature and pressure, contributing to cost reduction and energy saving for recycling. Generation of harmful NOx is only a problem to be solved. 2 refs., 6 figs., 1 tab.

Rhamnolipids elicit defense responses and induce disease resistance against biotrophic, hemibiotrophic, and necrotrophic pathogens that require different signaling pathways in Arabidopsis and highlight a central role for salicylic acid.

Science.gov (United States)

Sanchez, Lisa; Courteaux, Barbara; Hubert, Jane; Kauffmann, Serge; Renault, Jean-Hugues; Clément, Christophe; Baillieul, Fabienne; Dorey, Stéphan

2012-11-01

Plant resistance to phytopathogenic microorganisms mainly relies on the activation of an innate immune response usually launched after recognition by the plant cells of microbe-associated molecular patterns. The plant hormones, salicylic acid (SA), jasmonic acid, and ethylene have emerged as key players in the signaling networks involved in plant immunity. Rhamnolipids (RLs) are glycolipids produced by bacteria and are involved in surface motility and biofilm development. Here we report that RLs trigger an immune response in Arabidopsis (Arabidopsis thaliana) characterized by signaling molecules accumulation and defense gene activation. This immune response participates to resistance against the hemibiotrophic bacterium Pseudomonas syringae pv tomato, the biotrophic oomycete Hyaloperonospora arabidopsidis, and the necrotrophic fungus Botrytis cinerea. We show that RL-mediated resistance involves different signaling pathways that depend on the type of pathogen. Ethylene is involved in RL-induced resistance to H. arabidopsidis and to P. syringae pv tomato whereas jasmonic acid is essential for the resistance to B. cinerea. SA participates to the restriction of all pathogens. We also show evidence that SA-dependent plant defenses are potentiated by RLs following challenge by B. cinerea or P. syringae pv tomato. These results highlight a central role for SA in RL-mediated resistance. In addition to the activation of plant defense responses, antimicrobial properties of RLs are thought to participate in the protection against the fungus and the oomycete. Our data highlight the intricate mechanisms involved in plant protection triggered by a new type of molecule that can be perceived by plant cells and that can also act directly onto pathogens.

A Practical Irradiance Model for Bifacial PV Modules

Energy Technology Data Exchange (ETDEWEB)

Marion, Bill; MacAlpine, Sara; Deline, Chris; Asgharzadeh, Amir; Toor, Fatima; Riley, Daniel; Stein, Joshua; Hansen, Clifford

2017-06-21

A model, suitable for a row or multiple rows of photovoltaic (PV) modules, is presented for estimating the backside irradiance for bifacial PV modules. The model, which includes the effects of shading by the PV rows, is based on the use of configuration factors to determine the fraction of a source of irradiance that is received by the backside of the PV module. Backside irradiances are modeled along the sloped height of the PV module, but assumed not to vary along the length of the PV row. The backside irradiances are corrected for angle-of-incidence losses and may be added to the front side irradiance to determine the total irradiance resource for the PV cell. Model results are compared with the measured backside irradiances for NREL and Sandia PV systems, and with results when using ray tracing software.

Adaptation of bacteriophages to new hosts through overcoming the interspecific barrier

Directory of Open Access Journals (Sweden)

Е. N. Andriychuk

2016-10-01

Full Text Available Four wild type phage isolates were tested on P. syringae isolated from potato tuber samples collected in the Kiev and Cherkasy regions of Ukraine. The isolated phages formed clear plaques and had a virion size of 2 to 12 nm. Electron microscopy showed that the phages were of similar size and structure and consisted of isometric particles with long tails characteristic of the Podoviridae family. The effectiveness of phage culturing on bacteria different from the original host was also studied on two phytopathogenic strains of Pseudomonas savastanoi pv. рhaseolicola 4013 and P. syringae pv. tabaci 223. However, no stable isolates could be extracted from P. savastanoi pv. phaseolicola as the plages became inactive after a few passages on the bacterial culture. In order to overcome this, the phages were first cultured on P. syringae pv. tabaci before being transferred to P. savastanoi pv. рhaseolicola. The titers obtained were compared with phage titers from the original host bacteria. Thus, it was determined that the changes occuring in phages after their transfer to the Pseudomonas strain 4013 were irreversible. The changes were evaluated by comparing the effectiveness of phage culturing after a cycle of passages on strains 4013 and 223 where the phages were adapted to strain 4013 after being cultured on strain 223. Additionally, the effectiveness of phage culturing on strain 223 was also determined. The change in the effectiveness of phage culturing for the entire phage range suggests the presence of a defensive system in bacteria when the phages were transferred from strain 223 to strain 4013. The irreversibility of the changes occuring in phages was also tested and it was determined that phages 223/4 and 7591/2 adapt to original hosts and swiftly restore their original titers. Phage 7591/1, however, showed titers that were lower than the ones obtained from the original host culture. The testing of the irreversibility of changes in phages

Antagonistic activity of Bacillus subtilis SB1 and its biocontrol effect on tomato bacterial wilt

Science.gov (United States)

A potential biocontrol agent of bacterial wilt, Bacillus subtilis SB1, isolated from tomato roots, showed a broad-spectrum of antimicrobial activity in in vitro experiments. It inhibited the growth of many plant pathogens, including Ralstonia solanacearum, Xanthomonas oryzae pv. oryzae, Fusarium ox...

Power of design - the future of building-integrated PV

International Nuclear Information System (INIS)

Abbate, Cinzia

2001-01-01

This paper discusses strategies to make building integrated photovoltaic (PV) systems more acceptable and to allow PV material to compete with conventional construction material. The history of developments in building integration and difficulties encountered by architects wishing to use PV products are explored, and the Dutch Amersfoot project in Utrecht involving a new suburb of 501 house covered with PV panels is described. Questions raised regarding architectural integration of PV systems, and PV systems and the construction market are discussed. The Italian PV programme, financial and political constraints, and the positioning of PV on existing structures are reported

Microbial contaminants of cultured Hibiscus cannabinus and Telfaria ...

African Journals Online (AJOL)

Nine microbial contaminants comprising of five bacteria and four fungi species were isolated from Hibiscus cannabinus and Telfaria occidentalis cultured tissues. The rate of occurrence of bacteria isolates was higher than that of fungi. The bacterial isolates includes Pseudomonas syringae pv phaseolicoli, Bacillus ...

Dicty_cDB: Contig-U06475-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available hensi glutathione S-... 33 4.0 AY754335_1( AY754335 |pid:none) Anopheles stephensi ..... 33 4.0 AE016853_1995( AE016853 |pid:none) Pseudomonas syringae pv. tomato... 33 4.0 AY573189_1( AY573189 |pid:none) Anopheles step

PSCAD Modules Representing PV Generator

Energy Technology Data Exchange (ETDEWEB)

Muljadi, E.; Singh, M.; Gevorgian, V.

2013-08-01

Photovoltaic power plants (PVPs) have been growing in size, and the installation time is very short. With the cost of photovoltaic (PV) panels dropping in recent years, it can be predicted that in the next 10 years the contribution of PVPs to the total number of renewable energy power plants will grow significantly. In this project, the National Renewable Energy Laboratory (NREL) developed a dynamic modeling of the modules to be used as building blocks to develop simulation models of single PV arrays, expanded to include Maximum Power Point Tracker (MPPT), expanded to include PV inverter, or expanded to cover an entire PVP. The focus of the investigation and complexity of the simulation determines the components that must be included in the simulation. The development of the PV inverter was covered in detail, including the control diagrams. Both the current-regulated voltage source inverter and the current-regulated current source inverter were developed in PSCAD. Various operations of the PV inverters were simulated under normal and abnormal conditions. Symmetrical and unsymmetrical faults were simulated, presented, and discussed. Both the three-phase analysis and the symmetrical component analysis were included to clarify the understanding of unsymmetrical faults. The dynamic model validation was based on the testing data provided by SCE. Testing was conducted at SCE with the focus on the grid interface behavior of the PV inverter under different faults and disturbances. The dynamic model validation covers both the symmetrical and unsymmetrical faults.

OnToPV - a virtual guidance through the PV-plant ''Solardach New Munich Trade Fair''; OnToPV - eine virtuelle Fuehrung druch die PV-Anlage ''Solardach Neue Messe Muenchen''

Energy Technology Data Exchange (ETDEWEB)

Stich, C.; Becker, G.; Zehner, M. [Fachhochschule Muenchen (Germany). Fachbereich Elektrotechnik; Giesler, B. [Shell Solar GmbH, Muenchen (Germany); Weber, W.; Flade, F. [Solarenergiefoerderverein Bayern e.V., Muenchen (Germany)

2003-07-01

OnToPV is the project of an online tour guide through the PV-plant of the new Munich trade fair. The first focs was to provide an interactive circuit of a PV-plant. Within a virtual tour different areas of the plant should be made accessible over the internet. For this purpose a three-dimensional, multimedia guidance was developed for the PV-plant of the new Munich trade fair with informative diagrams, *.pdf-files and retrievable video-files. In such a way interested internet-users could experience with minimum system requirements, local- and time-independently the PV-plant in its structure and components and could receive different background informations in addition. From the view of the plant operators such an internet project serves on the one hand as an additional source of information where questions could be referred to and on the other hand as sort of advertisement for the technology and the PV-system. In addition the attractiveness of the internet appearance of the plant operator rises and the public awareness of such projects could increase. Seen from the user perspective - such an internet project gives private or business users the possibility to inform themselves interactively, purposefully and with the possibility to move through the plant on their own. Users could utilize the guidance through the plant without overcoming far geographical distances, saving time and money. Perhaps this source of information helps awaking a larger consciousness for renewable energies. The result OnToPV showed the various possibilities offered by projects of this kind in the internet. Ideas of possible extensions as for example the integration of current PV-plant operational data or of a virtual learning platform illustrate the perspectives of the project. Virtual guidance of this kind for various types of power plants are conceivable. (orig.)

PV monitoring at Jubilee Campus - Nottingham University

Energy Technology Data Exchange (ETDEWEB)

Riffat, S.B.; Gan, G.

2002-07-01

This report summarises the results of a project monitoring the efficiency of photovoltaic (PV) modules integrated in the roofs of atria to meet the energy consumption needs of ventilation fans in the academic buildings at the Jubilee Campus of the University of Nottingham. Details are given of the instrumentation of one atrium to allow the monitoring the effectiveness of the ventilation in cooling the PV arrays integrated in the atrium roof, the economic analysis of the benefit of cooling the PV system, and the use of computational fluid dynamics (CFD) modelling to predict the performance of the atrium. The design of the PV system, the calculated system efficiency, the high cost of atrium integrated PV power supplies, the periodic failure of the inverters, and the overheating of the PV array and the atrium space in the summer are discussed.

Natural variation in partial resistance to Pseudomonas syringae is controlled by two major QTLs in Arabidopsis thaliana.

Directory of Open Access Journals (Sweden)

Laure Perchepied

Full Text Available BACKGROUND: Low-level, partial resistance is pre-eminent in natural populations, however, the mechanisms underlying this form of resistance are still poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we used the model pathosystem Pseudomonas syringae pv. tomato DC3000 (Pst - Arabidopsis thaliana to study the genetic basis of this form of resistance. Phenotypic analysis of a set of Arabidopsis accessions, based on evaluation of in planta pathogen growth revealed extensive quantitative variation for partial resistance to Pst. It allowed choosing a recombinant inbred line (RIL population derived from a cross between the accessions Bayreuth and Shahdara for quantitative genetic analysis. Experiments performed under two different environmental conditions led to the detection of two major and two minor quantitative trait loci (QTLs governing partial resistance to Pst and called PRP-Ps1 to PRP-Ps4. The two major QTLs, PRP-Ps1 and PRP-Ps2, were confirmed in near isogenic lines (NILs, following the heterogeneous inbred families (HIFs strategy. Analysis of marker gene expression using these HIFs indicated a negative correlation between the induced amount of transcripts of SA-dependent genes PR1, ICS and PR5, and the in planta bacterial growth in the HIF segregating at PRP-Ps2 locus, suggesting an implication of PRP-Ps2 in the activation of SA dependent responses. CONCLUSIONS/SIGNIFICANCE: These results show that variation in partial resistance to Pst in Arabidopsis is governed by relatively few loci, and the validation of two major loci opens the way for their fine mapping and their cloning, which will improve our understanding of the molecular mechanisms underlying partial resistance.

PV-DSM: Policy actions to speed commercialization

International Nuclear Information System (INIS)

Hoff, T.; Wenger, H.J.; Keane, D.M.

1993-01-01

Pacific Gas and Electric Company (PG ampersand E) recently applied Demand-Side Management (DSM) evaluation techniques to photovoltaic (PV) technology to develop the concept of photovoltaics as a Demand-Side Management option (PV-DSM). The analysis demonstrated that PV-DSM has the potential to be economically attractive. Two criticisms in response to that analysis are that the assumptions of 25 year financing and a 25 year evaluation period are unrealistic. This paper responds to those criticisms and documents the mathematical relationships to calculate the value of PV-DSM from a customer's perspective. It demonstrates how regulatory and government agencies could implement policies to resolve both issues and speed PV commercialization

Could abiotic stress tolerance in wild relatives of rice be used to improve Oryza sativa?

Science.gov (United States)

Atwell, Brian J; Wang, Han; Scafaro, Andrew P

2014-02-01

Oryza sativa and Oryza glaberrima have been selected to acquire and partition resources efficiently as part of the process of domestication. However, genetic diversity in cultivated rice is limited compared to wild Oryza species, in spite of 120,000 genotypes being held in gene banks. By contrast, there is untapped diversity in the more than 20 wild species of Oryza, some having been collected from just a few coastal locations (e.g. Oryza schlechteri), while others are widely distributed (e.g. Oryza nivara and Oryza rufipogon). The extent of DNA sequence diversity and phenotypic variation is still being established in wild Oryza, with genetic barriers suggesting a vast range of morphologies and function even within species, such as has been demonstrated for Oryza meridionalis. With increasing climate variability and attempts to make more marginal land arable, abiotic and biotic stresses will be managed over the coming decades by tapping into the genetic diversity of wild relatives of O. sativa. To help create a more targeted approach to sourcing wild rice germplasm for abiotic stress tolerance, we have created a climate distribution map by plotting the natural occurrence of all Oryza species against corresponding temperature and moisture data. We then discuss interspecific variation in phenotype and its significance for rice, followed by a discussion of ways to integrate germplasm from wild relatives into domesticated rice. Crown Copyright © 2013. Published by Elsevier Ireland Ltd. All rights reserved.

The possibility of developing hybrid PV/T solar system

Science.gov (United States)

Dobrnjac, M.; Zivkovic, P.; Babic, V.

2017-05-01

An alternative and cost-effective solution to developing integrated PV system is to use hybrid photovoltaic/thermal (PV/T) solar system. The temperature of PV modules increases due to the absorbed solar radiation that is not converted into electricity, causing a decrease in their efficiency. In hybrid PV/T solar systems the reduction of PV module temperature can be combined with a useful fluid heating. In this paper we present the possibility of developing a new hybrid PV/T solar system. Hybrid PV/T system can provide electrical and thermal energy, thus achieving a higher energy conversion rate of the absorbed solar radiation. We developed PV/T prototype consisted of commercial PV module and thermal panel with our original solution of aluminium absorber with special geometric shapes. The main advantages of our combined PV/T system are: removing of heat from the PV panel; extending the lifetime of photovoltaic cells; excess of the removing heat from PV part is used to heat the fluid in the thermal part of the panel; the possibility of using on the roof and facade constructions because less weight.

Survey of the transcriptome of Aspergillus oryzae via massively parallel mRNA sequencing.

Science.gov (United States)

Wang, Bin; Guo, Guangwu; Wang, Chao; Lin, Ying; Wang, Xiaoning; Zhao, Mouming; Guo, Yong; He, Minghui; Zhang, Yong; Pan, Li

2010-08-01

Aspergillus oryzae, an important filamentous fungus used in food fermentation and the enzyme industry, has been shown through genome sequencing and various other tools to have prominent features in its genomic composition. However, the functional complexity of the A. oryzae transcriptome has not yet been fully elucidated. Here, we applied direct high-throughput paired-end RNA-sequencing (RNA-Seq) to the transcriptome of A. oryzae under four different culture conditions. With the high resolution and sensitivity afforded by RNA-Seq, we were able to identify a substantial number of novel transcripts, new exons, untranslated regions, alternative upstream initiation codons and upstream open reading frames, which provide remarkable insight into the A. oryzae transcriptome. We were also able to assess the alternative mRNA isoforms in A. oryzae and found a large number of genes undergoing alternative splicing. Many genes and pathways that might be involved in higher levels of protein production in solid-state culture than in liquid culture were identified by comparing gene expression levels between different cultures. Our analysis indicated that the transcriptome of A. oryzae is much more complex than previously anticipated, and these results may provide a blueprint for further study of the A. oryzae transcriptome.

Enhanced accumulation of U(VI) by Aspergillus oryzae mutant generated by dielectric barrier discharge air plasma

International Nuclear Information System (INIS)

Wencheng Song; North China Electric Power University, Beijing; Xiangxue Wang; Soochow University, Suzhou; Wen Tao; Hongqing Wang; Tasawar Hayat; Quaid-I-Azam University, Islamabad; Xiangke Wang; Soochow University, Suzhou; King Abdulaziz University, Jeddah

2016-01-01

Aspergillus oryzae was isolated from radionuclides' contaminated soils, and dielectric barrier discharge plasma was used to mutate A. oryzae to improve bioremediation capability of U(VI) pollution. The maximum accumulation capacities of U(VI) on mutated A.oryzae was 627.4 mg/g at T = 298 K and pH = 5.5, which was approximately twice than that of raw A.oryzae. XPS analysis indicated that U(VI) accumulation on mutated A. oryzae was largely attributable to nitrogen- and oxygen-containing functional groups on fungal mycelia. The mutated A. oryzae can be harnessed as bioremediation agents for radionuclides pollution. (author)

PV Obelisk - Information system with photovoltaics

International Nuclear Information System (INIS)

Ruoss, D.; Rasmussen, J.

2004-01-01

This final report for the Swiss Federal Office of Energy (SFOE) describes the development of an information system powered by a photovoltaic (PV) array. As an innovative approach, the 'PV-Obelisk' project is the combination of PV with a multi-functional pillar made of natural stone in an aesthetic way. The PV modules serve both as a power supply and as a design element. Two initial prototypes led the way to a third, optimised consumer configuration that was planned to guarantee maximum user frequency. Test operation in front of the 'Heidiland' motor way restaurant confirmed the market analyses made and delivered the expected results. The product, whose three LCD displays are updated via a mobile telephony-based text-message system, proved its technical reliability and showed a high user frequency. Because of the high overall energy consumption, PV power can only partially contribute to the energy supply needed. Various compromises in the technical and aesthetic areas are discussed that were made for the sake of product acceptance in the market. The range of application areas for such a 'PV Obelisk' are discussed and the need for early co-ordination with urban planners is stressed

The new NOZ-PV: Market-oriented

International Nuclear Information System (INIS)

Ter Horst, E.

1995-01-01

In the proposal for the new National Research Program for Photovoltaics (NOZ-PV) 1995-1999 the focus is on four subjects: solar cell technology, the industrial support, the stimulation of autonomous, favorable applications and markets for PV, and the realization of a training program PV in the Built Areas. The program will be carried out as a market-oriented program. 1 tab., 2 figs

Enhanced production of fructosyltransferase in Aspergillus oryzae by genome shuffling.

Science.gov (United States)

Wang, Shenghai; Duan, Mengjie; Liu, Yalan; Fan, Sen; Lin, Xiaoshan; Zhang, Yi

2017-03-01

To breed Aspergillus oryzae strains with high fructosyltransferase (FTase) activity using intraspecific protoplast fusion via genome-shuffling. A candidate library was developed using UV/LiCl of the conidia of A. oryzae SBB201. By screening for enzyme activity and cell biomass, two mutants (UV-11 and UV-76) were chosen for protoplast fusion and subsequent genome shuffling. After three rounds of genome recombination, a fusion mutant RIII-7 was obtained. Its FTase activity was 180 U g -1 , approximately double that of the original strain, and RIII-7 was genetically stable. In fermentation culture, FTase activity of the genome-shuffled strain reached a maximum of 353 U g -1 using substrate-feeding method, and this value was approximately 3.4-times higher than that of the original strain A. oryzae SBB201. Intraspecific protoplast fusion of A. oryzae significantly enhanced FTase activity and generated a potentially useful strain for industrial production.

Role of antioxidant scavenging enzymes and extracellular ...

African Journals Online (AJOL)

In the present work, we studied the role of antioxidant scavenging enzymes of plant pathogenic bacteria: catalase, ascorbate peroxidase and a virulence factor; extracelluar polysaccharide production in determining the virulence of Xanthomonas oryzae pv. oryzae (Xoo) isolates and its differential reaction to rice cultivars.

Annual technical report. PV domestic field trial

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-07-01

This report describes progress at the first five sites of the UK photovoltaic (PV) domestic field trial. All five sites are generating electricity, but one has not yet been commissioned and two sites are not yet monitoring performance. The BedZED development has roof-mounted PV modules and PV cells installed in sealed double-glazing. Solar slates/tiles have been installed at the Laing Homes development in Montagu Road, where the designer has sought to minimise the visual impact of the PV system on the roofs. At Hunters Moon, PV modules have been retrofitted and some unforeseen difficulties have arisen. PV is an integral part of the roof design at the state-of-the-art low energy development by Integer Houses at Greenfields. Corn Croft uses a British mounting system to facilitate integration of the modules flush with the roof. Installation issues and the progress of the trial are discussed.

PV in a sports arena; PV im Hexenkessel

Energy Technology Data Exchange (ETDEWEB)

Hoeche, B.

2008-05-19

The German soccer club Werder Bremen is reconstructing its stadium. Apart from higher spectator comfort and a better atmosphere, there will also be PV systems on the roof and external walls of the arena. (orig.)

The PV market - Past, present, and future

International Nuclear Information System (INIS)

Hammond, B.

1992-01-01

This paper forecasts the photovoltaic (PV) market growth for the 1900's. Ten years of PV history are reviewed and used to establish market trends in terms of average selling price (ASP) and kilowatts shipped by market segment. The market is segmented into indoor consumer, stand-alone, and grid-connected applications. Indoor consumer presently represents a saturated market and is fairly predictable. The stand-alone market (i.e. not connected to the utility grid) is fairly stable and predictable. The utility PV market, however, is highly dependent on a number of market factors such as the cost of conventional energy, the cost of PV systems, utility acceptance of PV, and regulatory controls. Government and institutional regulations, environmental issues, OPEC and Middle East politics will have the greatest impact on the cost of conventional fuels. Private and federal investment in PV technology development could have a significant impact on the cost of PV systems. Forecasts are provided through the year 2000 for indoor consumer, stand-alone, and utility markets. PV has unique attributes which make it a desirable source of energy in specific applications. It is a renewable source of energy, non-polluting, very reliable, predictable, low maintenance, modular, and has a very low operating cost. The energy source (sunlight) is distributed around the globe. Its limitations are high initial cost, no inherent energy storage, and low energy density

Optimal Design of Modern Transformerless PV Inverter Topologies

DEFF Research Database (Denmark)

Saridakis, Stefanos; Koutroulis, Eftichios; Blaabjerg, Frede

2013-01-01

the operational lifetime period of the PV installation, is also considered in the optimization process. According to the results of the proposed design method, different optimal values of the PV inverter design variables are derived for each PV inverter topology and installation site. The H5, H6, neutral point...... clamped, active-neutral point clamped and conergy-NPC PV inverters designed using the proposed optimization process feature lower levelized cost of generated electricity and lifetime cost, longer mean time between failures and inject more PV-generated energy into the electric grid than their nonoptimized......The design optimization of H5, H6, neutral point clamped, active-neutral point clamped, and conergy-NPC transformerless photovoltaic (PV) inverters is presented in this paper. The components reliability in terms of the corresponding malfunctions, affecting the PV inverter maintenance cost during...

Random Mutagenesis of the Aspergillus oryzae Genome Results in Fungal Antibacterial Activity

Directory of Open Access Journals (Sweden)

Cory A. Leonard

2013-01-01

Full Text Available Multidrug-resistant bacteria cause severe infections in hospitals and communities. Development of new drugs to combat resistant microorganisms is needed. Natural products of microbial origin are the source of most currently available antibiotics. We hypothesized that random mutagenesis of Aspergillus oryzae would result in secretion of antibacterial compounds. To address this hypothesis, we developed a screen to identify individual A. oryzae mutants that inhibit the growth of Methicillin-resistant Staphylococcus aureus (MRSA in vitro. To randomly generate A. oryzae mutant strains, spores were treated with ethyl methanesulfonate (EMS. Over 3000 EMS-treated A. oryzae cultures were tested in the screen, and one isolate, CAL220, exhibited altered morphology and antibacterial activity. Culture supernatant from this isolate showed antibacterial activity against Methicillin-sensitive Staphylococcus aureus, MRSA, and Pseudomonas aeruginosa, but not Klebsiella pneumonia or Proteus vulgaris. The results of this study support our hypothesis and suggest that the screen used is sufficient and appropriate to detect secreted antibacterial fungal compounds resulting from mutagenesis of A. oryzae. Because the genome of A. oryzae has been sequenced and systems are available for genetic transformation of this organism, targeted as well as random mutations may be introduced to facilitate the discovery of novel antibacterial compounds using this system.

Random Mutagenesis of the Aspergillus oryzae Genome Results in Fungal Antibacterial Activity

Science.gov (United States)

Leonard, Cory A.; Brown, Stacy D.; Hayman, J. Russell

2013-01-01

Multidrug-resistant bacteria cause severe infections in hospitals and communities. Development of new drugs to combat resistant microorganisms is needed. Natural products of microbial origin are the source of most currently available antibiotics. We hypothesized that random mutagenesis of Aspergillus oryzae would result in secretion of antibacterial compounds. To address this hypothesis, we developed a screen to identify individual A. oryzae mutants that inhibit the growth of Methicillin-resistant Staphylococcus aureus (MRSA) in vitro. To randomly generate A. oryzae mutant strains, spores were treated with ethyl methanesulfonate (EMS). Over 3000 EMS-treated A. oryzae cultures were tested in the screen, and one isolate, CAL220, exhibited altered morphology and antibacterial activity. Culture supernatant from this isolate showed antibacterial activity against Methicillin-sensitive Staphylococcus aureus, MRSA, and Pseudomonas aeruginosa, but not Klebsiella pneumonia or Proteus vulgaris. The results of this study support our hypothesis and suggest that the screen used is sufficient and appropriate to detect secreted antibacterial fungal compounds resulting from mutagenesis of A. oryzae. Because the genome of A. oryzae has been sequenced and systems are available for genetic transformation of this organism, targeted as well as random mutations may be introduced to facilitate the discovery of novel antibacterial compounds using this system. PMID:23983696

Random Mutagenesis of the Aspergillus oryzae Genome Results in Fungal Antibacterial Activity.

Science.gov (United States)

Leonard, Cory A; Brown, Stacy D; Hayman, J Russell

2013-01-01

Multidrug-resistant bacteria cause severe infections in hospitals and communities. Development of new drugs to combat resistant microorganisms is needed. Natural products of microbial origin are the source of most currently available antibiotics. We hypothesized that random mutagenesis of Aspergillus oryzae would result in secretion of antibacterial compounds. To address this hypothesis, we developed a screen to identify individual A. oryzae mutants that inhibit the growth of Methicillin-resistant Staphylococcus aureus (MRSA) in vitro. To randomly generate A. oryzae mutant strains, spores were treated with ethyl methanesulfonate (EMS). Over 3000 EMS-treated A. oryzae cultures were tested in the screen, and one isolate, CAL220, exhibited altered morphology and antibacterial activity. Culture supernatant from this isolate showed antibacterial activity against Methicillin-sensitive Staphylococcus aureus, MRSA, and Pseudomonas aeruginosa, but not Klebsiella pneumonia or Proteus vulgaris. The results of this study support our hypothesis and suggest that the screen used is sufficient and appropriate to detect secreted antibacterial fungal compounds resulting from mutagenesis of A. oryzae. Because the genome of A. oryzae has been sequenced and systems are available for genetic transformation of this organism, targeted as well as random mutations may be introduced to facilitate the discovery of novel antibacterial compounds using this system.

PV-HYBRID and MINI-GRID. Proceedings

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-07-01

Within the 3rd European Conference at the Centre de Congres in Aix en Provence (France) between 11th and 12th May, 2006, the following lessons were held: (1) Small electric networks: European drivers and projects for the integration of RES and DG into the electricity grids of the future (Manuel Sanchez-Jimenez); (2) PV hybrid system within mini grids - IEA PVPS programme (Meuch Konraf); (3) Renewables for the developing world (Alvaro Ponce Plaza); (4) Rural electicity supply using photovoltaic / - Diesel hybrid systems: Attractive for investors in the renewable energy sector? (Andreas Hahn); (5) Economic analysis of stand-alone and grid-connected photovoltaic systems under current tariff structure of Taiwan (Yaw-Juen Wang); (6) Using wind-PV-diesel hybrid system for electrification of remote village in Western Libya (N.M. Kreama); (7) Venezuela's renewable energy program for small towns and rural areas ''Sembrando Luz'' (Jorge Torres); (8) AeroSmart5, the professional, sysem-compatible small-scale wind energy converter will be tested in field tests (Fabian Jochem); (9) Lifetime, test procedures and recommendations for optimal operating strategies for lead-acid-batteries in renewable energy systems - A survey on results from European projects from the 5th framework programme (Rudi Kaiser); (10) Prototype of a reversible fuel cell system for autonomous power supplies (Tom Smolinska); (11) Interconnection management in microgrids (Michel Vandenbergh); (12) Control strategy for a small-scale stand-alone power system based on renewable energy and hydrogen (Harald Miland); (13) Standard renewable electricity supply for people in rural areas - mini-grids in western provinces of China (Michael Wollny); (14) The Brava island a ''100% renewable energy'' project (Jean-Christian Marcel); (15) Breakthrough to a new era of PV-hybrid systems with the help of standardised components communication? (Michael Mueller); (16) Standardized

The biosynthesis, structure and gelatinization properties of starches from wild and cultivated African rice species (Oryza barthii and Oryza glaberrima).

Science.gov (United States)

Wang, Kai; Wambugu, Peterson W; Zhang, Bin; Wu, Alex Chi; Henry, Robert J; Gilbert, Robert G

2015-09-20

The molecular structure and gelatinization properties of starches from domesticated African rice (Oryza glaberrima) and its wild progenitor (Oryza barthii) are determined and comparison made with Asian domesticated rice (Oryza sativa), the commonest commercial rice. This suggests possible enzymatic processes contributing to the unique traits of the African varieties. These have similar starch structures, including smaller amylose molecules, but larger amounts of amylose chains across the whole amylose chain-length distribution, and higher amylose contents, than O. sativa. They also show a higher proportion of two- and three-lamellae spanning amylopectin branch chains (degree of polymerization 34-100) than O. sativa, which contributes to their higher gelatinization temperatures. Fitting amylopectin chain-length distribution with a biosynthesis-based mathematical model suggests that the reason for this difference might be because O. glaberrima and O. barthii have more active SSIIIa and/or less active SBEIIb enzymes. Copyright © 2015 Elsevier Ltd. All rights reserved.

PENGUJIAN BEBERAPA JENIS INSEKTISIDA NABATI TERHADAP KUTU BERAS (Sitophilus oryzae L

Directory of Open Access Journals (Sweden)

Muhammad Isnaini

2015-08-01

Full Text Available The purpose of this study first to determine whether or not capable of  natural insecticides to kill Sitophilus oryzae L and to determine effective of  natural insecticides to kill Sitophilus oryzae L. This type of research is an experimental research with quantitative descriptive and The data collection techniques used is the observation and documentation. The data analyzed with ANOVA analysis techniques followed by BJND test. Based on the comparison of the calculated F value contained in the ANOVA analysis is greater than the F table , either at the significant level of 5 % and the 1% significance level (79.57 > 2.67 / 4:43. Thus stated that H1 accepted and rejected H0. The results showed that the first, the natural insecticide able to kill Sitophilus oryzae L and mortality rate highest in Cymbopogon citratus treatment that is equal to 13.2 with the total percentage of mortality of 66%, both effective plant-based insecticides to kill Sitophilus oryzae L that leaves just Cymbopogon citratus (66% and Morinda citrifolia L (60%.The conclusions obtained from this study: First, some kind of  natural insecticide able to kill Sitophilus oryzae L,  second based on the results of the ANOVA analysis of all types of insecticides to kill Sitophilus oryzae L effectively, but if effectiveness was seen by the number of mortality up to 50 % or more, then just Cymbopogon citratus and Morinda citrifolia L.

Environmental impact of PV cell waste scenario.

Science.gov (United States)

Bogacka, M; Pikoń, K; Landrat, M

2017-12-01

Rapid growth of the volume of waste from PV cells is expected in the following years. The problem of its utilization seems to be the most important issue for future waste management systems. The environmental impacts of the PV recycling scenario are presented in the manuscript. The analysis is based on the LCA approach and the average data available in specialized databases for silicon standard PV cell is used. The functional unit includes parameters like: efficiency, composition, surface area. The discussion on the environmental impact change due to the location of the PV production and waste processing plants is presented in the manuscript. Additionally, the discussion on the environmental effect of substituting different energy resources with PV cells is presented in the manuscript. The analysis of the PV cell life cycle scenario presented in the article was performed using the SIMA PRO software and data from Ecoinvent 3.0 database together with additional data obtained from other sources. Copyright © 2017 Elsevier Ltd. All rights reserved.

Novel laboratory mouse papillomavirus (MusPV) infection.

Science.gov (United States)

Ingle, A; Ghim, S; Joh, J; Chepkoech, I; Bennett Jenson, A; Sundberg, J P

2011-03-01

Most papillomaviruses (PVs) are oncogenic. There are at least 100 different human PVs and 65 nonhuman vertebrate hosts, including wild rodents, which have species-specific PV infections. Florid papillomatosis arose in a colony of NMRI-Foxn1(nu)/Foxn1(nu) (nude) mice at the Advanced Centre for Treatment Research and Education in Cancer in India. Lesions appeared at the mucocutaneous junctions of the nose and mouth. Histologically, lesions were classical papillomas with epidermal hyperplasia on thin fibrovascular stalks in a verrucous pattern. Koilocytotic cells were observed in the stratum granulosum of the papillomatous lesions. Immunohistochemically, these abnormal cells were positive for PV group-specific antigens. With transmission electron microscopy, virus particles were observed in crystalline intranuclear inclusions within keratinocytes. The presence of a mouse PV, designated MusPV, was confirmed by amplification of PV DNA with degenerative primers specific for PVs. This report is the first of a PV and its related disease in laboratory mice.

PV Working with Industry, 2nd Quarter, 2000

Energy Technology Data Exchange (ETDEWEB)

Poole, L.; Moon, S.

2000-06-29

NREL PV Working With Industry is a quarterly newsletter devoted to the research, development, and deployment performed by NREL staff in concert with their industry and university partners. The Second Quarter, 2000, issue is titled ``Our Shared PV Future''. It contains a review of several important PV-related meetings held in the prior three months: the NCPV Program Review, the 16 European PV Conference, and year-2000 Earth Day activities in Denver, CO. The editorialist is Paul Maycock, Publisher of PV News.

Evidence for biotrophic lifestyle and biocontrol potential of dark septate endophyte Harpophora oryzae to rice blast disease.

Directory of Open Access Journals (Sweden)

Zhen-Zhu Su

Full Text Available The mutualism pattern of the dark septate endophyte (DSE Harpophora oryzae in rice roots and its biocontrol potential in rice blast disease caused by Magnaporthe oryzae were investigated. Fluorescent protein-expressing H. oryzae was used to monitor the colonization pattern. Hyphae invaded from the epidermis to the inner cortex, but not into the root stele. Fungal colonization increased with root tissue maturation, showing no colonization in the meristematic zone, slight colonization in the elongation zone, and heavy colonization in the differentiation zone. H. oryzae adopted a biotrophic lifestyle in roots accompanied by programmed cell death. Real-time PCR facilitated the accurate quantification of fungal growth and the respective plant response. The biocontrol potential of H. oryzae was visualized by inoculation with eGFP-tagged M. oryzae in rice. H. oryzae protected rice from M. oryzae root invasion by the accumulation of H2O2 and elevated antioxidative capacity. H. oryzae also induced systemic resistance against rice blast. This systemic resistance was mediated by the OsWRKY45-dependent salicylic acid (SA signaling pathway, as indicated by the strongly upregulated expression of OsWRKY45. The colonization pattern of H. oryzae was consistent with the typical characteristics of DSEs. H. oryzae enhanced local resistance by reactive oxygen species (ROS and high antioxidative level and induced OsWRKY45-dependent SA-mediated systemic resistance against rice blast.

Grid Integrated Distributed PV (GridPV) Version 2.

Energy Technology Data Exchange (ETDEWEB)

Reno, Matthew J.; Coogan, Kyle

2014-12-01

This manual provides the documentation of the MATLAB toolbox of functions for using OpenDSS to simulate the impact of solar energy on the distribution system. The majority of the functio ns are useful for interfacing OpenDSS and MATLAB, and they are of generic use for commanding OpenDSS from MATLAB and retrieving information from simulations. A set of functions is also included for modeling PV plant output and setting up the PV plant in th e OpenDSS simulation. The toolbox contains functions for modeling the OpenDSS distribution feeder on satellite images with GPS coordinates. Finally, example simulations functions are included to show potential uses of the toolbox functions. Each function i n the toolbox is documented with the function use syntax, full description, function input list, function output list, example use, and example output.

EFEITO ANTIBIÓTICO DO PRÓPOLIS SOBRE BACTÉRIAS FITOPATOGÊNICAS

OpenAIRE

BIANCHINI, L.; BEDENDO, I.P.

1998-01-01

O efeito antibiótico de extrato aquoso de própolis, em várias concentrações, foi avaliado para cinco espécies de bactérias fitopatogênicas. Agrobacterium tumefaciens, Clavibacter michiganensis subsp. michiganensis e Xanthomonas axonopodis pv. phaseoli foram completamente inibidas em meio de cultura contendo 10% de extrato de própolis. Erwinia chrysanthemi foi parcialmente inibida, enquanto Pseudomonas syringae pv. tabaci se mostrou insensível ao extrato, desenvolvendo colônias idênticas àquel...

A walk on the wild side: Oryza species as source for rice abiotic stress tolerance.

Science.gov (United States)

Menguer, Paloma Koprovski; Sperotto, Raul Antonio; Ricachenevsky, Felipe Klein

2017-01-01

Oryza sativa, the common cultivated rice, is one of the most important crops for human consumption, but production is increasingly threatened by abiotic stresses. Although many efforts have resulted in breeding rice cultivars that are relatively tolerant to their local environments, climate changes and population increase are expected to soon call for new, fast generation of stress tolerant rice germplasm, and current within-species rice diversity might not be enough to overcome such needs. The Oryza genus contains other 23 wild species, with only Oryza glaberrima being also domesticated. Rice domestication was performed with a narrow genetic diversity, and the other Oryza species are a virtually untapped genetic resource for rice stress tolerance improvement. Here we review the origin of domesticated Oryza sativa from wild progenitors, the ecological and genomic diversity of the Oryza genus, and the stress tolerance variation observed for wild Oryza species, including the genetic basis underlying the tolerance mechanisms found. The summary provided here is important to indicate how we should move forward to unlock the full potential of these germplasms for rice improvement.

Flexible packaging for PV modules

Science.gov (United States)

Dhere, Neelkanth G.

2008-08-01

Economic, flexible packages that provide needed level of protection to organic and some other PV cells over >25-years have not yet been developed. However, flexible packaging is essential in niche large-scale applications. Typical configuration used in flexible photovoltaic (PV) module packaging is transparent frontsheet/encapsulant/PV cells/flexible substrate. Besides flexibility of various components, the solder bonds should also be flexible and resistant to fatigue due to cyclic loading. Flexible front sheets should provide optical transparency, mechanical protection, scratch resistance, dielectric isolation, water resistance, UV stability and adhesion to encapsulant. Examples are Tefzel, Tedlar and Silicone. Dirt can get embedded in soft layers such as silicone and obscure light. Water vapor transmittance rate (WVTR) of polymer films used in the food packaging industry as moisture barriers are ~0.05 g/(m2.day) under ambient conditions. In comparison, light emitting diodes employ packaging components that have WVTR of ~10-6 g/(m2.day). WVTR of polymer sheets can be improved by coating them with dense inorganic/organic multilayers. Ethylene vinyl acetate, an amorphous copolymer used predominantly by the PV industry has very high O2 and H2O diffusivity. Quaternary carbon chains (such as acetate) in a polymer lead to cleavage and loss of adhesional strength at relatively low exposures. Reactivity of PV module components increases in presence of O2 and H2O. Adhesional strength degrades due to the breakdown of structure of polymer by reactive, free radicals formed by high-energy radiation. Free radical formation in polymers is reduced when the aromatic rings are attached at regular intervals. This paper will review flexible packaging for PV modules.

Interharmonics from Grid-Connected PV Systems

DEFF Research Database (Denmark)

Sangwongwanich, Ariya; Yang, Yongheng; Sera, Dezso

2017-01-01

As the penetration level of grid-connected Photovoltaic (PV) systems increases, the power quality is one of the major concerns for system operators and the demands are becoming even stricter. The impact of interharmonics on the grid has been acknowledged in recent research when considering a large......-scale adoption of PV inverters. However, the origins of interharmonics remain unclear. Thus, this paper performs tests on a commercial PV inverter to explore interharmonic generation and more important investigates the mechanism of interharmonic emission. The investigation reveals that the perturbation...... of the solutions. Simulation results indicate that the constant-voltage MPPT method is the most suitable solution to the mitigation of interharmonics introduced by the MPPT operation, as it avoids the perturbation in the PV voltage during operation....

Optimal Solar PV Arrays Integration for Distributed Generation

Energy Technology Data Exchange (ETDEWEB)

Omitaomu, Olufemi A [ORNL; Li, Xueping [University of Tennessee, Knoxville (UTK)

2012-01-01

Solar photovoltaic (PV) systems hold great potential for distributed energy generation by installing PV panels on rooftops of residential and commercial buildings. Yet challenges arise along with the variability and non-dispatchability of the PV systems that affect the stability of the grid and the economics of the PV system. This paper investigates the integration of PV arrays for distributed generation applications by identifying a combination of buildings that will maximize solar energy output and minimize system variability. Particularly, we propose mean-variance optimization models to choose suitable rooftops for PV integration based on Markowitz mean-variance portfolio selection model. We further introduce quantity and cardinality constraints to result in a mixed integer quadratic programming problem. Case studies based on real data are presented. An efficient frontier is obtained for sample data that allows decision makers to choose a desired solar energy generation level with a comfortable variability tolerance level. Sensitivity analysis is conducted to show the tradeoffs between solar PV energy generation potential and variability.

Comparative Chemistry of Aspergillus oryzae (RIB40) and A. flavus (NRRL 3357)

Science.gov (United States)

Rank, Christian; Klejnstrup, Marie Louise; Petersen, Lene Maj; Kildgaard, Sara; Frisvad, Jens Christian; Gotfredsen, Charlotte Held; Larsen, Thomas Ostenfeld

2012-01-01

Aspergillus oryzae and A. flavus are important species in industrial biotechnology and food safety and have been some of the first aspergilli to be fully genome sequenced. Bioinformatic analysis has revealed 99.5% gene homology between the two species pointing towards a large coherence in the secondary metabolite production. In this study we report on the first comparison of secondary metabolite production between the full genome sequenced strains of A. oryzae (RIB40) and A. flavus (NRRL 3357). Surprisingly, the overall chemical profiles of the two strains were mostly very different across 15 growth conditions. Contrary to previous studies we found the aflatrem precursor 13-desoxypaxilline to be a major metabolite from A. oryzae under certain growth conditions. For the first time, we additionally report A. oryzae to produce parasiticolide A and two new analogues hereof, along with four new alkaloids related to the A. flavus metabolites ditryptophenalines and miyakamides. Generally the secondary metabolite capability of A. oryzae presents several novel end products likely to result from the domestication process from A. flavus. PMID:24957367

Commercialization of PV-powered pumping systems for use in utility PV service programs. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

The project described in this report was a commercialization effort focused on cost-effective remote water pumping systems for use in utility-based photovoltaic (PV) service programs. The project combined a commercialization strategy tailored specifically for electric utilities with the development of a PV-powered pumping system that operates conventional ac pumps rather than relying on the more expensive and less reliable PV pumps on the market. By combining these two attributes, a project goal was established of creating sustained utility purchases of 250 PV-powered water pumping systems per year. The results of each of these tasks are presented in two parts contained in this Final Summary Report. The first part summarizes the results of the Photovoltaic Services Network (PSN) as a new business venture, while the second part summarizes the results of the Golden Photon system installations. Specifically, results and photographs from each of the system installations are presented in this latter part.

Reaction of common bean lines to Xanthomonas axonopodis pv. phaseoli and Curtobacterium flaccumfaciens pv. flaccumfaciens

Directory of Open Access Journals (Sweden)

Tamires Ribeiro

2016-12-01

Full Text Available The aim of this study was to evaluate the resistance of 58 common bean lines against common bacterial blight (Xanthomonas axonopodis pv. phaseoli and bacterial wilt (Curtobacterium flaccumfaciens pv. flaccumfaciens. The experimental design consisted of completely randomized blocks, with four replications per pathogen. The results were subjected to variance analysis by the F test at 1% probability. Significant differences between the treatments indicated different resistance levels among the lines against both pathogens. According to the Scott-Knott test, six lines were resistant to Xanthomonas axonopodis pv. phaseoli, 14 moderately resistant, and 38 susceptible. To Curtobacterium flaccumfaciens pv. flaccumfaciens, 11 lines were resistant, 26 moderately resistant and 21 susceptible. Among these, the lines Pr10-3-4/1, Pr10-5-2/1 and Pr10-5- 2/2 of the black bean group and C10-2-4/2 of the Carioca group were resistant to both major bacterial diseases affecting common bean in Brazil.

Extensive Field Survey, Laboratory and Greenhouse Studies Reveal Complex Nature of Pseudomonas syringae-Associated Hazelnut Decline in Central Italy.

Science.gov (United States)

Lamichhane, Jay Ram; Bartoli, Claudia; Varvaro, Leonardo

2016-01-01

Pseudomonas avellanae (Pav) has been reported as the causal agent of bacterial decline and bacterial canker of hazelnut in Italy and Greece, respectively. Both hazelnut diseases were reported to be similar in terms of symptoms, severity and persistence. In this study, we found that both symptomatic and asymptomatic trees in the field were colonized by Pav. Multilocus Sequence Typing (MLST) analysis showed that Pav strains isolated during this study in Italy belong to the P. syringae phylogroup 1 and they are closely related to Pav strains previously isolated in Greece from hazelnut bacterial canker. On the other hand, strains isolated in earlier studies from hazelnut decline in Italy belong to both phylogroup 1 and 2 of P. syringae. Both phylogroup 1 strains of P. syringae from Greece and Italy are different than strains isolated in this study in terms of their capacity to excrete fluorescent pigments on different media. Despite the same plant genotype and cropping practices adopted, the incidence of hazelnut decline ranged from nearly 0 to 91% across our study sites. No disease developed on plants inoculated with Pav through wounding while leaf scar inoculations produced only mild disease symptoms. Based on our results and the previously reported correlation between pedo-climatic conditions and hazelnut decline, we conclude that hazelnut decline in central Italy could be incited by a combination of predisposing (adverse pedo-climatic conditions) and contributing factors (Pav). Because this is a true decline different from "bacterial canker" described in Greece, we refer to it as hazelnut decline (HD).

Extensive Field Survey, Laboratory and Greenhouse Studies Reveal Complex Nature of Pseudomonas syringae-Associated Hazelnut Decline in Central Italy.

Directory of Open Access Journals (Sweden)

Jay Ram Lamichhane

Full Text Available Pseudomonas avellanae (Pav has been reported as the causal agent of bacterial decline and bacterial canker of hazelnut in Italy and Greece, respectively. Both hazelnut diseases were reported to be similar in terms of symptoms, severity and persistence. In this study, we found that both symptomatic and asymptomatic trees in the field were colonized by Pav. Multilocus Sequence Typing (MLST analysis showed that Pav strains isolated during this study in Italy belong to the P. syringae phylogroup 1 and they are closely related to Pav strains previously isolated in Greece from hazelnut bacterial canker. On the other hand, strains isolated in earlier studies from hazelnut decline in Italy belong to both phylogroup 1 and 2 of P. syringae. Both phylogroup 1 strains of P. syringae from Greece and Italy are different than strains isolated in this study in terms of their capacity to excrete fluorescent pigments on different media. Despite the same plant genotype and cropping practices adopted, the incidence of hazelnut decline ranged from nearly 0 to 91% across our study sites. No disease developed on plants inoculated with Pav through wounding while leaf scar inoculations produced only mild disease symptoms. Based on our results and the previously reported correlation between pedo-climatic conditions and hazelnut decline, we conclude that hazelnut decline in central Italy could be incited by a combination of predisposing (adverse pedo-climatic conditions and contributing factors (Pav. Because this is a true decline different from "bacterial canker" described in Greece, we refer to it as hazelnut decline (HD.

A Practical Irradiance Model for Bifacial PV Modules: Preprint

Energy Technology Data Exchange (ETDEWEB)

Marion, Bill; MacAlpine, Sara; Deline, Chris; Asgharzadeh, Amir; Toor, Fatima; Riley, Daniel; Stein, Joshua; Hansen, Clifford

2017-06-15

A model, suitable for a row or multiple rows of photovoltaic (PV) modules, is presented for estimating the backside irradiance for bifacial PV modules. The model, which includes the effects of shading by the PV rows, is based on the use of configuration factors (CFs) to determine the fraction of a source of irradiance that is received by the backside of the PV module. Backside irradiances are modeled along the sloped height of the PV module, but assumed not to vary along the length of the PV row. The backside irradiances are corrected for angle-of-incidence losses and may be added to the front side irradiance to determine the total irradiance resource for the PV cell. Model results are compared with the measured backside irradiances for NREL and Sandia PV systems, and with results when using the RADIANCE ray tracing program.

Multifunctional a-Si PV systems

Energy Technology Data Exchange (ETDEWEB)

Peippo, K; Lund, P; Vartiainen, E [Helsinki Univ. of Technology, Otaniemi (Finland). Advanced Energy Systems

1998-10-01

The optimal use of the various forms of solar energy (passive, active, daylighting, photovoltaics) in buildings calls for an optimal integration of the technologies. As energy conservation potential in space heating may soon be exhausted, electricity efficiency and on-site generation will play an increasing role in energy-conscious building design. There, dispersed PV systems integrated into buildings show a significant market potential, due to a number of benefits: no extra land area is required, PV-array may replace conventional cladding materials and become a building element. Moreover, the produced PV-electricity is more valuable for the building owner than for an electric utility

A novel non-thermostable deuterolysin from Aspergillus oryzae.

Science.gov (United States)

Maeda, Hiroshi; Katase, Toru; Sakai, Daisuke; Takeuchi, Michio; Kusumoto, Ken-Ichi; Amano, Hitoshi; Ishida, Hiroki; Abe, Keietsu; Yamagata, Youhei

2016-09-01

Three putative deuterolysin (EC 3.4.24.29) genes (deuA, deuB, and deuC) were found in the Aspergillus oryzae genome database ( http://www.bio.nite.go.jp/dogan/project/view/AO ). One of these genes, deuA, was corresponding to NpII gene, previously reported. DeuA and DeuB were overexpressed by recombinant A. oryzae and were purified. The degradation profiles against protein substrates of both enzymes were similar, but DeuB showed wider substrate specificity against peptidyl MCA-substrates compared with DeuA. Enzymatic profiles of DeuB except for thermostability also resembled those of DeuA. DeuB was inactivated by heat treatment above 80° C, different from thermostable DeuA. Transcription analysis in wild type A. oryzae showed only deuB was expressed in liquid culture, and the addition of the proteinous substrate upregulated the transcription. Furthermore, the NaNO3 addition seems to eliminate the effect of proteinous substrate for the transcription of deuB.

Aspergillus oryzae-based cell factory for direct kojic acid production from cellulose.

Science.gov (United States)

Yamada, Ryosuke; Yoshie, Toshihide; Wakai, Satoshi; Asai-Nakashima, Nanami; Okazaki, Fumiyoshi; Ogino, Chiaki; Hisada, Hiromoto; Tsutsumi, Hiroko; Hata, Yoji; Kondo, Akihiko

2014-05-18

Kojic acid (5-Hydroxy-2-(hydroxymethyl)-4-pyrone) is one of the major secondary metabolites in Aspergillus oryzae. It is widely used in food, pharmaceuticals, and cosmetics. The production cost, however, is too high for its use in many applications. Thus, an efficient and cost-effective kojic acid production process would be valuable. However, little is known about the complete set of genes for kojic acid production. Currently, kojic acid is produced from glucose. The efficient production of kojic acid using cellulose as an inexpensive substrate would help establish cost-effective kojic acid production. A kojic acid transcription factor gene over-expressing the A. oryzae strain was constructed. Three genes related to kojic acid production in this strain were transcribed in higher amounts than those found in the wild-type strain. This strain produced 26.4 g/L kojic acid from 80 g/L glucose. Furthermore, this strain was transformed with plasmid harboring 3 cellulase genes. The resultant A. oryzae strain successfully produced 0.18 g/L of kojic acid in 6 days of fermentation from the phosphoric acid swollen cellulose. Kojic acid was produced directly from cellulose material using genetically engineered A. oryzae. Because A. oryzae has efficient protein secretion ability and secondary metabolite productivity, an A. oryzae-based cell factory could be a platform for the production of various kinds of bio-based chemicals.

Efficient formation of heterokaryotic sclerotia in the filamentous fungus Aspergillus oryzae.

Science.gov (United States)

Wada, Ryuta; Jin, Feng Jie; Koyama, Yasuji; Maruyama, Jun-ichi; Kitamoto, Katsuhiko

2014-01-01

Heterokaryon formation by hyphal fusion occurs during a sexual/parasexual cycle in filamentous fungi, and therefore, it is biotechnologically important for crossbreeding. In the industrial filamentous fungus Aspergillus oryzae, a parasexual cycle has been reported, and it was recently suggested that sexual reproduction should be possible. However, as A. oryzae enters into hyphal fusion with a much lower frequency than Neurospora crassa, the process of heterokaryon formation has not been extensively characterized in A. oryzae. Here, we developed a detection system for heterokaryon formation by expressing red or green fluorescent proteins in nuclei and conferring uridine/uracil or adenine auxotrophy to MAT1-1 and MAT1-2 strains of A. oryzae. The heterokaryon formation of A. oryzae was investigated in paired culture using the genetically modified strains. No sclerotial formation was observed in the hyphal contact regions of the two strains with the same auxotrophy, whereas numerous sclerotia were formed between the strains with different auxotrophies. In most of the formed sclerotia, the uridine/uracil and adenine auxotrophies were complemented, and both red and green fluorescence were detected, indicating that heterokaryotic fusants were formed by hyphal fusion before or during sclerotial formation. Moreover, overexpressing the sclR gene, which encodes a transcription factor promoting sclerotial formation, increased the number of heterokaryotic sclerotia formed between the two auxotrophic strains. Notably, these effects in sclerotial formation of heterokaryotic fusants were observed independently of the mating type pairing combinations. Taken together, these findings demonstrated that paring of different auxotrophs and sclR overexpression promote the formation of heterokaryotic sclerotia in A. oryzae.

PV installations, protection and the code

Energy Technology Data Exchange (ETDEWEB)

Silecky, L. [Mersen, Toronto, ON (Canada)

2010-12-15

This article discussed the need for improved standards in Ontario's solar industry to ensure safety for the systems and also safety for the workers. Photovoltaic cells used in solar arrays can now deliver between 50 vDC to 600 vDC. The workings of such a high voltage photocell must be understood in order to understand its protection needs. Since PVs are semiconductors and susceptible to damage from short circuits and overloads, a fast-acting overcurrent protective device (OCPD) should be used. Combiner boxes are also needed to provide a clean method of safely connecting all the wires that are needed in the system, including surge protection and a means of isolation between the PV array and the inverter. Section 50 of the Canadian Electrical Code outlines the requirements for solar PV systems, but it does not mention the protection of DC circuits, including DC fuse protectors which are manufactured to provide a high degree of protection for the PV array. As the photovoltaic (PV) market continues to grow in Ontario, the PV industry also has a responsibility to ensure it is in compliance with codes and standards related to photovoltaic systems. This author suggested that Article 690 of the National Electric Code (NEC) is a good document to use when determining the requirements for PV systems. 3 figs.

An evaluation of aflatoxin and cyclopiazonic acid production in Aspergillus oryzae.

Science.gov (United States)

Kim, Nam Yeun; Lee, Jin Hee; Lee, Inhyung; Ji, Geun Eog

2014-06-01

To date, edible fungi such as Aspergillus flavus var. oryzae (A. oryzae) has been considered as safe. However, some strains can produce mycotoxins. Thus, the biosynthetic ability to produce mycotoxins should be reevaluated to determine the safety of edible fungi. We analyzed the production of aflatoxins and cyclopiazonic acid (CPA) from edible fungi such as A. oryzae isolated from various Korean foods using multiplex PCR, enzyme-linked immunosorbent assay, and high-performance liquid chromatography (HPLC). In the multiplex PCR analysis of aflatoxin biosynthetic genes omtB, aflR, ver-1, and omtA, 5 of 19 Aspergillus strains produced all PCR products. Among them, aflatoxin B1 and aflatoxin B2 were detected from only A. flavus KACC 41403 by HPLC. Aflatoxins were not detected from the other four strains that produced all positive PCR bands. Aflatoxin also was not detected from 12 strains that had PCR patterns without aflR or ver-1 and from 2 strains that did not produce any of the expected PCR products. Only the seven A. oryzae strains that produced all of the positive PCR bands including the CPA biosynthetic genes maoA, dmaT, and pks-nrps produced CPA. CPA and aflatoxin production must be evaluated before A. oryzae strains are used for the development of fermented foods.

Experimental grid connected PV system power analysis

Science.gov (United States)

Semaoui, Smail; Abdeladim, Kamel; Arab, Amar Hadj; Boulahchich, Saliha; Amrouche, Said Ould; Yassaa, Noureddine

2018-05-01

Almost 80 % of Algerian territory is appropriate for the exploitation of solar energy. The Algerian energetic strategy provides a substantial injection of PV electricity to the national grid. Currently, about 344 MWp of PV arrays which corresponds approximately to 2,34 km2 of module surfaces, are connected on electricity grid over the national territory. The Algerian Northern regions are characterized by strong pollution and high humidity. These phenomena affect the energetic productivity of PV generator. The objective of our study is to analyze experimental grid connected PV system power in coastal locations. Hence, experiments have been conducted on three identical PV systems to determine the electrical performances. Transformer-less inverters are the most attractive for the ground-based photovoltaic (PV) system due to their efficiencies, reduced cost and weight. Besides, the absence of the galvanic isolation generates problems of capacitive leakage current on the AC side and the degradation of the insulation resistance on the DC side of the inverter. In this work, experimental study of the behavior of single-phase inverters without transformers is presented. The main objective of this work is to study the degradation of the insulation resistance at the input of the inverter, and the capacitive leakage current at the output of the inverter. This study was achieved at the CDER on a rainy day of 15/03/2017, on the first PV plant connected to the low voltage network in Algeria. This investigation can help forecasting the PV array energetic production by taking into account natural conditions.

China PV Business and Applications Evaluation

Energy Technology Data Exchange (ETDEWEB)

Sherring, Chris (Sherring Energy Associates)

1999-08-30

This report provides an overview of photovoltaics (PV) business and applications in China. Although more than 70 million people in China are without access to grid electricity, many of the unelectrified regions benefit from considerable renewable resources, including good solar insolation. Current annual PV sales are still modest, however, and are estimated to be between 2.0 and 2.5 megawatts. This and other significant PV data, including information regarding the current status of key aspects of Chinese businesses, markets, and distribution channels, are included in the report. Detailed company profiles of Chinese business organizations and summaries of visits made to these companies (as well as to more remote sites in Inner Mongolia to examine PV usage by the end-use customer) in September-October 1998 are also presented.

Robust PV Degradation Methodology and Application

Energy Technology Data Exchange (ETDEWEB)

Jordan, Dirk [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Deline, Christopher A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kurtz, Sarah [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kimball, Greg [SunPower; Anderson, Mike [SunPower

2017-11-15

The degradation rate plays an important role in predicting and assessing the long-term energy generation of PV systems. Many methods have been proposed for extracting the degradation rate from operational data of PV systems, but most of the published approaches are susceptible to bias due to inverter clipping, module soiling, temporary outages, seasonality, and sensor degradation. In this manuscript, we propose a methodology for determining PV degradation leveraging available modeled clear-sky irradiance data rather than site sensor data, and a robust year-over-year (YOY) rate calculation. We show the method to provide reliable degradation rate estimates even in the case of sensor drift, data shifts, and soiling. Compared with alternate methods, we demonstrate that the proposed method delivers the lowest uncertainty in degradation rate estimates for a fleet of 486 PV systems.

Investigation of intercellular salicylic acid accumulation during compatible and incompatible Arabidopsis-pseudomonas syringae interactions using a fast neutron-generated mutant allele of EDS5 identified by genetic mapping and whole-genome sequencing.

Directory of Open Access Journals (Sweden)

Jessie L Carviel

Full Text Available A whole-genome sequencing technique developed to identify fast neutron-induced deletion mutations revealed that iap1-1 is a new allele of EDS5 (eds5-5. RPS2-AvrRpt2-initiated effector-triggered immunity (ETI was compromised in iap1-1/eds5-5 with respect to in planta bacterial levels and the hypersensitive response, while intra- and intercellular free salicylic acid (SA accumulation was greatly reduced, suggesting that SA contributes as both an intracellular signaling molecule and an antimicrobial agent in the intercellular space during ETI. During the compatible interaction between wild-type Col-0 and virulent Pseudomonas syringae pv. tomato (Pst, little intercellular free SA accumulated, which led to the hypothesis that Pst suppresses intercellular SA accumulation. When Col-0 was inoculated with a coronatine-deficient strain of Pst, high levels of intercellular SA accumulation were observed, suggesting that Pst suppresses intercellular SA accumulation using its phytotoxin coronatine. This work suggests that accumulation of SA in the intercellular space is an important component of basal/PAMP-triggered immunity as well as ETI to pathogens that colonize the intercellular space.

Immobilization of Isolated Lipase From Moldy Copra (Aspergillus Oryzae)

OpenAIRE

Dali, Seniwati; Patong, A. B. D. Rauf; Jalaluddin, M. Noor; Pirman; Hamzah, Baharuddin

2011-01-01

Enzyme immobilization is a recovery technique that has been studied in several years, using support as a media to help enzyme dissolutions to the reaction substrate. Immobilization method used in this study was adsorption method, using specific lipase from Aspergillus oryzae. Lipase was partially purified from the culture supernatant of Aspergillus oryzae. Enzyme was immobilized by adsorbed on silica gel. Studies on free and immobilized lipase systems for determination of optimum pH, optimum ...

Optimal Design of Modern Transformerless PV Inverter Topologies

OpenAIRE

Saridakis, Stefanos; Koutroulis, Eftichios; Blaabjerg, Frede

2013-01-01

The design optimization of H5, H6, neutral point clamped, active-neutral point clamped, and conergy-NPC transformerless photovoltaic (PV) inverters is presented in this paper. The components reliability in terms of the corresponding malfunctions, affecting the PV inverter maintenance cost during the operational lifetime period of the PV installation, is also considered in the optimization process. According to the results of the proposed design method, different optimal values of the PV inver...

Solar cell junction temperature measurement of PV module

KAUST Repository

Huang, B.J.; Yang, P.E.; Lin, Y.P.; Lin, B.Y.; Chen, H.J.; Lai, R.C.; Cheng, J.S.

2011-01-01

The present study develops a simple non-destructive method to measure the solar cell junction temperature of PV module. The PV module was put in the environmental chamber with precise temperature control to keep the solar PV module as well

Photovoltaic (PV) Pricing Trends: Historical, Recent, and Near-Term Projections

Energy Technology Data Exchange (ETDEWEB)

Feldman, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Barbose, Galen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Margolis, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wiser, Ryan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Darghouth, Naim [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Goodrich, Alan [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2012-11-30

The installed capacity of global and U.S. photovoltaic (PV) systems has soared in recent years, driven by declining PV prices and government incentives. The U.S. Department of Energy’s (DOE) SunShot Initiative aims to make PV cost competitive without incentives by reducing the cost of PV-generated electricity by about 75% between 2010 and 2020. This summary report—based on research at Lawrence Berkeley National Laboratory (LBNL) and the National Renewable Energy Laboratory (NREL)—examines progress in PV price reductions to help DOE and other PV stakeholders manage the transition to a market-driven PV industry, and to provide clarity surrounding the wide variety of potentially conflicting data available about PV system prices.

sativa L.) Cultivars

African Journals Online (AJOL)

Abstract. Ten rice cultivars from the International Rice Germplasm Centre originating from Bangladesh were analysedfor the~r genetics of resistance to bacterial blight. The test cultivars were selected on the basis of their high level ofresistance to races IV & VI ofXanthomonas oryzae pv. oryzae. The mode ofinheri- tance was ...

The Value of Transparency in Distributed Solar PV Markets

Energy Technology Data Exchange (ETDEWEB)

OShaughnessy, Eric J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zamzam, Ahmed S [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-12-01

Market transparency refers to the degree of customer awareness of product options and fair market prices for a given good. In The Value of Transparency in Distributed Solar PV Markets, we use residential solar photovoltaic (PV) quote data to study the value of transparency in distributed solar PV markets. We find that improved market transparency results in lower installation offer prices. Further, the results of this study suggest that PV customers benefit from gaining access to more PV quotes.

Utilization of Aspergillus oryzae to produce pectin lyase from various agro-industrial residues

OpenAIRE

Koser, Safia; Anwar, Zahid; Iqbal, Zafar; Anjum, Awais; Aqil, Tahir; Mehmood, Sajid; Irshad, Muhammad

2014-01-01

The present study was aimed to investigate the culture influence on pectin lyase production potential of fungal strain Aspergillus oryzae. The enzyme profile of A. oryzae showed highest activity of pectin lyase after 3rd day of incubation on lemon peel waste under solid state fermentation conditions. To induce the pectin lyase synthesis capability of A. oryzae at optimal level various culture variables including physical and nutritional parameters were optimized by adopting classical optimiza...

Survey of the transcriptome of Aspergillus oryzae via massively parallel mRNA sequencing

OpenAIRE

Wang, Bin; Guo, Guangwu; Wang, Chao; Lin, Ying; Wang, Xiaoning; Zhao, Mouming; Guo, Yong; He, Minghui; Zhang, Yong; Pan, Li

2010-01-01

Aspergillus oryzae, an important filamentous fungus used in food fermentation and the enzyme industry, has been shown through genome sequencing and various other tools to have prominent features in its genomic composition. However, the functional complexity of the A. oryzae transcriptome has not yet been fully elucidated. Here, we applied direct high-throughput paired-end RNA-sequencing (RNA-Seq) to the transcriptome of A. oryzae under four different culture conditions. With the high resoluti...

Optimal design of PV and HP system

DEFF Research Database (Denmark)

Nepper-Rasmussen, Bjarke Christian; Rasmussen, Theis Bo

2015-01-01

Methods of utilizing residential produced photovoltaic (PV) power by converting to thermal energy through heat pumps (HP) are present in literature, where thermal energy is dispersed as either heat or hot water at the instant moment of PV production. In this paper an alternative solution is descr...... that the thermal storage with a BT is a better investment than a PV system without HP or no investment. Furthermore, it showed that the optimization model developed in this project is capable of finding the optimal combination of component sizes based on our data.......Methods of utilizing residential produced photovoltaic (PV) power by converting to thermal energy through heat pumps (HP) are present in literature, where thermal energy is dispersed as either heat or hot water at the instant moment of PV production. In this paper an alternative solution...... is described, where the thermal energy is stored in a buffer tank (BT) capable of dispersing heat to either the heating system of a house or a hot water tank, for later use. The thermal storage solution including a BT can increase the self-consumption of residentially produced PV power and thereby shift...

Learning in PV trends and future prospects

International Nuclear Information System (INIS)

Schaeffer, G.J.; De Moor, H.H.C.

2004-06-01

For large scale application of PV cost reduction is essential. It is shown in this study that the price evolution is on track and even accelerating the last 15 years. Using an experience curve approach a learning rate of little over 20% was found consistent with other studies. As data were collected for small rooftop grid connected systems, it could be shown that this learning rate is not only found for modules, but also for BOS (all costs apart from the modules) in Germany as well as in the Netherlands. Projections of the future price of PV systems show that a learning rate of at least 20% is needed to make introduction of PV affordable. It is very effective to invest in learning, thus increasing the learning rate, as well as developing market segments were the value of PV is higher, such as residential PV systems in southern Europe

PV solar system feasibility study

International Nuclear Information System (INIS)

Ashhab, Moh’d Sami S.; Kaylani, Hazem; Abdallah, Abdallah

2013-01-01

Highlights: ► This research studies the feasibility of PV solar systems. ► The aim is to develop the theory and application of a hybrid system. ► Relevant research topics are reviewed and some of them are discussed in details. ► A prototype of the PV solar system is designed and built. - Abstract: This research studies the feasibility of PV solar systems and aims at developing the theory and application of a hybrid system that utilizes PV solar system and another supporting source of energy to provide affordable heating and air conditioning. Relevant research topics are reviewed and some of them are discussed in details. Solar heating and air conditioning research and technology exist in many developed countries. To date, the used solar energy has been proved to be inefficient. Solar energy is an abundant source of energy in Jordan and the Middle East; with increasing prices of oil this source is becoming more attractive alternative. A good candidate for the other system is absorption. The overall system is designed such that it utilizes solar energy as a main source. When the solar energy becomes insufficient, electricity or diesel source kicks in. A prototype of the PV solar system that operates an air conditioning unit is built and proper measurements are collected through a data logging system. The measured data are plotted and discussed, and conclusions regarding the system performance are extracted.

Data monitoring system for PV solar generators

International Nuclear Information System (INIS)

Stoev, M.; Katerski, A.; Williams, A.

2000-01-01

The two 1.5 kWp photovoltaic (PV) solar generators are installed and the new PC data monitoring system is developed by applying EC standards for European Solar Test Installation (ESTI). The schematic system diagram of PV generator is presented. The recording parameters for analytical and global monitoring are discussed. The meteorological data from ESTI sensors, temperature sensor and electrical data from inverter and calibrated shunt are stored via analog digital converters (ADC) on a hard disk of data storage PC. Data Logger and Monitor software for automatic data acquisition, treatment and visual distance control of all output PV data from PV solar generator has been created

Two novel antimicrobial defensins from rice identified by gene coexpression network analyses.

Science.gov (United States)

Tantong, Supaluk; Pringsulaka, Onanong; Weerawanich, Kamonwan; Meeprasert, Arthitaya; Rungrotmongkol, Thanyada; Sarnthima, Rakrudee; Roytrakul, Sittiruk; Sirikantaramas, Supaart

2016-10-01

Defensins form an antimicrobial peptides (AMP) family, and have been widely studied in various plants because of their considerable inhibitory functions. However, their roles in rice (Oryza sativa L.) have not been characterized, even though rice is one of the most important staple crops that is susceptible to damaging infections. Additionally, a previous study identified 598 rice genes encoding cysteine-rich peptides, suggesting there are several uncharacterized AMPs in rice. We performed in silico gene expression and coexpression network analyses of all genes encoding defensin and defensin-like peptides, and determined that OsDEF7 and OsDEF8 are coexpressed with pathogen-responsive genes. Recombinant OsDEF7 and OsDEF8 could form homodimers. They inhibited the growth of the bacteria Xanthomonas oryzae pv. oryzae, X. oryzae pv. oryzicola, and Erwinia carotovora subsp. atroseptica with minimum inhibitory concentration (MIC) ranging from 0.6 to 63μg/mL. However, these OsDEFs are weakly active against the phytopathogenic fungi Helminthosporium oryzae and Fusarium oxysporum f.sp. cubense. This study describes a useful method for identifying potential plant AMPs with biological activities. Copyright © 2016 Elsevier Inc. All rights reserved.

Simulation of Distributed PV Power Output in Oahu Hawaii

Energy Technology Data Exchange (ETDEWEB)

Lave, Matthew Samuel [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

2016-08-01

Distributed solar photovoltaic (PV) power generation in Oahu has grown rapidly since 2008. For applications such as determining the value of energy storage, it is important to have PV power output timeseries. Since these timeseries of not typically measured, here we produce simulated distributed PV power output for Oahu. Simulated power output is based on (a) satellite-derived solar irradiance, (b) PV permit data by neighborhood, and (c) population data by census block. Permit and population data was used to model locations of distributed PV, and irradiance data was then used to simulate power output. PV power output simulations are presented by sub-neighborhood polygons, neighborhoods, and for the whole island of Oahu. Summary plots of annual PV energy and a sample week timeseries of power output are shown, and a the files containing the entire timeseries are described.

Design optimization of transformerless grid-connected PV inverters including reliability

DEFF Research Database (Denmark)

Koutroulis, Eftichios; Blaabjerg, Frede

2012-01-01

Of the Electricity (LCOE) generated during the PV system lifetime period is minimized. The LCOE is calculated also considering the failure rates of the components, which affect the reliability performance and lifetime maintenance cost of the PV inverter. A design example is presented, demonstrating that compared...... to the non-optimized PV inverter structures, the PV inverters designed using the proposed optimization methodology exhibit lower total manufacturing and lifetime maintenance cost and inject more energy into the electric-grid and by that minimizing LCOE.......This paper presents a new methodology for optimal design of transformerless Photovoltaic (PV) inverters targeting a cost-effective deployment of grid-connected PV systems. The optimal values and types of the PV inverter components are calculated such that the PV inverter Levelized Cost...

Design Optimization of Transformerless Grid-Connected PV Inverters Including Reliability

DEFF Research Database (Denmark)

Koutroulis, Eftichios; Blaabjerg, Frede

2013-01-01

such that the PV inverter LCOE generated during the PV system lifetime period is minimized. The LCOE is also calculated considering the failure rates of the components, which affect the reliability performance and lifetime maintenance cost of the PV inverter. A design example is presented, demonstrating...... that compared to the nonoptimized PV inverter structures, the PV inverters designed using the proposed optimization methodology exhibit lower total manufacturing and lifetime maintenance cost and inject more energy into the electric-grid and by that minimizing LCOE.......This paper presents a new methodology for optimal design of transformerless photovoltaic (PV) inverters targeting a cost-effective deployment of grid-connected PV systems. The optimal switching frequency as well as the optimal values and types of the PV inverter components is calculated...

Impedance characterization of PV modules in outdoor conditions

DEFF Research Database (Denmark)

Oprea, Matei-lon; Thorsteinsson, Sune; Spataru, Sergiu

2016-01-01

Impedance spectroscopy (IS) has been used for laboratory characterizations of photovoltaic (PV) technologies under well controlled conditions. This work applies IS for outdoor characterization of PV panels, in order to observe the effect of irradiance (G) and temperature (T) on the PV module’s...

Performance of a 34 kWp grid-connected PV system in Indonesia - A comparison of tropical and European PV systems

NARCIS (Netherlands)

Veldhuis, A.J.; Reinders, Angelina H.M.E.

2014-01-01

We analysed a monitored grid-connected PV system of 34 kWp in Indonesia to investigate the performance of PV systems in tropical climates. The PV system has been installed in Jayapura, the capital of the Province of Papua, Indonesia, by the beginning of 2012. Due to the aged gensets and frequent

Study of bypass diodes configuration on PV modules

Energy Technology Data Exchange (ETDEWEB)

Silvestre, S.; Boronat, A.; Chouder, A. [Electronics Engineering Department - UPC., C/Jordi Girona 1-3, Modul C4 Campus Nord UPC., 08034 Barcelona (Spain)

2009-09-15

A procedure of simulation and modelling solar cells and PV modules, working partially shadowed in Pspice environment, is presented. Simulation results have been contrasted with real measured data from a commercial PV module of 209 Wp from Siliken. Some cases of study are presented as application examples of this simulation methodology, showing its potential on the design of bypass diodes configuration to include in a PV module and also on the study of PV generators working in partial shading conditions. (author)

Latin America as new PV market opportunity

International Nuclear Information System (INIS)

Weiss, Ingrid

2015-01-01

It is important to recognize solar energy as an international and strategic opportunity for the European market to expand. The objective of this paper is to apply the methodology created during the PV Parity project for analyzing PV Competitiveness in the emerging residential PV market in Brazil, using information from the State of Rio de Janeiro. The dynamic competitiveness analysis was performed considering the price with and without taxes in order to assess the year when PV will reach grid parity in Rio de Janeiro and how the taxes impact on the results. Results are divided into 3 scenarios: Optimistic, Conservative, and Conservative Moderate. The LCOE of residential systems will likely become competitive with the residential electricity tariffs between 2020 and 2030, assuming the residential tariffs in Rio de Janeiro. This is an indicator that PV energy business opportunities are increasing in Brazil and, with the adequate policy support, its market competitiveness could be improved. We are also looking in other markets of Latin America. (full text)

Dissipation of heat from building integrated PV

Energy Technology Data Exchange (ETDEWEB)

Taylor, C.M.L.

2001-07-01

The objectives of the project were to investigate methods for improving heat transfer and the reflection of heat from PV modules in building integrated situations and to develop the design of a building integrated PV element with improved heat transfer characteristics, with the aim of reducing the operating temperature of the PV cells. The prototypes developed for improving heat transfer have only shown small reductions in the PV cell operating temperature and these results have not been fully quantified due to problems associated with experimental testing. The improvement in the overall electrical performance of PV modules operating at lower temperatures is consequently even smaller. As a result, none of the prototypes can be considered to be economically viable. Based upon the theoretical and experimental results of this work, it is the recommendation of this project that no further work be conducted in improving BIPV performance through improved heat transfer of BIPV. (Author)

The potential of solar PV in Ontario

International Nuclear Information System (INIS)

McMonagle, R.

2005-01-01

Canada has lagged behind other industrialized nations in the growth of solar energy markets. Currently, over 78 per cent of the global market for solar energy is for grid-connected applications where power is fed into the electrical distribution network. Less than 3.5 per cent of the Canadian solar market is grid-connected. This report investigated the potential size of the photovoltaic (PV) market in Ontario given adequate support from both governments and utilities. The forecast was based on sustainable growth levels that the solar industry as a whole might maintain over an extended period of time. It was suggested that it is technically feasible to install over 3000 MW of PV in single, detached homes in the province, which could generate over 3200 GWh each year. If the right policy conditions were put in place, the technical potential for PV on all buildings in Ontario is over 14,000 MW by 2025, which would generate over 13,000 GWh annually. Support mechanisms such as the Advanced Renewable Tariff (ART) or Standard Offer Contracts (SOC) will enable the PV industry to build capacity. Future markets for PV include new homes, commercial buildings and the existing housing stock. With a properly designed system, it is forecasted that the deployment of PV by 2025 could result in the involvement of 400,000 homes with over 1200 MW of installed capacity and over 290 MW installed annually by 2025. Recommendations to Ontario Power Authority's (OPA) report supply mix report focused on the use of SOCs as the appropriate support mechanism to start building solar capacity in Ontario, as projections using SOCs would see Ontario following the growth patterns of other nations. It was concluded that the OPA report does not acknowledge the current growth rates of PV globally, nor does it fully consider the potential of PV in Ontario. 9 refs., 8 figs

Identification of bacterial blight resistance genes Xa4 in Pakistani ...

African Journals Online (AJOL)

SERVER

2008-03-04

Mar 4, 2008 ... Bacterial blight (BB) caused by Xanthomonas oryzae pv oryzae (Xoo) is a major biotic constraint in the irrigated rice belts. Genetic resistance is the most effective and economical control for bacterial blight. Molecular survey was conducted to identify the rice germplasm/lines for the presence of Xa4, a.

A detailed thermal-electrical model of three photovoltaic/thermal (PV/T) hybrid air collectors and photovoltaic (PV) module: Comparative study under Algiers climatic conditions

International Nuclear Information System (INIS)

Slimani, Mohamed El Amine; Amirat, Madjid; Kurucz, Ildikó; Bahria, Sofiane; Hamidat, Abderrahmane; Chaouch, Wafa Braham

2017-01-01

Highlights: • A detailed thermal and electrical model for PV and PV/T systems has been presented. • The developed numerical model was validated successfully with previously published experimental results. • A comparative study between four solar devices (PV and PV/T systems) was carried out. • The experimental weather conditions of Algiers site are used in the numerical model. • The glazed double-pass photovoltaic/thermal air collector shows the best overall energy efficiency. - Abstract: The thermal photovoltaic hybrid collector is a genuine cogeneration technology; it can produce electricity and heat simultaneously. In this paper, a comparative study is presented between four solar device configurations: photovoltaic module (PV-I), conventional hybrid solar air collector (PV/T-II), glazed hybrid solar air collector (PV/T-III) and glazed double-pass hybrid solar air collector (PV/T-IV). A numerical model is developed and validated through experimental results indicated in the previous literature. The numerical model takes the heat balance equations and different thermal and electrical parameters into account for each configuration included in this study, the energy performances are evaluated with a sample weather data of Algiers site. The numerical results show that the daily average of overall energy efficiency reaches: 29.63%, 51.02%, 69.47% and 74% for the first (PV-I), the second (PV/T-II), the third (PV/T-III) and the fourth (PV/T-IV) configurations respectively. These values are obtained with an air flow of 0.023 kg/s and introducing a sample of experimental weather data collected in Algiers site for a sunny day in summer.

Impact of residential PV adoption on Retail Electricity Rates

International Nuclear Information System (INIS)

Cai, Desmond W.H.; Adlakha, Sachin; Low, Steven H.; De Martini, Paul; Mani Chandy, K.

2013-01-01

The price of electricity supplied from home rooftop photo voltaic (PV) solar cells has fallen below the retail price of grid electricity in some areas. A number of residential households have an economic incentive to install rooftop PV systems and reduce their purchases of electricity from the grid. A significant portion of the costs incurred by utility companies are fixed costs which must be recovered even as consumption falls. Electricity rates must increase in order for utility companies to recover fixed costs from shrinking sales bases. Increasing rates will, in turn, result in even more economic incentives for customers to adopt rooftop PV. In this paper, we model this feedback between PV adoption and electricity rates and study its impact on future PV penetration and net-metering costs. We find that the most important parameter that determines whether this feedback has an effect is the fraction of customers who adopt PV in any year based solely on the money saved by doing so in that year, independent of the uncertainties of future years. These uncertainties include possible changes in rate structures such as the introduction of connection charges, the possibility of PV prices dropping significantly in the future, possible changes in tax incentives, and confidence in the reliability and maintainability of PV. -- Highlights: •Households who install PV reduce their electricity consumption from the grid. •Electricity rates must increase for utility companies to recover its fixed costs. •However, higher electricity rates give households more incentives to adopt PV. •We find that this feedback has significant impact on PV uptake only in later years. •Utility companies could lose a significant fraction of high consumption customers

Remote and Centralized Monitoring of PV Power Plants

DEFF Research Database (Denmark)

Kopacz, Csaba; Spataru, Sergiu; Sera, Dezso

2014-01-01

the inverters within each PV plant. The monitoring software stores the PV measurements in a data warehouse optimized for managing and data mining large amounts of data, from where it can be later visualized, analyzed and exported. By combining PV production measurements data with I-V curve measurements...

SunShot 2030 for Photovoltaics (PV): Envisioning a Low-cost PV Future

Energy Technology Data Exchange (ETDEWEB)

Cole, Wesley J. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Frew, Bethany A. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gagnon, Pieter J. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Richards, James [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sun, Yinong [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Margolis, Robert M. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Woodhouse, Michael A. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-09-12

In this report we summarize the implications, impacts, and deployment potential of reaching the SunShot 2030 targets for the electricity system in the contiguous United States. We model 25 scenarios of the U.S. power sector using the Regional Energy Deployment Systems (ReEDS) and Distributed Generation (dGen) capacity expansion models. The scenarios cover a wide range of sensitivities to capture future uncertainties relating to fuel prices, retirements, renewable energy capital costs, and load growth. We give special attention to the potential for storage costs to also rapidly decline due to its large synergies with low-cost solar. The ReEDS and dGen models project utility- and distributed-scale power sector evolution, respectively, for the United States. Both models have been designed with special emphasis on capturing the unique traits of renewable energy, including variability and grid integration requirements. Across the suite of scenarios modeled, we find that reaching the SunShot 2030 target has the potential to lead to significant capacity additions of PV in the United States. By 2050, PV penetration levels are projected to reach 28-46 percent of total generation. If storage also sees significant reductions in cost, then the 2050 solar penetration levels could reach 41-64 percent. PV deployment is projected to occur in all of the lower 48 states, though the specific deployment level is scenario dependent. The growth in PV is projected to be dominated by utility-scale systems, but the actual mix between utility and distributed systems could ultimately vary depending on how policies, system costs, and rate structures evolve.

The Value of Transparency in Distributed Solar PV Markets

Energy Technology Data Exchange (ETDEWEB)

OShaughnessy, Eric J. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Margolis, Robert M. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-10-09

Distributed solar photovoltaic (PV) markets are relatively non-transparent: PV price and product information is not readily available, searching for this information is costly (in terms of time and effort), and customers are mostly unfamiliar with the new technology. Quote aggregation, where third-party companies collect PV quotes on behalf of customers, may be one way to increase PV market transparency. In this paper, quote aggregation data are analyzed to study the value of transparency for distributed solar PV markets. The results suggest that easier access to more quotes results in lower prices. We find that installers tend to offer lower prices in more competitive market environments. We supplement the empirical analysis with key findings from interviews of residential PV installers.

Low concentrator PV optics optimization

Science.gov (United States)

Sharp, Leonard; Chang, Ben

2008-08-01

Purpose: Cost reduction is a major focus of the solar industry. Thin film technologies and concentration systems are viable ways to reducing cost, with unique strengths and weakness for both. Most of the concentrating PV work focuses on high concentration systems for reducing energy cost. Meanwhile, many believe that low concentrators provide significant cost reduction potential while addressing the mainstream PV market with a product that acts as a flat panel replacement. This paper analyzes the relative benefit of asymmetric vs. symmetric optics for low-concentrators in light of specific PV applications. Approach: Symmetric and asymmetric concentrating PV module performance is evaluated using computer simulation to determine potential value across various geographic locations and applications. The selected optic design is modeled against standard cSi flat panels and thin film to determine application fit, system level energy density and economic value. Results: While symmetric designs may seem ideal, asymmetric designs have an advantage in energy density. Both designs are assessed for aperture, optimum concentration ratio, and ideal system array configuration. Analysis of performance across climate specific effects (diffuse, direct and circumsolar) and location specific effects (sunpath) are also presented. The energy density and energy production of low concentrators provide a compelling value proposition. More significantly, the choice of optics for a low concentrating design can affect real world performance. With the goal of maximizing energy density and return on investment, this paper presents the advantages of asymmetric optic concentration and illustrates the value of this design within specific PV applications.

Some factors affecting reproduction in the Rice weevil Sitophilus Oryzae (L.)

International Nuclear Information System (INIS)

Hasaballa, Z.A.; Abdelkawy, F.K.

1992-01-01

Laboratory investigations on the effects or radiation, type of food and population density on the reproductive potential of the rice weevil. Sitophilus Oryzae were conducted at 30 degree C. and 75% R.H. The results indicate that the survival number of adult weevils infesting wheat grains increased markedly after 45 and 90 days of infestation. The survival and reproductive potential of the rice weevils declined significantly after exposure to gamma rays. This decline was more pronounced after 90 days and appeared to be markedly dose dependent. It was noticed that the rate of reproduction of the rice weevils was greatly influenced by insect crowding, science adults of S. Oryzae reared under crowded conditions failed to increase in numbers for 3 months as was expected. The reproduction of S. Oryzae was affected by the type of food. Wheat grains were more suitable than rice and maize grains as the average survival numbers of S. Oryzae reared on wheat grains were more after 45 and 90 days than those reared on rice and maize grains.3 tab

Commercialization and business development of grid-connected PV at SMUD

International Nuclear Information System (INIS)

Osborn, D.E.

1998-01-01

SMUD has completed its first 5 year, 6 MW PV commercialization effort based on the sustained, orderly development of the utility PV market. SMUD has begun a 5 year, 10 MW program designed to complete a process that will result in PV being at a market competitive price by 2002 and as a sustainable business opportunity for SMUD. As part of this effort, by the end of 1997, SMUD had installed over 450 PV systems totaling 6 MW. These included over 420 residential rooftop systems as well as commercial buildings, parking lots and substation systems. Under its new Business Plan, SMUD has signed contracts for an additional 10 MW of PV systems for 1998 through 2002 with cost decreasing to less than $3/W. As part of its new competitive business strategy responding to changes the utility industry is undergoing, SMUD has incorporated PV as a key business opportunity. SMUD has established partnerships with its customers through the PV Pioneer green pricing program, with DOE and UPVG through TEAM-UP and Million Solar Roofs to advance PV commercialization and to develop rooftops as PV power plant sites and with other utilities through its PV Partnership program

Elimination of Sitophilus oryzae (L.) by irradiation

Energy Technology Data Exchange (ETDEWEB)

Castro, Fernanda Peixoto [Exercito Brasileiro, Brasilia, DF (Brazil). Diretoria de Suprimento. Dept. Logistico]. E-mail: peixotocastro@dlog.eb.mil.br; Vital, Helio de Carvalho [Centro Tecnologico do Exercito (CTEx), Rio de Janeiro, RJ (brazil)]. E-mail: vital@ctex.eb.br

2005-07-01

Food treatment by exposure to ionizing radiation, known as food irradiation, presents several attractive features such as: leaving no residues, posing no threat to consumer health, usually causing no damage to sensory or nutritional properties and acting uniformly throughout the volume of the products. This work investigated the efficiency of irradiation for eliminating Sitophilus oryzae (L.), also known as 'the rice weevil', a small beetle frequently found in infested grains. A total of 444 individuals of Sitophilus oryzae (L.) found in corn meal and noodles supplies were irradiated with gamma ray doses of 0, 0.6, 0.9, 1.0, 1.2, 1.5 and 2.0 kGy and then visually monitored for 4 days in order to determine the number of insects still alive. The least-squares fitting method was used to determine the survival curves as functions of post-irradiation time and dose. The living fraction of the irradiated population was found to decrease exponentially with time. The results indicated that doses of 2.0, 1.5 and 0.6 kGy cause immediate death, instantaneous immobility and death of the species within one week, respectively. The findings suggest that disinfestation of Sitophilus oryzae (L.) by irradiation is an interesting option to the dangerous use of toxic chemicals. (author)

Elimination of Sitophilus oryzae (L.) by irradiation

International Nuclear Information System (INIS)

Castro, Fernanda Peixoto

2005-01-01

Food treatment by exposure to ionizing radiation, known as food irradiation, presents several attractive features such as: leaving no residues, posing no threat to consumer health, usually causing no damage to sensory or nutritional properties and acting uniformly throughout the volume of the products. This work investigated the efficiency of irradiation for eliminating Sitophilus oryzae (L.), also known as 'the rice weevil', a small beetle frequently found in infested grains. A total of 444 individuals of Sitophilus oryzae (L.) found in corn meal and noodles supplies were irradiated with gamma ray doses of 0, 0.6, 0.9, 1.0, 1.2, 1.5 and 2.0 kGy and then visually monitored for 4 days in order to determine the number of insects still alive. The least-squares fitting method was used to determine the survival curves as functions of post-irradiation time and dose. The living fraction of the irradiated population was found to decrease exponentially with time. The results indicated that doses of 2.0, 1.5 and 0.6 kGy cause immediate death, instantaneous immobility and death of the species within one week, respectively. The findings suggest that disinfestation of Sitophilus oryzae (L.) by irradiation is an interesting option to the dangerous use of toxic chemicals. (author)

Rhizomucor miehei triglyceride lipase is processed and secreted from transformed Aspergillus oryzae.

Science.gov (United States)

Huge-Jensen, B; Andreasen, F; Christensen, T; Christensen, M; Thim, L; Boel, E

1989-09-01

The cDNA encoding the precursor of the Rhizomucor miehei triglyceride lipase was inserted in an Aspergillus oryzae expression vector. In this vector the expression of the lipase cDNA is under control of the Aspergillus oryzae alpha-amylase gene promoter and the Aspergillus niger glucoamylase gene terminator. The recombinant plasmid was introduced into Aspergillus oryzae, and transformed colonies were selected and screened for lipase expression. Lipase-positive transformants were grown in a small fermentor, and recombinant triglyceride lipase was purified from the culture broth. The purified enzymatically active recombinant lipase (rRML) secreted from A. oryzae was shown to have the same characteristics with respect to mobility on reducing SDS-gels and amino acid composition as the native enzyme. N-terminal amino acid sequencing indicated that approximately 70% of the secreted rRML had the same N-terminal sequence as the native Rhizomucor miehei enzyme, whereas 30% of the secreted rRML was one amino acid residue shorter in the N-terminal. The recombinant lipase precursor, which has a 70 amino acid propeptide, is thus processed in and secreted from Aspergillus oryzae. We have hereby demonstrated the utility of this organism as a host for the production of recombinant triglyceride lipases.

Recombinant expression and purification of an Oxysterol Binding Protein from Aspergillus oryzae 3.042

Directory of Open Access Journals (Sweden)

Zhang Xian

2017-01-01

Full Text Available A full-length cDNA encoding a candidate Oxysterol-binding protein(OSBP from Aspergillus oryzae (AoOSBP was cloned and expressed in Escherichia coli as a maltose-binding protein (MBP fusion protein. The MBP-AoOSBP protein from the importantly industrial fungus A. oryzae was purified by amylose resin and chromatography column. SDS-PAGE showed that MBP-AoOSBP has an estimated molecular weight of 182 kDa. OSBP and its homologues (ORPs own the affinity for oxysterols, cholesterol and glycerophospholipids. According to the superiority of A. oryzae in the fermented foods and also in food-grade productions pharmaceutical enzyme manufacture, it is meaningful to identify the biochemical properties of OSBP in A. oryzae.

TRNSYS HYBRID wind diesel PV simulator

Energy Technology Data Exchange (ETDEWEB)

Quinlan, P.J.A.; Mitchell, J.W.; Klein, S.A.; Beckman, W.A.; Blair, N.J. [Univ. of Wisconsin, Madison, WI (United States)

1996-12-31

The Solar Energy Laboratory (SEL) has developed a wind diesel PV hybrid systems simulator, UW-HYBRID 1.0, an application of the TRNSYS 14.2 time-series simulation environment. An AC/DC bus links up to five diesels and wind turbine models, along with PV modules, a battery bank, and an AC/DC converter. Multiple units can be selected. PV system simulations include solar angle and peak power tracking options. Weather data are Typical Meteorological Year data, parametrically generated synthesized data, or external data files. PV performance simulations rely on long-standing SEL-developed algorithms. Loads data are read as scalable time series. Diesel simulations include estimated fuel-use and waste heat output, and are dispatched using a least-cost of fuel strategy. Wind system simulations include varying air density, wind shear and wake effects. Time step duration is user-selectable. UW-HYBRID 1.0 runs in Windows{reg_sign}, with TRNSED providing a customizable user interface. 12 refs., 6 figs.

Environmental and exergy benefit of nanofluid-based hybrid PV/T systems

International Nuclear Information System (INIS)

Hassani, Samir; Saidur, R.; Mekhilef, Saad; Taylor, Robert A.

2016-01-01

Highlights: • Environmental and ExPBT analysis of different PV/T configurations is presented. • The exergy payback time of nanofluid-based hybrid PV/T system is about 2 years. • Nanofluid-based hybrid PV/T system is a reliable solution for pollution prevention. • Nanofluid-based hybrid PV/T system is highly recommended at high solar concentration. - Abstract: Photovoltaic/thermal (PV/T) solar systems, which produce both electrical and thermal energy simultaneously, represent a method to achieve very high conversion rates of sunlight into useful energy. In recent years, nanofluids have been proposed as efficient coolants and optical filter for PV/T systems. Aim of this paper is to theoretically analyze the life cycle exergy of three different configurations of nanofluids-based PV/T hybrid systems, and compare their performance to a standard PV and PV/T system. Electrical and thermal performance of the analyzed solar collectors was investigated numerically. The life cycle exergy analysis revealed that the nanofluids-based PV/T system showed the best performance compared to a standard PV and PV/T systems. At the optimum value of solar concentration C, nanofluid-based PV/T configuration with optimized optical and thermal properties produces ∼1.3 MW h/m 2 of high-grade exergy annually with the lowest exergy payback time of 2 years, whereas these are ∼0.36, ∼0.79 MW h/m 2 and 3.48, 2.55 years for standard PV and PV/T systems, respectively. In addition, the nanofluids-based PV/T system can prevent the emissions of about 448 kg CO 2 eq m −2 yr −1 . Overall, it was found that the nanofluids-based PV/T with optimized optical and thermal properties has potential for further development in a high-concentration solar system.

Less CO2 by means of photovoltaic energy (PV)

International Nuclear Information System (INIS)

Alsema, E.A.; Van Brummelen, M.

1992-11-01

Regarding the title subject special attention is paid to the technical limitations of a fast introduction of the use of photovoltaic (PV) energy conversion. After a brief introduction on PV systems and the operation of a solar cell in chapter two, a state of the art is given of PV technology and possible price developments for PV modules and Balance-Of-System (BOS) components up to the year 2000 in chapters three and four. In chapter five the potential of installing grid-connected PV systems in the Netherlands is determined, taking into account the options of using existing buildings (PV systems on the roof), unexplored ground, in the verge of highways or railroads, industrial areas and airports. In chapter six non-economical bottlenecks for a large-scale introduction of grid-connected PV systems are discussed: the industrial production capacity for PV modules and other components, the fitting-in into the public electricity supply, and institutional aspects of installing PV systems on roofs. In chapter seven it is determined how much costs can be saved and CO 2 emission can be reduced when PV capacity is fitted-in into the Dutch electric power supply. The calculations are based on the Global Shift scenario. In chapter eight two scenarios (an optimistic scenario and a more realistic scenario) for the introduction of PV systems are outlined. For both scenarios the financial consequences and the contribution to the electric power supply are indicated. In chapter nine the net energy yield, being the result of the previously discussed introduction scenarios, is calculated, followed by a calculation of the avoided CO 2 emission, as well as the costs to avoid such emission. 25 figs., 15 tabs., 116 refs., 1 annex

Accelerating residential PV expansion: supply analysis for competitive electricity markets

International Nuclear Information System (INIS)

Payne, Adam; Williams, Robert H.; Duke, Richard

2001-01-01

Photovoltaic (PV) technology is now sufficiently advanced that market support mechanisms such as net metering plus a renewable portfolio standard (RPS) could induce rapid PV market growth in grid-connected applications. With such support mechanisms, markets would be sufficiently large that manufacturers could profitably build and operate 100 MW p /yr PV module factories, and electricity costs for residential rooftop PV systems would compare favorably with residential electricity prices in certain areas (e.g., California and the greater New York region in the US). This prospect is illustrated by economic and market analyses for one promising technology (amorphous silicon thin-film PV) from the perspectives of both module manufacturers and buyers of new homes with rooftop PV systems. With public policies that reflect the distributed and environmental benefits offered by PV-and that can sustain domestic PV market demand growth at three times the historical growth rate for a period of the order of two decades - PV could provide 3% of total US electricity supply by 2025. (Author)

The Arabidopsis thaliana non-specific phospholipase C2 is involved in the response to Pseudomonas syringae attack

Czech Academy of Sciences Publication Activity Database

Krčková, Zuzana; Kocourková, Daniela; Daněk, Michal; Brouzdová, Jitka; Pejchar, Přemysl; Janda, Martin; Pokotylo, I.; Ott, P.G.; Valentová, O.; Martinec, Jan

2018-01-01

Roč. 121, č. 2 (2018), s. 297-310 ISSN 0305-7364 R&D Projects: GA ČR(CZ) GAP501/12/1942 Institutional support: RVO:61389030 Keywords : Arabidopsis thaliana * effector-triggered immunity * flagellin * MAMP-triggered immunity * non-specific phospholipase C * phosphatidylcholine-specific phospholipase C * Pseudomonas syringae * reactive oxygen species Subject RIV: ED - Physiology OBOR OECD: Plant sciences, botany Impact factor: 4.041, year: 2016

PV panel model based on datasheet values

DEFF Research Database (Denmark)

Sera, Dezso; Teodorescu, Remus; Rodriguez, Pedro

2007-01-01

This work presents the construction of a model for a PV panel using the single-diode five-parameters model, based exclusively on data-sheet parameters. The model takes into account the series and parallel (shunt) resistance of the panel. The equivalent circuit and the basic equations of the PV cell....... Based on these equations, a PV panel model, which is able to predict the panel behavior in different temperature and irradiance conditions, is built and tested....

Good and bad practices in pv plants

OpenAIRE

Martinez Moreno, Francisco; Helleputte, F.; Tyutyundzhiev, N.; Rabal Echeverria, Daniel; Conlon, Michael; Fartaria, Tomás; Oteiza, David

2013-01-01

The PVCROPS project (PhotoVolta ic Cost r€duction, Reliability, Operational performance, Prediction and Simulation), cofinanced by European Commission in the frame of Seventh Framework Programme, has compiled in the “Good and bad practices: Manual to improve the quality and reduce the cost of PV systems” a collection of good and bad practices in actual PV plants . All the situations it collects represent the state-of-the-art of existing PV installations all around Europe. They show how ...

Real Time Photovoltaic Array Simulator for Testing Grid-Connected PV Inverters

DEFF Research Database (Denmark)

Sera, Dezso; Valentini, Massimo; Raducu, Alin

2008-01-01

In this paper a real time flexible PV array simulator is presented. It is a system that can simulate different PV panel arrays in specific environmental conditions. To evaluate performance of the Maximum Power Point Tracking (MPPT) of grid-connected Photovoltaic (PV) inverters only measurements...... undertaken with an appropriate PV array simulator provide accurate and reproducible results. Thus the PV array simulator has been developed and implemented. MPPT efficiency tests on a commercial grid-connected PV inverter have been performed to validate the PV array simulator....

Energy metrics analysis of hybrid - photovoltaic (PV) modules

Energy Technology Data Exchange (ETDEWEB)

Tiwari, Arvind [Department of Electronics and Communication, Krishna Institute of Engineering and Technology, 13 k.m. stone, Ghaziabad - Meerut Road, Ghaziabad 201 206, UP (India); Barnwal, P.; Sandhu, G.S.; Sodha, M.S. [Centre for Energy Studies, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110 016 (India)

2009-12-15

In this paper, energy metrics (energy pay back time, electricity production factor and life cycle conversion efficiency) of hybrid photovoltaic (PV) modules have been analyzed and presented for the composite climate of New Delhi, India. For this purpose, it is necessary to calculate (1) the energy consumption in making different components of the PV modules and (2) the annual energy (electrical and thermal) available from the hybrid-PV modules. A set of mathematical relations have been reformulated for computation of the energy metrics. The manufacturing energy, material production energy, energy use and distribution energy of the system have been taken into account, to determine the embodied energy for the hybrid-PV modules. The embodied energy and annual energy outputs have been used for evaluation of the energy metrics. For hybrid PV module, it has been observed that the EPBT gets significantly reduced by taking into account the increase in annual energy availability of the thermal energy in addition to the electrical energy. The values of EPF and LCCE of hybrid PV module become higher as expected. (author)

Real time PV manufacturing diagnostic system

Energy Technology Data Exchange (ETDEWEB)

Kochergin, Vladimir [MicroXact Inc., Blacksburg, VA (United States); Crawford, Michael A. [MicroXact Inc., Blacksburg, VA (United States)

2015-09-01

The main obstacle Photovoltaic (PV) industry is facing at present is the higher cost of PV energy compared to that of fossil energy. While solar cell efficiencies continue to make incremental gains these improvements are so far insufficient to drive PV costs down to match that of fossil energy. Improved in-line diagnostics however, has the potential to significantly increase the productivity and reduce cost by improving the yield of the process. On this Phase I/Phase II SBIR project MicroXact developed and demonstrated at CIGS pilot manufacturing line a high-throughput in-line PV manufacturing diagnostic system, which was verified to provide fast and accurate data on the spatial uniformity of thickness, an composition of the thin films comprising the solar cell as the solar cell is processed reel-to-reel. In Phase II project MicroXact developed a stand-alone system prototype and demonstrated the following technical characteristics: 1) ability of real time defect/composition inconsistency detection over 60cm wide web at web speeds up to 3m/minute; 2) Better than 1mm spatial resolution on 60cm wide web; 3) an average better than 20nm spectral resolution resulting in more than sufficient sensitivity to composition imperfections (copper-rich and copper-poor regions were detected). The system was verified to be high vacuum compatible. Phase II results completely validated both technical and economic feasibility of the proposed concept. MicroXact’s solution is an enabling technique for in-line PV manufacturing diagnostics to increase the productivity of PV manufacturing lines and reduce the cost of solar energy, thus reducing the US dependency on foreign oil while simultaneously reducing emission of greenhouse gasses.

Methods for the Optimal Design of Grid-Connected PV Inverters

DEFF Research Database (Denmark)

Koutroulis, Eftichios; Blaabjerg, Frede

2011-01-01

and the efficient processing of this power by the DC/AC inverter. In this paper two new methods are presented for the optimal design of a PV inverter power section, output filter and MPPT control strategy. The influences of the electric grid regulations and standards as well as the PV array operational......The DC/AC inverters are used in grid-connected PV energy production systems as the power processing interface between the PV energy source and the electric grid. The energy injected into the electric grid by the PV installation depends on the amount of power extracted from the PV power source...

L-lactic acid production from starch by simultaneous saccharification and fermentation in a genetically engineered Aspergillus oryzae pure culture.

Science.gov (United States)

Wakai, Satoshi; Yoshie, Toshihide; Asai-Nakashima, Nanami; Yamada, Ryosuke; Ogino, Chiaki; Tsutsumi, Hiroko; Hata, Yoji; Kondo, Akihiko

2014-12-01

Lactic acid is a commodity chemical that can be produced biologically. Lactic acid-producing Aspergillus oryzae strains were constructed by genetic engineering. The A. oryzae LDH strain with the bovine L-lactate dehydrogenase gene produced 38 g/L of lactate from 100g/L of glucose. Disruption of the wild-type lactate dehydrogenase gene in A. oryzae LDH improved lactate production. The resulting strain A. oryzae LDHΔ871 produced 49 g/L of lactate from 100g/L of glucose. Because A. oryzae strains innately secrete amylases, A. oryzae LDHΔ871 produced approximately 30 g/L of lactate from various starches, dextrin, or maltose (all at 100 g/L). To our knowledge, this is the first report describing the simultaneous saccharification and fermentation of lactate from starch using a pure culture of transgenic A. oryzae. Our results indicate that A. oryzae could be a promising host for the bioproduction of useful compounds such as lactic acid. Copyright © 2014 Elsevier Ltd. All rights reserved.

Identification and toxigenic potential of the industrially important fungi, Aspergillus oryzae and Aspergillus sojae.

Science.gov (United States)

Jørgensen, Thomas R

2007-12-01

Mold strains belonging to the species Aspergillus oryzae and Aspergillus sojae are highly valued as koji molds in the traditional preparation of fermented foods, such as miso, sake, and shoyu, and as protein production hosts in modern industrial processes. A. oryzae and A. sojae are relatives of the wild molds Aspergillus flavus and Aspergillus parasiticus. All four species are classified to the A. flavus group. Strains of the A. flavus group are characterized by a high degree of morphological similarity. Koji mold species are generally perceived of as being nontoxigenic, whereas wild molds are associated with the carcinogenic aflatoxins. Thus, reliable identification of individual strains is very important for application purposes. This review considers the pheno- and genotypic markers used in the classification of A. flavus group strains and specifically in the identification of A. oryzae and A. sojae strains. Separation of A. oryzae and A. sojae from A. flavus and A. parasiticus, respectively, is inconsistent, and both morphologic and molecular evidence support conspecificity. The high degree of identity is reflected by the divergent identification of reference cultures maintained in culture collections. As close relatives of aflatoxin-producing wild molds, koji molds possess an aflatoxin gene homolog cluster. Some strains identified as A. oryzae and A. sojae have been implicated in aflatoxin production. Identification of a strain as A. oryzae or A. sojae is no guarantee of its inability to produce aflatoxins or other toxic metabolites. Toxigenic potential must be determined specifically for individual strains. The species taxa, A. oryzae and A. sojae, are currently conserved by societal issues.

Abscisic acid-cytokinin antagonism modulates resistance against pseudomonas syringae in Tobacco

DEFF Research Database (Denmark)

Grosskinsky, Dominik Kilian; van der Graaff, Eric; Roitsch, Thomas Georg

2014-01-01

Phytohormones are known as essential regulators of plant defenses, with ethylene, jasmonic acid, and salicylic acid as the central immunity backbone, while other phytohormones have been demonstrated to interact with this. Only recently, a function of the classic phytohormone cytokinin in plant...... immunity has been described in Arabidopsis, rice, and tobacco. Although interactions of cytokinins with salicylic acid and auxin have been indicated, the complete network of cytokinin interactions with other immunity-relevant phytohormones is not yet understood. Therefore, we studied the interaction...... of kinetin and abscisic acid as a negative regulator of plant immunity to modulate resistance in tobacco against Pseudomonas syringae. By analyzing infection symptoms, pathogen proliferation, and accumulation of the phytoalexin scopoletin as a key mediator of kinetin-induced resistance in tobacco...

Design Optimization of Transformerless Grid-Connected PV Inverters Including Reliability

OpenAIRE

Koutroulis, Eftichios; Blaabjerg, Frede

2013-01-01

This paper presents a new methodology for optimal design of transformerless photovoltaic (PV) inverters targeting a cost-effective deployment of grid-connected PV systems. The optimal switching frequency as well as the optimal values and types of the PV inverter components is calculated such that the PV inverter LCOE generated during the PV system lifetime period is minimized. The LCOE is also calculated considering the failure rates of the components, which affect the reliability performance...

Terawatt Challenge for Thin-Film PV

Energy Technology Data Exchange (ETDEWEB)

Zweibel, K.

2005-08-01

The evolution of PV into one of the world's largest industries is not going to happen without major unforeseen problems. However, this study attempts to address the obvious ones, so that we can put aside the mythology of PV (for example, that it is only ''boutique power'' or that one must pave the world with it to be useful) and get on with changing the world's energy infrastructure. With the years of rapid market growth now under way in PV, the author is sure this will not be the last effort to understand the real potential and pitfalls of meeting the Challenge.

Correlation between temperature and phenology prediction error in rice (Oryza sativa L.)

NARCIS (Netherlands)

Oort, van P.A.J.; Zhang, T.; Vries, de M.E.; Heinemann, A.B.; Meinke, H.B.

2011-01-01

For rice (Oryza sativa L.), simulation models like ORYZA2000 and CERES-Rice have been used to explore adaptation options to climate change and weather-related stresses (drought, heat). Output of these models is very sensitive to accurate modelling of crop development, i.e. phenology. What has to

Utilization of Aspergillus oryzae to produce pectin lyase from various agro-industrial residues

Directory of Open Access Journals (Sweden)

Safia Koser

2014-07-01

Full Text Available The present study was aimed to investigate the culture influence on pectin lyase production potential of fungal strain Aspergillus oryzae. The enzyme profile of A. oryzae showed highest activity of pectin lyase after 3rd day of incubation on lemon peel waste under solid state fermentation conditions. To induce the pectin lyase synthesis capability of A. oryzae at optimal level various culture variables including physical and nutritional parameters were optimized by adopting classical optimization technique. Therefore, through fermentation process optimization the production of pectin lyase was substantially induced up to the level of 875 U/mL, when fermentation medium of lemon peel waste inoculated with 5 mL spore suspension of A. oryzae. The optimal fermentation conditions for maximum pectin lyase yield were as: optimum pH 5, 70% moisture level and incubated at 40 °C in addition with 1% sterile glucose solution as readily available carbon source and 0.2% yeast extract as an inexpensive nitrogen supplement (1%. The results obtained in current investigation so far demonstrated that culture conditions have great influence on the pectin lyase production potential of A. oryzae.

National survey report on PV power applications in Switzerland 2006

International Nuclear Information System (INIS)

Huesser, P.; Hostettler, T.

2007-01-01

This annual report was published by the Swiss Federal Office of Energy (SFOE) as part of the International Energy Agency's work on the exchange and dissemination of information on photovoltaic power systems (PVPS). The political situation in Switzerland with regard to the promotion of photovoltaics (PV) and new legislation in the energy area is discussed. The report provides information on installed PV power, costs and prices and the Swiss PV industry. Examples of PV applications are presented and data on the cumulative installed PV power in various application sectors is presented and discussed. Highlights, major projects and various demonstration and field-test programmes are dealt with, as are public budgets for market stimulation. Figures on the development, production and prices of PV cells and modules are presented. Swiss balance-of-system products are reviewed, as are PV-related services and the value of the Swiss PV business. A review of non-technical factors and new initiatives completes the report.

National survey report on PV power applications in Switzerland 2006

Energy Technology Data Exchange (ETDEWEB)

Huesser, P. [Nova Energie GmbH, Aarau (Switzerland); Hostettler, T. [Ingenieurbuero Hostettler, Berne (Switzerland)

2007-07-01

This annual report was published by the Swiss Federal Office of Energy (SFOE) as part of the International Energy Agency's work on the exchange and dissemination of information on photovoltaic power systems (PVPS). The political situation in Switzerland with regard to the promotion of photovoltaics (PV) and new legislation in the energy area is discussed. The report provides information on installed PV power, costs and prices and the Swiss PV industry. Examples of PV applications are presented and data on the cumulative installed PV power in various application sectors is presented and discussed. Highlights, major projects and various demonstration and field-test programmes are dealt with, as are public budgets for market stimulation. Figures on the development, production and prices of PV cells and modules are presented. Swiss balance-of-system products are reviewed, as are PV-related services and the value of the Swiss PV business. A review of non-technical factors and new initiatives completes the report.

Accelerating residential PV expansion: demand analysis for competitive electricity markets

International Nuclear Information System (INIS)

Duke, Richard; Williams, Robert; Payne, Adam

2005-01-01

This article quantifies the potential market for grid-connected, residential photovoltaic (PV) electricity integrated into new homes built in the US. It complements an earlier supply-side analysis by the authors that demonstrates the potential to reduce PV module prices below $1.5/W p by scaling up existing thin-film technology in 100 MW p /yr manufacturing facilities. The present article demonstrates that, at that price, PV modules may be cost effective in 125,000 new home installations per year (0.5 GW p /yr). While this market is large enough to support multiple scaled up thin-film PV factories, inefficient energy pricing and demand-side market failures will inhibit prospective PV consumers without strong public policy support. Net metering rules, already implemented in many states to encourage PV market launch, represent a crude but reasonable surrogate for efficient electricity pricing mechanisms that may ultimately emerge to internalize the externality benefits of PV. These public benefits include reduced air pollution damages (estimated costs of damage to human health from fossil fuel power plants are presented in Appendix A), deferral of transmission and distribution capital expenditures, reduced exposure to fossil fuel price risks, and increased electricity system reliability for end users. Thus, net metering for PV ought to be implemented as broadly as possible and sustained until efficient pricing is in place. Complementary PV 'buydowns' (e.g., a renewable portfolio standard with a specific PV requirement) are needed to jumpstart regional PV markets

Do feed-in tariffs drive PV cost or viceversa?

International Nuclear Information System (INIS)

Antonelli, Marco; Desideri, Umberto

2014-01-01

Highlights: • The distribution of PV installations on the territory is not a function of the solar radiation. • Cost of PV plants were adapted to the FIT framework. • The FIT for PV in Italy was considered an incentive to financial investment. • The FIT for PV in Italy did not stimulate the development of national PV industry. - Abstract: A survey of the PV market in Italy was done studying a number of installations of different sizes whose economic data were known and assessed. The Italian market has experienced a boom in the PV market after the first mechanism of feed-in tariffs was promoted in 2005. The variations of the tariff structure in the following years have caused significant changes in the market structure in terms of average size and technical characteristics of installed plants. However, an Italian PV industry was not stimulated by the incentives and only companies involved in installation and maintenance were created. At the same time, the cost of the PV plants components, design and commissioning have followed quite a particular trend, which is more determined by the tariffs than by the market development and structure. It is quite clear that the costs of PV plants component are not driven by the amount of installations but by the tariffs, with a trend that follows the decreases in the incentives and not the global installed power. It is therefore very important to study the right tariff mechanisms and benefits to avoid financial disturbances on the market and to promote a real competitive market instead of a simple financial operation under a fake façade of green economy

Solar Energy: Incentives to Promote PV in EU27

Directory of Open Access Journals (Sweden)

María del P. Pablo-Romero

2013-11-01

Full Text Available The growth in the use of renewable energies in the EU has been remarkable. Among these energies is PV. The average annual growth rate for the EU-27 countries in installed PV capacity in the period 2005-2012 was 41.2%. While the installed capacity of PV has reached almost 82 % of National Renewable Energy Action Plan (NREAP targets for the EU-27 countries for 2020, it is still far from being used at its full potential. Over recent years, several measures have been adopted in the EU to enhance and promote PV. This paper undertakes a complete review of the state of PV power in Europe and the measures taken to date to promote it in EU-27. 25 countries have adopted measures to promote PV. The most widespread measure to promote PV use is Feed- in Tariffs. Tariffs are normally adjusted, in a decreasing manner, annually. Nevertheless, currently, seven countries have decided to accelerate this decrease rate in view of cost reduction of the installations and of higher efficiencies. The second instrument used to promote PV in the EU-27 countries is the concession of subsidies. Nevertheless, subsidies have the disadvantage of being closely linked to budgetary resources and therefore to budgetary constraints. In most EU countries, subsidies for renewable energy for PV are being lowered. Twelve EU-27 countries adopted tax measures. Low-interest loans and green certificate systems were only sparingly used.

Kauai Island Utility Co-op (KIUC) PV integration study.

Energy Technology Data Exchange (ETDEWEB)

Ellis, Abraham; Mousseau, Tom (Knoxville, TN)

2011-08-01

This report investigates the effects that increased distributed photovoltaic (PV) generation would have on the Kauai Island Utility Co-op (KIUC) system operating requirements. The study focused on determining reserve requirements needed to mitigate the impact of PV variability on system frequency, and the impact on operating costs. Scenarios of 5-MW, 10-MW, and 15-MW nameplate capacity of PV generation plants distributed across the Kauai Island were considered in this study. The analysis required synthesis of the PV solar resource data and modeling of the KIUC system inertia. Based on the results, some findings and conclusions could be drawn, including that the selection of units identified as marginal resources that are used for load following will change; PV penetration will displace energy generated by existing conventional units, thus reducing overall fuel consumption; PV penetration at any deployment level is not likely to reduce system peak load; and increasing PV penetration has little effect on load-following reserves. The study was performed by EnerNex under contract from Sandia National Laboratories with cooperation from KIUC.

A global strategy for the European PV industry

International Nuclear Information System (INIS)

Viaud, M.; Despotou, E.; Latour, M.; Hoffmann, W.; Macias, E.; Cameron, M.; Laborde, E.

2004-01-01

The objective was to develop a comprehensive strategy that answers to the need of today European PV industry. Namely: - Develop PV markets in Europe - Develop export markets. - Position the European PV industry within the European political environment and support the effort of national actors in their local objectives. This method lends itself to brainstorming to create actions and synergies, on order to achieve strategy objectives. The whole work is based on working groups clearly defined on the purpose, where all EPIA members are invited to participate. The overall first results are presented during the 19. EU PV Conference in Paris and EPIA will do recommendations on actions to be undertaken in the future. This strategy is co-financed by EPIA members and the 6. Framework Programme for research of the European Commission through the PV Catapult project. (authors)

Aflatoxin B1 Detoxification by Aspergillus oryzae from Meju, a Traditional Korean Fermented Soybean Starter.

Science.gov (United States)

Lee, Kyu Ri; Yang, Sun Min; Cho, Sung Min; Kim, Myunghee; Hong, Sung-Yong; Chung, Soo Hyun

2016-11-04

Aflatoxins are classified as Group 1 (carcinogenic to humans) by the International Agency for Research on Cancer (IARC). In this study, a total of 134 fungal strains were isolated from 65 meju samples, and two fungal isolates were selected as potential aflatoxin B₁ (AFB₁)-biodetoxification fungi. These fungi were identified as Aspergillus oryzae MAO103 and A. oryzae MAO104 by sequencing the beta-tubulin gene. The two A. oryzae strains were able to degrade more than 90% of AFB1 (initial concentration: 40 µg/L) in a culture broth in 14 days. The mutagenic effects of AFB₁ treated with A. oryzae MAO103 and MAO104 significantly decreased to 5.7% and 6.4%, respectively, in the frame-shift mutation of Ames tests using Salmonella typhimurium TA 98. The base-substituting mutagenicity of AFB₁ was also decreased by the two fungi. Moreover, AFB1 production by A. flavus was significantly decreased by the two A. oryzae strains on soybean-based agar plates. Our data suggest that the two AFB1-detoxification A. oryzae strains have potential application to control AFB₁ in foods and feeds.

A Practical Optimization Method for Designing Large PV Plants

DEFF Research Database (Denmark)

Kerekes, Tamas; Koutroulis, E.; Eyigun, S.

2011-01-01

Nowadays Photovoltaic (PV) plants have multi MW sizes, the biggest plants reaching tens of MW of capacity. Such large-scale PV plants are made up of several thousands of PV panels, each panel being in the range of 150-350W. This means that the design of a Large PV power plant is a big challenge...... and configuring such a plant should be implemented taking into consideration not only the cost of the installation, but also the Annual Energy Production, the Performance Ratio and the Levelized Cost Of Energy. In this paper, an algorithm is presented including the most important models of the PV system...

Dynamics of Membrane Potential Variation and Gene Expression Induced by Spodoptera littoralis, Myzus persicae, and Pseudomonas syringae in Arabidopsis

Science.gov (United States)

Bricchi, Irene; Bertea, Cinzia M.; Occhipinti, Andrea; Paponov, Ivan A.; Maffei, Massimo E.

2012-01-01

Background Biotic stress induced by various herbivores and pathogens invokes plant responses involving different defense mechanisms. However, we do not know whether different biotic stresses share a common response or which signaling pathways are involved in responses to different biotic stresses. We investigated the common and specific responses of Arabidopsis thaliana to three biotic stress agents: Spodoptera littoralis, Myzus persicae, and the pathogen Pseudomonas syringae. Methodology/Principal Findings We used electrophysiology to determine the plasma membrane potential (Vm) and we performed a gene microarray transcriptome analysis on Arabidopsis upon either herbivory or bacterial infection. Vm depolarization was induced by insect attack; however, the response was much more rapid to S. littoralis (30 min −2 h) than to M. persicae (4–6 h). M. persicae differentially regulated almost 10-fold more genes than by S. littoralis with an opposite regulation. M. persicae modulated genes involved in flavonoid, fatty acid, hormone, drug transport and chitin metabolism. S. littoralis regulated responses to heat, transcription and ion transport. The latest Vm depolarization (16 h) was found for P. syringae. The pathogen regulated responses to salicylate, jasmonate and to microorganisms. Despite this late response, the number of genes differentially regulated by P. syringae was closer to those regulated by S. littoralis than by M. persicae. Conclusions/Significance Arabidopsis plasma membranes respond with a Vm depolarization at times depending on the nature of biotic attack which allow setting a time point for comparative genome-wide analysis. A clear relationship between Vm depolarization and gene expression was found. At Vm depolarization timing, M. persicae regulates a wider array of Arabidopsis genes with a clear and distinct regulation than S. littoralis. An almost completely opposite regulation was observed between the aphid and the pathogen, with the former

Improvement of heterologous protein production in Aspergillus oryzae by RNA interference with alpha-amylase genes.

Science.gov (United States)

Nemoto, Takashi; Maruyama, Jun-ichi; Kitamoto, Katsuhiko

2009-11-01

Aspergillus oryzae RIB40 has three alpha-amylase genes (amyA, amyB, and amyC), and secretes alpha-amylase abundantly. However, large amounts of endogenous secretory proteins such as alpha-amylase can compete with heterologous protein in the secretory pathway and decrease its production yields. In this study, we examined the effects of suppression of alpha-amylase on heterologous protein production in A. oryzae, using the bovine chymosin (CHY) as a reporter heterologous protein. The three alpha-amylase genes in A. oryzae have nearly identical DNA sequences from those promoters to the coding regions. Hence we performed silencing of alpha-amylase genes by RNA interference (RNAi) in the A. oryzae CHY producing strain. The silenced strains exhibited a reduction in alpha-amylase activity and an increase in CHY production in the culture medium. This result suggests that suppression of alpha-amylase is effective in heterologous protein production in A. oryzae.

PV investment in Europe

Energy Technology Data Exchange (ETDEWEB)

Hueser, Pius [Nova Energy GmbH, (Switzerland)

2007-06-15

This presentation is mainly about how the PV market in Europe has been growing, and which elements are going to determine if this market succeed or failed not only in Europe but also in the rest of the world. In the first part of this presentation, it is mentioned how in 2005 the development of some PV technologies triggered the PV market growth without any marketing control. Then, there are explained the aspects that changed such situation out of control, therefore, it emerged the beginning of the consolidation of this market. There are briefly explained those factors that are going to determine if this market succeed or failed in the future. Finally, there are given examples of some the PV investments. [Spanish] Esta presentacion habla principalmente de la manera en como ha crecido el Mercado de sistemas fotovoltaicos en Europa, asi tambien se mencionan los elementos fundamentales que determinaran el exito o fracaso de este mercado, no solamente en Europa sino tambien en el resto del mundo, en un futuro. En la primera parte de esta presentacion, se describe como en el 2005, debido al desarrollo de algunas tecnologias fotovoltaicas se desencadeno el crecimiento desenfrenado del mercado fotovoltaico. Despues, se explican los aspectos que hicieron que dicho crecimiento tomara su curso, teniendo como resultado el inicio de un mercado mas consolidado. Se explican brevemente los factores que determinaran si este mercado encuentra el exito o el fracaso en un futuro. Finalmente, se dan ejemplos de algunas adquisiciones fotovoltaicas.

China PV Business and Applications Evaluation; TOPICAL

International Nuclear Information System (INIS)

Sherring, Chris

1999-01-01

This report provides an overview of photovoltaics (PV) business and applications in China. Although more than 70 million people in China are without access to grid electricity, many of the unelectrified regions benefit from considerable renewable resources, including good solar insolation. Current annual PV sales are still modest, however, and are estimated to be between 2.0 and 2.5 megawatts. This and other significant PV data, including information regarding the current status of key aspects of Chinese businesses, markets, and distribution channels, are included in the report. Detailed company profiles of Chinese business organizations and summaries of visits made to these companies (as well as to more remote sites in Inner Mongolia to examine PV usage by the end-use customer) in September-October 1998 are also presented

Hpa1 harpin needs nitroxyl terminus to promote vegetative growth ...

Indian Academy of Sciences (India)

2014-01-27

Jan 27, 2014 ... When Hpa1 was applied to plants, it acted to enhance the vegetative growth but did not affect the .... Plants were grown in pots containing potting soils in an environ- mentally .... adapted to dark for 20 minutes and then adjusted to PPFD 1500 ... X. oryzae pv. oryzae Hpa1 contains 140 amino acids and has.

Rating PV Power and Energy: Cell, Module, and System Measurements

Energy Technology Data Exchange (ETDEWEB)

Emery, Keith

2016-06-02

A summary of key points related to research-level measurements of current vs. voltage measurement theory including basic PV operation, equivalent circuit, and concept of spectral error; PV power performance including PV irradiance sensors, simulators and commercial and generic I-V systems; PV measurement artifacts, intercomparisons, and alternative rating methods.

Pathway and rate-limiting step of glyphosate degradation by Aspergillus oryzae A-F02.

Science.gov (United States)

Fu, Gui-Ming; Chen, Yan; Li, Ru-Yi; Yuan, Xiao-Qiang; Liu, Cheng-Mei; Li, Bin; Wan, Yin

2017-09-14

Aspergillus oryzae A-F02, a glyphosate-degrading fungus, was isolated from an aeration tank in a pesticide factory. The pathway and rate-limiting step of glyphosate (GP) degradation were investigated through metabolite analysis. GP, aminomethylphosphonic acid (AMPA), and methylamine were detected in the fermentation liquid of A. oryzae A-F02, whereas sarcosine and glycine were not. The pathway of GP degradation in A. oryzae A-F02 was revealed: GP was first degraded into AMPA, which was then degraded into methylamine. Finally, methylamine was further degraded into other products. Investigating the effects of the exogenous addition of substrates and metabolites showed that the degradation of GP to AMPA is the rate-limiting step of GP degradation by A. oryzae A-F02. In addition, the accumulation of AMPA and methylamine did not cause feedback inhibition in GP degradation. Results showed that degrading GP to AMPA was a crucial step in the degradation of GP, which determines the degradation rate of GP by A. oryzae A-F02.

Deletion of creB in Aspergillus oryzae increases secreted hydrolytic enzyme activity.

Science.gov (United States)

Hunter, A J; Morris, T A; Jin, B; Saint, C P; Kelly, J M

2013-09-01

Aspergillus oryzae has been used in the food and beverage industry for centuries, and industrial strains have been produced by multiple rounds of selection. Targeted gene deletion technology is particularly useful for strain improvement in such strains, particularly when they do not have a well-characterized meiotic cycle. Phenotypes of an Aspergillus nidulans strain null for the CreB deubiquitinating enzyme include effects on growth and repression, including increased activity levels of various enzymes. We show that Aspergillus oryzae contains a functional homologue of the CreB deubiquitinating enzyme and that a null strain shows increased activity levels of industrially important secreted enzymes, including cellulases, xylanases, amylases, and proteases, as well as alleviated inhibition of spore germination on glucose medium. Reverse transcription-quantitative PCR (RT-qPCR) analysis showed that the increased levels of enzyme activity in both Aspergillus nidulans and Aspergillus oryzae are mirrored at the transcript level, indicating transcriptional regulation. We report that Aspergillus oryzae DAR3699, originally isolated from soy fermentation, has a similar phenotype to that of a creB deletion mutant of the RIB40 strain, and it contains a mutation in the creB gene. Collectively, the results for Aspergillus oryzae, Aspergillus nidulans, Trichoderma reesei, and Penicillium decumbens show that deletion of creB may be broadly useful in diverse fungi for increasing production of a variety of enzymes.

PV System Component Fault and Failure Compilation and Analysis.

Energy Technology Data Exchange (ETDEWEB)

Klise, Geoffrey Taylor; Lavrova, Olga; Gooding, Renee Lynne

2018-02-01

This report describes data collection and analysis of solar photovoltaic (PV) equipment events, which consist of faults and fa ilures that occur during the normal operation of a distributed PV system or PV power plant. We present summary statistics from locations w here maintenance data is being collected at various intervals, as well as reliability statistics gathered from that da ta, consisting of fault/failure distributions and repair distributions for a wide range of PV equipment types.

Aspergillus oryzae NRRL 35191 from coffee, a non-toxigenic endophyte with the ability to synthesize kojic acid

Science.gov (United States)

Aspergillus oryzae was isolated as an endophyte from coffee leaves and found to produce kojic acid in culture. When inoculated in cacao seedlings (Theobroma cacao L.), A. oryzae grew endophytically and synthesize kojic acid in planta. Cacao seedlings inoculated with A. oryzae produced higher levels...

Examples of successful architectural integration of PV: Germany

International Nuclear Information System (INIS)

Hagemann, I.B.

2004-01-01

In Germany building-integrated photovoltaics (BIPV) are developing rapidly, and much progress has been achieved in the past five years. BIPV can be used today in different ways on both existing and new buildings. Architects and designers are discovering BIPV. With the help of custom-made products available on the German market they are beginning to explore the technical limits of an aesthetic and structural integration of PV in buildings. As a result some exciting high-profile building projects with PV have been built, for example, the small service pavilion Meereslauschen in Steinhude or the new headquarters building of the Wood Trade Association in Munich. These projects show that the use of PV is very varied and offers opportunities for creative architects. However non-technical problems still need to be solved to allow a meaningful and widespread application of PV in the built environment. To decrease costs it is essential to develop further standard BIPV components. The aim of such developments should be to replace standard PV modules by products in which PV and structural building elements are melded into one design and structural unit. (author)

PV experience curves for the Netherlands

International Nuclear Information System (INIS)

Gerwig, R.

2005-01-01

Experience curves are one of several tools used by policy makers to take a look at market development. Numerous curves have been constructed for PV but none specific to the Netherlands. The objective of this report is to take a look at the price development of grid-connected PV systems in the Netherlands using the experience curve theory. After a literature and internet search and attempts to acquire information from PV companies information on 51% of the totally installed capacity was found. Curves for the period 1991-2001 were constructed based on system price, BOS (balance-of-system) price and inverter price. The progress ratio of the locally learning BOS was similar to the globally learning module market. This indicates that the pace of development of the Dutch PV market is similar to the globally followed pace. Improvement of the detail of the data might help to get a better idea of which BOS components have declined most. The similar progress ratio also shows the importance of investing both in module and system research as is the case in the Netherlands

Optimal design of orientation of PV/T collector with reflectors

International Nuclear Information System (INIS)

Kostic, Lj.T.; Pavlovic, T.M.; Pavlovic, Z.T.

2010-01-01

Hybrid conversion of solar radiation implies simultaneous solar radiation conversion into thermal and electrical energy in the PV/Thermal collector. In order to get more thermal and electrical energy, flat solar radiation reflectors have been mounted on PV/T collector. To obtain higher solar radiation intensity on PV/T collector, position of reflectors has been changed and optimal position of reflectors has been determined by both experimental measurements and numerical calculation so as to obtain maximal concentration of solar radiation intensity. The calculated values have been found to be in good agreement with the measured ones, both yielding the optimal position of the flat reflector to be the lowest (5 o ) in December and the highest (38 o ) in June. In this paper, the thermal and electrical efficiency of PV/T collector without reflectors and with reflectors in optimal position have been calculated. Using these results, the total efficiency and energy-saving efficiency of PV/T collector have been determined. Energy-saving efficiency for PV/T collector without reflectors is 60.1%, which is above the conventional solar thermal collector, whereas the energy-saving efficiency for PV/T collector with reflectors in optimal position is 46.7%, which is almost equal to the values for conventional solar thermal collector. Though the energy-saving efficiency of PV/T collector decreases slightly with the solar radiation intensity concentration factor, i.e. the thermal and electrical efficiency of PV/T collector with reflectors are lower than those of PV/T collector without reflectors, the total thermal and electrical energy generated by PV/T collector with reflectors in optimal position are significantly higher than total thermal and electrical energy generated by PV/T collector without reflectors.

Battery storage for PV power systems: an overview

Energy Technology Data Exchange (ETDEWEB)

Chaurey, A; Deambi, S [Tata Energy Research Inst., New Delhi (India)

1992-06-01

Batteries used in photovoltaic applications are required to have particular properties in order to minimize the system cost, in addition to meeting stringent reliability requirements associated with PV system installations. The battery sizing, installations, operation and maintenance, thus, are fundamentally different from those used in several other energy storage applications. The current paper gives an overview of battery systems commonly used in PV installation, as well as several new options which are found suitable or have been modified suitably to meet PV energy storage requirements. The systems are discussed briefly with respect to their construction, performance characteristics and compatibility with PV systems. The battery sizing procedures are also reviewed. (Author).

Assessing the PV business opportunities in Greece

International Nuclear Information System (INIS)

Patlitzianas, Konstantinos D.; Skylogiannis, Georgios K.; Papastefanakis, Dimitrios

2013-01-01

Highlights: • An approach of qualitative judgments for the PV opportunities through the assessing of the licenses’ value in Greece. • It can be supplied in other countries by applying different weights to the criteria. • It can be used by everyone in order to find a suitable PV investment without the need of experts in the field. - Abstract: Greece, as a member of the European Union (EU), has undertaken the obligation to meet the expected goals for the penetration of Renewable Energy Sources (RES) in the national energy balance in compliance with “20–20–20” goals (20% of the Gross Energy Consumption and 40% of the Gross Electricity Consumption should be covered by RES). Although the development of RES, and particularly of Photovoltaic (PV), in Greece during the last years has presented a satisfactory growth, the country is still far away from the above goals. The main reason for this delay is that – except the financial crisis – many licenses are inactive and waiting funding in order to be utilized. Additionally, the latest law (L.4152/2013) has forbidden the interconnection of new PV power Plants to the grid until the end of 2013. The above fact determines the significance of the existing PV Licenses in achieving the national goals. The aim of this paper is to present an integrated approach of qualitative judgments for the PV business opportunities through the assessing of the licenses’ value in Greece. The approach, which is based on a Multi Criteria Decision Making (MCDM) theory of quantifying multiple qualitative judgments, takes into account the real factors which can affect the expected production and cost of the PV installation and therefore the RoI (Return of Investment)

Addressing firefighter safety around solar PV systems

Energy Technology Data Exchange (ETDEWEB)

Harris, B. [Sustainable Energy Technologies, Calgary, AB (Canada)

2010-11-15

The article discussed new considerations for installing photovoltaic (PV) systems that address the needs of fire service personnel. The presence of a PV system presents a multitude of dangers for firefighters, including electrical shock, the inhalation of toxic gases from being unable to cut a hole through the roof, falling debris and flying glass, and dead loading on a compromised structure and tripping on conduits. Mapping systems should be modified so that buildings with PV systems are identified for first responders, including firefighters who should learn that solar modules present an electrical hazard during the day but not at night; covering PV modules with foam or salvage covers may not shut the system down to a safe level; it takes a few moments for the power in PV modules to reduce to zero; and PV modules or conduit should never be cut, broke, chopped, or walked upon. The California Department of Forestry and Fire Protection recommends creating pathways and allowing easier access to the roof by setting the modules back from roof edges, creating a structurally sound pathway for firefighters to walk on and space to cut ventilation holes. However, the setback rule makes the economics of solar installation less viable for residential applications. The technological innovations aimed at addressing system safety all focus on limiting firefighter contact with live electrical components to within the extra-low-voltage (ELV) band. Some of the inverters on the market that support ELV system architecture were described. 1 fig.

Performance Parameters for Grid-Connected PV Systems

Energy Technology Data Exchange (ETDEWEB)

Marion, B.; Adelstein, J.; Boyle, K.; Hayden, H.; Hammond, B.; Fletcher, T.; Canada, B.; Narang, D.; Shugar, D.; Wenger, H.; Kimber, A.; Mitchell, L.; Rich, G.; Townsend, T.

2005-02-01

The use of appropriate performance parameters facilitates the comparison of grid-connected photovoltaic (PV) systems that may differ with respect to design, technology, or geographic location. Four performance parameters that define the overall system performance with respect to the energy production, solar resource, and overall effect of system losses are the following: final PV system yield, reference yield, performance ratio, and PVUSA rating. These performance parameters are discussed for their suitability in providing desired information for PV system design and performance evaluation and are demonstrated for a variety of technologies, designs, and geographic locations. Also discussed are methodologies for determining system a.c. power ratings in the design phase using multipliers developed from measured performance parameters.The use of appropriate performance parameters facilitates the comparison of grid-connected photovoltaic (PV) systems that may differ with respect to design, technology, or geographic location. Four performance parameters that define the overall system performance with respect to the energy production, solar resource, and overall effect of system losses are the following: final PV system yield, reference yield, performance ratio, and PVUSA rating. These performance parameters are discussed for their suitability in providing desired information for PV system design and performance evaluation and are demonstrated for a variety of technologies, designs, and geographic locations. Also discussed are methodologies for determining system a.c. power ratings in the design phase using multipliers developed from measured performance parameters.

A Software Tool for Optimal Sizing of PV Systems in Malaysia

Directory of Open Access Journals (Sweden)

Tamer Khatib

2012-01-01

Full Text Available This paper presents a MATLAB based user friendly software tool called as PV.MY for optimal sizing of photovoltaic (PV systems. The software has the capabilities of predicting the metrological variables such as solar energy, ambient temperature and wind speed using artificial neural network (ANN, optimizes the PV module/ array tilt angle, optimizes the inverter size and calculate optimal capacities of PV array, battery, wind turbine and diesel generator in hybrid PV systems. The ANN based model for metrological prediction uses four meteorological variables, namely, sun shine ratio, day number and location coordinates. As for PV system sizing, iterative methods are used for determining the optimal sizing of three types of PV systems, which are standalone PV system, hybrid PV/wind system and hybrid PV/diesel generator system. The loss of load probability (LLP technique is used for optimization in which the energy sources capacities are the variables to be optimized considering very low LLP. As for determining the optimal PV panels tilt angle and inverter size, the Liu and Jordan model for solar energy incident on a tilt surface is used in optimizing the monthly tilt angle, while a model for inverter efficiency curve is used in the optimization of inverter size.

The role of horizontal transfer in the evolution of a highly variable lipopolysaccharide biosynthesis locus in xanthomonads that infect rice, citrus and crucifers

Directory of Open Access Journals (Sweden)

Bogdanove Adam J

2007-12-01

Full Text Available Abstract Background Lipopolysaccharide (LPS is a pathogen associated molecular pattern (PAMP of animal and plant pathogenic bacteria. Variation at the interstrain level is common in LPS biosynthetic gene clusters of animal pathogenic bacteria. This variation has been proposed to play a role in evading the host immune system. Even though LPS is a modulator of plant defense responses, reports of interstrain variation in LPS gene clusters of plant pathogenic bacteria are rare. Results In this study we report the complete sequence of a variant 19.9 kb LPS locus present in the BXO8 strain of Xanthomonas oryzae pv. oryzae (Xoo, the bacterial blight pathogen of rice. This region is completely different in size, number and organization of genes from the LPS locus present in most other strains of Xoo from India and Asia. Surprisingly, except for one ORF, all the other ORFs at the BXO8 LPS locus are orthologous to the genes present at this locus in a sequenced strain of X. axonopodis pv. citri (Xac; a pathogen of citrus plants. One end of the BXO8 LPS gene cluster, comprised of ten genes, is also present in the related rice pathogen, X. oryzae pv. oryzicola (Xoc. In Xoc, the remainder of the LPS gene cluster, consisting of seven genes, is novel and unrelated to LPS gene clusters of any of the sequenced xanthomonads. We also report substantial interstrain variation suggestive of very recent horizontal gene transfer (HGT at the LPS biosynthetic locus of Xanthomonas campestris pv. campestris (Xcc, the black rot pathogen of crucifers. Conclusion Our analyses indicate that HGT has altered the LPS locus during the evolution of Xanthomonas oryzae pathovars and suggest that the ancestor of all Xanthomonas oryzae pathovars had an Xac type of LPS gene cluster. Our finding of interstrain variation in two major xanthomonad pathogens infecting different hosts suggests that the LPS locus in plant pathogenic bacteria, as in animal pathogens, is under intense

Evaluation of commercial soy sauce koji strains of Aspergillus oryzae for γ-aminobutyric acid (GABA) production.

Science.gov (United States)

Ab Kadir, Safuan; Wan-Mohtar, Wan Abd Al Qadr Imad; Mohammad, Rosfarizan; Abdul Halim Lim, Sarina; Sabo Mohammed, Abdulkarim; Saari, Nazamid

2016-10-01

In this study, four selected commercial strains of Aspergillus oryzae were collected from soy sauce koji. These A. oryzae strains designated as NSK, NSZ, NSJ and NST shared similar morphological characteristics with the reference strain (A. oryzae FRR 1675) which confirmed them as A. oryzae species. They were further evaluated for their ability to produce γ-aminobutyric acid (GABA) by cultivating the spore suspension in a broth medium containing 0.4 % (w/v) of glutamic acid as a substrate for GABA production. The results showed that these strains were capable of producing GABA; however, the concentrations differed significantly (P sauce production.

Delta Power Control Strategy for Multistring Grid-Connected PV Inverters

DEFF Research Database (Denmark)

Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

2017-01-01

, is required for grid support (e.g., during frequency deviation). In this paper, a cost-effective solution to realize delta power control (DPC) for grid-connected PV systems is presented, where the multistring PV inverter configuration is adopted. This control strategy is a combination of maximum power point...... tracking (MPPT) and constant power generation (CPG) modes. In this control scheme, one PV string operating in the MPPT mode estimates the available power, whereas the other PV strings regulate the total PV power by the CPG control strategy in such a way that the delta power constraint for the entire PV...... system is achieved. Simulations and experiments have been performed on a 3-kW single-phase grid-connected PV system. The results have confirmed the effectiveness of the proposed DPC strategy, where the power reserve according to the delta power constraint is achieved under several operating conditions....

The prospects for cost competitive solar PV power

International Nuclear Information System (INIS)

Reichelstein, Stefan; Yorston, Michael

2013-01-01

New solar Photovoltaic (PV) installations have grown globally at a rapid pace in recent years. We provide a comprehensive assessment of the cost competitiveness of this electric power source. Based on data available for the second half of 2011, we conclude that utility-scale PV installations are not yet cost competitive with fossil fuel power plants. In contrast, commercial-scale installations have already attained cost parity in the sense that the generating cost of power from solar PV is comparable to the retail electricity prices that commercial users pay, at least in certain parts of the U.S. This conclusion is shown to depend crucially on both the current federal tax subsidies for solar power and an ideal geographic location for the solar installation. Projecting recent industry trends into the future, we estimate that utility-scale solar PV facilities are on track to become cost competitive by the end of this decade. Furthermore, commercial-scale installations could reach “grid parity” in about ten years, if the current federal tax incentives for solar power were to expire at that point. - Highlights: ► Assessment of the cost competitiveness of new solar Photovoltaic (PV) installations. ► Utility-scale PV installations are not yet cost competitive with fossil fuel power plants. ► Commercial-scale installations have already attained cost parity in certain parts of the U.S. ► Utility-scale solar PV facilities are on track to become cost competitive by the end of this decade

Overview of Recent Grid Codes for PV Power Integration

DEFF Research Database (Denmark)

Craciun, Bogdan-Ionut; Kerekes, Tamas; Sera, Dezso

2012-01-01

The challenge to bring down the cost of produced photovoltaic (PV) power had a major impact on the PV market and in consequence the grid operators experienced higher and higher PV power penetration. The growing share of this decentralized generation plants started to affect the grid stability...

LonWorks as Fieldbus for PV-Installations; LonWorks als Feldbus fuer PV-Anlagen

Energy Technology Data Exchange (ETDEWEB)

Bergen, Ch. von

2003-07-01

The growing market for photovoltaics increasingly requires suitable quality controls covering plant operators, planners and installers, as well as the electric utilities. Additionally, the interest of the general public in the behaviour of photovoltaic (PV) plants is growing. This includes information from everyday practice. Alongside data retrieval, other themes such as the operative management of the unit and energy management become increasingly important for grid-connected PV systems. Todays measuring systems are not compatible with each other. Data communication between different PV plants with computer-aided analysis- and visualisation programmes is very complicated. LonWorks was introduced by Motorola and Toshiba in 1991. Today it leads the world market for field bus systems. With plug and play, components by several manufacturers can easily be incorporated into a LonWorks network. Today more than 3,500 companies use LonWorks technology. The goal of this project is to introduce the very popular LonWorks technology as a new standard for PV applications. The first objective was to develop a LonWorks interface for our Convert inverters and to connect them into a small network. In a second step we installed a LonWorks system at the 260 kW{sub p} PV plant 'Felsenau' in Berne, Switzerland. All 68 inverters are controlled over power line with LonWorks. The on-site PC acts as LonWorks DataServer and making remote information monitoring and data gathering possible. As soon as a functional error occurs, an alarm will be transmitted via modem to the SMSC (Short Message Service Centre). After two years of operation we can say that all expectations were fulfilled by our new system. Knowledge gained from this project has shown that LonWorks has lived up its considerable promise and can be regarded as a high-quality piece of technology. Integration into an overall system is technically very easy. To do this, however, relatively expensive software solutions have

Performance analysis of PV panel under varying surface temperature

Directory of Open Access Journals (Sweden)

Kumar Tripathi Abhishek

2018-01-01

Full Text Available The surface temperature of PV panel has an adverse impact on its performance. The several electrical parameters of PV panel, such as open circuit voltage, short circuit current, power output and fill factor depends on the surface temperature of PV panel. In the present study, an experimental work was carried out to investigate the influence of PV panel surface temperature on its electrical parameters. The results obtained from this experimental study show a significant reduction in the performance of PV panel with an increase in panel surface temperature. A 5W PV panel experienced a 0.4% decrease in open circuit voltage for every 1°C increase in panel surface temperature. Similarly, there was 0.6% and 0.32% decrease in maximum power output and in fill factor, respectively, for every 1°C increase in panel surface temperature. On the other hand, the short circuit current increases with the increase in surface temperature at the rate of 0.09%/°C.

Solar photovoltaic (PV) energy; latest developments in the building integrated and hybrid PV systems

International Nuclear Information System (INIS)

Zahedi, A.

2006-01-01

Environmental concerns are growing and interest in environmental issues is increasing and the idea of generating electricity with less pollution is becoming more and more attractive. Unlike conventional generation systems, fuel of the solar photovoltaic energy is available at no cost. And solar photovoltaic energy systems generate electricity pollution-free and can easily be installed on the roof of residential as well as on the wall of commercial buildings as grid-connected PV application. In addition to grid-connected rooftop PV systems, solar photovoltaic energy offers a solution for supplying electricity to remote located communities and facilities, those not accessible by electricity companies. The interest in solar photovoltaic energy is growing worldwide. Today, more than 3500MW of photovoltaic systems have been installed all over the world. Since 1970, the PV price has continuously dropped [8]. This price drop has encouraged worldwide application of small-scale residential PV systems. These recent developments have led researchers concerned with the environment to undertake extensive research projects for harnessing renewable energy sources including solar energy. The usage of solar photovoltaic as a source of energy is considered more seriously making future of this technology looks promising. The objective of this contribution is to present the latest developments in the area of solar photovoltaic energy systems. A further objective of this contribution is to discuss the long-term prospect of the solar photovoltaic energy as a sustainable energy supply. [Author

Comparison of the genomes and transcriptomes associated with the different protease secretions of Aspergillus oryzae 100-8 and 3.042.

Science.gov (United States)

Zhao, Guozhong; Yao, Yunping; Hou, Lihua; Wang, Chunling; Cao, Xiaohong

2014-10-01

Aspergillus oryzae is used to produce traditional fermented foods and beverages. A. oryzae 3.042 produces a neutral protease and an alkaline protease but rarely an acid protease, which is unfavourable to soy-sauce fermentation. A. oryzae 100-8 was obtained by N(+) ion implantation mutagenesis of A. oryzae 3.042, and the protease secretions of these two strains are different. Sequencing the genome of A. oryzae 100-8 and comparing it to the genomes of A. oryzae 100-8 and 3.042 revealed some differences, such as single nucleotide polymorphisms, nucleotide deletion or insertion. Some of these differences may reflect the ability of A. oryzae to secrete proteases. Transcriptional sequencing and analysis of the two strains during the same growth processes provided further insights into the genes and pathways involved in protease secretion.

A strategic model for PV dissemination in Thailand

Energy Technology Data Exchange (ETDEWEB)

Hiranvarodom, S. [Rajamangala Inst. of Technology, Dept. of Electrical Engineering, Pathumthani (Thailand); Hill, R. [University of Northumbria, Newcastle Photovoltaics Applications Centre, Newcastle upon Tyne (United Kingdom); O' Keefe, P. [University of Northumbria, Dept. of Geography and Environmental Management, Newcastle upon Tyne (United Kingdom)

1999-07-01

The process of information dissemination is necessary for the successful implementation for photovoltaic (PV) programmes in developing countries, and it is essential to consider the strategies for implementation of a PV project to ensure that it will be successful. This paper proposes a strategic model for PV dissemination in Thailand and discusses the roles of key players in the implementation of the strategy and the responsibilities of these organisations. (Author)

The world PV market 2000: shifting from subsidy to 'fully economic'?

International Nuclear Information System (INIS)

Maycock, Paul

2000-01-01

This article presents an overview of the world grid-connected photovoltaic (PV) market concentrating on the US, Japan and Germany. The PV markets in the three countries are examined, and PV module shipments, the economics of residential PVs in the markets, and forecasts of the grid-connected market are discussed. Details are given of the German 100,000 roofs PV roof subsidy programme to stimulate the residential and commercial grid-connected market. A summary of the grid-connected PV markets in the three countries, and economic information on German grid-connected PV roofs are tabulated

Water Extract from Spent Mushroom Substrate of Hericium erinaceus Suppresses Bacterial Wilt Disease of Tomato

Science.gov (United States)

Kwak, A Min; Min, Kyeong Jin; Lee, Sang Yeop

2015-01-01

Culture filtrates of six different edible mushroom species were screened for antimicrobial activity against tomato wilt bacteria Ralstonia solanacearum B3. Hericium erinaceus, Lentinula edodes (Sanjo 701), Grifola frondosa, and Hypsizygus marmoreus showed antibacterial activity against the bacteria. Water, n-butanol, and ethyl acetate extracts of spent mushroom substrate (SMS) of H. erinaceus exhibited high antibacterial activity against different phytopathogenic bacteria: Pectobacterium carotovorum subsp. carotovorum, Agrobacterium tumefaciens, R. solanacearum, Xanthomonas oryzae pv. oryzae, X. campestris pv. campestris, X. axonopodis pv. vesicatoria, X. axonopodis pv. citiri, and X. axonopodis pv. glycine. Quantitative real-time PCR revealed that water extracts of SMS (WESMS) of H. erinaceus induced expressions of plant defense genes encoding β-1,3-glucanase (GluA) and pathogenesis-related protein-1a (PR-1a), associated with systemic acquired resistance. Furthermore, WESMS also suppressed tomato wilt disease caused by R. solanacearum by 85% in seedlings and promoted growth (height, leaf number, and fresh weight of the root and shoot) of tomato plants. These findings suggest the WESMS of H. erinaceus has the potential to suppress bacterial wilt disease of tomato through multiple effects including antibacterial activity, plant growth promotion, and defense gene induction. PMID:26539048

Economic perspective of PV electricity in Oman

International Nuclear Information System (INIS)

Al-Badi, A.H.; Albadi, M.H.; Al-Lawati, A.M.; Malik, A.S.

2011-01-01

Solar and wind energies are likely to play an important role in the future energy generation in Oman. This paper utilizes average daily global solar radiation and sunshine duration data of 25 locations in Oman to study the economic prospects of solar energy. The study considers a solar PV power plant of 5-MW at each of the 25 locations. The global solar radiation varies between slightly greater than 4 kWh/m 2 /day at Sur to about 6 kWh/m 2 /day at Marmul while the average value in the 25 locations is more than 5 kWh/m 2 /day. The results show that the renewable energy produced each year from the PV power plant varies between 9000 MWh at Marmul and 6200 MWh at Sur while the mean value is 7700 MWh of all the 25 locations. The capacity factor of PV plant varies between 20% and 14% and the cost of electricity varies between 210 US$/MWh and 304 US$/MWh for the best location to the least attractive location, respectively. The study has also found that the PV energy at the best location is competitive with diesel generation without including the externality costs of diesel. Renewable energy support policies that can be implemented in Oman are also discussed. -- Research highlights: → The global solar radiation values for 25 locations in Oman are obtained using satellite data that are corrected by data from ground stations. → The study considers a solar PV power plant of 5-MW to calculate the capacity factor (CF) and the cost of energy (COE) at each of the 25 locations. → The study has found that the CF of PV plant varies between 20% and 14% and the corresponding COE varies between 210 US$/MWh and 304 US$/MWh for the best location to the least attractive location, respectively. → The study has found that the PV energy at the best location is competitive with diesel generation without including the externality costs of diesel. → Since PV energy is not competitive with fossil fuel-based generation in most locations renewable energy support mechanisms have been

Photovoltaic (PV) contribution to the primary frequency control

International Nuclear Information System (INIS)

Rafa, Adel Hamad

2012-01-01

Photovoltaic (PV) technology is among the most efficient and cost effective renewable energy kinds currently available on the market. The connection of a large number of PVs to the grid may influence the frequency and voltage stability of the power system. This paper proposes load-frequency control technique for system with high penetration of photovoltaic (PV). The proposed controller has been successfully implemented and tested using PSCAD/EMTDC. In this study, the impact of photovoltaic (PV) on frequency stability of the system is studies in detail. This study shows that large penetration of photovoltaic (PV) with load and frequency control has a significant impact on the stability and security level of electrical network.(author)

Photovoltaic-thermal (PV/T) solar collectors: Features and performance modelling

International Nuclear Information System (INIS)

Atienza-Márquez, Antonio; Bruno, Joan Carles; Coronas, Alberto; Korolija, Ivan; Greenough, Richard; Wright, Andy

2017-01-01

Currently, the electrical efficiency of photovoltaic (PV) solar cells ranges between 5–25%. One of the most important parameters that affects the electrical efficiency of a PV collector is the temperature of its cells: the higher temperature, the lower is the efficiency. Photovoltaic/thermal (PV/T) technology is a potential solution to ensure an acceptable solar energy conversion. The PV/T technology produces both electrical and thermal energy simultaneously. It is suitable for low temperature applications (25–40 o C) and overall efficiency increases compared to individual collectors. This paper describes an installation in a single-family house where PV/T collectors are coupled with a ground heat exchanger and a heat pump for domestic hot water and space heating purposes. The aim of this work is twofold. First, the features of the PV/T technology are analyzed. Second, a model of a flat-plate PV/T water collector was developed in TRNSYS in order to analyze collectors performance. (author)

Measurement and analysis on optical characteristics of Aspergillus oryzae spores in infrared band

Science.gov (United States)

Li, Le; Hu, Yihua; Gu, Youlin; Chen, Wei; Xu, Shilong; Zhao, Xinying

2015-10-01

Spore is an important part of bioaerosols. The optical characteristics of spore is a crucial parameter for study on bioaerosols. The reflection within the waveband of 2.5 to15μm were measured by squash method. Based on the measured data, Complex refractive index of Aspergillus oryzae spores within the waveband of 3 to 5μm and 8 to 14 μm were calculated by using Krames-Kronig (K-K) relationship. Then,the mass extinction coefficient of Aspergillus oryzae spores within the waveband of 3 to 5μm and 8 to 14μm were obtained by utilizing Mie scattering theory, and the results were analyzed and discussed. The average mass extinction coefficient of Aspergillus oryzae spores is 0.51 m2/g in the range of 3 to 5μm and 0.48m2/g in the range of 8 to 14μm. Compared with common inorganic compounds, Aspergillus oryzae spores possesses a good extinction performance in infrared band.

Impact of Rooftop Solar PV on Residential Distribution Network

DEFF Research Database (Denmark)

Bhattarai, Bishnu Prasad; Bak-Jensen, Birgitte; Pillai, Jayakrishnan Radhakrishna

Increased environmental awareness in recent years has encouraged rapid growth of renewable energy sources especially solar PV and wind. Among them, small scale solar PV has been gaining more momentum especially at residential level. Even today moderate penetration of grid tied rooftop solar PV has...... become reality in many countries. In spite of various benefits, higher penetration of rooftop PVs might come up with number of detrimental effects, with power quality and overcurrent protection being the major ones. Therefore, it is reasonable to quantify both drawback and benefits of rooftop PV...

Autolysis of Aspergillus oryzae Mycelium and Effect on Volatile Flavor Compounds of Soy Sauce.

Science.gov (United States)

Xu, Ning; Liu, Yaqi; Hu, Yong; Zhou, Mengzhou; Wang, Chao; Li, Dongsheng

2016-08-01

The autolyzed mycelia of Aspergillus oryzae are rich in proteins, nucleic acids, sugar, and other biomacromolecules, and are one of the main contributors to the flavor profile of commercially important fermented goods, including soy sauce and miso. We induced autolysis of the mycelia of A. oryzae over 1 to 10 d, and found that the maximum dissolved amounts of total protein and nucleic acid ratio accounted for 28.63% and 88.93%, respectively. The organic acid content, such as citric acid, tartaric acid, succinic acid, lactic acid, and acetic acid, initially increased and then decreased as autolysis progressed, corresponding to changes in pH levels. The main characteristic flavor compounds in soy sauce, namely, ethanol, 2-phenylethanol, and 2-methoxy-4-vinylphenol, were all detected in the autolysate. Subsequently, we tested the effect of adding mycelia of A. oryzae during the fermentation process of soy sauce for 60 d, and found that addition of 1.2‰ A. oryzae mycelia provided the richest flavor. Overall, our findings suggest that compounds found in the autolysate of A. oryzae may promote the flavor compounds of soy sauce, such as alcohols, aldehydes, phenols, and esters. © 2016 Institute of Food Technologists®

A novel blast resistance gene, Pi54rh cloned from wild species of rice, Oryza rhizomatis confers broad spectrum resistance to Magnaporthe oryzae.

Science.gov (United States)

Das, Alok; Soubam, D; Singh, P K; Thakur, S; Singh, N K; Sharma, T R

2012-06-01

The dominant rice blast resistance gene, Pi54 confers resistance to Magnaporthe oryzae in different parts of India. In our effort to identify more effective forms of this gene, we isolated an orthologue of Pi54 named as Pi54rh from the blast-resistant wild species of rice, Oryza rhizomatis, using allele mining approach and validated by complementation. The Pi54rh belongs to CC-NBS-LRR family of disease resistance genes with a unique Zinc finger (C(3)H type) domain. The 1,447 bp Pi54rh transcript comprises of 101 bp 5'-UTR, 1,083 bp coding region and 263 bp 3'-UTR, driven by pathogen inducible promoter. We showed the extracellular localization of Pi54rh protein and the presence of glycosylation, myristoylation and phosphorylation sites which implicates its role in signal transduction process. This is in contrast to other blast resistance genes that are predicted to be intracellular NBS-LRR-type resistance proteins. The Pi54rh was found to express constitutively at basal level in the leaves, but upregulates 3.8-fold at 96 h post-inoculation with the pathogen. Functional validation of cloned Pi54rh gene using complementation test showed high degree of resistance to seven isolates of M. oryzae collected from different geographical locations of India. In this study, for the first time, we demonstrated that a rice blast resistance gene Pi54rh cloned from wild species of rice provides broad spectrum resistance to M. oryzae hence can be used in rice improvement breeding programme.

Improving the efficiency of photovoltaic (PV) panels by oil coating

International Nuclear Information System (INIS)

Abd-Elhady, M.S.; Fouad, M.M.; Khalil, T.

2016-01-01

Highlights: • It is possible to improve the efficiency of PV panels by increasing the amount of light transmitted to the panel. • Coating PV panels by a fine layer of Labovac oil increases the amount of sun light transmitted to the panel. • Coating PV panels by a fine layer of Labovac oil increases the power output of the panel. • Coating PV panels with a layer of Labovac oil has to be applied in cold countries and not in hot regions. - Abstract: The objective of this research is to develop a new technique for improving the efficiency of Photovoltaic (PV) panels. This technique is done by coating the front surface of the PV panel by a fine layer of oil in order to increase the amount of light transmitted to the panel, and consequently its efficiency. Different types of oils are examined, including both mineral oils and natural oils. In case of mineral oils; vacuum pump oil (Labovac oil), engine oil (Mobil oil) and brake oil (Abro oil) are examined, while in case of natural oils; olive and sunflower oils are examined. An experimental setup has been developed to examine the performance of the PV panels as a function of oil coatings. The experimental setup consists of an artificial sun, the PV panel under investigation, a cooling system and a measuring system to measure the performance of the panel. It has been found that coating the PV panel with a fine layer of Labovac oil, ∼1 mm thick, improves the efficiency of the PV panel by more than 20%, and this is due to the high transmissivity of the Labovac oil compared to other oils. However, the Labovac oil has a drawback which is overheating of the panel due to its high transmissivity. Coating of PV panels with a fine layer of Labovac oil should be done only in cold regions, in order to avoid the heating effect that can decrease the power output of PV panels.

Assessing the influence of the temporal resolution of electrical load and PV generation profiles on self-consumption and sizing of PV-battery systems

International Nuclear Information System (INIS)

Beck, T.; Kondziella, H.; Huard, G.; Bruckner, T.

2016-01-01

Highlights: • MILP optimization model for operation and investment of PV-battery systems. • Use of high resolution (10 s) electrical household load and PV generation profiles. • Analysis of influence of temporal resolution on self-consumption and optimal sizing. • Electrical load profile characteristics influence required temporal resolution. - Abstract: The interest in self-consumption of electricity generated by rooftop photovoltaic systems has grown in recent years, fueled by decreasing levelized costs of electricity and feed-in tariffs as well as increasing end customer electricity prices in the residential sector. This also fostered research on grid-connected PV-battery storage systems, which are a promising technology to increase self-consumption. In this paper a mixed-integer linear optimization model of a PV-battery system that minimizes the total discounted operating and investment costs is developed. The model is employed to study the effect of the temporal resolution of electrical load and PV generation profiles on the rate of self-consumption and the optimal sizing of PV and PV-battery systems. In contrast to previous studies high resolution (10 s) measured input data for both PV generation and electrical load profiles is used for the analysis. The data was obtained by smart meter measurements in 25 different households in Germany. It is shown that the temporal resolution of load profiles is more critical for the accuracy of the determination of self-consumption rates than the resolution of the PV generation. For PV-systems without additional storage accurate results can be obtained by using 15 min solar irradiation data. The required accuracy for the electrical load profiles depends strongly on the load profile characteristics. While good results can be obtained with 60 s for all electrical load profiles, 15 min data can still be sufficient for load profiles that do not exhibit most of their electricity consumption at power levels above 2 k

Design procedures of hybrid PV/SMES system

International Nuclear Information System (INIS)

Hamad, Ismail; El-Sayas, M. A.

2006-01-01

This paper presents accurate procedures to determine the design parameters of an autonomous hybrid PV/SMES system. Integrating Superconductive magnetic energy storage as a recent storage technology with photovoltaic power system enhances the PV output utilization during the solar radiation fluctuations period. this is because of SMES fast response to any PV output fluctuation. The load demand is supplied either from PV plant or through SMES or from both. Imposed to the technical and economical constrains, the optimum solar cells area and the proper capacity and rating of SMES system are assessed. Regarding solar radiation profile, clear and cloudy days are accurately considered for investigation. Three indices are suggested to express the cloudy and fluctuations conditions. These indices represent the non-utilized PV energy due to clouds (x), fluctuation period (T f ) and location of fluctuations period(t s t). The incremental changes in the design parameters are computed for any variation in these indices. Differentiation between the role of BS and SMES in affecting the results is determined and quantitatively analyzed. The results of clear day condition with SMES are the bas quantities for these changes. Complete analysis of the most effective parameters is presented. Eventually, mathematical models are deduced for each parameter which assists in predicting its behavior against the independent variable.(Author)

The Value of Transparency in Distributed Solar PV Markets | Solar Research

Science.gov (United States)

suggest that PV customers benefit from gaining access to more PV quotes. Context Prospective PV customers are relatively non-transparent; customers are largely unaware of market prices and may not obtain the lowest available price. PV customers that use quote aggregators-third-party companies that collect quotes

On the Impact of Partial Shading on PV Output Power

DEFF Research Database (Denmark)

Sera, Dezso; Baghzouz, Yahia

2008-01-01

clarifies the mechanism of partial PV shading on a number of PV cells connected in series and/or parallel with and without bypass diodes. The analysis is presented in simple terms and can be useful to someone who wishes to determine the impact of some shading geometry on a PV system. The analysis...... is illustrated by measurements on a commercial 70 W panel, and a 14.4 kW PV array....

Review of PV Inverter Technology Cost and Performance Projections

Energy Technology Data Exchange (ETDEWEB)

Navigant Consulting Inc.

2006-01-01

The National Renewable Energy Laboratory (NREL) has a major responsibility in the implementation of the U.S. Department of Energy's (DOE's) Solar Energy Technologies Program. Sandia National Laboratories (SNL) has a major role in supporting inverter development, characterization, standards, certifications, and verifications. The Solar Energy Technologies Program recently published a Multiyear Technical Plan, which establishes a goal of reducing the Levelized Energy Cost (LEC) for photovoltaic (PV) systems to $0.06/kWh by 2020. The Multiyear Technical Plan estimates that, in order to meet the PV system goal, PV inverter prices will need to decline to $0.25-0.30 Wp by 2020. DOE determined the need to conduct a rigorous review of the PV Program's technical and economic targets, including the target set for PV inverters. NREL requested that Navigant Consulting Inc.(NCI) conduct a review of historical and projected cost and performance improvements for PV inverters, including identification of critical barriers identified and the approaches government might use to address them.

Solar Photovoltaic (PV) Distributed Generation Systems - Control and Protection

Science.gov (United States)

Yi, Zhehan

This dissertation proposes a comprehensive control, power management, and fault detection strategy for solar photovoltaic (PV) distribution generations. Battery storages are typically employed in PV systems to mitigate the power fluctuation caused by unstable solar irradiance. With AC and DC loads, a PV-battery system can be treated as a hybrid microgrid which contains both DC and AC power resources and buses. In this thesis, a control power and management system (CAPMS) for PV-battery hybrid microgrid is proposed, which provides 1) the DC and AC bus voltage and AC frequency regulating scheme and controllers designed to track set points; 2) a power flow management strategy in the hybrid microgrid to achieve system generation and demand balance in both grid-connected and islanded modes; 3) smooth transition control during grid reconnection by frequency and phase synchronization control between the main grid and microgrid. Due to the increasing demands for PV power, scales of PV systems are getting larger and fault detection in PV arrays becomes challenging. High-impedance faults, low-mismatch faults, and faults occurred in low irradiance conditions tend to be hidden due to low fault currents, particularly, when a PV maximum power point tracking (MPPT) algorithm is in-service. If remain undetected, these faults can considerably lower the output energy of solar systems, damage the panels, and potentially cause fire hazards. In this dissertation, fault detection challenges in PV arrays are analyzed in depth, considering the crossing relations among the characteristics of PV, interactions with MPPT algorithms, and the nature of solar irradiance. Two fault detection schemes are then designed as attempts to address these technical issues, which detect faults inside PV arrays accurately even under challenging circumstances, e.g., faults in low irradiance conditions or high-impedance faults. Taking advantage of multi-resolution signal decomposition (MSD), a powerful signal

Lifetime Evaluation of PV Inverters considering Panel Degradation Rates and Installation Sites

DEFF Research Database (Denmark)

Sangwongwanich, Ariya; Yang, Yongheng; Sera, Dezso

2017-01-01

The PV inverter lifetime is affected by the installed sites related to different solar irradiance and ambient temperature profiles. In fact, the installation site also affects the PV panel degradation rate, and thus the long-term power production. Prior-art lifetime analysis in PV inverters has...... not yet investigated the impact of panel degradation. This paper thus evaluates the lifetime of PV inverters considering panel degradation rates and installation sites. Evaluations have been carried out on PV systems installed in Denmark and Arizona. The results reveal that the PV panel degradation rate...... has a considerable impact on the PV inverter lifetime, especially in the hot climate (e.g., Arizona), where the panel degrades at a faster rate. In that case, the PV inverter lifetime estimation can be deviated by 54%, if the impact of PV panel degradation is not taken into account....

Rise of a Cereal Killer: The Biology of Magnaporthe oryzae Biotrophic Growth.

Science.gov (United States)

Fernandez, Jessie; Orth, Kim

2018-01-23

The rice blast fungus, Magnaporthe oryzae, causes one of the most destructive diseases of cultivated rice in the world. Infections caused by this recalcitrant pathogen lead to the annual destruction of approximately 10-30% of the rice harvested globally. The fungus undergoes extensive developmental changes to be able to break into plant cells, build elaborate infection structures, and proliferate inside host cells without causing visible disease symptoms. From a molecular standpoint, we are still in the infancy of understanding how M. oryzae manipulates the host during this complex multifaceted infection. Here, we describe recent advances in our understanding of the cell biology of M. oryzae biotrophic interaction and key molecular factors required for the disease establishment in rice cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparative chemistry of Aspergillus oryzae (RIB40) and A. flavus (NRRL 3357)

DEFF Research Database (Denmark)

Rank, Christian; Klejnstrup, Marie Louise; Petersen, Lene Maj

2012-01-01

Aspergillus oryzae and A. flavus are important species in industrial biotechnology and food safety and have been some of the first aspergilli to be fully genome sequenced. Bioinformatic analysis has revealed 99.5% gene homology between the two species pointing towards a large coherence in the sec...... alkaloids related to the A. flavus metabolites ditryptophenalines and miyakamides. Generally the secondary metabolite capability of A. oryzae presents several novel end products likely to result from the domestication process from A. flavus.......Aspergillus oryzae and A. flavus are important species in industrial biotechnology and food safety and have been some of the first aspergilli to be fully genome sequenced. Bioinformatic analysis has revealed 99.5% gene homology between the two species pointing towards a large coherence...

Optimization of a PV/T (photovoltaic/thermal) active solar still

International Nuclear Information System (INIS)

Saeedi, F.; Sarhaddi, F.; Behzadmehr, A.

2015-01-01

In this paper, the optimization of a PV/T (photovoltaic/thermal) active solar still is carried out. Analytical expressions for glass cover temperature, basin temperature, brackish water temperature and fresh water productivity are obtained by writing energy balance for different components of PV/T active solar still. The output electrical power of PV/T active solar still is calculated by four-parameter I–V (current–voltage) model. Objective function in present study is the energy efficiency of PV/T active solar still. A computer simulation program has been developed in order to obtain thermal and electrical parameters, respectively. The simulation results of the present study are in fair agreement with the experimental data of previous literatures. Finally, the optimization of PV/T active solar still has been carried out and the optimized value of mass flow rate, number of PV/T collector and the objective function have been obtained. Furthermore, the effect of various operating parameters on energy efficiency have been investigated. - Highlights: • The comprehensive optimization of a PV/T active solar still is carried out. • Present study is based on numerical simulation. • A modified energy efficiency for PV/T active solar still is obtained. • The effect of design and operating parameters is investigated on energy efficiency

Design of direct solar PV driven air conditioner

KAUST Repository

Huang, Bin-Juine

2015-12-05

© 2015 Elsevier Ltd. Solar air conditioning system directly driven by stand-alone solar PV is studied. The air conditioning system will suffer from loss of power if the solar PV power generation is not high enough. It requires a proper system design to match the power consumption of air conditioning system with a proper PV size. Six solar air conditioners with different sizes of PV panel and air conditioners were built and tested outdoors to experimentally investigate the running probabilities of air conditioning at various solar irradiations. It is shown that the instantaneous operation probability (OPB) and the runtime fraction (RF) of the air conditioner are mainly affected by the design parameter rpL (ratio of maximum PV power to load power). The measured OPB is found to be greater than 0.98 at instantaneous solar irradiation IT > 600 W m-2 if rpL > 1.71 RF approaches 1.0 (the air conditioner is run in 100% with solar power) at daily-total solar radiation higher than 13 MJ m-2 day-1, if rpL > 3.

PV supply chain growing pains

Energy Technology Data Exchange (ETDEWEB)

Wilkins, A. [Matrix Energy Inc., Montreal, PQ (Canada)

2010-11-15

This article discussed issues involving the supply chain for photovoltaic (PV) equipment that is emerging in Ontario as a result of the Feed-in-Tariff (FIT) program that was launched in late 2009. The rapidly developing PV supply chain may not be taking a sustainable path. The domestic-content requirement is making manufacturers outlay capital to set up manufacturing in Ontario without reliable market data. Only a small number of dealer/installers have any meaningful experience designing and installing grid-tie PV. Until recently, wholesale distributors designed and supplied most grid-tie PV systems in Canada, and solar dealers/installers or electricians or electrical contractors did the installation. Instead of selling directly to dealer/installers, solar manufacturers should develop strong relationships with wholesalers, who have system design experience and product training. This would allow manufacturers to focus on their core strength, reach more customers, and keep lower inventory levels. Wholesale distributors in turn provide dealer/installers with expertise in product and system design, training from a range of manufacturers, marketing and logistics support, and immediate access to inventory. Manufacturers generally lack appropriate accounting, engineering, marketing, and logistics services to deal with a multitude of active accounts, and they are not structured to work with architects and engineers to do complete system design. Partnering with wholesale distributors allows manufacturers to take on the residential and small-scale commercial sectors by building brand awareness and increasing market share and sales across Canada. 2 figs.