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1

World-Wide Importance of Phoma Stem Canker ( Leptosphaeria maculans and L. biglobosa ) on Oilseed Rape ( Brassica napus )  

Microsoft Academic Search

Phoma stem canker is an internationally important disease of oilseed rape (Brassica napus, canola, rapeseed), causing serious losses in Europe, Australia and North America. UK losses of €56M per season are estimated\\u000a using national disease survey data and a yield loss formula. Phoma stem canker pathogen populations comprise two main species,\\u000a Leptosphaeria maculans, associated with damaging stem base cankers, and

B. D. L. Fitt; H. Brun; M. J. Barbetti; S. R. Rimmer

2006-01-01

2

Most AAL Toxin-Sensitive Nicotiana Species are Resistant to the Tomato Fungal Pathogen Alternaria alternata f. sp. lycopersici  

Microsoft Academic Search

The phytopathogenic fungus Alternaria alternata f. sp. lycopersici produces AAL toxins required to colonize susceptible tomato (Lycopersicon esculentum) plants. AAL toxins and fumonisins of the unrelated fungus Fusarium moniliforme are sphinganine-analog mycotoxins (SAMs), which are toxic for some plant species and mammalian cell lines. Insensitivity of tomato to SAMs is determined by the Alternaria stem canker gene 1 (Asc-1), and

Bas F. Brandwagt; Tarcies J. A. Kneppers; Gerard M. van der Weerden; H. John J. Nijkamp; Jacques Hille

2001-01-01

3

Phosphonate applied by trunk injection controls stem canker and decreases Phytophthora pod rot (black pod) incidence in cocoa in Sulawesi  

Microsoft Academic Search

Stem canker and Phytophthora pod rot (PPR) or black pod caused by Phytophthora palmivora are serious diseases of cocoa (Theobroma cacao L.) in Sulawesi, Indonesia, causing high yield losses for smallholders, possibly exceeded only by losses due to the cocoa\\u000a pod borer (CPB), Conopomorpha cramerella. Potassium phosphonate (phosphite) applied by trunk injection has been demonstrated to effectively control canker and

P. J. McMahon; A. Purwantara; A. Wahab; M. Imron; S. Lambert; P. J. Keane; D. I. Guest

2010-01-01

4

Stability of Sweet Potato Cultivars to Alternaria Leaf and Stem Blight Disease  

Technology Transfer Automated Retrieval System (TEKTRAN)

Alternaria leaf petiole and stem blight is an economically important disease of sweet potato (Ipomoea batatus L) in tropical and sub-tropical environments. Published research on cultivar resistance to the sweet potato disease is limited. To evaluate cultivar reaction and stability to the disease, mu...

5

TPCP: Pitch canker PITCH CANKER  

E-print Network

TPCP: Pitch canker PITCH CANKER INTRODUCTION Pitch canker is one of the most serious threats crown. Large amounts of pitch accumulate on and below the cankers. The wood beneath the cankers is deeply pitch soaked, often to the pith. This characteristic distinguishes pitch canker, from cankers

6

Assessing quantitative resistance against Leptosphaeria maculans (phoma stem canker) in Brassica napus (oilseed rape) in young plants.  

PubMed

Quantitative resistance against Leptosphaeria maculans in Brassica napus is difficult to assess in young plants due to the long period of symptomless growth of the pathogen from the appearance of leaf lesions to the appearance of canker symptoms on the stem. By using doubled haploid (DH) lines A30 (susceptible) and C119 (with quantitative resistance), quantitative resistance against L. maculans was assessed in young plants in controlled environments at two stages: stage 1, growth of the pathogen along leaf veins/petioles towards the stem by leaf lamina inoculation; stage 2, growth in stem tissues to produce stem canker symptoms by leaf petiole inoculation. Two types of inoculum (ascospores; conidia) and three assessment methods (extent of visible necrosis; symptomless pathogen growth visualised using the GFP reporter gene; amount of pathogen DNA quantified by PCR) were used. In stage 1 assessments, significant differences were observed between lines A30 and C119 in area of leaf lesions, distance grown along veins/petioles assessed by visible necrosis or by viewing GFP and amount of L. maculans DNA in leaf petioles. In stage 2 assessments, significant differences were observed between lines A30 and C119 in severity of stem canker and amount of L. maculans DNA in stem tissues. GFP-labelled L. maculans spread more quickly from the stem cortex to the stem pith in A30 than in C119. Stem canker symptoms were produced more rapidly by using ascospore inoculum than by using conidial inoculum. These results suggest that quantitative resistance against L. maculans in B. napus can be assessed in young plants in controlled conditions. Development of methods to phenotype quantitative resistance against plant pathogens in young plants in controlled environments will help identification of stable quantitative resistance for control of crop diseases. PMID:24454767

Huang, Yong-Ju; Qi, Aiming; King, Graham J; Fitt, Bruce D L

2014-01-01

7

Assessing Quantitative Resistance against Leptosphaeria maculans (Phoma Stem Canker) in Brassica napus (Oilseed Rape) in Young Plants  

PubMed Central

Quantitative resistance against Leptosphaeria maculans in Brassica napus is difficult to assess in young plants due to the long period of symptomless growth of the pathogen from the appearance of leaf lesions to the appearance of canker symptoms on the stem. By using doubled haploid (DH) lines A30 (susceptible) and C119 (with quantitative resistance), quantitative resistance against L. maculans was assessed in young plants in controlled environments at two stages: stage 1, growth of the pathogen along leaf veins/petioles towards the stem by leaf lamina inoculation; stage 2, growth in stem tissues to produce stem canker symptoms by leaf petiole inoculation. Two types of inoculum (ascospores; conidia) and three assessment methods (extent of visible necrosis; symptomless pathogen growth visualised using the GFP reporter gene; amount of pathogen DNA quantified by PCR) were used. In stage 1 assessments, significant differences were observed between lines A30 and C119 in area of leaf lesions, distance grown along veins/petioles assessed by visible necrosis or by viewing GFP and amount of L. maculans DNA in leaf petioles. In stage 2 assessments, significant differences were observed between lines A30 and C119 in severity of stem canker and amount of L. maculans DNA in stem tissues. GFP-labelled L. maculans spread more quickly from the stem cortex to the stem pith in A30 than in C119. Stem canker symptoms were produced more rapidly by using ascospore inoculum than by using conidial inoculum. These results suggest that quantitative resistance against L. maculans in B. napus can be assessed in young plants in controlled conditions. Development of methods to phenotype quantitative resistance against plant pathogens in young plants in controlled environments will help identification of stable quantitative resistance for control of crop diseases. PMID:24454767

Huang, Yong-Ju; Qi, Aiming; King, Graham J.; Fitt, Bruce D. L.

2014-01-01

8

First report on the use of moderately halophilic bacteria against stem canker of greenhouse tomatoes caused by Botrytis cinerea  

Microsoft Academic Search

Experiments were conducted to study the effect of moderately halophilic bacteria isolated from different Tunisian Sebkhas\\u000a (hypersaline soils), on stem canker caused byBotrytis cinerea on tomato plants grown under greenhouse conditions. Treatments performed with moderately halophilic isolates ofBacillus subtilis J9 andHalomonas sp. K2-5 significantly reduced stem lesion expansion byB. cinerea on tomato plants under greenhouse conditions. The use of such

Najla Sadfi-Zouaoui; Badiâa Essghaier; Ibtissem Hannachi; Mohamed Rabeh Hajlaoui; Abdellatif Boudabous

2007-01-01

9

Inheritance of resistance to southern stem canker (Diaporthe phaseolorum f.s. meridionalis) in soybean [Glycine max (L.) Merr.  

E-print Network

heterozygous for reaction to the fungus. The segregation pattern observed among the Fz plants was characteristic for a 63:1 ratio (X =2. 78; P & 0. 05). The F, , lines followed a 37:26:1 ratio (X =4. 70; P & 0. 05), which is an expansion of the ti3... AND CONCLUSIONS REFERENCES 38 40 APPENDIX 44 71 LIST OF TABLES Page Table 1. Description of parent lines 14 Table 2. Crossing plan. 15 Table 3. Reaction of parent lines to stem canker . Table 4. Reaction of Crockett, Johnston, and their progenies...

Ngeleka, Kadima

1990-01-01

10

Canker sore  

MedlinePLUS

... and minerals in the diet (especially iron, folic acid , or vitamin B-12 ) Hormonal changes Food allergies Anyone can develop a canker sore. Women are more likely to get them than men. Canker sores may run in families.

11

Alternaria redefined  

PubMed Central

Alternaria is a ubiquitous fungal genus that includes saprobic, endophytic and pathogenic species associated with a wide variety of substrates. In recent years, DNA-based studies revealed multiple non-monophyletic genera within the Alternaria complex, and Alternaria species clades that do not always correlate to species-groups based on morphological characteristics. The Alternaria complex currently comprises nine genera and eight Alternaria sections. The aim of this study was to delineate phylogenetic lineages within Alternaria and allied genera based on nucleotide sequence data of parts of the 18S nrDNA, 28S nrDNA, ITS, GAPDH, RPB2 and TEF1-alpha gene regions. Our data reveal a Pleospora/Stemphylium clade sister to Embellisia annulata, and a well-supported Alternaria clade. The Alternaria clade contains 24 internal clades and six monotypic lineages, the assemblage of which we recognise as Alternaria. This puts the genera Allewia, Brachycladium, Chalastospora, Chmelia, Crivellia, Embellisia, Lewia, Nimbya, Sinomyces, Teretispora, Ulocladium, Undifilum and Ybotromyces in synonymy with Alternaria. In this study, we treat the 24 internal clades in the Alternaria complex as sections, which is a continuation of a recent proposal for the taxonomic treatment of lineages in Alternaria. Embellisia annulata is synonymised with Dendryphiella salina, and together with Dendryphiella arenariae, are placed in the new genus Paradendryphiella. The sexual genera Clathrospora and Comoclathris, which were previously associated with Alternaria, cluster within the Pleosporaceae, outside Alternaria s. str., whereas Alternariaster, a genus formerly seen as part of Alternaria, clusters within the Leptosphaeriaceae. Paradendryphiella is newly described, the generic circumscription of Alternaria is emended, and 32 new combinations and 10 new names are proposed. A further 10 names are resurrected, while descriptions are provided for 16 new Alternaria sections. Taxonomic novelties: New combinations - Alternaria abundans (E.G. Simmons) Woudenb. & Crous, Alternaria alternariae (Cooke) Woudenb. & Crous, Alternaria atra (Preuss) Woudenb. & Crous, Alternaria bornmuelleri (Magnus) Woudenb. & Crous, Alternaria botrytis (Preuss) Woudenb. & Crous, Alternaria caespitosa (de Hoog & C. Rubio) Woudenb. & Crous, Alternaria cantlous (Yong Wang bis & X.G. Zhang) Woudenb. & Crous, Alternaria caricis (E.G. Simmons) Woudenb. & Crous, Alternaria cinerea (Baucom & Creamer) Woudenb. & Crous, Alternaria didymospora (Munt.-Cvetk.) Woudenb. & Crous, Alternaria fulva (Baucom & Creamer) Woudenb. & Crous, Alternaria hyacinthi (de Hoog & P.J. Mull. bis) Woudenb. & Crous, Alternaria indefessa (E.G. Simmons) Woudenberg & Crous, Alternaria leptinellae (E.G. Simmons & C.F. Hill) Woudenb. & Crous, Alternaria lolii (E.G. Simmons & C.F. Hill) Woudenb. & Crous, Alternaria multiformis (E.G. Simmons) Woudenb. & Crous, Alternaria obclavata (Crous & U. Braun) Woudenb. & Crous, Alternaria obovoidea (E.G. Simmons) Woudenb. & Crous, Alternaria oudemansii (E.G. Simmons) Woudenb. & Crous, Alternaria oxytropis (Q. Wang, Nagao & Kakish.) Woudenb. & Crous, Alternaria penicillata (Corda) Woudenb. & Crous, Alternaria planifunda (E.G. Simmons) Woudenb. & Crous, Alternaria proteae (E.G. Simmons) Woudenb. & Crous, Alternaria scirpinfestans (E.G. Simmons & D.A. Johnson) Woudenb. & Crous, Alternaria scirpivora (E.G. Simmons & D.A. Johnson) Woudenb. & Crous, Alternaria septospora (Preuss) Woudenb. & Crous, Alternaria slovaca (Svob.-Pol., L. Chmel & Bojan.) Woudenb. & Crous, Alternaria subcucurbitae (Yong Wang bis & X.G. Zhang) Woudenb. & Crous, Alternaria tellustris (E.G. Simmons) Woudenb. & Crous, Alternaria tumida (E.G. Simmons) Woudenb. & Crous, Paradendryphiella salina (G.K. Sutherl.) Woudenb. & Crous, Paradendryphiella arenariae (Nicot) Woudenb. & Crous. New names - Alternaria aspera Woudenb. & Crous, Alternaria botryospora Woudenb. & Crous, Alternaria brassicae-pekinensis Woudenb. & Crous, Alternaria breviramosa Woudenb. & Crous, Alternaria chlamydosporigena Woudenb. & Crous, Alternaria concatenata

Woudenberg, J.H.C.; Groenewald, J.Z.; Binder, M.; Crous, P.W.

2013-01-01

12

Evaluation of potato clones for resistance to stem canker and tuber black scurf in field studies following artificial inoculation with Rhizoctonia solani AG3 in Maine  

Microsoft Academic Search

Potato clones were evaluated for resistance to Rhizoctonia stem canker, stolon lesion and black scurf in field experiments during the 1997 and 1998 growing seasons. Seed pieces were inoculated with Rhizoctonia solani Anastomosis group 3 (AG-3) by dipping them in a slurry or suspension of inoculum. Uninoculated controls were also planted. Seed emergence was assessed beginning at two weeks after

O. M. Olanya; D. H. Lambert; A. F. Reeves; G. A. Porter

2009-01-01

13

Relating plant and pathogen development to optimise fungicide control of phoma stem canker ( Leptosphaeria maculans ) on winter oilseed rape ( Brassica napus )  

Microsoft Academic Search

In winter oilseed rape experiments at Rothamsted in 2000\\/01 to 2002\\/03 growing seasons, the severity of phoma stem canker\\u000a epidemics in summer depended on the timing of phoma leaf spot epidemics in the previous autumn, and hence on the timing of\\u000a Leptosphaeria maculans ascospore release. The first major release of L. maculans ascospores was earlier in 2000 (26 September) and

Julie M. Steed; Andreas Baierl; Bruce D. L. Fitt

2007-01-01

14

Progeny differences of hinoki ( Chamaecyparis obtusa ) and sawara ( C. pisifera ) against resinous stem canker disease and spatial distribution of damage (disease severity) in a progeny test  

Microsoft Academic Search

The incidence and severity of resinous stem canker disease were investigated in hinoki (Chamaecyparis obtusa) and sawara (C. pisifera) at a progeny test located in Yamatsuri Town, Fukushima Prefecture, Japan. Symptoms of the disease were observed in 307 trees\\u000a out of 933 investigated trees (32.9%). The damage was more severe on lower slopes than on upper slopes, indicating that micro-environmental

Makoto Takahashi; Minoru Mukouda; Kenji Nishimura

1998-01-01

15

Canker Sores  

MedlinePLUS

... as clusters of very small ulcers (less than a millimeter in some cases) that sometimes merge together to form larger ulcers. They usually heal in just over one week. Most of the time, canker sores are self-limiting. This means that they will go away even ...

16

Alternaria blight  

Technology Transfer Automated Retrieval System (TEKTRAN)

Alternaria blight of chickpea is caused by the fungal pathogen Alternaria alternata. The pathogen has wide host range, and affects all above ground parts of the plant. The disease occurs sporadically and occasionally could be economically important and causes significant damage. The pathogen can ...

17

First outbreak of pitch canker in a South African pine plantation  

Microsoft Academic Search

Fusarium circinatum, the causal agent of pitch canker, was first reported in South Africa in 1990 on Pinus patula seedlings in a nursery. Subsequent to this outbreak the pathogen has spread throughout South African pine nurseries causing\\u000a a serious root and collar rot disease of various Pinus spp. The stem canker disease on plantation trees that typifies pitch canker in

T. A. Coutinho; E. T. Steenkamp; K. Mongwaketsi; M. Wilmot; M. J. Wingfield

2007-01-01

18

Formation of canker lesions on stems and black scurf on tubers in experimentally inoculated potato plants by isolates of AG2-1, AG3 and AG5 of Rhizoctonia solani: a pilot study and literature review  

Microsoft Academic Search

Development of black scurf on potato tubers (cv. Nicola) was compared in plants inoculated with isolates of Rhizoctonia solani of three anastomosis groups (AG2-1, AG3 and AG5) which occur in potato crops in Finland. All isolates induced stem canker lesions but only isolates of AG3 formed efficiently black scurf on progeny tubers. Among the AG2-1 and AG5 isolates tested, only

Mari J. Lehtonen; Paula. S. Wilson; Paavo Ahvenniemi; Jari P. T. Valkonen

2009-01-01

19

Myrothecium roridum leaf spot and stem canker on watermelon in the southern Great Plains: Possible factors for its outbreak  

Technology Transfer Automated Retrieval System (TEKTRAN)

Diseases are generally the greatest yield-limiting factor for watermelon across the U.S. In 2010, a foliar and stem-lesion disease was observed for the first time in Oklahoma causing moderate to severe defoliation. Using microscopic examination, the physical features of the fungus were consistent ...

20

Association of Nematodes and Dogwood Cankers  

PubMed Central

Dogwood canker is a serious production problem of unknown etiology. From May 1985 through April 1989, cankers from 290 flowering dogwood trees in 15 separate nurseries were sampled for nematodes. Seventy-three percent (213) of the cankers contained nematodes. Panagrolaimus rigidus (Schneider) Thorne (115/290) and Aphelenchoides spp. (91/290) were the most frequently collected taxa. Panagrolaimus rigidus was reared on 2% water agar with unidentified bacteria as the food source. Aphelenchoides spp. were reared in antibiotic-amended agar culture with the fungus Glomerella cingulata (Stoneman) Spauld. &Schrenk as a food source. Repeated attempts to culture Aphelenchoides spp. on dogwood callus tissue were unsuccessful. Artificially created stem wounds inoculated with combinations of Aphelenchoides spp. and P. rigidus callused completely in 60 days with no indication of canker development. Very low numbers of nematodes were recovered from inoculated trees, but P. rigidus and one Aphelenchoides sp. were efficient dispersers and occurred in treatments other than those in which they were inoculated. PMID:19279869

Self, Louann H.; Bernard, Ernest C.

1994-01-01

21

Most AAL toxin-sensitive Nicotiana species are resistant to the tomato fungal pathogen Alternaria alternata f. sp. lycopersici.  

PubMed

The phytopathogenic fungus Alternaria alternata f. sp. lycopersici produces AAL toxins required to colonize susceptible tomato (Lycopersicon esculentum) plants. AAL toxins and fumonisins of the unrelated fungus Fusarium moniliforme are sphinganine-analog mycotoxins (SAMs), which are toxic for some plant species and mammalian cell lines. Insensitivity of tomato to SAMs is determined by the Alternaria stem canker gene 1 (Asc-1), and sensitivity is associated with a mutated Asc-1. We show that SAM-sensitive species occur at a low frequency in the Nicotiana genus and that candidate Asc-1 homologs are still present in those species. In Nicotiana spp., SAM-sensitivity and insensitivity also is mediated by a single codominant locus, suggesting that SAM-sensitive genotypes are host for A. alternata f. sp. lycopersici. Nicotiana umbratica plants homozygous for SAM-sensitivity are indeed susceptible to A. alternata f. sp. lycopersici. In contrast, SAM-sensitive genotypes of Nicotiana spegazzinii, Nicotiana acuminata var. acuminata, Nicotiana bonariensis, and Nicotiana langsdorffii are resistant to A. alternata f. sp. lycopersici infection concomitant with localized cell death. Additional (nonhost) resistance mechanisms to A. alternata f. sp. lycopersici that are not based on an insensitivity to SAMs are proposed to be present in Nicotiana species. PMID:11310733

Brandwagt, B F; Kneppers, T J; Van der Weerden, G M; Nijkamp, H J; Hille, J

2001-04-01

22

Citrus Canker: Alternatives for Control  

NSDL National Science Digital Library

What do you do when county officials show up to cut down the orange trees in your backyard? What causes citrus canker and how is it spread? This plant pathogen was the first microbe to have its genome sequenced outside of the US. There is much to investigate before deciding on the best alternative for control. * examine international alternatives for the control of citrus canker

Linda Weinland (Edison College; Biology)

2006-05-20

23

Clinical Characteristics of Alternaria Keratitis  

PubMed Central

Purpose. Alternaria spp. are an uncommon cause of mycotic keratitis. Previous studies on Alternaria keratitis have generally been limited to case reports. We examined the clinical characteristics of Alternaria keratitis in this study. Methods. The characteristics and outcomes of 7 patients with culture-proven Alternaria keratitis treated in our hospital were compared with 25 previously reported cases. Results. The risk factors for Alternaria keratitis were trauma in 5 patients and soft contact lenses in 1 patient. Six patients with early diagnosis (<2 weeks) were cured with medical antimicrobial treatment; a patch graft was required in 1 patient with perforation. When incorporated with previous reports on Alternaria keratitis (n = 32), 14 (44%) infections followed trauma, 10 (31%) were associated with preexisting corneal disease or previous ocular surgery, and 5 (16%) occurred in soft contact lens wearers. Successful medical treatment was achieved in 23 (72%) patients, including 10 out of 21 eyes (48%) treated with natamycin and/or amphotericin B. Therapeutic penetrating keratoplasty was performed in 9 (28%) cases. Conclusions. Alternaria keratitis is generally associated with specific risk factors and responds to medical treatment when early diagnosis is performed and prompt antifungal treatment is initiated. PMID:24778867

Lin, Hsin-Chiung; Chen, Phil Y. F.; Ma, David H. K.; Tan, Hsin-Yuan

2014-01-01

24

Clinical characteristics of alternaria keratitis.  

PubMed

Purpose. Alternaria spp. are an uncommon cause of mycotic keratitis. Previous studies on Alternaria keratitis have generally been limited to case reports. We examined the clinical characteristics of Alternaria keratitis in this study. Methods. The characteristics and outcomes of 7 patients with culture-proven Alternaria keratitis treated in our hospital were compared with 25 previously reported cases. Results. The risk factors for Alternaria keratitis were trauma in 5 patients and soft contact lenses in 1 patient. Six patients with early diagnosis (<2 weeks) were cured with medical antimicrobial treatment; a patch graft was required in 1 patient with perforation. When incorporated with previous reports on Alternaria keratitis (n = 32), 14 (44%) infections followed trauma, 10 (31%) were associated with preexisting corneal disease or previous ocular surgery, and 5 (16%) occurred in soft contact lens wearers. Successful medical treatment was achieved in 23 (72%) patients, including 10 out of 21 eyes (48%) treated with natamycin and/or amphotericin B. Therapeutic penetrating keratoplasty was performed in 9 (28%) cases. Conclusions. Alternaria keratitis is generally associated with specific risk factors and responds to medical treatment when early diagnosis is performed and prompt antifungal treatment is initiated. PMID:24778867

Hsiao, Ching-Hsi; Yeh, Lung-Kun; Chen, Hung-Chi; Lin, Hsin-Chiung; Chen, Phil Y F; Ma, David H K; Tan, Hsin-Yuan

2014-01-01

25

The HPLC-Fluorescence Detection of Coumarins in ‘Hamlin’ Sweet Orange and ‘Marsh’ Grapefruit Leaf Cankers  

Technology Transfer Automated Retrieval System (TEKTRAN)

Canker is a devastating disease for the citrus fresh fruit market and is caused by the pathogenic bacterium Xanthomonas citri var. citri (Xcc). Infection occurs by bacterial penetration through physical damage of leaves, peel and stems, and also by bacterial entry through the stomates of these photo...

26

CITRUS CANKER: PLANT PATHOLOGY VERSUS PUBLIC POLICY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Increasing international travel and trade has resulted in an unprecedented number of plant pathogen introductions, including Xanthomonas axonopodis pv citri, (Xac), the bacterium that causes citrus canker. The disease affects commercial and dooryard citrus, and has far-reaching politi...

27

Canker Sores (Aphthous Stomatitis or Recurrent Mouth Ulcers)  

MedlinePLUS

Canker Sores (Aphthous Stomatitis or Recurrent Mouth Ulcers) What Is It? Symptoms Diagnosis Expected Duration Prevention Treatment When To Call a Professional Prognosis Additional Info What Is It? Canker sores are ...

28

Alternaria Blight on Wheat in India  

Microsoft Academic Search

Alternaria blight (Alternaria triticina Prasada and Prabhu) of wheat was first recorded in India in 1924 and has recently achieved prominence due to the susceptibility of Mexican wheats to the fungus. The symptoms of the disease and the conditions under which the plants are most susceptible are described. The disease may be controlled by hot water seed treatment, the use

S. S. Sokhi

1974-01-01

29

Research progress for integrated canker management  

Technology Transfer Automated Retrieval System (TEKTRAN)

Fruit losses due to citrus canker, caused by Xanthomonas citri subsp. citri (Xcc), vary each crop season depending on citrus variety, tree age, flushing condition, leafminer control, and coincidence of weather events with occurrence of susceptible fruit and foliage. In 2013, crop losses in Hamlin f...

30

78 FR 58992 - Notice of Request for Extension of Approval of an Information Collection; Citrus Canker...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Approval of an Information Collection; Citrus Canker; Interstate Movement of Regulated...quarantined areas to prevent the spread of citrus canker. DATES: We will consider all...regulated nursery stock and fruit from citrus canker quarantined areas, contact...

2013-09-25

31

Toxicity of catechol to alternaria spp  

Microsoft Academic Search

In slide-germination tests concentration of 50 p.p.m. or more of catechol were inhibitory to spore germination ofAlternaria tomato, A. solani, A. melongenae, A. longipes, A. brassicicola. A. brassicae, A. raphani, A. triticina and anAlternaria sp. isolated from onion. More than 70 % inhibition of conidial germination was caused by 100 p.p.m. of the compound. Nearly complete or complete inhibition occurred

R. S. Singh; H. S. Chaube

1971-01-01

32

Cryphonectria canker on Tibouchina in Colombia By M. J. WINGFIELD  

E-print Network

canker disease on Tibouchina spp. (Melastomataceae) in Colombia. We used morphological studies on Tibouchina urvilleana (DC). Logn. (Melastomataceae), which is native to Brazil. In a subsequent survey

33

The control of black pod, canker and seedling blight of cocoa, caused by Phytophthora palmivora , with potassium phosphonate  

Microsoft Academic Search

Trunk injected potassium phosphonate (8 or 16 g a.i. per tree every 6 months) controls black pod and stem canker of cocoa:\\u000a Foliar sprays of potassium phosphonate (20 g a.i. per tree every 6 months) or Ridomil Plus 72WP (0.72 g a.i. per tree every\\u000a 6 weeks during the wet season) do not control black pod. Trunk injection is less

R. D. Anderson; D. I. Guest

1990-01-01

34

Characteristics of Multi-rater Estimates of Citrus Canker Severity  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker (CC, caused by Xanthomonas citri) was under eradication for 10 y in Florida. A total of 28 CC surveyors and plant pathologists rated severity of CC symptoms on 200 images to investigate the range of abilities and some factors that influence canker severity estimation. Actual dis...

35

Managing citrus canker for the fresh fruit industry  

Technology Transfer Automated Retrieval System (TEKTRAN)

The establishment of citrus canker in Florida changed the way the $400 million dollar industry grows, packs ships and stores fruit. Canker regulations have become less strict, but there is still a requirement for compliance for growers and packers to move fruit from Florida to other areas. The comp...

36

APS PRESS ONLINE LESSONS IN PLANT PATHOLOGY - CITRUS CANKER  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker is a simple disease and a complex socioeconomic/political problem. The citrus canker eradication program over the past decade has been compromised by legal battles that halted eradication combined with exacerbation of the disease and tree susceptibility by the introduction of the Asia...

37

Alternaria Keratitis after Deep Anterior Lamellar Keratoplasty  

PubMed Central

To describe a case of Alternaria keratitis in a 30-year-old male patient who presented with bilateral vascularised central corneal opacity and underwent deep anterior lamellar keratoplasty (DALK) in the left eye. Patient was treated for recurrent epithelial defect with a bandage contact lens in the follow-up visits after DALK. Subsequently, patient presented with pigmented fungal keratitis, which on culture examination of the corneal scrapping demonstrated Alternaria species. Patient had to undergo a repeat DALK as the keratitis did not resolve with medical therapy alone. Patient did not have a recurrence for 11 months following the regraft. This case report highlights the importance of considering the Alternaria species as a possibile cause of non-resolving fungal keratitis after DALK. PMID:24669155

Naik, Mekhla; Mohd. Shahbaaz; Sheth, Jay; Sunderamoorthy, S. K.

2014-01-01

38

Experiments with Biocontrol of Alternaria alternata  

Technology Transfer Automated Retrieval System (TEKTRAN)

A biocontrol yeast (WRL-76) developed by USDA-ARS at the Western Regional Research lab was evaluated for control of Alternaria alternata on pistachio. The experiment was conducted over a four year period in a Madera Co., CA orchard. Counts of damaged vs. intact fruit clusters were taken on 100 contr...

39

Alternaria alternata mannitol dehydrogenase, a fungal allergen  

Microsoft Academic Search

RationaleMannitol dehydrogenase (MtDH) has previously been shown to be the major allergen of Cladosporium herbarum. Since cross-reactivity has been demonstrated for several fungal allergens we have cloned the homolog protein of Alternaria alternata and tested it in respect to its IgE-reactivity.

P. B. Schneider; U. Denk; C. Ebner; M. Breitenbach; B. Simon-Nobbe

2004-01-01

40

Spatial relationships between nitrogen status and pitch canker disease in slash pine planted adjacent to a poultry operation.  

PubMed

Pitch canker disease (Fusarium circinatum Nirenberg & O'Donnell) causes serious shoot dieback, reduced growth and mortality in pines found in the southern and western USA, and has been linked to nutrient imbalances. Poultry houses with forced-air ventilation systems produce nitrogen (N) emissions. This study analyzed spatial correlations between pitch canker disease and foliar, forest floor, soil, and throughfall N in a slash pine (Pinus elliottii var. elliottii Engelm.) plantation adjacent to a poultry operation in north Florida, USA. Tissue and throughfall N concentrations were highest near the poultry houses and remained elevated for 400 m. Disease incidence ranged from 57-71% near the poultry houses and was spatially correlated with N levels. Similarly, stem mortality ranged from 41-53% in the most heavily impacted area, and declined to 0-9% at distances greater than 400 m. These results suggest that nutritional processes exacerbate changes in disease susceptibility and expression in slash pine. PMID:17049465

Lopez-Zamora, Isabel; Bliss, Christine; Jokela, Eric J; Comerford, N B; Grunwald, Sabine; Barnard, E; Vasquez, G M

2007-05-01

41

Citrus Canker: The Pathogen and Its Impact  

NSDL National Science Digital Library

This Web site, currently featured on the home page of the American Phytopathological Society, contains a research report regarding the Asiatic citrus canker that has had devastating effects on Florida's citrus industry. The report, in a journal article format, thoroughly relates the natural history and current status of the disease, as well as detailing the methods and results of the (primarily genetic) experiments conducted in this study. One of the most appealing features of this Web site is the quality of the photos within the report. These photos can be viewed separately from the report in a slide show. While navigating this site is relatively straightforward, the lack of a table of contents can make finding your place in the body of the text somewhat confusing.

2002-01-01

42

40 CFR 180.1256 - Alternaria destruens strain 059; exemption from the requirement of a tolerance.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Alternaria destruens strain 059; exemption from the requirement of... § 180.1256 Alternaria destruens strain 059; exemption from the requirement of...microbial pesticide Alternaria destruens Strain 059 when used in or on all raw...

2011-07-01

43

Horsfall-Barratt recalibration and replicated severity estimates of citrus canker  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker is a serious disease of citrus in tropical and subtropical citrus growing regions. Accurate and precise assessment of citrus canker and other plant pathogens is needed to obtain good quality data. Citrus canker assessment data were used to ascertain some of the mechanics of the Horsfal...

44

Copper Sprays and Windbreaks for Control of Citrus Canker on Young Orange Trees in Southern Brazil  

Technology Transfer Automated Retrieval System (TEKTRAN)

The benefit of windbreaks and copper sprays for control of citrus canker caused by Xanthomonas axonopodis pv. citri was investigated in a commercial citrus orchard located in a citrus canker endemic area in southern Brazil. Control of canker was evaluated as incidence and severity of lesions on foli...

45

First report of Neofusicoccum parvum causing canker and die-back of Eucalyptus in Spain  

E-print Network

First report of Neofusicoccum parvum causing canker and die-back of Eucalyptus in Spain Eugenia disease in Eucalyptus globulus in North Spain. Keywords Eucalyptus canker. Neofusicoccum parvum . Botryosphaeriaceae A canker disease outbreak was observed for the first time on Eucalyptus globulus in North Spain

46

First Record of Alternaria simsimi Causing Leaf Spot on Sesame (Sesamum indicum L.) in Korea.  

PubMed

Leaf spot disease was observed in sesame (Sesamum indicum L.) during 2009 and 2010 in Korea. The pathogen was identified as Alternaria simsimi based on morphological and cultural characteristics. The morphological identification was well supported by phylogenetic analysis of the ribosomal DNA-internal transcribed spacer region. A. simsimi isolates caused spot symptoms on leaves and stems of sesame plants 2 wk after artificial inoculation, which were similar to those observed in the field. This is the first record of leaf spot disease in Korea caused by A. simsimi. PMID:25606015

Choi, Young Phil; Paul, Narayan Chandra; Lee, Hyang Burm; Yu, Seung Hun

2014-12-01

47

First Record of Alternaria simsimi Causing Leaf Spot on Sesame (Sesamum indicum L.) in Korea  

PubMed Central

Leaf spot disease was observed in sesame (Sesamum indicum L.) during 2009 and 2010 in Korea. The pathogen was identified as Alternaria simsimi based on morphological and cultural characteristics. The morphological identification was well supported by phylogenetic analysis of the ribosomal DNA-internal transcribed spacer region. A. simsimi isolates caused spot symptoms on leaves and stems of sesame plants 2 wk after artificial inoculation, which were similar to those observed in the field. This is the first record of leaf spot disease in Korea caused by A. simsimi. PMID:25606015

Choi, Young Phil; Paul, Narayan Chandra

2014-01-01

48

STEM?!?!  

ERIC Educational Resources Information Center

The author's son has been an engineer since birth. He never asked "why" as a toddler, it was always "how's it work?" So that he wanted a STEM-based home education was no big surprise. In this article, the author considers what kind of curricula would work best for her complex kid.

Merrill, Jen

2012-01-01

49

The Eucalyptus canker pathogen Chrysoporthe cubensis discovered in eastern Australia  

E-print Network

The Eucalyptus canker pathogen Chrysoporthe cubensis discovered in eastern Australia Geoffrey S Pathology Centre, The University of Queensland/Agri-Science Queensland, Qld 4068, Australia. B Forestry these trees are planted as non-natives. Although the majority of Eucalyptus spp. are native to Australia, Chr

50

Developing Transgenic Citrus for Resistance to Huanglongbing and Citrus Canker  

Technology Transfer Automated Retrieval System (TEKTRAN)

Huanglongbing (HLB) and Citrus Bacterial Canker (CBC) are serious threats to citrus production, and resistant transgenic citrus is desirable. Genes for antimicrobial peptides (AMPs) with diverse promoters have been used to generate thousands of rootstock and scion transformants. D35S::D4E1 transfor...

51

PROSPECTS FOR CONTROL OF CITRUS CANKER WITH NOVEL CHEMICAL COMPOUNDS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Field trials conducted in Brazil demonstrate that copper formulations (copper hydroxide, CH; copper oxychloride, COC) even at reduced rates are consistently effective for control of canker on moderately susceptible orange varieties. Contact activity to replace and/or reduce copper could minimize po...

52

Citrus diseases with global ramifications including citrus canker and huanglongbing  

Technology Transfer Automated Retrieval System (TEKTRAN)

Although there are a number of diseases that plague citrus production worldwide, two bacterial diseases are particularly problematic. Both are of Asian origin and currently cause severe economic damage: Asiatic citrus canker (ACC) and citrus huanglongbing (HLB). Although ACC has been found in the ...

53

Automating the assessment of citrus canker symptoms with image analysis  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker (CC, caused by Xanthomonas citri) is a serious disease of citrus in Florida and other citrus-growing regions. Severity of symptoms can be estimated by visual rating, but there is inter- and intra-rater variation. Automated image analysis (IA) may offer a way of reducing some of ...

54

Quantitative PCR Method for Diagnosis of Citrus Bacterial Canker  

PubMed Central

For diagnosis of citrus bacterial canker by PCR, an internal standard is employed to ensure the quality of the DNA extraction and that proper requisites exist for the amplification reaction. The ratio of PCR products from the internal standard and bacterial target is used to estimate the initial bacterial concentration in citrus tissues with lesions. PMID:11375206

Cubero, J.; Graham, J. H.; Gottwald, T. R.

2001-01-01

55

Distribution of canker lesions on grapefruit in Florida  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker, caused by the plant pathogenic bacterium Xanthomonas citri subsp. citri (Xcc) is an important disease of grapefruit in Florida. To establish disease distribution on fruit, six samples of 24 diseased grapefruit were collected from two groves in east Florida. A plane was sliced through ...

56

Infection and decontamination of citrus-canker-inoculated leaf surfaces  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker (Xanthomonas citri subsp. citri, Xcc) is now considered endemic in Florida and continues to spread. Personnel and equipment decontamination is practiced in both disease-endemic and disease-free areas to reduce the risk of bacterial spread by man or machinery. We used grapefruit leaf su...

57

Large-spored Alternaria pathogens in section Porri disentangled  

PubMed Central

The omnipresent fungal genus Alternaria was recently divided into 24 sections based on molecular and morphological data. Alternaria sect. Porri is the largest section, containing almost all Alternaria species with medium to large conidia and long beaks, some of which are important plant pathogens (e.g. Alternaria porri, A. solani and A. tomatophila). We constructed a multi-gene phylogeny on parts of the ITS, GAPDH, RPB2, TEF1 and Alt a 1 gene regions, which, supplemented with morphological and cultural studies, forms the basis for species recognition in sect. Porri. Our data reveal 63 species, of which 10 are newly described in sect. Porri, and 27 species names are synonymised. The three known Alternaria pathogens causing early blight on tomato all cluster in one clade, and are synonymised under the older name, A. linariae. Alternaria protenta, a species formerly only known as pathogen on Helianthus annuus, is also reported to cause early blight of potato, together with A. solani and A. grandis. Two clades with isolates causing purple blotch of onion are confirmed as A. allii and A. porri, but the two species cannot adequately be distinguished based on the number of beaks and branches as suggested previously. This is also found among the pathogens of Passifloraceae, which are reduced from four to three species. In addition to the known pathogen of sweet potato, A. bataticola, three more species are delineated of which two are newly described. A new Alternaria section is also described, comprising two large-spored Alternaria species with concatenate conidia. PMID:25492985

Woudenberg, J.H.C.; Truter, M.; Groenewald, J.Z.; Crous, P.W.

2014-01-01

58

Large-spored Alternaria pathogens in section Porri disentangled.  

PubMed

The omnipresent fungal genus Alternaria was recently divided into 24 sections based on molecular and morphological data. Alternaria sect. Porri is the largest section, containing almost all Alternaria species with medium to large conidia and long beaks, some of which are important plant pathogens (e.g. Alternaria porri, A. solani and A. tomatophila). We constructed a multi-gene phylogeny on parts of the ITS, GAPDH, RPB2, TEF1 and Alt a 1 gene regions, which, supplemented with morphological and cultural studies, forms the basis for species recognition in sect. Porri. Our data reveal 63 species, of which 10 are newly described in sect. Porri, and 27 species names are synonymised. The three known Alternaria pathogens causing early blight on tomato all cluster in one clade, and are synonymised under the older name, A. linariae. Alternaria protenta, a species formerly only known as pathogen on Helianthus annuus, is also reported to cause early blight of potato, together with A. solani and A. grandis. Two clades with isolates causing purple blotch of onion are confirmed as A. allii and A. porri, but the two species cannot adequately be distinguished based on the number of beaks and branches as suggested previously. This is also found among the pathogens of Passifloraceae, which are reduced from four to three species. In addition to the known pathogen of sweet potato, A. bataticola, three more species are delineated of which two are newly described. A new Alternaria section is also described, comprising two large-spored Alternaria species with concatenate conidia. PMID:25492985

Woudenberg, J H C; Truter, M; Groenewald, J Z; Crous, P W

2014-09-01

59

Characterization of Alternaria infectoria extracellular vesicles  

PubMed Central

Many fungi use membrane vesicles to transport complex molecules across their cell walls. Like mammalian exosomes, fungal vesicles contain lipids, proteins, and polysaccharides, many of which are associated with virulence. Here we identify and characterize extracellular vesicles (EVs) in Alternaria infectoria, a ubiquitous, environmental filamentous fungus that is also an opportunistic human pathogen. Examination of the A. infectoria EVs revealed a morphology similar to that of vesicles described in other fungal species. Of note, proteomic analysis detected a reduced number of vesicle-associated proteins. There were two prevalent categories among the 20 identified proteins, including the polysaccharide metabolism group, probably related to plant host invasion or biosynthesis/degradation of cell wall components, and the nuclear proteins, especially DNA repair enzymes. We also found enzymes related to pigment synthesis, adhesion to the host cell, and trafficking of vesicles/organelles/molecules. This is the first time EV secretions have been identified in a filamentous fungus. We believe that these vesicles might have a role in virulence. PMID:24576997

Silva, Branca M.A.; Prados-Rosales, Rafael; Espadas-Moreno, Javier; Wolf, Julie M.; Luque-Garcia, Jose L.; Gonçalves, Teresa; Casadevall, Arturo

2015-01-01

60

Characterization of new Alternaria alternata--specific rat monoclonal antibodies.  

PubMed

In this study, three different rat hybridoma cell lines secreting monoclonal antibodies (mAbs) recognizing the spores from Alternaria alternata, a plant pathogenic fungus, contaminant of food products and important cause of both allergic rhinitis and asthma, have been characterized. These three mAbs are all of IgM isotype. Two antibodies, A1 and F10, were cross-reactive antibodies recognizing spores from Alternaria, Cladosporium, Penicillium, Aspergillus and Stachybotrys genera, but not the yeasts Saccharomyces cerevisiae or Candida albicans. Competitive and sandwich assays demonstrated that these two mAbs were directed against the same or very close repetitive(s) epitope(s). A1-based sandwich ELISA efficiently detected this epitope in various mould (but not yeast)-soluble extracts prepared from strains grown in the laboratory. Moreover, this A1-based sandwich ELISA detected its cognate epitope in air and dust samples obtained from dwellings. The third antibody, E5, recognized only the spores of Alternaria and the phylogenetically very close Ulocladium botrytis. This E5 antibody is directed against a repetitive epitope found in Alternaria and Ulocladium laboratory extracts and can be used in a sandwich assay for the quantification of these moulds. Therefore, E5 antibody is a promising tool for the development of Alternaria-Ulocladium-specific immunoassays, while A1 and F10 could be interesting tools for the quantification of the total mould biomass. PMID:21892786

Denis, Olivier; Van Cauwenberge, Anne; Treutens, Greta; Es Saadi, Bouazza; Symoens, Françoise; Popovic, Nathalie; Huygen, Kris

2012-03-01

61

CITRUS CANKER: DOING BATTLE WITH THE BEAST FOR NEARLY A CENTURY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Asiatic citrus canker (ACC) has a long history in Florida. The disease was first found around 1910 and spread throughout the southeastern US on imported citrus seedlings from Japan. After an extensive eradication program, canker was declared eradicated from Florida and the adjacent states in 1933....

62

ENHANCED DETECTION AND ISOLATION OF THE WALNUT PATHOGEN BRENNARIA RUBRIFACIENS: CAUSAL AGENT OF DEEP BARK CANKER  

Technology Transfer Automated Retrieval System (TEKTRAN)

Deep bark canker (DBC) of walnut is caused by the bacterium Brenneria rubrifaciens which produces the red pigment rubrifacine. This disease of English walnut trees, is characterized by deep vertical cankers which exude sap laden with B. rubrifaciens. Although DBC is not observed on younger trees, ...

63

A novel Fusarium species causes a canker disease of the critically endangered conifer, Torreya taxifolia  

Technology Transfer Automated Retrieval System (TEKTRAN)

A canker disease of Florida torreya (Torreya taxifolia), here designated CDFT, has been implicated in the decline of this critically endangered species in its native range of northern Florida and southeastern Georgia. In our current surveys of eight Florida torreya sites, cankers were present on all...

64

Population Structure of Geosmithia morbida, the Causal Agent of Thousand Cankers Disease of Walnut Trees in  

E-print Network

Population Structure of Geosmithia morbida, the Causal Agent of Thousand Cankers Disease of Walnut. Graves3 , Colleen Hartel4 , Jay W. Pscheidt5 , Jadelys Tonos4 , Kirk Broders6 , Whitney Cranshaw1 morbida and the walnut twig beetle Pityophthorus juglandis are associated with thousand cankers disease

65

Automated image analysis of the severity of foliar citrus canker symptoms  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker (caused by Xanthomonas citri subsp. citri) is a destructive disease, reducing yield, and rendering fruit unfit for fresh sale. Accurate assessment of citrus canker severity and other diseases is needed for several purposes, including monitoring epidemics and evaluation of germplasm. ...

66

Mutagenicity of stemphyltoxin III, a metabolite of Alternaria alternata.  

PubMed Central

Some common decay organisms of vegetables and ripened fruits are Alternaria species. Even fruits and vegetables kept under refrigeration can be spoiled by Alternaria species because the mold grows at low temperatures. Alternaria alternata is commonly found in grain in areas with a high incidence of esophageal cancer. Three metabolites, altertoxins I, II, and III, have been isolated from A. alternata and have hydroxyperylenequinone structures. Although other perylenequinone metabolites such as stemphyperylenol and stemphyltoxins I, II, III, and IV, have been isolated from Stemphylium botryosum var. lactucum, a plant pathogen and mold, we isolated and identified stemphyltoxin III from A. alternata. This metabolite was tested for mutagenicity in the Ames Salmonella typhimurium plate incorporation assay with and without Aroclor 1254-induced rat S-9 metabolic activation. A positive response was noted with and without metabolic activation in S. typhimurium TA98 and TA1537, and there was a marginal response in strain TA100. PMID:2036005

Davis, V M; Stack, M E

1991-01-01

67

A Novel Alternaria Species Isolated from Peucedanum japonicum in Korea  

PubMed Central

We isolated and examined a new Alternaria sp., which causes leaf spots on Peucedanum japonicum in Korea, by using molecular and morphological methods. Phylogenetic analysis based on a combined internal transcribed spacer region analysis and two protein-coding genes (gpd and Alt a1) demonstrated that the causal fungus was most closely related to A. cinerariae and A. sonchi, and relevant to A. brassicae. However, conidial morphology indicated that it is a novel species within the genus Alternaria, and therefore we have assigned the fungus a new name in this study. PMID:24808728

Deng, Jian Xin; Cho, Hye Sun; Paul, Narayan Chandra; Lee, Hyang Burm

2014-01-01

68

Molecular systematics of citrus-associated Alternaria species.  

PubMed

The causal agents of Alternaria brown spot of tangerines and tangerine hybrids, Alternaria leaf spot of rough lemon and Alternaria black rot of citrus historically have been referred to as Alternaria citri or A. alternata. Ten species of Alternaria recently were described among a set of isolates from leaf lesions on rough lemon (Citrus jambhiri) and tangelo (C. paradisi × C. reticulata), and none of these isolates was considered representative of A. alternata or A. citri. To test the hypothesis that these newly described morphological species are congruent with phylogenetic species, selected Alternaria brown spot and leaf spot isolates, citrus black rot isolates (post-harvest pathogens), isolates associated with healthy citrus tissue and reference species of Alternaria from noncitrus hosts were scored for sequence variation at five genomic regions and used to estimate phylogenies. These data included 432 bp from the 5' end of the mitochondrial ribosomal large subunit (mtLSU), 365 bp from the 5' end of the beta-tubulin gene, 464 bp of an endopolygalacturonase gene (endoPG) and 559 and 571 bp, respectively, of two anonymous genomic regions (OPA1-3 and OPA2-1). The mtLSU and beta-tubulin phylogenies clearly differentiated A. limicola, a large-spored species causing leaf spot of Mexican lime, from the small-spored isolates associated with citrus but were insufficiently variable to resolve evolutionary relationships among the small-spored isolates from citrus and other hosts. Sequence analysis of translation elongation factor alpha, calmodulin, actin, chitin synthase and 1, 3, 8-trihydroxynaphthalene reductase genes similarly failed to uncover significant variation among the small-spored isolates. Phylogenies estimated independently from endoPG, OPA1-3 and OPA2-1 data were congruent, and analysis of the combined data from these regions revealed nine clades, eight of which contained small-spored, citrus-associated isolates. Lineages inferred from analysis of the combined dataset were in general agreement with described morphospecies, however, three clades contained more than one morphological species and one morphospecies (A. citrimacularis) was polyphyletic. Citrus black rot isolates also were found to be members of more than a single lineage. The number of morphospecies associated with citrus exceeded that which could be supported under a phylogenetic species concept, and isolates in only five of nine phylogenetic lineages consistently were correlated with a specific host, disease or ecological niche on citrus. We advocate collapsing all small-spored, citrus-associated isolates of Alternaria into a single phylogenetic species, A. alternata. PMID:21148834

Peever, T L; Su, G; Carpenter-Boggs, L; Timmer, L W

2004-01-01

69

SOLID SUBSTRATE PRODUCTION OF ALTERNARIA ALTERNATA F. SP. SPHENOCLEAE.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sphenoclea zeyanica (gooseweed), a major weed of paddy rice in Southeast Asia, is one of the targets in a biological weed control research program in the Philippines. Afungal pathogen, Alternaria alternata f. sp. sphenocleae, is being evaluated as a biological control agent for this weed. The feas...

70

Alternaria alternata and its allergens: a comprehensive review.  

PubMed

Alternaria alternata is mainly an outdoor fungus whose spores disseminate in warm, dry air, so in temperate climates, their count peaks in the summers. Alternaria may also be found in damp, insufficiently ventilated houses, where its allergenic properties cocreate the sick building syndrome. Mold-induced respiratory allergies and research on Alternaria both have a lengthy history: the first was described as early as 1698 and the second dates back to 1817. However, the two were only linked in 1930 when Alternaria spores were found to cause allergic asthma. The allergenic extracts from Alternaria hyphae and spores still remain in use but are variable and insufficiently standardized as they are often a random mixture of allergenic ingredients and coincidental impurities. In contrast, contemporary biochemistry and molecular biology make it possible to obtain pure allergen molecules. To date, 16 allergens of A. alternata have been isolated, many of which are enzymes: Alt a 4 (disulfide isomerase), Alt a 6 (enolase), Alt a 8 (mannitol dehydrogenase), Alt a 10 (alcohol dehydrogenase), Alt a 13 (glutathione-S-transferase), and Alt a MnSOD (Mn superoxide dismutase). Others have structural and regulatory functions: Alt a 5 and Alt a 12 comprise the structure of large ribosomal subunits and mediate translation, Alt a 3 is a molecular chaperone, Alt a 7 regulates transcription, Alt a NTF2 facilitates protein import into the nucleus, and Alt a TCTP acts like a cytokine. The function of four allergenic proteins, Alt a 1, Alt a 2, Alt a 9, and Alt a 70 kDa, remains unknown. PMID:25205364

Kustrzeba-Wójcicka, Irena; Siwak, Emilia; Terlecki, Grzegorz; Wola?czyk-M?drala, Anna; M?drala, Wojciech

2014-12-01

71

Airborne fungal spores of Alternaria, meteorological parameters and predicting variables.  

PubMed

Alternaria is frequently found as airborne fungal spores and is recognized as an important cause of respiratory allergies. The aerobiological monitoring of fungal spores was performed using a Burkard volumetric spore traps. To establish predicting variables for daily and weakly spore counts, a stepwise multiple regression between spore concentrations and independent variables (meteorological parameters and lagged values from the series of spore concentrations: previous day or week concentration (Alt t?-?1) and mean concentration of the same day or week in other years (C mean)) was made with data obtained during 2009-2011. Alternaria conidia are present throughout the year in the atmosphere of Tetouan, although they show important seasonal fluctuations. The highest levels of Alternaria spores were recorded during the spring and summer or autumn. Alternaria showed maximum daily values in April, May or October depending on year. When the spore variables of Alternaria, namely C mean and Alt t?-?1, and meteorological parameters were included in the equation, the resulting R (2) satisfactorily predict future concentrations for 55.5 to 81.6 % during the main spore season and the pre-peak 2. In the predictive model using weekly values, the adjusted R (2) varied from 0.655 to 0.676. The Wilcoxon test was used to compare the results from the expected values and the pre-peak spore data or weekly values for 2012, indicating that there were no significant differences between series compared. This test showed the C mean, Alt t?-?1, frequency of the wind third quadrant, maximum wind speed and minimum relative humidity as the most efficient independent variables to forecast the overall trend of this spore in the air. PMID:24844880

Filali Ben Sidel, Farah; Bouziane, Hassan; Del Mar Trigo, Maria; El Haskouri, Fatima; Bardei, Fadoua; Redouane, Abdelbari; Kadiri, Mohamed; Riadi, Hassane; Kazzaz, Mohamed

2015-03-01

72

Airborne fungal spores of Alternaria, meteorological parameters and predicting variables  

NASA Astrophysics Data System (ADS)

Alternaria is frequently found as airborne fungal spores and is recognized as an important cause of respiratory allergies. The aerobiological monitoring of fungal spores was performed using a Burkard volumetric spore traps. To establish predicting variables for daily and weakly spore counts, a stepwise multiple regression between spore concentrations and independent variables (meteorological parameters and lagged values from the series of spore concentrations: previous day or week concentration (Alt t - 1) and mean concentration of the same day or week in other years ( C mean)) was made with data obtained during 2009-2011. Alternaria conidia are present throughout the year in the atmosphere of Tetouan, although they show important seasonal fluctuations. The highest levels of Alternaria spores were recorded during the spring and summer or autumn. Alternaria showed maximum daily values in April, May or October depending on year. When the spore variables of Alternaria, namely C mean and Alt t - 1, and meteorological parameters were included in the equation, the resulting R 2 satisfactorily predict future concentrations for 55.5 to 81.6 % during the main spore season and the pre-peak 2. In the predictive model using weekly values, the adjusted R 2 varied from 0.655 to 0.676. The Wilcoxon test was used to compare the results from the expected values and the pre-peak spore data or weekly values for 2012, indicating that there were no significant differences between series compared. This test showed the C mean, Alt t - 1, frequency of the wind third quadrant, maximum wind speed and minimum relative humidity as the most efficient independent variables to forecast the overall trend of this spore in the air.

Filali Ben Sidel, Farah; Bouziane, Hassan; del Mar Trigo, Maria; El Haskouri, Fatima; Bardei, Fadoua; Redouane, Abdelbari; Kadiri, Mohamed; Riadi, Hassane; Kazzaz, Mohamed

2015-03-01

73

[Colonization characteristics of endophytic bacteria NJ13 in Panax ginseng and its biocontrol efficiency against Alternaria leaf spot of ginseng].  

PubMed

To reveal the colonization characteristics in host of endophytic biocontrol bacteria NJ13 isolated from Panax ginseng, this study obtained the marked strain NJ13-R which was double antibiotic resistant to rifampicin and streptomycin through enhancing the method of inducing antibiotic. The colonization characteristics in ginseng and its biocontrol efficiency against Alternaria spot of ginseng in the field were studied. The results showed that the strain could colonize in root, stem and leaf of ginseng and the colonization amount was positive correlated with inoculation concentration. Meanwhile, the strain could infect and then transfer in different tissues of ginseng The colonization amount of strain in roots and leaves of ginseng increased first and then decreased. However, the tendency of colonization amount of strain in stems was ascend at first and then descend slowly, and was more than that in roots and leaves along with time, which had a preference to specific tissue of its host. In field experiment, the endophytic bacteria NJ13 was proved to be effective in controlling Alternaria leaf spot of ginseng. The biocontrol efficiency of fermentation broth at the concentration of 0.76 x 10(8) cfu x mL(-1) reached 75.62%, which was close to the controlling level (73.06%) of 0.67 mg x L(-1) 50% cyprodinil WG. PMID:25282882

Chen, Chang-Qing; Li, Tong; Li, Xin-Lian; Jiang, Yun; Tian, Lei; Xu, Peng

2014-05-01

74

Development of a qPCR technique to screen for resistance to Asiatic citrus canker  

Technology Transfer Automated Retrieval System (TEKTRAN)

Asiatic citrus canker (Acc) (causal organism Xanthomonas citri subspc. citri (Xcc) is threatening sustainability of the Florida citrus industry. Resistant cultivars, whether developed through conventional breeding or genetic transformation, will be he best solution for dealint with Acc. In Florida...

75

Evaluation of fungicides and biocontrol agents against Phomopsis canker of tea under field conditions  

Microsoft Academic Search

An experiment was conducted to study the efficacy of contact and systemic fungicides and biocontrol agents in controlling\\u000a Phomopsis canker disease of tea under field conditions. Among the various treatments, soil application and wound dressing\\u000a of biocontrol agents was found to be superior to fungicides in controlling Phomopsis canker. Dressing wounds with contact\\u000a fungicides such as copper oxychloride and mancozeb

P. Ponmurugan; U. I. Baby

2007-01-01

76

Frequency of Alternaria brassicicola in commercial cabbage seeds in Japan  

Microsoft Academic Search

Plug seedlings, widely used in cabbage cultivation in Japan, are often infected by seed-borne pathogens, especially the serious\\u000a pathogen Alternaria brassicicola. Because information on seed infestation is scant in Japan, we investigated fungal infestation in commercial batches of cabbage\\u000a seeds produced between 1984 and 2001. A total of 123 lots were divided into six groups by production period (1984–1989, 1994–1998,

Masaharu Kubota; Kazuo Abiko; Yukio Yanagisawa; Kazufumi Nishi

2006-01-01

77

Alternaria alternata TCTP, a novel cross-reactive ascomycete allergen  

Microsoft Academic Search

Defining more comprehensively the allergen repertoire of the ascomycete Alternaria alternata is undoubtedly of immense medical significance since this mold represents one of the most important, worldwide occurring fungal species responsible for IgE-mediated hypersensitivity reactions ranging from rhinitis and ocular symptoms to severe involvement of the lower respiratory tract including asthma with its life-threatening complications. Performing a hybridization screening of

Raphaela Rid; Kamil Önder; Susan MacDonald; Roland Lang; Thomas Hawranek; Christof Ebner; Wolfgang Hemmer; Klaus Richter; Birgit Simon-Nobbe; Michael Breitenbach

2009-01-01

78

A new alternariol glucoside from fungus Alternaria alternate cib-137.  

PubMed

A new secondary metabolite, 2-O-methylalternariol 4-O-?-[4-methoxyl-glucopyranoside] (1), together with four known compounds alternariol methyl ether (2), altenuene (3), isoaltenuene (4) and 2-(2'S-hydroxypropyl)-5-methyl-7-hydroxychromone (5), was isolated from the fungus Alternaria alternate cib-137. Its structure was elucidated on the basis of spectroscopic data. Compounds 3 and 4 demonstrated moderate activity against Staphylococcus aureus. PMID:25520187

Xu, Guo-Bo; Pu, Xiang; Bai, Huan-Huan; Chen, Xiao-Zhen; Li, Guo-You

2015-05-01

79

Antiproliferative, antifungal, and antibacterial activities of endophytic alternaria species from cupressaceae.  

PubMed

Recent research has shown the bioprospecting of endophytic fungi from Cupressaceae. Here, we further uncover that the healthy cypress plants such as Cupressus arizonica, Cupressus sempervirens var. cereiformis, and Thuja orientalis host highly bioactive endophytic Alternaria fungal species. Indeed, endophytic Alternaria alternata, Alternaria pellucida, and Alternaria tangelonis were recovered from healthy Cupressaceous trees. Biodiversity and bioactivity of recovered endophytic Alternaria species were a matter of biogeography and host identity. We further extracted such Alternaria's metabolites and highlighted their significant antiproliferative, growth inhibitory, and antibacterial activities against the model target fungus Pyricularia oryzae and the model pathogenic bacteria Bacillus sp., Erwinia amylovora, and Pseudomonas syringae. In vitro assays also indicated that endophytic Alternaria species significantly inhibited the growth of cypress fungal phytopathogens Diplodia seriata, Phaeobotryon cupressi, and Spencermartinsia viticola. In conclusion, since the recovered Alternaria species were originally reported as pathogenic and allergenic fungi, our findings suggest a possible ecological niche for them inside the foliar tissues of Cupressaceous trees. Moreover, in this study, the significant bioactivities of endophytic Alternaria species in association with Cupressaceae plant family are reported. PMID:24801337

Soltani, Jalal; Hosseyni Moghaddam, Mahdieh S

2014-09-01

80

Differential gene expression in Alternaria gaisen exposed to dark and light  

Technology Transfer Automated Retrieval System (TEKTRAN)

Character states observed during sporulation have been the basis for segregation and description of many of the small-spored species of Alternaria. Phylogenetic analyses of ITS and housekeeping genes from small-spored Alternaria spp. do not support most of the currently defined morphological specie...

81

Alternaria roseogrisea, a new species from achenes of Helianthus annuus (sunflower)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Alternaria roseogrisea was isolated from the achenes of Helianthus annuus L. during studies conducted in 1983-85 to document the diversity of fungi occurring in sunflower seeds and the possible role these fungi play in degradation of oilseed quality. A. roseogrisea was reported as "Alternaria sp. 2...

82

Oak tree canker disease supports arthropod diversity in a natural ecosystem.  

PubMed

Microorganisms have many roles in nature. They may act as decomposers that obtain nutrients from dead materials, while some are pathogens that cause diseases in animals, insects, and plants. Some are symbionts that enhance plant growth, such as arbuscular mycorrhizae and nitrogen fixation bacteria. However, roles of plant pathogens and diseases in natural ecosystems are still poorly understood. Thus, the current study addressed this deficiency by investigating possible roles of plant diseases in natural ecosystems, particularly, their positive effects on arthropod diversity. In this study, the model system was the oak tree (Quercus spp.) and the canker disease caused by Annulohypoxylon truncatum, and its effects on arthropod diversity. The oak tree site contained 44 oak trees; 31 had canker disease symptoms while 13 were disease-free. A total of 370 individual arthropods were detected at the site during the survey period. The arthropods belonged to 25 species, 17 families, and seven orders. Interestingly, the cankered trees had significantly higher biodiversity and richness compared with the canker-free trees. This study clearly demonstrated that arthropod diversity was supported by the oak tree canker disease. PMID:25288984

Lee, Yong-Bok; An, Su Jung; Park, Chung Gyoo; Kim, Jinwoo; Han, Sangjo; Kwak, Youn-Sig

2014-03-01

83

Increased resistance against citrus canker mediated by a citrus mitogen-activated protein kinase.  

PubMed

Mitogen-activated protein kinases (MAPK) play crucial roles in plant immunity. We previously identified a citrus MAPK (CsMAPK1) as a differentially expressed protein in response to infection by Xanthomonas aurantifolii, a bacterium that causes citrus canker in Mexican lime but a hypersensitive reaction in sweet oranges. Here, we confirm that, in sweet orange, CsMAPK1 is rapidly and preferentially induced by X. aurantifolii relative to Xanthomonas citri. To investigate the role of CsMAPK1 in citrus canker resistance, we expressed CsMAPK1 in citrus plants under the control of the PR5 gene promoter, which is induced by Xanthomonas infection and wounding. Increased expression of CsMAPK1 correlated with a reduction in canker symptoms and a decrease in bacterial growth. Canker lesions in plants with higher CsMAPK1 levels were smaller and showed fewer signs of epidermal rupture. Transgenic plants also revealed higher transcript levels of defense-related genes and a significant accumulation of hydrogen peroxide in response to wounding or X. citri infection. Accordingly, nontransgenic sweet orange leaves accumulate both CsMAPK1 and hydrogen peroxide in response to X. aurantifolii but not X. citri infection. These data, thus, indicate that CsMAPK1 functions in the citrus canker defense response by inducing defense gene expression and reactive oxygen species accumulation during infection. PMID:23777433

de Oliveira, Maria Luiza Peixoto; de Lima Silva, Caio Cesar; Abe, Valéria Yukari; Costa, Marcio Gilberto Cardoso; Cernadas, Raúl Andrés; Benedetti, Celso Eduardo

2013-10-01

84

Oak Tree Canker Disease Supports Arthropod Diversity in a Natural Ecosystem  

PubMed Central

Microorganisms have many roles in nature. They may act as decomposers that obtain nutrients from dead materials, while some are pathogens that cause diseases in animals, insects, and plants. Some are symbionts that enhance plant growth, such as arbuscular mycorrhizae and nitrogen fixation bacteria. However, roles of plant pathogens and diseases in natural ecosystems are still poorly understood. Thus, the current study addressed this deficiency by investigating possible roles of plant diseases in natural ecosystems, particularly, their positive effects on arthropod diversity. In this study, the model system was the oak tree (Quercus spp.) and the canker disease caused by Annulohypoxylon truncatum, and its effects on arthropod diversity. The oak tree site contained 44 oak trees; 31 had canker disease symptoms while 13 were disease-free. A total of 370 individual arthropods were detected at the site during the survey period. The arthropods belonged to 25 species, 17 families, and seven orders. Interestingly, the cankered trees had significantly higher biodiversity and richness compared with the canker-free trees. This study clearly demonstrated that arthropod diversity was supported by the oak tree canker disease. PMID:25288984

Lee, Yong-Bok; An, Su Jung; Park, Chung Gyoo; Kim, Jinwoo; Han, Sangjo; Kwak, Youn-Sig

2014-01-01

85

Subconjunctival Injection of Fluconazole in the Treatment of Fungal Alternaria Keratitis.  

PubMed

Abstract Purpose: We report two cases of Alternaria keratitis refractory to the conventional antifungal medical treatment successfully treated with subconjunctival fluconazole injection. Methods: Report of two cases. Results: After subconjunctival injection of fluconazole (2?mg/mL) 0.5?mL twice a day for 5 days then once a day till 14 days, two cases of Alternaria keratitis refractory to the conventional antifungal medical treatment were successfully treated. No severe local and systemic side effects were found in these two patients. Conclusions: Alternaria keratitis has a varied clinical presentation and suspicion must be maintained for unusual causes of infectious keratitis. Alternaria keratitis can be difficult to eradicate even with traditional antifungals such as amphotericin B and natamycin. Subconjunctival injection of fluconazole could be effective for Alternaria keratitis unresponsive to conventional antifungal medical treatment. PMID:24830382

Tsai, Shih-Hao; Lin, Yen-Chun; Hsu, Huan-Chen; Chen, Yan-Ming

2014-05-15

86

Effect of substrate on metabolite production of Alternaria alternata.  

PubMed

Alternariol and alternariol monomethyl ether are commonly associated with weathered grain sorghum. Production of these metabolites and altenuene by isolates of Alternaria alternata was evaluated on various sterile grain substrates. At 35% moisture content and 25 C, metabolite yields were highest on rice, intermediate on sorghums, and lowest on wheat and yellow corn. Fourteen-to 21-day cultures on milled rice were best in terms of ease of metabolite recovery, even though yields were higher on 28-day cultures of rough and brown rice. Metabolite production was reduced when rice was supplemented with yeast extract or yeast extract plus Czapek-Dox broth. PMID:945039

Burroughs, R; Seitz, L M; Sauer, D B; Mohr, H E

1976-05-01

87

A New Canker Disease of Apple, Pear, and Plum Rootstocks Caused by Diaporthe ambigua in South Africa  

E-print Network

A New Canker Disease of Apple, Pear, and Plum Rootstocks Caused by Diaporthe ambigua in South., Wingfield. B. D.. Wingfield. M. 1., and Calitz. F. J. 1996. A new canker disease of apple. pear, and plum was found to be the c:J.useof a newly recognized disease of apple. pear, and plum rootstocks in South Africa

88

112 2010 USDA Research Forum on Invasive Species GTR-NRS-P-75 THOUSAND CANKERS PATHWAY ASSESSMENT: MOVEMENT OF  

E-print Network

vector is the walnut twig beetle, Pityophthorus juglandis (WTB). The common name for the disease is "thousand cankers" due to the coalescing cankers surrounding multiple beetle entry points. The WTB, Colorado, and New Mexico. The eastern edge of the disease is the Front Range of Colorado. Our objectives

89

REAL-TIME PCR DETECTION AND DEVELOPMENT OF A BIOASSAY FOR THE DEEP BARK CANKER PATHOGEN, BRENNARIA RUBRIFACIENS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Deep Bark Canker (DBC), caused by the bacterium Brennaria rubrifaciens afflicts English walnut cultivars and is characterized by late onset of symptoms in trees greater than 15 years old. These symptoms include deep bleeding vertical cankers along the trunk and larger branches that exude a bacteria...

90

Development and validation of standard area diagrams as assessment aids for estimating the severity of citrus canker on unripe oranges  

Technology Transfer Automated Retrieval System (TEKTRAN)

Canker (caused by Xanthomonas citri subsp. citri) is an important disease of citrus in Brazil and elsewhere in the world, and can cause severe disease on the fruit. The severity of citrus canker of fruit must often be estimated visually. The objective of this research was to construct and validate s...

91

Antifungal activity of some plant extracts on Alternaria alternata, the causal agent of alternaria leaf spot of potato.  

PubMed

Pure methanol (m) and methanol water (mw) extracts of 5 plants namely: peppermint, eucalyptus, lavandula, Russian knapweed and datura were screened for their antifungal ability against Alternaria alternata, the causal agent of Alternaria leaf spot of potato at 5, 10 and 15% concentrations in vitro. Fungicide mancozeb 0.2% was also used for better comparison. Poisoned food technique and spore germination assay method were used to evaluate the antifungal efficacy of plant extracts. Present findings showed that methanol extracts of eucalyptus, peppermint and lavandula had impressive antifungal effects in inhibiting the mycelial growth as well as spore germination of the pathogen. It was also found that methanol extracts were quite more effective than methanol water extracts in this regard. Methanol extracts of peppermint (15%), lavandula (15%), peppermint (10%) and eucalyptus (15%) demonstrated promising ability in inhibiting the mycelial growth of A. alternata by 0.13, 0.40, 0.43 and 0.50 cm, mycelial growth respectively, while majority of methanol water extracts had either less or no effects in this connection. Spore germination of A. alternata was prominently reduced by methanol extracts, while those of methanol water extracts had very less effects in this regard. Mancozeb (0.2%), methanol extracts of eucalyptus (15%) and peppermint (10%) by 2, 6 and 7% spore germination were best, while methanol water extracts of datura 10, 15 and 5%, lavandula 15 and 10% and also Russian knapweed 5% represented no effect and by 91, 89, 87, 87, 85 and 85% spore germination were at par with control. Findings from this study confirmed that plant extracts can be used as less hazardous natural fungicides in controlling plant pathogenic fungi, thus reducing the dependence on the synthetic fungicides. Methanol extracts of peppermint, eucalyptus and lavandula might be promising materials for natural formulations in controlling Alternaria leaf spot of potato in the field. PMID:21313872

Zaker, M; Mosallanejad, H

2010-11-01

92

Chemical constituents of marine mangrove-derived endophytic fungus Alternaria tenuissima EN-192  

NASA Astrophysics Data System (ADS)

A chemical investigation of the ethyl acetate extract of the fermentation broth of Alternaria tenuissima EN-192, an endophytic fungus obtained from the stems of the marine mangrove plant Rhizophora stylosa, resulted in the isolation of nine known secondary metabolites, including four indole-diterpenoids: penijanthine A ( 1), paspaline ( 2), paspalinine ( 3), and penitrem A ( 4); three tricycloalternarene derivatives: tricycloalternarene 3a ( 5), tricycloalternarene 1b ( 6), and tricycloalternarene 2b ( 7); and two alternariol congeners: djalonensone ( 8) and alternariol ( 9). The chemical structures of these metabolites were characterized through a combination of detailed spectroscopic analyses and their comparison with reports from the literature. The inhibitory activities of each isolated compound against four bacteria were evaluated and compounds 5 and 8 displayed moderate activity against the aquaculture pathogenic bacterium Vibrio anguillarum, with inhibition zone diameters of 8 and 9 mm, respectively, at 100 ?g/disk. To the best of our knowledge, this is the first report on the secondary metabolites of mangrove-derived A lternaria tenuissima and also the first report of the isolation of indole-diterpenoids from fungal genus A lternaria.

Sun, Hong; Gao, Shushan; Li, Xiaoming; Li, Chunshun; Wang, Bingui

2013-03-01

93

Alternaria Inhibits Double-stranded RNA-Induced Cytokines Productions through TLR3  

PubMed Central

Background Fungi may be involved in asthma and chronic rhinosinusitis (CRS). PBMCs from CRS patients produce IL-5, IL-13 and INF-? by Alternaria. In addition, Alternaria produces potent Th2-like adjuvant effects in the airway. Therefore, we hypothesized that Alternaria may inhibit Th1-type defense mechanisms against virus infection. Methods Dendritic cells (DCs) were generated from mouse bone marrow. The functional responses were assessed by expression of cell surface molecules by FACS (MHC Class II, CD40, CD80, CD86 and OX40L. Production of IL-6, IP-10, I-TAC and IFN -? were measured by ELISA. TLR3 mRNA and protein expression were detected by quantitative Real time-PCR and Western blot. Results Alternaria and poly I:C enhanced cell surface expression of MHC Class II, CD40, CD80, CD86 and OX40L, and IL-6 production in a concentration-dependent manner. However, Alternaria significantly inhibited IP-10, I-TAC and IFN-? production induced by viral double-stranded RNA (dsRNA)-mimic poly I:C. TLR3 mRNA expression and protein production by poly I:C were significantly inhibited by Alternaria. These reactions are likely caused by heat-stable factor(s) in Alternaria extract with >100 kDa molecular mass. Conclusion These findings suggest that fungus, Alternaria may inhibit production of IFN-? and other cytokines by DCs by suppressing TLR3 expression. These results indicate that Alternaria may inhibit host innate immunity against virus infection. PMID:23711857

Wada, Kota; Kobayashi, Takao; Matsuwaki, Yoshinori; Moriyama, Hiroshi; Kita, Hirohito

2014-01-01

94

Deinococcus citri sp. nov., isolated from citrus leaf canker lesions.  

PubMed

A Gram-stain-positive, strictly aerobic, non-motile, coccoid bacterium, designated NCCP-154(T), was isolated from citrus leaf canker lesions and was subjected to a polyphasic taxonomic study. Strain NCCP-154(T) grew at 10-37 °C (optimum 30 °C) and at pH 7.0-8.0 (optimum pH 7.0). The novel strain exhibited tolerance of UV irradiation (>1000 J m(-2)). Based on 16S rRNA gene sequence analysis, strain NCCP-154(T) showed the highest similarity to Deinococcus gobiensis CGMCC 1.7299(T) (98.8?%), and less than 94?% similarity to other closely related taxa. The chemotaxonomic data [major menaquinone, MK-8; cell-wall peptidoglycan type, A3? (Orn-Gly2); major fatty acids, summed feature 3 (C16?:?1?7c/iso-C15?:?0 2-OH; 35.3?%) followed by C16?:?0 (12.7?%), iso-C17?:?1?9c (9.2?%), C17?:?1?8c (7.4?%) and iso-C17?:?0 (6.9?%); major polar lipids made up of several unidentified phosphoglycolipids and glycolipids and an aminophospholipid, and mannose as the predominant whole-cell sugar] also supported the affiliation of strain NCCP-154(T) to the genus Deinococcus. The level of DNA-DNA relatedness between strain NCCP-154(T) and D. gobiensis JCM 16679(T) was 63.3±3.7?%. The DNA G+C content of strain NCCP-154(T) was 70.0 mol%. Based on the phylogenetic analyses, DNA-DNA hybridization and physiological and biochemical characteristics, strain NCCP-154(T) can be differentiated from species with validly published names. Therefore, it represents a novel species of the genus Deinococcus. The name Deinococcus citri sp. nov. is proposed, with the type strain NCCP-154(T) (?=?JCM 19024(T)?=?DSM 24791(T)?=?KCTC 13793(T)). PMID:25256704

Ahmed, Iftikhar; Abbas, Saira; Kudo, Takuji; Iqbal, Muhammad; Fujiwara, Toru; Ohkuma, Moriya

2014-12-01

95

Natural occurrence of Alternaria mycotoxins in sorghum and ragi from North Bihar, India.  

PubMed

The natural occurrence of major Alternaria mycotoxins i.e. alternariol (AOH), alternariol methyl ether (AME), altenuene (ALT), altertoxin-1 (ATX-1) and tenuazonic acid (TA) has been investigated in sorghum (Sorghum vulgare Pers.) and ragi (Eleusine coracana Gaertn.) collected from North Bihar. Nine out of 20 sorghum samples, and three out of eight ragi samples, were found to be contaminated with one to three Alternaria mycotoxins. The toxin elaborating potential of Alternaria alternata (Fr.) Keissler strains isolated from sorghum and ragi have also been investigated. Out of 16 isolates of A. alternata (Fr.) Keissler, mycotoxins were detected in only 10. PMID:2079114

Ansari, A A; Shrivastava, A K

1990-01-01

96

Alternaria hungarica sp. nov., a minor foliar pathogen of wheat in Hungary.  

PubMed

During routine wheat disease surveys in Hungary in 2007 Alternaria was isolated from leaf samples collected in Debrecen. Macro- and micro-morphological examinations and ITS sequence analyses indicated that the isolates represented a new Alternaria species, which we described as A. hungarica. The usually solitary conidia of A. hungarica resemble those of A. mouchaccae and A. molesta. However growth and sporulation pattern are more like those of A. geniostomatis and A. soliaridae. Phylogenetic analysis of ITS sequences indicated that this new species can be distinguished from all other examined Alternaria and Embellisia species. Pathogenicity tests indicated that A. hungarica can be considered a minor pathogen of wheat. PMID:20943568

Tóth, Beáta; Csosz, Mária; Szabó-Hevér, Agnes; Simmons, Emory G; Samson, Robert A; Varga, János

2011-01-01

97

Different Transcriptional Response to Xanthomonas citri subsp. citri between Kumquat and Sweet Orange with Contrasting Canker Tolerance  

PubMed Central

Citrus canker disease caused by Xanthomonas citri subsp. citri (Xcc) is one of the most devastating biotic stresses affecting the citrus industry. Meiwa kumquat (Fortunella crassifolia) is canker-resistant, while Newhall navel orange (Citrus sinensis Osbeck) is canker-sensitive. To understand the molecular mechanisms underlying the differences in responses to Xcc, transcriptomic profiles of these two genotypes following Xcc attack were compared by using the Affymetrix citrus genome GeneChip. A total of 794 and 1324 differentially expressed genes (DEGs) were identified as canker-responsive genes in Meiwa and Newhall, respectively. Of these, 230 genes were expressed in common between both genotypes, while 564 and 1094 genes were only significantly expressed in either Meiwa or Newhall. Gene ontology (GO) annotation and Singular Enrichment Analysis (SEA) of the DEGs showed that genes related to the cell wall and polysaccharide metabolism were induced for basic defense in both Meiwa and Newhall, such as chitinase, glucanase and thaumatin-like protein. Moreover, apart from inducing basic defense, Meiwa showed specially upregulated expression of several genes involved in the response to biotic stimulus, defense response, and cation binding as comparing with Newhall. And in Newhall, abundant photosynthesis-related genes were significantly down-regulated, which may be in order to ensure the basic defense. This study revealed different molecular responses to canker disease in Meiwa and Newhall, affording insight into the response to canker and providing valuable information for the identification of potential genes for engineering canker tolerance in the future. PMID:22848606

Fu, Xing-Zheng; Gong, Xiao-Qing; Zhang, Yue-Xin; Wang, Yin; Liu, Ji-Hong

2012-01-01

98

Fungal meningoencephalitis caused by Alternaria: a clinical case.  

PubMed

Cerebral phaeohyphomycosis is an infrequent infectious condition associated with a high mortality rate. The authors describe a very rare case that occurred in an immunocompetent 18-year-old man who developed severe meningoencephalitis and arachnoiditis caused by Alternaria alternata, which were diagnosed in the context of difficult-to-treat hydrocephalus. Etiological diagnosis was made based on fungal culture and histopathologic examination. Empirical treatment consisted of an early aggressive antifungal combination therapy consisting of intravenous liposomal amphotericin B (5 mg/kg per day) and voriconazole (4 mg/kg every 12 h), which initially induced a favorable response. Following the fungus identification, the choice for the combination of posaconazole (400 mg every 12 h) plus flucytosine (4000 mg/day) proved to be effective in the suppression of the signs and symptoms of this uncommon cerebral mycosis. At a 12-month follow-up visit no recurrence had occurred and posaconazole was then stopped. PMID:23381981

Silveira, Cícero J C; Amaral, Joana; Gorayeb, Rodrigo P; Cabral, José; Pacheco, Teresa

2013-02-01

99

The phytopathogenic fungus Alternaria brassicicola: phytotoxin production and phytoalexin elicitation.  

PubMed

The metabolites and phytotoxins produced by the phytopathogenic fungus Alternaria brassicicola (Schwein.) Wiltshire, as well as the phytoalexins induced in host plants, were investigated. Brassicicolin A emerged as the most selective phytotoxic metabolite produced in liquid cultures of A. brassicicola and spirobrassinin as the major phytoalexin produced in infected leaves of Brassica juncea (whole plants). In detached infected leaves of B. juncea, the main component was N'-acetyl-3-indolylmethanamine, the product of detoxification of the phytoalexin brassinin by A. brassicicola. In addition, the structure elucidation of three hitherto unknown metabolites having a fusicoccane skeleton was carried out and the antifungal activity of several plant defenses against A. brassicicola was determined. PMID:19223049

Pedras, M Soledade C; Chumala, Paulos B; Jin, Wei; Islam, Mohammed S; Hauck, Dominic W

2009-02-01

100

Intranasal fungal (Alternaria) infection related to nasal steroid spray.  

PubMed

During the past three decades intranasal corticosteroid sprays have been proven to be efficient and reasonably safe for the treatment of rhinitis, sinusitis and nasal polyposis. The adverse effects are generally localized and self-limited and rarely systemic or significant. We report an immunocompetent female treated with triamcinolone acetonide nasal spray for chronic rhinitis in whom an intranasal fungal infection with Alternaria species developed three months later. The infection was refractory to topical therapies alone, and was resolved with a combination of systemic and topical antifungal therapy. We also described the clinical manifestations of this rare infection and our therapeutic experience. In addition, we reviewed previous literature of fungal infections related to nasal corticosteroid sprays and compared them with our report. PMID:24018172

Chang, Geng-He; Wang, Wen-Hung

2013-01-01

101

IMAGE ANALYSIS VERSUS VISUAL ASSESSMENT OF INCIDENCE AND SEVERITY OF CITRUS CANKER SYMPTOMS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Xanthomonas axonopodis pv citri causes citrus canker. Disease assessment is important for monitoring epidemics. Visual assessment (VA) is presently the only reliable means of detection. To investigate how VA of symptoms compared to image analysis we used digital images of 214 citrus le...

102

Lateral organ boundaries 1 is a disease susceptibility gene for citrus bacterial canker disease  

Microsoft Academic Search

Citrus bacterial canker (CBC) disease occurs worldwide and incurs considerable costs both from control measures and yield losses. Bacteria that cause CBC require one of six known type III transcription activator-like (TAL) effector genes for the characteristic pustule formation at the site of infection. Here, we show that Xanthomonas citri subspecies citri strain Xcc306, with the type III TAL effector

Y. Hu; J. Zhang; H. Jia; D. Sosso; T. Li; W. B. Frommer; B. Yang; F. F. White; N. Wang; J. B. Jones

2014-01-01

103

The activity of citrus canker lseions on grapefruit in Florida, June 2009-January 2010  

Technology Transfer Automated Retrieval System (TEKTRAN)

Lesions of citrus canker, caused by Xanthomonas citri subsp. citri (Xcc), on citrus fruit preclude sale of the fruit to the fresh market; the fruit must be juiced, which is less profitable. Assessing lesion activity in orchard-grown grapefruit provides information on the population dynamics of fruit...

104

Update on packing line protocols for citrus canker and their effects on bacterial survival  

Technology Transfer Automated Retrieval System (TEKTRAN)

Markets for Florida citrus are severely restricted by regulations in place to minimize the spread of citrus canker to citrus producing areas. Included in these regulations are accepted protocols for sanitation and coating of fruit. However, these measures do not eradicate all the living bacterial ce...

105

The Eucalyptus canker pathogen Holocryphia eucalypti on Eucalyptus in New Zealand  

E-print Network

The Eucalyptus canker pathogen Holocryphia eucalypti on Eucalyptus in New Zealand M. Gryzenhout, South Africa. C Scion Research, New Zealand Forest Institute Ltd, Rotorua, New Zealand. D Corresponding and morphological characterisation, we show for the first time that H. eucalypti is present in New Zealand

106

Prevalence, distribution and identification of Phytophthora species from bleeding canker on European beech  

Technology Transfer Automated Retrieval System (TEKTRAN)

While bleeding canker of European beech (Fagus sylvatica) has long been recognized as a problem, the cause in the northeastern United States has not been clear. To resolve this, we surveyed for disease prevalence, identified the pathogens involved, proved their pathogenicity, compared protocols for ...

107

Canker and twig dieback of blueberry caused by Pestalotiopsis spp. and a Truncatella sp. in Chile  

Technology Transfer Automated Retrieval System (TEKTRAN)

Blueberry (Vaccinium spp.) has great economic importance in Chile, currently with about 8,500 ha being cultivated. Recently, the presence of canker and dieback symptoms has been observed along the productive blueberry zone of Chile extending from the V Region (32º49´ South lat.) in the north to the ...

108

Report on the National Survey to Assess the Presence of Bleeding Canker of Horse Chestnut Trees  

E-print Network

Report on the National Survey to Assess the Presence of Bleeding Canker of Horse Chestnut Trees trees from 128 rural sites and 1244 trees in 112 urban sites were inspected. All regions had some symptomatic trees and overall, 44% of the trees inspected in the rural environment and 55% of the urban trees

109

Figure 1. Rapidly wilting black walnut in the final stage of thousand cankers  

E-print Network

been noted in some Front Range communities in Colorado since 2001 and the twig beetle has been gallery. Figure 3. Distribution of the walnut twig beetle. In green are states and the California county 1998. Pest Alert Walnut Twig Beetle and Thousand Cankers Disease of Black Walnut Within the past decade

110

THE EFFECT OF HURRICANES AND TROPICAL STORMS ON LONG DISTANCE SPREAD OF CITRUS CANKER  

Technology Transfer Automated Retrieval System (TEKTRAN)

Asiatic citrus canker (ACC) is a serious disease of citrus that causes foliar and fruit lesions leading to extensive yield and quality losses. During Fall 2004, Florida experienced 3 hurricanes (Charlie, Francis, Jeanne) and one tropical storm (Ivan) whose paths crossed the majority of the commercia...

111

LONG DISTANCE SPREAD OF CITRUS CANKER RELATED TO HURRICANES AND TROPICAL STORMS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Asiatic citrus canker (ACC) is a serious disease of citrus that causes foliar and fruit lesions leading to extensive yield and quality losses. During Fall 2004, Florida experienced 3 hurricanes (Charlie, Francis, Jeanne) and one tropical storm (Ivan) whose paths crossed the majority of the commercia...

112

ANNUAL AND POLYETIC PROGRESSION OF CITRUS CANKER ON TREES PROTECTED WITH COPPER SPRAYS  

Technology Transfer Automated Retrieval System (TEKTRAN)

: Mathematical models are important tools for comparative analysis of epidemics. In this paper, parameters obtained from the mathematical model that best fitted to the annual progress curves of citrus canker incidence were used to evaluate the effect of copper sprays and windbreaks on the annual and...

113

DETECTION OF BRENNARIA RUBRIFACIENS THE CAUSATIVE AGENT OF DEEP BARK CANKER (DBC)OF WALNUT  

Technology Transfer Automated Retrieval System (TEKTRAN)

DBC afflicts English walnut cultivars and is characterized by late onset in trees greater than 15 years old. Symptoms include deep bleeding vertical cankers that exude a bacterial-laden reddish brown sap. We have developed a robust PCR-based technique to detect B. rubrifaciens in soil and symptomles...

114

Optimal strategies for the eradication of Asiatic citrus canker in heterogeneous host landscapes  

Technology Transfer Automated Retrieval System (TEKTRAN)

The eradication of non-native plant pathogens is a key challenge in plant disease epidemiology. Asiatic citrus canker is an economically significant disease of citrus caused by the bacterial plant pathogen Xanthomonas citri subsp. citri. The pathogen is a major exotic disease problem in many citru...

115

GENETIC DIVERSITY AND WORLDWIDE PROLIFERATION OF CITRUS BACTERIAL CANKER PATHOGENS IDENTIFIED IN HIRTORIC SPECIMENS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus bacterial canker (CBC) caused by Xanthomonas axonopodis pv. citri (Xac) may have originated in Southeast Asia based on symptoms present on early herbarium specimens. The disease was first introduced into the United States in 1911 and has spread to most citrus producing areas in the world. Thi...

116

GENETIC DIVERSITY AND WORLDWIDE PROLIFERATION OF CITRUS BACTERIAL CANKER PATHOGENS IDENTIFIED IN HISTORIC SPECIMENS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus bacterial canker (CBC) caused by Xanthomonas axonopodis pv. citri (Xac) may have originated in Southeast Asia, based on symptoms present on early herbarium specimens. The disease was first introduced into the United States in 1911 and has spread to most citrus producing areas in the world. Th...

117

REPEATABILITY AND COMPARISION OF IMAGE ANALYSIS AND VISUAL ASSESSMENT FOR DISEASE ASSESSMENT OF CITRUS CANKER  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker, a disease of several citrus species, is caused by the bacterial pathogen Xanthomonas axonopodis pv citri (Xac). The disease is of concern in several wet tropical and subtropical citrus growing regions as infection results in yield loss and severely blemished fruit unsuitable for the f...

118

Evidence for a new introduction of the pitch canker fungus Fusarium circinatum in South Africa  

E-print Network

Evidence for a new introduction of the pitch canker fungus Fusarium circinatum in South Africa E. T of Pinus species in many parts of the world. The fungus was first recorded in South Africa in 1990 of the fungus elsewhere in South Africa. However, limited genetic structure was found within the respective WCP

119

Genetic diversity of citrus bacterial canker pathogens preserved in herbarium specimens  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus bacterial canker (CBC) caused by Xanthomonas axonopodis pv. citri (Xac) was first documented in India and Java in the mid 19th century. Since that time the known distribution of the disease has steadily increased. Concurrent with the dispersion of the pathogen, the diversity of described str...

120

Occurrence of Leaf Blight on Cosmos Caused by Alternaria cosmosa in Korea.  

PubMed

In 2011, a leaf blight disease was observed on cosmos (Cosmos bipinnatus) leaves in Nonsan, Korea. The causal pathogen was isolated and identified based on morphological and molecular approaches. Morphological characteristics of the pathogen matched well with the Alternaria cosmosa and also easily distinguishable from Alternaria zinniae reported from cosmos seeds by producing branched beak. Phylogenetically, the pathogen could not be distinguished from A. passiflorae based on the sequence analysis of a combined data set of Alt a1 and gpd genes. However, A. passiflorae was distinguished from the present species by having conidiophores with 4 to 5 conidiogenous loci. The results indicate that the present Alternaria species is A. cosmosa. Pathogenicity tests revealed that the isolate was pathogenic to the leaves of Cosmos bipinnatus. This is the first report of Alternaria blight disease caused by A. cosmosa on cosmos in Korea. PMID:25774114

Deng, Jian Xin; Lee, Ji Hye; Paul, Narayan Chandra; Cho, Hye Sun; Lee, Hyang Burm; Yu, Seung Hun

2015-03-01

121

INOCULATION STRATEGIES TO ASSESS BIOLOGICAL INTERACTIONS BETWEEN FUSARIUM AND ALTERNARIA SPECIES INFECTING SORGHUM  

Technology Transfer Automated Retrieval System (TEKTRAN)

Three bioassays were assessed for experimental utility to either characterize fungal species potentially pathogenic to sorghum [Sorghum bicolor (L.) Moench] or to screen germplasm for advancement in breeding programs. Isolates of species commonly associated with sorghum, Alternaria alternata, Fusari...

122

40 CFR 180.1256 - Alternaria destruens strain 059; exemption from the requirement of a tolerance.  

Code of Federal Regulations, 2014 CFR

...from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of the microbial pesticide Alternaria destruens Strain 059 when used in or on all raw agricultural commodities when applied/used in...

2014-07-01

123

40 CFR 180.1256 - Alternaria destruens strain 059; exemption from the requirement of a tolerance.  

Code of Federal Regulations, 2010 CFR

...from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of the microbial pesticide Alternaria destruens Strain 059 when used in or on all raw agricultural commodities when applied/used in...

2010-07-01

124

40 CFR 180.1256 - Alternaria destruens strain 059; exemption from the requirement of a tolerance.  

Code of Federal Regulations, 2012 CFR

...from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of the microbial pesticide Alternaria destruens Strain 059 when used in or on all raw agricultural commodities when applied/used in...

2012-07-01

125

Occurrence of Leaf Blight on Cosmos Caused by Alternaria cosmosa in Korea  

PubMed Central

In 2011, a leaf blight disease was observed on cosmos (Cosmos bipinnatus) leaves in Nonsan, Korea. The causal pathogen was isolated and identified based on morphological and molecular approaches. Morphological characteristics of the pathogen matched well with the Alternaria cosmosa and also easily distinguishable from Alternaria zinniae reported from cosmos seeds by producing branched beak. Phylogenetically, the pathogen could not be distinguished from A. passiflorae based on the sequence analysis of a combined data set of Alt a1 and gpd genes. However, A. passiflorae was distinguished from the present species by having conidiophores with 4 to 5 conidiogenous loci. The results indicate that the present Alternaria species is A. cosmosa. Pathogenicity tests revealed that the isolate was pathogenic to the leaves of Cosmos bipinnatus. This is the first report of Alternaria blight disease caused by A. cosmosa on cosmos in Korea. PMID:25774114

Deng, Jian Xin; Lee, Ji Hye; Paul, Narayan Chandra; Cho, Hye Sun; Lee, Hyang Burm; Yu, Seung Hun

2015-01-01

126

Alternaria toxins in wheat from the Autonomous Province of Vojvodina, Serbia: a preliminary survey.  

PubMed

Although Fusarium species remain a main source of mycotoxin contamination of wheat, in recent years, due to the evident climatic changes, other mycotoxigenic fungi have been recognised as important wheat contaminants. Alternaria species, especially A. alternata, have been found as contaminants of wheat as well as wheat-based products. Under favourable conditions A. alternata very often produce alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA) and others Alternaria toxins. The aim of the present study was to examine the presence of three Alternaria toxins (AOH, AME and TeA) in wheat samples harvested during three years (2011-13). To this end, 92 samples were collected during wheat harvesting from different growing regions of the Autonomous Province of Vojvodina, which represents the most important wheat-growing area in Serbia. The presence of Alternaria toxins was analysed by HPLC with electrospray ionisation triple quadrupole mass spectrometry (LC-ESI-MS/MS). Among all the analysed wheat samples, 63 (68.5%) were contaminated with TeA, 11 (12.0%) with AOH and 6 (6.5%) with AME. Furthermore, the maximum and mean toxin concentrations were 2676 and 92.4 µg kg(-1), 48.9 and 18.6 µg kg(-1), and 70.2 and 39.0 µg kg(-1) for TeA, AOH and AME, respectively. Co-occurrence of three Alternaria toxins in wheat samples was detected in six samples; a combination of two toxins was found in two samples; and 64 samples contained one toxin. The results showed that among 92 analysed wheat samples, only 20 (21.7%) samples were without Alternaria toxins. The presence of Alternaria toxins was also investigated in terms of weather conditions recorded during the period of investigation, as well as with the sampling region. This study represents the first preliminary report of the natural occurrence of Alternaria toxins in wheat (Triticum aestivum) from Serbia. PMID:25585540

Jani? Hajnal, Elizabet; Or?i?, Dejan; Torbica, Aleksandra; Kos, Jovana; Mastilovi?, Jasna; Škrinjar, Marija

2015-03-01

127

ATP release and Ca2+ signalling by human bronchial epithelial cells following Alternaria aeroallergen exposure  

PubMed Central

Exposure of human bronchial epithelial (HBE) cells from normal and asthmatic subjects to extracts from Alternaria alternata evoked a rapid and sustained release of ATP with greater efficacy observed in epithelial cells from asthmatic patients. Previously, Alternaria allergens were shown to produce a sustained increase in intracellular Ca2+ concentration ([Ca2+]i) that was dependent on the coordinated activation of specific purinergic receptor (P2Y2 and P2X7) subtypes. In the present study, pretreatment with a cell-permeable Ca2+-chelating compound (BAPTA-AM) significantly inhibited ATP release, indicating dependency on [Ca2+]i. Alternaria-evoked ATP release exhibited a greater peak response and a slightly lower EC50 value in cells obtained from asthmatic donors compared to normal control cells. Furthermore, the maximum increase in [Ca2+]i resulting from Alternaria treatment was greater in cells from asthmatic patients compared to normal subjects. The vesicle transport inhibitor brefeldin A and BAPTA-AM significantly blocked Alternaria-stimulated incorporation of fluorescent lipid (FM1-43)-labelled vesicles into the plasma membrane and ATP release. In addition, inhibiting uptake of ATP into exocytotic vesicles with bafilomycin also reduced ATP release comparable to the effects of brefeldin A and BAPTA-AM. These results indicate that an important mechanism for Alternaria-induced ATP release is Ca2+ dependent and involves exocytosis of ATP. Serine and cysteine protease inhibitors also reduced Alternaria-induced ATP release; however, the sustained increase in [Ca2+]i typically observed following Alternaria exposure appeared to be independent of protease-activated receptor (PAR2) stimulation. PMID:23858006

O'Grady, Scott M; Patil, Nandadavi; Melkamu, Tamene; Maniak, Peter J; Lancto, Cheryl; Kita, Hirohito

2013-01-01

128

Barrier Disrupting Effects of Alternaria Alternata Extract on Bronchial Epithelium from Asthmatic Donors  

PubMed Central

Sensitization and exposure to the allergenic fungus Alternaria alternata has been associated with increased risk of asthma and asthma exacerbations. The first cells to encounter inhaled allergens are epithelial cells at the airway mucosal surface. Epithelial barrier function has previously been reported to be defective in asthma. This study investigated the contribution of proteases from Alternaria alternata on epithelial barrier function and inflammatory responses and compared responses of in vitro cultures of differentiated bronchial epithelial cells derived from severely asthmatic donors with those from non-asthmatic controls. Polarised 16HBE cells or air-liquid interface (ALI) bronchial epithelial cultures from non-asthmatic or severe asthmatic donors were challenged apically with extracts of Alternaria and changes in inflammatory cytokine release and transepithelial electrical resistance (TER) were measured. Protease activity in Alternaria extracts was characterised and the effect of selectively inhibiting protease activity on epithelial responses was examined using protease inhibitors and heat-treatment. In 16HBE cells, Alternaria extracts stimulated release of IL-8 and TNF?, with concomitant reduction in TER; these effects were prevented by heat-treatment of the extracts. Examination of the effects of protease inhibitors suggested that serine proteases were the predominant class of proteases mediating these effects. ALI cultures from asthmatic donors exhibited a reduced IL-8 response to Alternaria relative to those from healthy controls, while neither responded with increased thymic stromal lymphopoietin (TSLP) release. Only cultures from asthmatic donors were susceptible to the barrier-weakening effects of Alternaria. Therefore, the bronchial epithelium of severely asthmatic individuals may be more susceptible to the deleterious effects of Alternaria. PMID:24009658

Blume, Cornelia; Swindle, Emily J.; Jayasekera, Nivenka P.; Dennison, Patrick W.; Shamji, Betty W. H.; Edwards, Matthew J.; Holgate, Stephen T.; Howarth, Peter H.; Davies, Donna E.

2013-01-01

129

Artificial neural network models of relationships between Alternaria spores and meteorological factors in Szczecin (Poland)  

Microsoft Academic Search

Alternaria is an airborne fungal spore type known to trigger respiratory allergy symptoms in sensitive patients. Aiming to reduce the\\u000a risk for allergic individuals, we constructed predictive models for the fungal spore circulation in Szczecin, Poland. Monthly\\u000a forecasting models were developed for the airborne spore concentrations of Alternaria, which is one of the most abundant fungal taxa in the area.

Agnieszka Grinn-Gofron; Agnieszka Strzelczak

2008-01-01

130

Alternaria-derived serine protease activity drives IL-33–mediated asthma exacerbations  

PubMed Central

Background The fungal allergen Alternaria alternata is implicated in severe asthma and rapid onset life-threatening exacerbations of disease. However, the mechanisms that underlie this severe pathogenicity remain unclear. Objective We sought to investigate the mechanism whereby Alternaria was capable of initiating severe, rapid onset allergic inflammation. Methods IL-33 levels were quantified in wild-type and ST2?/? mice that lacked the IL-33 receptor given inhaled house dust mite, cat dander, or Alternaria, and the effect of inhibiting allergen-specific protease activities on IL-33 levels was assessed. An exacerbation model of allergic airway disease was established whereby mice were sensitized with house dust mite before subsequently being challenged with Alternaria (with or without serine protease activity), and inflammation, remodeling, and lung function assessed 24 hours later. Results Alternaria, but not other common aeroallergens, possessed intrinsic serine protease activity that elicited the rapid release of IL-33 into the airways of mice through a mechanism that was dependent upon the activation of protease activated receptor-2 and adenosine triphosphate signaling. The unique capacity of Alternaria to drive this early IL-33 release resulted in a greater pulmonary inflammation by 24 hours after challenge relative to the common aeroallergen house dust mite. Furthermore, this Alternaria serine protease–IL-33 axis triggered a rapid, augmented inflammation, mucus release, and loss of lung function in our exacerbation model. Conclusion Alternaria-specific serine protease activity causes rapid IL-33 release, which underlies the development of a robust TH2 inflammation and exacerbation of allergic airway disease. PMID:24636086

Snelgrove, Robert J.; Gregory, Lisa G.; Peiró, Teresa; Akthar, Samia; Campbell, Gaynor A.; Walker, Simone A.; Lloyd, Clare M.

2014-01-01

131

Identification and characterization of microsatellite from Alternaria brassicicola to assess cross-species transferability and utility as a diagnostic marker.  

PubMed

Alternaria blight caused by Alternaria brassicicola (Schwein.) Wiltshire and A. brassicae (Berk.) Sacc., is one of the most important disease of rapeseed-mustard, characterized by the formation of spots on leaves, stem, and siliquae with premature defoliation and stunting of growth. These two species are very difficult to differentiate based on disease symptoms or spore morphology. Therefore, the aim of present investigation was to identify and characterize transferable microsatellite loci from A. brassicicola to A. brassicae for the development of diagnostic marker. A total of 8,457 microsatellites were identified from transcript sequences of A. brassicicola. The average density of microsatellites was one microsatellite per 1.94 kb of transcript sequence screened. The most frequent repeat was tri-nucleotide (74.03 %), whereas penta-nucleotide (1.14 %) was least frequent. Among amino acids, arginine (13.11 %) showed maximum abundance followed by lysine (10.11 %). A total of 32 alleles were obtained across the 31 microsatellite loci for the ten isolates of A. brassicicola. In cross-species amplifications, 5 of the 31 markers amplified the corresponding microsatellite regions in twenty isolates of A. brassicae and showed monomorphic banding pattern. Microsatellite locus ABS28 was highly specific for A. brassicicola, as no amplification was observed from twenty-nine other closely related taxa. Primer set, ABS28F/ABS28R, amplified a specific amplicon of 380 bp from all A. brassicicola isolates. Standard curves were generated for A. brassicicola isolate using SYBR Green I fluorescent dye for detection of amplification in real-time PCR assay. The lowest detection limit of assay was 0.01 ng. Thus, the primer set can be used as diagnostic marker to discriminate and diagnose A. brassicicola from synchronously occurring fungus, A. brassicae associated with rapeseed and mustard. PMID:25048820

Singh, Ruchi; Kumar, Sudheer; Kashyap, Prem Lal; Srivastava, Alok Kumar; Mishra, Sanjay; Sharma, Arun Kumar

2014-11-01

132

Screening antimicrobial peptides in-vitro for use in developing transgenic citrus resistant to huanglongbing and citrus canker  

Technology Transfer Automated Retrieval System (TEKTRAN)

Huanglongbing (HLB, associated with Candidatus Liberibacter sp.) and Asiatic citrus canker (ACC, causal organism Xanthomonas citri subsp. citri (XCC)) are bacterial diseases that seriously threaten sustainability of the Florida citrus industry. Sweet orange and grapefruit are highly susceptible to A...

133

Phoma glomerata (Corda) Wollenw. & Hochapfel a new threat causing cankers on shoots of peach trees in Greece  

Microsoft Academic Search

Shoot blights are common diseases of peach trees in Greece. This study is the first report of a shoot blight and canker disease\\u000a of peach in Greece caused by the fungus Phoma glomerata (Corda) Wollenw. & Hochapfel. The pathogen caused distinct cankers with abundant gumming on shoots of peach trees. The rate\\u000a of development of P. glomerata in vitro was

Thomas Thomidis; Themis J. Michailides; Efstathia Exadaktylou

134

Characterization of Alternaria strains from Argentinean blueberry, tomato, walnut and wheat.  

PubMed

Alternaria species have the ability to produce a variety of secondary metabolite, which plays important roles in food safety. Argentina is the second largest exporter of fresh and processed food products to Europe, however, few studies on Alternaria mycotoxins and other bioactive secondary metabolites have been carried out on Argentinean cereals, fruit and vegetables. Knowing the full chemical potential and the distribution of Alternaria spp. on crops, it is necessary to establish a toxicological risk assessment for food products for human consumption. In the present study, 87 Alternaria strains from different substrates (tomato, wheat, blueberries and walnuts) were characterized according to morphology and metabolite production. Aggressive dereplication (accurate mass, isotopic patterns and lists of all described compounds from Alternaria) was used for high-throughput evaluation of the chemical potential. Four strains belonged to the Alternaria infectoria sp.-grp., 6 to the Alternaria arborescens sp.-grp., 6 showed a sporulation pattern similar to that of "M" according to Simmons, 1 to that of Alternaria vaccinii, and the remaining 70 constituted a diverse group belonging to morphological groups "G" and "H". The cluster analysis yielded 16 almost identical dendrograms and grouped the Alternaria strains into four clusters and 11 singletons and outlier groups. The chemical analysis showed that AOH and AME were the most common metabolites produced, followed by TEN, ALXs and TeA. The A. infectoria sp.-grp. had no metabolites in common with the rest of the strains. Several secondary metabolites isolated from large-spored Alternaria species or other fungal genera were detected, such as dehydrocurvularin, pyrenochaetic acid and alternarienonic acid. The strains isolated from tomato produced lower amounts of metabolites than strains from blueberries, walnut and wheat, although individual strains from tomato produced the highest amount of some metabolites. The A. infectoria sp.-grp. was unique to cereals, whereas strains classified as belonging to the A. arborescens sp.-grp or having sporulation pattern "M" were only isolated from tomatoes. Otherwise, no clear association between substrate and identity could be found. The analyses in the study show that at least 75% of the Argentinean strains are able to produce potential mycotoxins. PMID:25498470

Andersen, Birgitte; Nielsen, Kristian F; Fernández Pinto, Virginia; Patriarca, Andrea

2015-03-01

135

First report of stem canker of Salsola tragus caused by Diaporthe eres in Russia  

Technology Transfer Automated Retrieval System (TEKTRAN)

Salsola tragus L. (Russian thistle, tumbleweed), family Chenopodiaceae, is a problematic invasive weed in the western United States and a target of biological control efforts. In September of 2007, dying Salsola tragus plants were found along the Azov Sea at Chushka, Russia. About 30 plants in the...

136

Hyperspectral and Thermal Imaging of Oilseed Rape (Brassica napus) Response to Fungal Species of the Genus Alternaria  

PubMed Central

In this paper, thermal (8-13 µm) and hyperspectral imaging in visible and near infrared (VNIR) and short wavelength infrared (SWIR) ranges were used to elaborate a method of early detection of biotic stresses caused by fungal species belonging to the genus Alternaria that were host (Alternaria alternata, Alternaria brassicae, and Alternaria brassicicola) and non-host (Alternaria dauci) pathogens to oilseed rape (Brassica napus L.). The measurements of disease severity for chosen dates after inoculation were compared to temperature distributions on infected leaves and to averaged reflectance characteristics. Statistical analysis revealed that leaf temperature distributions on particular days after inoculation and respective spectral characteristics, especially in the SWIR range (1000-2500 nm), significantly differed for the leaves inoculated with A. dauci from the other species of Alternaria as well as from leaves of non-treated plants. The significant differences in leaf temperature of the studied Alternaria species were observed in various stages of infection development. The classification experiments were performed on the hyperspectral data of the leaf surfaces to distinguish days after inoculation and Alternaria species. The second-derivative transformation of the spectral data together with back-propagation neural networks (BNNs) appeared to be the best combination for classification of days after inoculation (prediction accuracy 90.5%) and Alternaria species (prediction accuracy 80.5%). PMID:25826369

Baranowski, Piotr; Jedryczka, Malgorzata; Mazurek, Wojciech; Babula-Skowronska, Danuta; Siedliska, Anna; Kaczmarek, Joanna

2015-01-01

137

Isotope fractionation of selenium during fungal biomethylation by Alternaria alternata.  

PubMed

The natural abundance of stable Se isotopes may reflect sources and formation conditions of methylated Se. We aimed at (1) quantifying the degree of methylation of selenate [Se(VI)] and (hydro)selenite [Se(IV)] by the fungus Alternaria alternata at pH 4 and 7 and (2) determining the effects of these different Se sources and pH values on 82Se/76Se ratios (?82/76Se) in methylselenides. Alternaria alternata was incubated with Se(VI) and Se(IV) in closed microcosms for 11-15 days and additionally with Se(IV) for 3-5 days at 30 °C. We determined Se concentrations and ?82/76Se values in source Se(VI) and Se(IV), media, fungi, and trapped methylselenides. In Se(VI) incubations, methylselenide volatilization ended before the 11th day, and the amounts of trapped methylselenide were not significantly different among the 11-15 day incubations. In 11-15 days, 2.9-11% of Se(VI) and 21-29% of Se(IV) were methylated, and in 3-5 days, 3-5% of Se(IV) was methylated. The initial ?82/76Se values of Se(VI) and Se(IV) were -0.69±SD 0.07‰, and -0.20±0.05‰, respectively. The ?82/76Se values of methylselenides differed significantly between Se(VI) (-3.97‰ to -3.25‰) and Se(IV) (-1.44‰ to -0.16‰) as sources after 11-15 days of incubation; pH had little influence on ?82/76Se values. Thus, the ?82/76Se values of methylselenide indicate the source species of methylselenides used in this study. The strong isotope fractionation of Se(VI) is probably attributable to the different reduction steps of Se(VI) to Se(-II) which were rate-limiting explaining the low methylation yields, but not to the methylation itself. The shorter incubation of Se(IV) for 3-5 days showed a large Se isotope fractionation of at least -6‰ before the biomethylation reaction reached its end. This initial Se isotope fractionation during methylation of Se(IV) is much larger than previously published. PMID:21366259

Schilling, Kathrin; Johnson, Thomas M; Wilcke, Wolfgang

2011-04-01

138

Identification, characterization and mycotoxigenic ability of Alternaria spp. causing core rot of apple fruit in Greece.  

PubMed

Alternaria core rot is a major postharvest disease of apple fruit in several countries of the world, including Greece. The study was conducted aiming to identify the disease causal agents at species level, investigate the aggressiveness of Alternaria spp. isolates and the susceptibility of different apple varieties and determine the mycotoxigenic potential of Alternaria spp. isolates from apple fruit. Seventy-five Alternaria spp. isolates obtained from apple fruit showing core rot symptoms were identified as either Alternaria tenuissima or Alternaria arborescens at frequencies of 89.3 and 11.7%, respectively, based on the sequence of endopolygalacturonase (EndoPG) gene. Artificial inoculations of fruit of 4 different varieties (Fuji, Golden Delicious, Granny Smith and Red Delicious) and incubation at two different temperatures (2 and 25°C) showed that fruit of Fuji variety were the most susceptible and fruit of Golden Delicious the most resistant to both pathogens. In addition, the production of 3 mycotoxins, alternariol (AOH), alternariol monomethyl ether (AME) and tentoxin (TEN) was investigated in 30 isolates of both species. Mycotoxin determination was conducted both in vitro, on artificial nutrient medium and in vivo on artificially inoculated apple fruit, using a high performance liquid chromatography with diode array detector (HPLC-DAD). The results showed that most of the isolates of both species were able to produce all the 3 metabolites both in vivo and in vitro. On apple fruit A. tenuissima isolates produced more AOH than A. arborescens isolates, whereas the latter produced more TEN than the former. Such results indicate that Alternaria core rot represents a major threat of apple fruit production not only due to quantitative yield losses but also for qualitative deterioration of apple by-products. PMID:25560914

Ntasiou, Panagiota; Myresiotis, Charalampos; Konstantinou, Sotiris; Papadopoulou-Mourkidou, Euphemia; Karaoglanidis, George S

2015-03-16

139

Transgenic Indian mustard (Brassica juncea) expressing tomato glucanase leads to arrested growth of Alternaria brassicae.  

PubMed

Brassica juncea is an important oilseed crop of the Indian sub-continent. Yield loss due to fungal disease alternaria leaf spot caused by Alternaria brassicae is a serious problem in cultivation of this crop. Nonavailability of resistance genes within crossable germplasms of Brassica necessitates use of genetic engineering strategies to develop genetic resistance against this pathogen. The pathogenesis related (PR) proteins are group of plant proteins that are toxic to invading fungal pathogens, but are present in plant in trace amount. Thus, overexpression of PR proteins leads to increased resistance to pathogenic fungi in several crops. The PR protein glucanase hydrolyzes a major cell-wall component, glucan, of pathogenic fungi and acts as a plant defense barrier. We report the expression of a class I basic glucanase gene, under the control of CaMV 35S promoter, in Indian mustard and its genetic resistance against alternaria leaf spot. Southern and Northern hybridization confirmed stable integration and expression of the glucanase gene in mustard transgenics. Several independent transgenics were screened in vitro and under poly house conditions for their resistance against Alternaria brassicae. In an in vitro antifungal assay, transgenics arrested hyphal growth of Alternaria brassicae by 15-54%. Under pathogen-challenged conditions in poly house, the transgenics showed restricted number, size and spread of lesions caused by Alternaria brassicae. Also, the onset of disease was delayed in transgenics compared to untransformed parent plants. The results demonstrate potentiality of a PR protein from a heterologous source in developing alternaria leaf spot resistance in Indian mustard. PMID:17016733

Mondal, Kalyan K; Bhattacharya, R C; Koundal, K R; Chatterjee, S C

2007-02-01

140

Multilocus phylogeny and MALDI-TOF analysis of the plant pathogenic species Alternaria dauci and relatives.  

PubMed

The genus Alternaria includes numerous phytopathogenic species, many of which are economically relevant. Traditionally, identification has been based on morphology, but is often hampered by the tendency of some strains to become sterile in culture and by the existence of species-complexes of morphologically similar taxa. This study aimed to assess if strains of four closely-related plant pathogens, i.e., accurately Alternaria dauci (ten strains), Alternaria porri (six), Alternaria solani (ten), and Alternaria tomatophila (ten) could be identified using multilocus phylogenetic analysis and Matrix-Assisted Laser Desorption Ionisation Time of Flight (MALDI-TOF) profiling of proteins. Phylogenetic analyses were performed on three loci, i.e., the internal transcribed spacer (ITS) region of rRNA, and the glyceraldehyde-3-phosphate dehydrogenase (gpd) and Alternaria major antigen (Alt a 1) genes. Phylogenetic trees based on ITS sequences did not differentiate strains of A. solani, A. tomatophila, and A. porri, but these three species formed a clade separate from strains of A. dauci. The resolution improved in trees based on gpd and Alt a 1, which distinguished strains of the four species as separate clades. However, none provided significant bootstrap support for all four species, which could only be achieved when results for the three loci were combined. MALDI-TOF-based dendrograms showed three major clusters. The first comprised all A. dauci strains, the second included five strains of A. porri and one of A. solani, and the third included all strains of A. tomatophila, as well as all but one strain of A. solani, and one strain of A. porri. Thus, this study shows the usefulness of MALDI-TOF mass spectrometry as a promising tool for identification of these four species of Alternaria which are closely-related plant pathogens. PMID:23332831

Brun, Sophie; Madrid, Hugo; Gerrits Van Den Ende, Bert; Andersen, Birgitte; Marinach-Patrice, Carine; Mazier, Dominique; De Hoog, G Sybren

2013-01-01

141

Radicinols and radicinin phytotoxins produced by Alternaria radicina on carrots.  

PubMed

The phytotoxin epi-radicinol, a diastereomer of radicinol, was isolated from large cultures of Alternaria radicina grown on carrot slices and identified by GC-MS, LC-MS, (1)H NMR, and (13)C NMR. Four strains of A. radicina isolated from rotted carrot produced epi-radicinol as the major metabolite (up to 39414 microg/g) together with radicinol (up to 2423 microg/g), and, to a lesser extent, radicinin when cultured on carrot slices, whereas on rice they mainly produced radicinin (2486-53800 microg/g). Radicinin and epi-radicinol reduced root elongation of germinating carrot seeds at concentrations of 10-20 microg/mL. Carrot samples naturally infected by A. radicina contained detectable quantities of epi-radicinol also in combination with lower levels of radicinin or radicinol. Accumulation of radicinols and radicinin in stored carrots, either naturally contaminated or artificially inoculated with A. radicina, was stimulated by successive temperature rises from 1 to 10 degrees C and from 10 to 20 degrees C, reaching maximum levels of 60 microg/g epi-radicinol and 26 microg/g radicinin. This is the first report on the production of radicinols by A. radicina and its natural occurrence in carrots in association with radicinin. PMID:15161245

Solfrizzo, Michele; Vitti, Carolina; De Girolamo, Annalisa; Visconti, Angelo; Logrieco, Antonio; Fanizzi, Francesco P

2004-06-01

142

Abscisic acid enhances resistance to Alternaria solani in tomato seedlings.  

PubMed

The plant hormone abscisic acid (ABA) is an important regulator in many aspects of plant growth and development, as well as stress resistance. Here, we investigated the effects of exogenous ABA application on the interaction between tomato (Solanum lycopersicon L.) and Alternaria solani (early blight). Foliar spraying of 7.58 ?M ABA was effective in reducing disease severity in tomato plants. Previously, increased activities of phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO) and peroxidase (POD) were observed in exogenous ABA-treated tomato leaves. Moreover, these enzyme activities were maintained at higher levels in ABA-pretreated and A. solani challenged tomato plants. Tomato defense genes, such as PR1, ?-1, 3-glucanase (GLU), PPO, POD, and superoxide dismutase (SOD), were rapidly and significantly up-regulated by exogenous ABA treatment. Furthermore, a subsequent challenge of ABA-pretreated plants with the pathogen A. solani resulted in higher expression of defense genes, compared to water-treated or A. solani inoculated plants. Therefore, our results suggest that exogenous ABA could enhance disease resistance against A. solani infection in tomato through the activation of defense genes and via the enhancement of defense-related enzymatic activities. PMID:21530290

Song, Weiwei; Ma, Xinrong; Tan, Hong; Zhou, Jinyan

2011-07-01

143

Alternaria alternata TCTP, a novel cross-reactive ascomycete allergen.  

PubMed

Defining more comprehensively the allergen repertoire of the ascomycete Alternaria alternata is undoubtedly of immense medical significance since this mold represents one of the most important, worldwide occurring fungal species responsible for IgE-mediated hypersensitivity reactions ranging from rhinitis and ocular symptoms to severe involvement of the lower respiratory tract including asthma with its life-threatening complications. Performing a hybridization screening of an excised A. alternata cDNA library with a radioactively labeled Cladosporium herbarum TCTP probe, we were able to identify, clone and purify the respective A. alternata homologue of TCTP which again represents a multifunctional protein that has been evolutionarily conserved from unicellular eukaryotes like yeasts to humans and appears, summarizing current literature, to be involved in housekeeping processes such as cell growth as well as cell-cycle progression, the protection of cells against various stress conditions including for instance apoptosis, and in higher organisms even in the allergic response. In this context, our present study characterizes recombinant A. alternata TCTP as a novel minor allergen candidate that displays a prevalence of IgE reactivity of approximately 4% and interestingly shares common, cross-reactive IgE epitopes with its C. herbarum and human counterparts as determined via Western blotting and in vitro inhibition approaches. PMID:19683813

Rid, Raphaela; Onder, Kamil; MacDonald, Susan; Lang, Roland; Hawranek, Thomas; Ebner, Christof; Hemmer, Wolfgang; Richter, Klaus; Simon-Nobbe, Birgit; Breitenbach, Michael

2009-10-01

144

Treponemes-Infected Canker in a Japanese Racehorse: Efficacy of Maggot Debridement Therapy  

PubMed Central

A 3-year-old thoroughbred colt presented with canker on its left hind foot. Subsequent development of cottage cheese-like horns and dermatitis disturbed healing, despite the use of miscellaneous orthodox treatment approaches to the lesions. Histological examination revealed exudative and suppurative dermatitis, and proliferatively suppurative epidermitis infected with helically coiled treponemes. Total debridement under general anesthesia led to a temporary improvement, but the ground surface regenerated abnormal epidermis similar to that observed initially after surgery. Maggot debridement therapy (MDT) was attempted, which removed all the abnormal tissue. After MDT, general farriery trimming helped to correct the distorted ground surface, and the horse returned to constant training and eventually raced. This case shows that MDT was successfully used for treatment of an intractable and treponemes-infected canker. PMID:24833994

KUWANO, Atsutoshi; NIWA, Hidekazu; HIGUCHI, Tohru; MITSUI, Hideya; AGNE, Robert A.

2012-01-01

145

Effect of plant growth promoting rhizobacteria on bacterial canker of tomato  

Microsoft Academic Search

Use of plant growth promoting rhizobacteria in managing bacterial canker disease of tomato was studied in the present work. Tomato seeds were treated with PGPR strains viz., Bacillus pumilus INR7, Bacillus pumilus SE34, Bacillus pumilus T4, Bacillus subtilis GBO3, Bacillus amyloliquefaciens IN937a and Brevibacillus brevis IPC11 were subjected for seed germination and seedling vigor. Among the PGPR strains tested, only

N Girish; S Umesha

2005-01-01

146

Isolation and characterization of the grain mold fungi, Cochliobolus and Alternaria spp., from sorghum using semi-selective media and DNA sequence analyses  

Technology Transfer Automated Retrieval System (TEKTRAN)

Mold diseases, caused by fungal complexes including Alternaria, Cochliobolus and Fusarium species, limit sorghum grain production. Media were tested by plating Fusarium thapsinum, Alternaria sp. and Curvularia lunata, individually and competitively. Dichloran chloramphenicol rose bengal (DRBC) and m...

147

Genetic control of Eucalyptus urophylla and E. grandis resistance to canker caused by Chrysoporthe cubensis  

PubMed Central

Chrysophorte cubensis induced canker occurs in nearly all tropical and subtropical regions where eucalypts are planted, causing losses in both wood quality and volume productivity, especially so in the warmer and more humid regions of Brazil. The wide inter and intra-specific genetic variability of resistance to canker among Eucalyptus species facilitates the selection of resistant plants. In this study, we evaluated resistance to this pathogen in five Eucalyptus grandis (G) and 15 E. urophylla (U) trees, as well as in 495 individuals from 27 progenies derived from crosses between the trees. In the field, six-months-old test seedlings were inoculated with C. cubensis. Lesion length in the xylem and bark was measured eight months later. The results demonstrated that xylem lesions could preferentially be used for the selection of resistant clones. Eight trees (7 U and 1 G) were susceptible, and the remainder (8 U and 4 G) resistant. Individual narrow and broad sense heritability estimates were 17 and 81%, respectively, thereby suggesting that canker resistance is quantitative and highly dependent on dominance and epistasis. PMID:21637427

2010-01-01

148

QCM immunoassay for recombinant cysteine peptidase: a potential protein biomarker for diagnosis of citrus canker.  

PubMed

Citrus canker is one of the most important agricultural citrus diseases worldwide. It is caused by Xanthomonas citri subsp. citri (Xcc) bacterium that infects leaves and the fruits produce a cysteine peptidase (CPXaC), which makes it a potential target for the development of effective and rapid detection methods for citrus canker. We report here the studies on the development of piezoelectric immunoassay for CPXaC using a polyclonal antibody against CPXaC (anti-CPXaC). Three different strategies for covalent immobilization of anti-CPXaC on gold surfaces were evaluated by monitoring the frequency (?f) and energy dissipation (?D) variation in real time when 64.5×10(-8) mol L(-1) CPXaC was added. Anti-CPXaC immobilized with 11-mercaptoundecanoic acid (MUA) showed the best relation between the frequency and dissipation factor variation, and strong values for the kinetic and equilibrium binding constant were obtained. The immunosensor showed a detection limit of 13.0 nmol L(-1) with excellent specificity, showing no response for different proteins that include another cysteine peptidase that is used as a target to detect Xylella fastidiosa bacterium, responsible for another important citrus disease. These results provide good perspectives for the use of CPXaC as a new biomarker for citrus canker. PMID:23597909

Afonso, André S; Zanetti, Bianca F; Santiago, Adelita C; Henrique-Silva, Flavio; Mattoso, Luiz H C; Faria, Ronaldo C

2013-01-30

149

STEM, STEM Education, STEMmania  

ERIC Educational Resources Information Center

In this article, the author introduces integrative STEM (science, technology, engineering, and/or mathematics) education and discusses the importance of the program. The notion of integrative STEM education includes approaches that explore teaching and learning between/among any two or more of the STEM subject areas, and/or between a STEM subject…

Sanders, Mark

2009-01-01

150

Fistupyrone, a novel inhibitor of the infection of Chinese cabbage by Alternaria brassicicola, from Streptomyces sp. TP-A0569.  

PubMed

A new microbial metabolite, designated fistupyrone, was isolated from the culture broth of a plant-associated Streptomyces sp. TP-A0569. Fistupyrone inhibited the in vivo infection of the seedlings of Chinese cabbage by Alternaria brassicicola TP-F0423, the cause of Alternaria leaf spot, without any in vitro fungicidal activity. PMID:11132956

Igarashi, Y; Ogawa, M; Sato, Y; Saito, N; Yoshida, R; Kunoh, H; Onaka, H; Furumai, T

2000-10-01

151

Alt a 1 from Alternaria interacts with PR5 thaumatin-like proteins.  

PubMed

Alt a 1 is a protein found in Alternaria alternata spores related to virulence and pathogenicity and considered to be responsible for chronic asthma in children. We found that spores of Alternaria inoculated on the outer surface of kiwifruits did not develop hyphae. Nevertheless, the expression of Alt a 1 gene was upregulated, and the protein was detected in the pulp where it co-localized with kiwi PR5. Pull-down assays demonstrated experimentally that the two proteins interact in such a way that Alt a 1 inhibits the enzymatic activity of PR5. These results are relevant not only for plant defense, but also for human health as patients with chronic asthma could suffer from an allergic reaction when they eat fruit contaminated with Alternaria. PMID:24642375

Gómez-Casado, Cristina; Murua-García, Amaya; Garrido-Arandia, María; González-Melendi, Pablo; Sánchez-Monge, Rosa; Barber, Domingo; Pacios, Luis F; Díaz-Perales, Araceli

2014-05-01

152

Cutaneous infection with Alternaria triticina in a Bilateral lung transplant recipient.  

PubMed

We report the case of a 60-year-old man who was receiving immunosuppressive therapy for a bilateral lung transplant and presented with a crusted, violaceous plaque on the left hand. Based on histopathology and microbiological culture the patient was diagnosed with infection by Alternaria species. Treatment with itraconazole led to complete resolution of the skin lesion. Forty months later he developed four reddish, nodular, skin lesions on the left leg. Analysis of a biopsy from one of these lesions using histopathologic and molecular techniques identified a mold that shared 98% homology with a strain of Alternaria triticina. Alternaria species belong to a group of dematiaceous fungi that cause opportunistic infections in humans. The incidence of these infections is increasing, mainly in transplant centers. To the best of our knowledge, this is the first reported case of a human infection caused by A. triticina. PMID:24440281

González-Vela, M C; Armesto, S; Unda-Villafuerte, F; Val-Bernal, J F

2014-10-01

153

Molecular, ecological and evolutionary approaches to understanding Alternaria diseases of citrus.  

PubMed

SUMMARY Alternaria fungi cause four different diseases of citrus: Alternaria brown spot of tangerines, Alternaria leaf spot of rough lemon, Alternaria black rot of several citrus fruits and Mancha foliar of Mexican lime. The first three diseases are caused by the small-spored species, Alternaria alternata and the causal agents can only be differentiated using pathogenicity tests, toxin assays or genetic markers. Mancha foliar is caused by the morphologically distinct, large-spored species A. limicola. Substantial progress has been made in understanding the biology, ecology, population biology, systematics, molecular biology and biochemistry of the interactions between these pathogens and citrus. Epidemiological studies have focused on brown spot of tangerines and their hybrids and have contributed to the development of a model of disease development which has improved control and reduced fungicide use. Studies of the population genetics, host specificity and ecology of A. alternata from different ecological niches on citrus have revealed host specific forms of the pathogen which cause disease on different citrus species, the existence of three phylogenetic lineages of the fungus which cause brown spot world-wide, and closely related non-pathogenic isolates which colonize healthy citrus tissue. The role of host-specific toxins in Alternaria diseases of citrus has been extensively studied for over 20 years, and these pathosystems have become model systems for host-pathogen interactions. Recent molecular research has started to unravel the genetic basis of toxin production and the host susceptibility to toxin, and the role of extracellular, degradative enzymes in disease. PMID:20569403

Akimitsu, Kazuya; Peever, Tobin L; Timmer, L W

2003-11-01

154

Fungicidal activity of the plant saponin, CAY-1, for fungi isolated from diseased Vitis fruit and stems  

Technology Transfer Automated Retrieval System (TEKTRAN)

Members of ten fungal genera were isolated from diseased grape berries and stems collected from a vineyard. The isolated fungi included the grape pathogens, Greeneria uvicola and Colletotrichum sp. Secondary grape and human pathogens isolated included Alternaria spp., Aspergillus spp., Cladosporiu...

155

Short distance dispersal of splashed bacteria of Xanthomonas citri subsp. citri from canker-infected grapefruit tree canopies in turbulent wind  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker (Xanthomonas citri subsp citri [Xcc]) can result in yield loss and market restrictions. The pathogen is dispersed in rain splash and spread is promoted by wind. The goal of this study was to gain some insight into the behavior of the downwind plume of Xcc from ~1.5 m-tall canker-affect...

156

Activity of citrus canker lesions on leaves, shoots and fruit of grapefruit in a Florida orchard from June 2010 to January 2011  

Technology Transfer Automated Retrieval System (TEKTRAN)

Lesions of citrus canker, caused by Xanthomonas citri subsp. citri (Xcc), on citrus fruit preclude export to certain markets. Characterizing the population dynamics of bacteria in canker lesions in commercial orchards can help gauge risk associated with diseased fruit entering fresh markets. The aim...

157

First Report of Nectria galligena Causing European Canker of Apple Trees in Ontario. A. R. Biggs, Agriculture Canada Research Station, Vineland Station, Ontario LOR 2EO. Plant  

E-print Network

First Report of Nectria galligena Causing European Canker of Apple Trees in Ontario. A. R. Biggs for publication 19 July 1985. European canker of apple (Malus domestics Borkh. 'MacIntosh') caused by Nectria includes the apple-growing region of central Ontario. Reference: Booth, C. Commonw. Mycol. Inst. Pap. 73

Biggs, Alan R.

158

DEVELOPMENT OF A PCR-BASED METHOD FOR THE DETECTION OF BRENNARIA RUBRIFACIENS; THE CAUSAL AGENT OF DEEP BARK CANKER OF WALNUT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Deep Bark Canker (DBC), caused by the bacterium Brenneria rubrifaciens (previously known as Erwinia rubrifaciens), afflicts English walnut cultivars and is characterized by late onset of symptoms in trees greater than 15 years old. These symptoms include deep bleeding vertical cankers throughout th...

159

Stem Cells  

MedlinePLUS

Stem cells are cells with the potential to develop into many different types of cells in the body. ... the body. There are two main types of stem cells: embryonic stem cells and adult stem cells. Stem ...

160

Bacterial canker of plum trees, caused by Pseudomonas syringae pathovars, as a serious threat for plum production in the Netherlands.  

PubMed

In the Netherlands, bacterial canker in plum trees (Prunus domestica) is a serious and recent problem in plum production. It is caused by Pseudomonas syringae pathovars syringae and morsprunorum. The trunks of the affected plum trees are girdled by bacterial cankers resulting in sudden death of infected trees in 3-4 years after planting. Disease incidences can be very high, and sometimes complete orchards have to be removed. Recently, plum cultivation in the Netherlands has changed from a relatively extensive into an intensive cultivation. However, due to the risks of losses of trees due to bacterial canker, growers are reluctant to plant new plum orchards. In general nurseries and fruit growers are not familiar with bacterial diseases and lack knowledge in order to prevent infections. Therefore, control strategies to manage plum decline have to be developed. PMID:22702175

Wenneker, M; Janse, J D; De Bruine, J A

2011-01-01

161

Successful sequential treatment with itraconazole and ALA-PDT for chromoblastomycosis because of Alternaria alternata.  

PubMed

Alternaria alternata is a rare etiology of phaeohyphomycosis in immunocompromised patients, which has never been reported to cause chromoblastomycosis. As far as we know, this is the first chromoblastomycosis case successfully treated with a short course of systemic antifungals and subsequent 5-aminolevulinic acid-photodynamic therapy. PMID:25039437

Liu, Ze-Hu; Xia, Xiu-Jiao

2014-01-01

162

AFLP variability, toxin production, and pathogenicity of Alternaria species from Argentinean tomato fruits and puree.  

PubMed

Large amounts of tomato fruits and derived products are produced in Argentina and may be contaminated by Alternaria toxins. Limited information is available on the genetic variability, toxigenicity, and pathogenicity of Alternaria strains occurring on tomato. We analyzed 65 Alternaria strains isolated in Argentina from tomato fruits affected by black mould and from tomato puree, using amplified fragment length polymorphisms (AFLPs) technique. AFLP analysis resolved the set of strains in 3 main clusters (DICE similarity values of 58 and 60%) corresponding to A. alternata/tenuissima (44 strains), A. arborescens (15 strains) and to an unknown group (6 strains). Most of the representative strains, belonging to each AFLP cluster, when cultured on rice, produced tenuazonic acid (up to 46,760 mg/kg), alternariol monomethyl ether (AME, up to 1860 mg/kg), and alternariol (up to 70 mg/kg). The toxin profile related to the strains was not related to any AFLP cluster, except for AME which was produced at lower level by A. arborescens. Most of strains were pathogenic on two types of commonly cultivated tomato fruits. These findings provide new information on the variability within the Alternaria species complex associated with tomato disease. PMID:21303723

Somma, Stefania; Pose, Graciela; Pardo, Alejandro; Mulè, Giuseppina; Pinto, Virginia Fernandez; Moretti, Antonio; Logrieco, Antonio Francesco

2011-02-28

163

Biochemical Evaluation of Resistance Responses of Potato to Different Isolates of Alternaria Solani  

Technology Transfer Automated Retrieval System (TEKTRAN)

The resistance phenotypes of nine potato cultivars to five isolates of Alternaria solani, causal agent of early blight, were studied after inoculation and growth under greenhouse conditions. We identified potato cultivars with both susceptible and resistant phenotypes as well as A. solani isolates ...

164

BIOLOGICAL CONTROL 2,278-281 (1992) Production of Conidia of Alternaria cassiae with Alginate Pellets  

E-print Network

efficacy. A number of parameters of the alginate process were studied to develop an optimal alginate formulation for field appli- cation of Alternaria cassiae, a mycoherbicide for sickle- pod (Cassia obtusifolia agent's growth and release from the pellet, and the gel- lant. This study examines modifications

Cotty, Peter J.

165

Tall fescue is a potential spillover reservoir host for Alternaria species.  

PubMed

The spread of invasive species is complicated and multifaceted. Enemy spillover (i.e. the transfer of a natural enemy from a reservoir host to a novel host) is one mechanism that facilitates the spread of non-native species. The reservoir host is a species that harbors high abundance of the enemy with little cost to fitness. We asked whether Schedonorus arundinaceus (tall fescue), a highly invasive grass species in North America, is a potential reservoir host for the ubiquitous genus of fungi, Alternaria. We also asked whether spillover of Alternaria is possible among grasses that commonly occur with S. arundinaceus in grassland ecosystems. We performed a greenhouse cross inoculation of three isolates of Alternaria and six grass species (three native, three invasive, including S. arundinaceus). We determined that spillover is possible because the fungal isolates infected and caused disease symptoms on all six grasses and decreased biomass in two of the grass species. We also determined that the invasive grass species appear to be more competent hosts than the native species and that S. arundinaceus could be a likely reservoir host for Alternaria spp. because it can harbor the pathogen with no apparent fitness cost. PMID:24603832

Wilson, Hannah E; Carroll, George C; Roy, Bitty A; Blaisdell, G Kai

2014-01-01

166

Effect of Alternaria solani exudates on resistant and susceptible potato cultivars from two different pathogen isolates  

Technology Transfer Automated Retrieval System (TEKTRAN)

The resistance phenotypes of two potato cultivars to two isolates of Alternaria solani, causal agent of early blight, were studied under greenhouse conditions. The two isolates contain varying degrees of aggressiveness on both susceptible and resistant phenotypes of potatoes. A bioassay was used to ...

167

Release of alkenyl isothiocyanates and other volatiles from Brassica rapa seedlings during infection by Alternaria brassicae  

Microsoft Academic Search

When Brassica rapa seedlings were inoculated with the fungal pathogen Alternaria brassicae, 3-butenyl and 4-pentenyl isothiocyanates were released, together with dimethyl disulphide, dimethyl trisulphide, 4-oxoisophorone and a number of sesquiterpenes. Release of isothiocyanates is evidence for the catabolism of glucosinolates during infection, which is a prerequisite for their involvement in resistance.

Kevin J. Doughty; Margaret M. Blight; Clive H. Bock; Jane K. Fieldsend; John A. Pickett

1996-01-01

168

Antileukemic alpha-pyrone derivatives from the endophytic fungus Alternaria phragmospora  

Technology Transfer Automated Retrieval System (TEKTRAN)

Four new (1–4) and two known (5 and 6)a-pyrone derivatives have been isolated from Alternaria phragmospora, an endophytic fungus from Vinca rosea, leaves. The isolated compounds were chemically identi'ed to be 5-butyl-4-methoxy-6-methyl-2H-pyran-2-one (2) 5-butyl-6-(hydroxymethyl)-4-methoxy-2H-py...

169

Biocontrol of Alternaria triticina by plant growth promoting rhizobacteria on wheat  

Microsoft Academic Search

Eighteen isolates of fluorescent pseudomonads and Bacillus spp. were isolated from Alternaria triticina suppressive soils of wheat fields. These isolates were evaluated in the laboratory and greenhouse for the biocontrol of A. triticina. Six isolates were considered to have potential for the biocontrol of A. triticina on the basis of antibiotic sensitivity, fluorescence produced by Pseudomonas, inhibitory effect on A.

Z. A. Siddiqui

2007-01-01

170

Sugars and phenols in relation to Alternaria leaf blight of wheat  

Microsoft Academic Search

A number of commercial varieties of wheat were investigated with regard to the relationship between the degree of their susceptibilitv\\u000a toAlternaria triticina Prasada and Prabhu, and the sugar and phenol contents of their leaves. No correlation between these properties could be established.

S. S. Sokhi; L. M. Joshi

1973-01-01

171

The Role of Peroxidase and Polyphenol Oxidase Isozymes in Wheat Resistance to Alternaria triticina  

Microsoft Academic Search

Polyphenol oxidase activity was higher in resistant wheat cultivar ACC-8226 than in susceptible cultivar MP-845 in control sets and after inoculation of Alternaria triticina. However, similar polyphenol oxidase isozyme pattern was found in control and inoculated sets of both the cultivars, but the band intensity was higher after inoculation. Three and four peroxidase isozymes were found in ACC-8226 and MP-845,

M. Tyagi; Arvind M. Kayastha; B. Sinha

2000-01-01

172

Disruption of Glycosylphosphatidylinositol-Anchored Lipid Transfer Protein Gene Altered Cuticular Lipid Composition, Increased Plastoglobules, and Enhanced Susceptibility to Infection by the Fungal Pathogen Alternaria brassicicola1[W  

PubMed Central

All aerial parts of vascular plants are covered with cuticular waxes, which are synthesized by extensive export of intracellular lipids from epidermal cells to the surface. Although it has been suggested that plant lipid transfer proteins (LTPs) are involved in cuticular lipid transport, the in planta evidence is still not clear. In this study, a glycosylphosphatidylinositol-anchored LTP (LTPG1) showing higher expression in epidermal peels of stems than in stems was identified from an Arabidopsis (Arabidopsis thaliana) genome-wide microarray analysis. The expression of LTPG1 was observed in various tissues, including the epidermis, stem cortex, vascular bundles, mesophyll cells, root tips, pollen, and early-developing seeds. LTPG1 was found to be localized in the plasma membrane. Disruption of the LTPG1 gene caused alterations of cuticular lipid composition, but no significant changes on total wax and cutin monomer loads were seen. The largest reduction (10 mass %) in the ltpg1 mutant was observed in the C29 alkane, which is the major component of cuticular waxes in the stems and siliques. The reduced content was overcome by increases of the C29 secondary alcohols and C29 ketone wax loads. The ultrastructure analysis of ltpg1 showed a more diffuse cuticular layer structure, protrusions of the cytoplasm into the vacuole in the epidermis, and an increase of plastoglobules in the stem cortex and leaf mesophyll cells. Furthermore, the ltpg1 mutant was more susceptible to infection by the fungus Alternaria brassicicola than the wild type. Taken together, these results indicated that LTPG1 contributed either directly or indirectly to cuticular lipid accumulation. PMID:19321705

Lee, Saet Buyl; Go, Young Sam; Bae, Hyun-Jong; Park, Jong Ho; Cho, Sung Ho; Cho, Hong Joo; Lee, Dong Sook; Park, Ohkmae K.; Hwang, Inhwan; Suh, Mi Chung

2009-01-01

173

Reclassification of the butternut canker fungus, Sirococcus clavigignenti-juglandacearum, into the genus Ophiognomonia.  

PubMed

Sirococcus clavigignenti-juglandacearum (Sc-j), which causes a canker disease on butternut, is largely responsible for the decline of this tree in the United States and Canada. The original description of the species was based on anamorphic characters because the teleomorph is unknown. Recent phylogenetic investigations have found that Sc-j is not a member of the genus Sirococcus, and accurate taxonomic classification is required. The objective of this study is to use sequence data to determine the phylogenetic placement of Sc-j within the Gnomoniaceae, Diaporthales. Isolates were recovered from infected Juglans ailantifolia var. cordiformis (heartnut), Juglans cinerea (butternut), and Juglans nigra (black walnut) in Ontario and the eastern United States. The genes coding for ?-tubulin, actin, calmodulin, internal transcribed spacers 1 and 2, and the translation elongation factor 1-alpha from 28 isolates of Sc-j and representatives of the major lineages within the Gnomoniaceae were evaluated. There was no difference in the sequences of the five genes among the isolates of Sc-j studied, indicating a recent introduction followed by asexual reproduction and spread via conidia. The phylogenetic analyses demonstrate this fungus does not belong to the genus Sirococcus, and provides strong support (99% MP and 100% NJ bootstrap values, and 100% Bayesian posterior probabilities) for its inclusion in the genus Ophiognomonia, thereby supporting a reclassification of the butternut canker fungus to Ophiognomonia clavigignenti-juglandacearum. PMID:21215957

Broders, K D; Boland, G J

2011-01-01

174

Effects of simulated rainfall on disease development and weed control efficacy of the bioherbicidal fungi alternaria cassiae and colletotrichum truncatum  

Technology Transfer Automated Retrieval System (TEKTRAN)

Alternaria cassiae and Colletotrichum truncatum are virulent pathogens of sicklepod (Senna obtusifolia), and hemp sesbania (Sesbania exaltata), respectively, under favorable environmental conditions. In greenhouse experiments, the effects of simulated rainfall on pathogenesis and mortality of these ...

175

Differential responses of Central American and Mexican pine species and Pinus radiata to infection by the pitch canker fungus  

Microsoft Academic Search

Seedlings from a wide array of 23 species, varieties,and geographic races were screened for resistance topitch canker using artificial inoculation in agreenhouse. Seed to represent these taxa weregenerally collected in natural stands. In addition,seedlings from 79 families of P. radiata fromcommercial populations from Chile and New Zealand werescreened in a separate experiment. There was littlevariation in resistance among the commercial

G. R. Hodge; W. S. Dvorak

2000-01-01

176

Under severe HLB and citrus canker pressure, 'Triumph' and 'Jackson' perform better than 'Flame' and 'Marsh' grapefruit  

Technology Transfer Automated Retrieval System (TEKTRAN)

Huanglongbing (HLB) and Citrus Canker (CC) threaten the viability of Florida grapefruit production. ‘Triumph’ (T), reportedly a grapefruit/sweet orange hybrid, is similar to seedy white grapefruit with earlier maturity and lower bitterness. ‘Jackson’ (J) is a low-seeded budsport of ‘Triumph’. Tree h...

177

Characteristics of the perception of different severity measures of citrus canker and the relations between the various symptom types  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker is a disease of citrus and is caused by the bacterial pathogen Xanthomonas axonopodis pv citri (Xac). Ways of managing the disease are being sought, and accurate, precise, reproducible disease assessment is needed for monitoring epidemics. The objective of this study was to investigate...

178

Effect of alternative strategies for the disinfection of tomato seed infected with bacterial canker ( Clavibacter michiganensis subsp. michiganensis)  

Microsoft Academic Search

Currently there is a lack of effective seed treatments for bacterial pathogens, with Cu-based compounds (the only chemical treatments permitted under organic farming standards) only providing partial control. The aim of this study was to quantify the effect of alternative treatments for the control of bacterial canker (Clavibacter michiganensis subsp. michiganensis), a major seed-borne bacterial disease in tomato. Treatments assessed

A.-M. Kasselaki; D. Goumas; L. Tamm; J. Fuchs; J. Cooper; C. Leifert

2011-01-01

179

A new Real-time PCR-method for the quantification of the Pine Pitch Canker fungus Fusarium circinatum.  

E-print Network

enhanced by airborne spores, insect vectors and the movement of infected plant material. Detection of spore numbers from environmental samples and (iii) to determine the mating type of the fungal isolates brown flagging of Pine Pitch Canker WORKING SCHEME suspend spores in 20 ml 4X TE-buffer 65ºC DNA

California at Berkeley, University of

180

Under severe citrus canker and HLB (Huanglongbing) pressure, Triumph and Jackson perform better than Flame and Marsh grapefruit  

Technology Transfer Automated Retrieval System (TEKTRAN)

Huanglongbing (HLB) and Citrus Canker (CC) threaten the viability of Florida grapefruit production. Triumph (T), reportedly a grapefruit/sweet orange hybrid, is similar to seedy white grapefruit with earlier maturity and lower bitterness. Jackson (J) is a low-seeded budsport of Triumph. Tree health ...

181

Transcriptional Profiling of Canker-Resistant Transgenic Sweet Orange (Citrus sinensis Osbeck) Constitutively Overexpressing a Spermidine Synthase Gene  

PubMed Central

Citrus canker disease caused by Xanthomonas citri subsp. citri (Xcc) is one of the most devastating diseases affecting the citrus industry worldwide. In our previous study, the canker-resistant transgenic sweet orange (Citrus sinensis Osbeck) plants were produced via constitutively overexpressing a spermidine synthase. To unravel the molecular mechanisms underlying Xcc resistance of the transgenic plants, in the present study global transcriptional profiling was compared between untransformed line (WT) and the transgenic line (TG9) by hybridizing with Affymetrix Citrus GeneChip. In total, 666 differentially expressed genes (DEGs) were identified, 448 upregulated, and 218 downregulated. The DEGs were classified into 33 categories after Gene ontology (GO) annotation, in which 68 genes are in response to stimulus and involved in immune system process, 12 genes are related to cell wall, and 13 genes belong to transcription factors. These genes and those related to starch and sucrose metabolism, glutathione metabolism, biosynthesis of phenylpropanoids, and plant hormones were hypothesized to play major roles in the canker resistance of TG9. Semiquantitative RT-PCR analysis showed that the transcript levels of several candidate genes in TG9 were significantly higher than in WT both before and after Xcc inoculation, indicating their potential association with canker disease. PMID:23509803

Fu, Xing-Zheng; Liu, Ji-Hong

2013-01-01

182

Foliar application of biofilm formation-inhibiting compounds enhances control of citrus canker caused by Xanthomonas citri subsp. citri.  

PubMed

Citrus canker caused by the bacterium Xanthomonas citri subsp. citri is an economically important disease of citrus worldwide. Biofilm formation plays an important role in early infection of X. citri subsp. citri on host leaves. In this study, we assessed the hypothesis that small molecules inhibiting biofilm formation reduce X. citri subsp. citri infection and enhance the control of citrus canker disease. D-leucine and 3-indolylacetonitrile (IAN) were found to prevent biofilm formation by X. citri subsp. citri on different abiotic surfaces and host leaves at a concentration lower than the minimum inhibitory concentration (MIC). Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis indicated that IAN repressed expression of chemotaxis/motility-related genes in X. citri subsp. citri. In laboratory experiments, planktonic and biofilm cells of X. citri subsp. citri treated with D-leucine and IAN, either alone or in combination, were more susceptible to copper (CuSO4) than those untreated. In greenhouse assays, D-leucine and IAN applied alone or combined with copper reduced both the number of canker lesions and bacterial populations of X. citri subsp. citri on citrus host leaves. This study provides the basis for the use of foliar-applied biofilm inhibitors for the control of citrus canker alone or combined with copper-based bactericides. PMID:23901828

Li, Jinyun; Wang, Nian

2014-02-01

183

Identification of microsatellites from Geosmithia morbida, the fungus associated with Thousand Canker Disease (TCD) of Walnut, and their use  

E-print Network

Identification of microsatellites from Geosmithia morbida, the fungus associated with Thousand Canker Disease (TCD) affects trees of the genus Juglans. It is caused by a beetle/fungus symbiotic to spread throughout the range of J. nigra. The fungus associated with TCD is Geosmithia morbida, a newly

184

THE EFFECT OF WIND SPEED ON THE DISPERSAL PLUME OF BACTERIA DOWNWIND FROM CANKER-INFECTED GRAPEFRUIT TREES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Xanthomonas axonopodis pv citri causes citrus canker. Disease assessment is important for monitoring epidemics. Visual assessment (VA) is presently the only reliable means of detection. To investigate how VA of symptoms compared to image analysis we used digital images of 214 citrus le...

185

Visual rating and the use of image analysis for assessing different symptoms of citrus canker on grapefruit leaves  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker is caused by the bacterial pathogen Xanthomonas axonopodis pv citri (Xac) and infects several citrus species in wet tropical and subtropical citrus growing regions. Accurate, precise and reproducible disease assessment is needed for monitoring epidemics and disease response in breeding...

186

Analysis of the isothiocyanates present in cabbage leaves extract and their potential application to control Alternaria rot in bell peppers  

Microsoft Academic Search

The potential use of cabbage isothiocyanates to control Alternaria rot in bell pepper was tested. Solid phase microextraction and gas chromatography–mass spectrometry found allyl, benzyl, 2-phenylethyl and phenyl isothiocyanates in a ratio of 1:3.5:5.3:9.6, respectively, in cabbage leaves. The same proportion was used to prepare an isothiocyanate mixture from reagent grade isothiocyanates (MCIT) to test the effect on Alternaria alternata

R. Troncoso; C. Espinoza; A. Sánchez-Estrada; M. E. Tiznado; Hugo S. García

2005-01-01

187

Chitinase-mediated inhibitory activity of Brassica transgenic on growth of Alternaria brassicae.  

PubMed

Chitinase, capable of degrading the cell walls of invading phytopathogenic fungi, plays an important role in plant defense response, particularly when this enzyme is overexpressed through genetic engineering. In the present study, Brassica plant (Brassica juncea L.) was transformed with chitinase gene tagged with an overexpressing promoter 35 S CaMV. The putative transgenics were assayed for their inhibitory activity against Alternaria brassicae, the inducer of Alternaria leaf spot of Brassica both in vitro and under polyhouse conditions. In in vitro fungal growth inhibition assays, chitinase inhibited the fungal colony size by 12-56% over the non-trangenic control. The bioassay under artificial epiphytotic conditions revealed the delay in the onset of disease as well as reduced lesion number and size in 35S-chitinase Brassica as compared to the untransformed control plants. PMID:14570264

Mondal, Kalyan K; Chatterjee, Subhas Chandra; Viswakarma, Navin; Bhattacharya, Ram Charan; Grover, Anita

2003-09-01

188

Pre-harvest burning for control of tuber infection by Alternaria solani  

Microsoft Academic Search

Pre-harvest propane burning of vines and soil surface significantly reduced populations ofAlternaria solani spores on the soil surface in field studies. Infection of potato tubers harvested from burned fields was reduced in most\\u000a cases. Laboratory studies indicated a minimum temperature of 200°C for 1–2 seconds was required to significantly (P = 0.05)\\u000a reduce germination ofA. solani spores. This temperature was

L. K. Lahman; M. D. Harrison; M. Workman

1981-01-01

189

Isolation and purification of AAL-toxin from Alternaria alternata grown on rice.  

PubMed

An isolation and purification procedure is described for AAL-toxin, a secondary metabolite produced by Alternaria alternata. The method involves growth of the fungus on rice media, extraction with chloroform followed by methanol: water from fungus-infested rice, and purification of the aqueous layer that contains AAL-toxin by using chromatography methods. The AAL-toxin was of type A, and white in color, and its purity was > or = 95% with mol. wt 522 (M + 1). PMID:8470139

Abbas, H K; Vesonder, R F

1993-03-01

190

Effects of Aureobasidium pullulans on numbers of lesions on dwarf bean leaves caused by Alternaria zinniae  

Microsoft Academic Search

Inoculating dwarf bean leaves with spore suspensions ofAureobasidium pullulans one day before or simultaneously with inoculations made withAlternaria zinniae significantly decreased numbers of lesions caused by the latter fungus. Delaying inoculation withA. pullulans until 1 day after that withA. zinniae lessened the effect on lesion numbers. Increasing numbers ofA. pullulans spores progressively decreased numbers ofA. zinniae lesions. Three of five

J. Van Den Heuvel

1969-01-01

191

Changes in the leaf proteome profile of Mentha arvensis in response to Alternaria alternata infection  

Microsoft Academic Search

Plant pathogenic fungi cause important yield losses in crops. A proteomic approach was used to study the changes in the leaf proteome profile of the plant Mentha arvensis infected with a necrotrophic fungus, Alternaria alternata. High-resolution two-dimensional gel electrophoresis (2-DE) followed by colloidal Coomassie staining and mass spectrometric analysis was used to identify highly abundant proteins differentially expressed in response

Ragini Sinha; Sharmila Chattopadhyay

2011-01-01

192

Interaction between Alternaria alternata or Fusarium equiseti and Glomus mosseae and its effects on plant growth  

Microsoft Academic Search

The effect of inoculation with the saprophytic fungi Alternaria alternata or Fusarium equiseti on maize (Zea mays) and lettuce (Lactuca sativa) with or without arbuscular mycorrhizal (AM) colonization by Glomus mosseae was studied in a greenhouse trial. Plant dry weights of non-AM-inoculated maize and lettuce were unaffected by the presence\\u000a of A. alternata and F. equiseti. In contrast, A. alternata

C. B. McAllister; J. M. Garcia-Garrido; I. Garcia-Romera; A. Godeas; J. A. Ocampo

1997-01-01

193

Cutaneous fungal granulomas due to Alternaria spp. infection in a horse in New Zealand.  

PubMed

Equine cutaneous fungal granulomas have been previously referred to in New Zealand (Fairley 1998), and are described in the veterinary literature from around the world, including North America and Australia (Pascoe and Summers 1981; Genovese et al. 2001; Valentine et al. 2006), but no peer-reviewed reports appear published in the literature in New Zealand. Described here is a case of multiple cutaneous fungal granulomas caused by Alternaria spp. in a horse in New Zealand. PMID:21151220

Dicken, M; Munday, J S; Archer, R M; Mayhew, I G; Pandey, S K

2010-12-01

194

Maculosin, a Host-Specific Phytotoxin for Spotted Knapweed from Alternaria alternata  

Microsoft Academic Search

Several diketopiperazines have been isolated from liquid cultures of Alternaria alternata, the causal agent of black leaf blight of spotted knapweed, Centaurea maculosa Lam. One of these compounds, maculosin [the diketopiperazine cyclo-(-L-Pro-L-Tyr-)], was active in the nicked-leaf bioassay at 10-5 M; synthetic maculosin possessed chemical and biological activities identical to those of the natural product. Other diketopiperazines isolated from the

Andrea C. Stierle; John H. Cardellina; Gary A. Strobel

1988-01-01

195

Correlative evidence for peroxidase involvement in disease resistance against Alternaria leaf blight of tomato  

Microsoft Academic Search

Eighteen tomato genotypes, with varying degree of response to Alternaria leaf blight disease (ALBD) were used to assess the possible involvement of protease and peroxidase activities in disease\\u000a response. Pre-infectional protease activity varied noticeably in tested genotypes. Highest pre-infectional protease activity\\u000a was observed in susceptible genotype CLN-2123. Post-infectional protease activity level was generally lower when compared\\u000a with pre-infectional level in

Amjad HameedKhalid; Khalid Pervaiz Akhtar; Muhammad Yussouf Saleem; Muhammad Asghar

2010-01-01

196

Production of the Allergenic Protein Alt a 1 by Alternaria Isolates from Working Environments  

PubMed Central

The aim of the study was to evaluate the ability of Alternaria isolates from workplaces to produce Alt a 1 allergenic protein, and to analyze whether technical materials (cellulose, compost, leather) present within the working environment stimulate or inhibit Alt a 1 production (ELISA test). Studies included identification of the isolated molds by nucleotide sequences analyzing of the ITS1/ITS2 regions, actin, calmodulin and Alt a 1 genes. It has been shown that Alternaria molds are significant part of microbiocenosis in the archive, museum, library, composting plant and tannery (14%–16% frequency in the air). The presence of the gene encoding the Alt a 1 protein has been detected for the strains: Alternaria alternata, A. lini, A. limoniasperae A. nobilis and A. tenuissima. Environmental strains produced Alt a 1 at higher concentrations (1.103–6.528 ng/mL) than a ATCC strain (0.551–0.975 ng/mL). It has been shown that the homogenization of the mycelium and the use of ultrafiltration allow a considerable increase of Alt a 1 concentration. Variations in the production of Alt a 1 protein, depend on the strain and extraction methods. These studies revealed no impact of the technical material from the workplaces on the production of Alt a 1 protein. PMID:25689994

Skóra, Justyna; Otlewska, Anna; Gutarowska, Beata; Leszczy?ska, Joanna; Majak, Iwona; St?pie?, ?ukasz

2015-01-01

197

Citrus Black Rot is Caused by Phylogenetically Distinct Lineages of Alternaria alternata.  

PubMed

ABSTRACT Phylogenetic analysis revealed that isolates of Alternaria alternata causing black rot of citrus were associated with six well-supported evolutionary lineages. Isolates recovered from brown spot lesions on Minneola tangelo, leaf spot lesions on rough lemon, and healthy citrus tissue and noncitrus hosts were related closely to isolates from black-rotted fruit. Phylogenies estimated independently from DNA sequence data from an endopolygalacturonase gene (endoPG) and two anonymous regions of the genome (OPA1-3 and OPA2-1) had similar topologies, and phylogenetic analysis was performed on the combined data set. In the combined phylogeny, isolates from diverse ecological niches on citrus and noncitrus hosts were distributed in eight clades. Isolates from all lineages, regardless of ecological or host association, caused black rot in fruit inoculation assays, demonstrating that small-spored Alternaria isolates associated with different ecological niches on citrus and other plant hosts are potential black rot pathogens. These data also indicated that the fungi associated with black-rotted fruit do not form a natural evolutionary group distinct from other Alternaria pathogens and saprophytes associated with citrus. The use of the name A. citri to describe fungi associated with citrus black rot is not justified and it is proposed that citrus black rot fungi be referred to as A. alternata. PMID:18943316

Peever, T L; Carpenter-Boggs, L; Timmer, L W; Carris, L M; Bhatia, A

2005-05-01

198

Effects of meteorological factors on the levels of Alternaria spores on a potato crop  

NASA Astrophysics Data System (ADS)

Alternaria solani Soraeur produces early blight in Solanum tuberosum L., leading to significant agricultural losses. The current study was carried out on the extensive potato crop situated in north-western of Spain during 2007, 2008 and 2009. In this area potato crops are the most important source of income. In this work we used a Hirst-type volumetric spore-trap for the aerobiological monitoring of Alternaria spores. The highest spore concentrations were recorded during the 2009 cycle (10,555 spores), and the lowest concentrations were recorded during the 2008 cycle (5,471 spores). Over the 3 years of study, the highest concentrations were registered during the last stage of the crop. The aim of the study was to observe the influence of meteorological factors on the concentration of Alternaria spores, which can lead to serious infection and early blight. Prediction of the stages during which a crop is particularly vulnerable to infection allows for adjustment of the application of fungicide and is of environmental and agricultural importance. For this reason, we tested three models (P-Days, DD and IWP) to predict the first treatment and decrease the negative effect that these spores have on potato crops. The parameter that showed the most significant correlation with spore concentrations was minimum temperature. We used ARIMA (autoregressive integrated model of running mean) time-series models to determine the forecast. We considered weather data as predictor variables and the concentration of spores on the previous day as the fixed variable.

Escuredo, Olga; Seijo, Maria Carmen; Fernández-González, Maria; Iglesias, Isabel

2011-03-01

199

Novel insights into the genomic basis of citrus canker based on the genome sequences of two strains of Xanthomonas fuscans subsp. aurantifolii  

PubMed Central

Background Citrus canker is a disease that has severe economic impact on the citrus industry worldwide. There are three types of canker, called A, B, and C. The three types have different phenotypes and affect different citrus species. The causative agent for type A is Xanthomonas citri subsp. citri, whose genome sequence was made available in 2002. Xanthomonas fuscans subsp. aurantifolii strain B causes canker B and Xanthomonas fuscans subsp. aurantifolii strain C causes canker C. Results We have sequenced the genomes of strains B and C to draft status. We have compared their genomic content to X. citri subsp. citri and to other Xanthomonas genomes, with special emphasis on type III secreted effector repertoires. In addition to pthA, already known to be present in all three citrus canker strains, two additional effector genes, xopE3 and xopAI, are also present in all three strains and are both located on the same putative genomic island. These two effector genes, along with one other effector-like gene in the same region, are thus good candidates for being pathogenicity factors on citrus. Numerous gene content differences also exist between the three cankers strains, which can be correlated with their different virulence and host range. Particular attention was placed on the analysis of genes involved in biofilm formation and quorum sensing, type IV secretion, flagellum synthesis and motility, lipopolysacharide synthesis, and on the gene xacPNP, which codes for a natriuretic protein. Conclusion We have uncovered numerous commonalities and differences in gene content between the genomes of the pathogenic agents causing citrus canker A, B, and C and other Xanthomonas genomes. Molecular genetics can now be employed to determine the role of these genes in plant-microbe interactions. The gained knowledge will be instrumental for improving citrus canker control. PMID:20388224

2010-01-01

200

Surface barriers of mandarin 'okitsu' leaves make a major contribution to canker disease resistance.  

PubMed

Field evaluations have shown that Satsuma mandarin (Citrus unshiu) 'Okitsu' is one of the mandarin cultivars that shows substantial resistance to Xanthomonas citri subsp. citri (X. citri), the causal agent of citrus bacterial canker disease. However, the mechanisms underlying this resistance are not well understood. In this study, we have shown that 'Okitsu' leaves are nevertheless susceptible to X. citri infection during a period of their development; however, this period is shorter than that seen in the susceptible mandarin 'Clemenules' (C. clementina). Under controlled growth conditions, the resistance of 'Okitsu' to X. citri was associated with the age of the leaf and was evident in spray-inoculated plants but not in those inoculated by infiltration. Furthermore, X. citri showed reduced attachment and biofilm formation in 'Okitsu' leaves compared with 'Clemenules'. Taken together, our data suggest that structural features of the 'Okitsu' leaf surface, such as the physical properties of the cuticle, are involved in the resistance to X. citri. PMID:24548213

Favaro, María A; Micheloud, Norma G; Roeschlin, Roxana A; Chiesa, María A; Castagnaro, Atilio P; Vojnov, Adrián A; Gmitter, Fred G; Gadea, José; Rista, Luis M; Gariglio, Norberto F; Marano, María R

2014-09-01

201

Transgenic sweet orange plants expressing a dermaseptin coding sequence show reduced symptoms of citrus canker disease.  

PubMed

Citrus canker provoked by Xanthomonas axonopodis pv. citri is a bacterial disease causing severe losses in all citrus-producing areas around the world. Xanthomonas infection is considered as an endemic disease in Northeast and Northwest Argentina, affecting as much as 10% of commercial citrus plantations. There is not known natural resistance neither in orange varieties nor in rootstocks used for grafting of commercial cultivars. To introduce resistance to this disease, plants of Pineapple sweet orange were transformed with a genetic construct allowing constitutive accumulation of dermaseptin. In comparison with non-transformed plants, transgenic plants showed symptom reduction levels of up to 50% in in planta assays performed under controlled conditions. PMID:23896218

Furman, Nicolás; Kobayashi, Ken; Zanek, Maria Cecilia; Calcagno, Javier; Garcia, Maria Laura; Mentaberry, Alejandro

2013-09-20

202

Identification of bacteriophages for biocontrol of the kiwifruit canker phytopathogen Pseudomonas syringae pv. actinidiae.  

PubMed

Pseudomonas syringae pv. actinidiae is a reemerging pathogen which causes bacterial canker of kiwifruit (Actinidia sp.). Since 2008, a global outbreak of P. syringae pv. actinidiae has occurred, and in 2010 this pathogen was detected in New Zealand. The economic impact and the development of resistance in P. syringae pv. actinidiae and other pathovars against antibiotics and copper sprays have led to a search for alternative management strategies. We isolated 275 phages, 258 of which were active against P. syringae pv. actinidiae. Extensive host range testing on P. syringae pv. actinidiae, other pseudomonads, and bacteria isolated from kiwifruit orchards showed that most phages have a narrow host range. Twenty-four were analyzed by electron microscopy, pulse-field gel electrophoresis, and restriction digestion. Their suitability for biocontrol was tested by assessing stability and the absence of lysogeny and transduction. A detailed host range was performed, phage-resistant bacteria were isolated, and resistance to other phages was examined. The phages belonged to the Caudovirales and were analyzed based on morphology and genome size, which showed them to be representatives of Myoviridae, Podoviridae, and Siphoviridae. Twenty-one Myoviridae members have similar morphologies and genome sizes yet differ in restriction patterns, host range, and resistance, indicating a closely related group. Nine of these Myoviridae members were sequenced, and each was unique. The most closely related sequenced phages were a group infecting Pseudomonas aeruginosa and characterized by phages JG004 and PAK_P1. In summary, this study reports the isolation and characterization of P. syringae pv. actinidiae phages and provides a framework for the intelligent formulation of phage biocontrol agents against kiwifruit bacterial canker. PMID:24487530

Frampton, Rebekah A; Taylor, Corinda; Holguín Moreno, Angela V; Visnovsky, Sandra B; Petty, Nicola K; Pitman, Andrew R; Fineran, Peter C

2014-04-01

203

Adaptive Potential of Maritime Pine (Pinus pinaster) Populations to the Emerging Pitch Canker Pathogen, Fusarium circinatum  

PubMed Central

There is a concern on how emerging pests and diseases will affect the distribution range and adaptability of their host species, especially due to different conditions derived from climate change and growing globalization. Fusarium circinatum, which causes pitch canker disease in Pinus species, is an exotic pathogen of recent introduction in Spain that threatens its maritime pine (P. pinaster) stands. To predict the impact this disease will have on the species, we examine host resistance traits and their genetic architecture. Resistance phenotyping was done in a clonal provenance/progeny trial, using three-year-old cuttings artificially inoculated with the pathogen and maintained under controlled environmental conditions. A total number of 670 ramets were assessed, distributed in 10 populations, with a total of 47 families, 2 to 5 half-sibs per family, and 3–7 ramets per clone. High genetic variation was found at the three hierarchical levels studied: population, family and clone, being both additive and non-additive effects important. Narrow-sense and broad-sense heritability estimates were relatively high, with respective values of 0.43–0.58 and 0.51–0.8, depending on the resistance traits measured (lesion length, lesion length rate, time to wilting, and survival). These values suggest the species' high capacity of evolutionary response to the F. circinatum pathogen. A population originated in Northern Spain was the most resistant, while another from Morocco was the most susceptible. The total number of plants that did not show lesion development or presented a small lesion (length<30 mm) was 224 out of 670, indicating a high proportion of resistant trees in the offspring within the analyzed populations. We found large differences among populations and considerable genetic variation within populations, which should allow, through natural or artificial selection, the successful adaptation of maritime pine to pitch canker disease. PMID:25500822

Elvira-Recuenco, Margarita; Iturritxa, Eugenia; Majada, Juan; Alia, Ricardo; Raposo, Rosa

2014-01-01

204

Adaptive potential of maritime pine (Pinus pinaster) populations to the emerging pitch canker pathogen, Fusarium circinatum.  

PubMed

There is a concern on how emerging pests and diseases will affect the distribution range and adaptability of their host species, especially due to different conditions derived from climate change and growing globalization. Fusarium circinatum, which causes pitch canker disease in Pinus species, is an exotic pathogen of recent introduction in Spain that threatens its maritime pine (P. pinaster) stands. To predict the impact this disease will have on the species, we examine host resistance traits and their genetic architecture. Resistance phenotyping was done in a clonal provenance/progeny trial, using three-year-old cuttings artificially inoculated with the pathogen and maintained under controlled environmental conditions. A total number of 670 ramets were assessed, distributed in 10 populations, with a total of 47 families, 2 to 5 half-sibs per family, and 3-7 ramets per clone. High genetic variation was found at the three hierarchical levels studied: population, family and clone, being both additive and non-additive effects important. Narrow-sense and broad-sense heritability estimates were relatively high, with respective values of 0.43-0.58 and 0.51-0.8, depending on the resistance traits measured (lesion length, lesion length rate, time to wilting, and survival). These values suggest the species' high capacity of evolutionary response to the F. circinatum pathogen. A population originated in Northern Spain was the most resistant, while another from Morocco was the most susceptible. The total number of plants that did not show lesion development or presented a small lesion (length<30 mm) was 224 out of 670, indicating a high proportion of resistant trees in the offspring within the analyzed populations. We found large differences among populations and considerable genetic variation within populations, which should allow, through natural or artificial selection, the successful adaptation of maritime pine to pitch canker disease. PMID:25500822

Elvira-Recuenco, Margarita; Iturritxa, Eugenia; Majada, Juan; Alia, Ricardo; Raposo, Rosa

2014-01-01

205

Delimiting cryptic pathogen species causing apple Valsa canker with multilocus data  

PubMed Central

Fungal diseases are posing tremendous threats to global economy and food safety. Among them, Valsa canker, caused by fungi of Valsa and their Cytospora anamorphs, has been a serious threat to fruit and forest trees and is one of the most destructive diseases of apple in East Asia, particularly. Accurate and robust delimitation of pathogen species is not only essential for the development of effective disease control programs, but also will advance our understanding of the emergence of plant diseases. However, species delimitation is especially difficult in Valsa because of the high variability of morphological traits and in many cases the lack of the teleomorph. In this study, we delimitated species boundary for pathogens causing apple Valsa canker with a multifaceted approach. Based on three independent loci, the internal transcribed spacer (ITS), ?-tubulin (Btu), and translation elongation factor-1 alpha (EF1?), we inferred gene trees with both maximum likelihood and Bayesian methods, estimated species tree with Bayesian multispecies coalescent approaches, and validated species tree with Bayesian species delimitation. Through divergence time estimation and ancestral host reconstruction, we tested the possible underlying mechanisms for fungal speciation and host-range change. Our results proved that two varieties of the former morphological species V. mali represented two distinct species, V. mali and V. pyri, which diverged about 5 million years ago, much later than the divergence of their preferred hosts, excluding a scenario of fungi–host co-speciation. The marked different thermal preferences and contrasting pathogenicity in cross-inoculation suggest ecological divergences between the two species. Apple was the most likely ancestral host for both V. mali and V. pyri. Host-range expansion led to the occurrence of V. pyri on both pear and apple. Our results also represent an example in which ITS data might underestimate species diversity. PMID:24834333

Wang, Xuli; Zang, Rui; Yin, Zhiyuan; Kang, Zhensheng; Huang, Lili

2014-01-01

206

Characterization and pathogenicity of Alternaria spp. strains associated with grape bunch rot during post-harvest withering.  

PubMed

Alternaria is a fungal agent of grape bunch rot which occurs during withering, a process which produces passito style wines. Seven isolates of Alternaria spp. were characterized using morphological examination, genotypic analysis and pathogenicity. Six of these isolates produced conidiophores and conidia displaying sporulation patterns typical of the Alternaria alternata species-group. Variability in colony morphology and growth on different media was observed. Phylogenetic analysis of internal transcribed spacer (ITS) sequences clustered all isolates within a monophyletic clade, while intergenic spacer region (IGS)-RFLP profiles were congruent with those of A. alternata and Alternaria arborescens. RAPD-PCR proved helpful in discriminating between strains. To assay strain pathogenicity, grape berries were infected while undergoing withering conditions at different temperatures. Disease capacity was found to be strain dependent and varied consistently between the most and least aggressive strains. This study has provided interesting information on polymorphism within Alternaria spp. populations in withered grapes and on understanding the saprophytic role of this fungus during the post-harvest dehydrating process. PMID:24974273

Lorenzini, Marilinda; Zapparoli, Giacomo

2014-09-01

207

Immunochemical quantitation of airborne short ragweed, Alternaria, antigen E, and Alt-I allergens: a two-year prospective study  

SciTech Connect

We conducted a 2 yr prospective study to measure atmospheric short ragweed and Alternaria allergens by RAST inhibition analysis of eluates from filter sheets exposed in air samplers. In both years ragweed pollen and Alternaria spore counts, obtained with a rotoslide sampler, correlated significantly with immunochemically measured airborne ragweed and Alternaria allergenic activity. Airborne levels of the purified allergens AgE and Alt-I were successfully quantitated; these levels correlated closely with total airborne ragweed and Alternaria allergenic activities, respectively, and also with ragweed pollen and Alternaria spore counts. Eluates from filter sheets exposed during late summer and fall produced positive wheal-and-flare skin tests in patients with fall hay fever. In both years immunochemical measurements of allergenic activity due to airborne short ragweed correlated closely with mean symptom score indices in groups of short ragweed-sensitive individuals. Measurable levels of atmospheric ragweed allergenic activity were noted before and after the ragweed pollination season, and at these times we noted small increases in mean symptom score indices in the short ragweed-sensitive groups. Thus immunochemical analyses provide important information concerning levels of environmental allergens.

Agarwal, M.K.; Swanson, M.C.; Reed, C.E.; Yunginger, J.W.

1983-07-01

208

Modelling the progress of Asiatic citrus canker on Tahiti lime in relation to temperature and leaf wetness  

Microsoft Academic Search

The combined effect of temperature (15°C, 20°C, 25°C, 30°C, 35°C, 40°C and 42°C) and leaf wetness duration (0, 4, 8 12, 16,\\u000a 20 and 24 h) on infection and development of Asiatic citrus canker (Xanthomonas citri subsp. citri) on Tahiti lime plant was examined in growth chambers. No disease developed at 42°C and zero hours of leaf wetness. Periods\\u000a of leaf

R. S. C. Christiano; M. Dalla Pria; W. C. Jesus Junior; L. Amorim; A. Bergamin Filho

2009-01-01

209

Mycotoxin Production in Liquid Culture and on Plants Infected with Alternaria spp. Isolated from Rocket and Cabbage.  

PubMed

Fungi belonging to the genus Alternaria are common pathogens of fruit and vegetables with some species able to produce secondary metabolites dangerous to human health. Twenty-eight Alternaria isolates from rocket and cabbage were investigated for their mycotoxin production. Five different Alternaria toxins were extracted from synthetic liquid media and from plant material (cabbage, cultivated rocket, cauliflower). A modified Czapek-Dox medium was used for the in vitro assay. Under these conditions, more than 80% of the isolates showed the ability to produce at least one mycotoxin, generally with higher levels for tenuazonic acid. However, the same isolates analyzed in vivo seemed to lose their ability to produce tenuazonic acid. For the other mycotoxins; alternariol, alternariol monomethyl ether, altenuene and tentoxin a good correlation between in vitro and in vivo production was observed. In vitro assay is a useful tool to predict the possible mycotoxin contamination under field and greenhouse conditions. PMID:25751147

Siciliano, Ilenia; Ortu, Giuseppe; Gilardi, Giovanna; Gullino, Maria Lodovica; Garibaldi, Angelo

2015-01-01

210

Identification of Alternaria brassicicola genes expressed in planta during pathogenesis of Arabidopsis thaliana.  

PubMed

Alternaria brassicicola is a necrotrophic fungal pathogen that causes black spot disease on cruciferous plants including economically important Brassica species. The purpose of this study was to identify fungal genes expressed during infection of Arabidopsis. In order to identify candidate genes involved in pathogenicity, we employed suppression subtractive hybridization (SSH) between RNA isolated from A. brassicicola spores incubated in water and on the leaf surface of the Arabidopsis ecotype Landsberg. Two populations of cDNA were created from total RNA extracted after 24h when approximately 80% of the spores had germinated either on the leaf surface or in water. Following SSH, expression of clones was examined using dot-blot macro-arrays and virtual Northern blots. 47 cDNA clones differentially expressed between Alternaria infected Arabidopsis leaves and spore germination in water were selected for sequencing. Seventy-seven percent (36) of the cDNAs had significant homology to fungal sequences from databases examined, including available fungal genomes, while 13% (11) had no homology to sequences in the databases. All 36 genes had significant matches with genes of fungal origin, while 11 genes did not have significant hits in the databases examined. Five sequences were expressed on the plant leaf surface but not during spore germination in water according to virtual Northern blots. These five cDNAs were predicted to encode a cyanide hydratase, arsenic ATPase, formate dehydrogenase, major Alternaria allergen, and one unknown. RT-PCR was used to examine the expression of these five genes during infection of Brassica oleraceae var. capitata (cabbage), in vitro growth in nutrient rich media, and infection of Arabidopsis thaliana. Four of these genes are expressed in the nutrient rich medium, while the unknown gene P3F2 was only expressed during plant infection. The results of this study provide the first insight into genes expressed during A. brassicicola infection of Brassica species that may be involved in fungal pathogenesis. PMID:14732258

Cramer, Robert A; Lawrence, Christopher B

2004-02-01

211

Pyrone derivatives from the endophytic fungus Alternaria tenuissima SP-07 of Chinese herbal medicine Salvia przewalskii.  

PubMed

Three new pyrones, solanapyrones P-R (1-3), were afforded by the extracts of the endophytic fungus Alternaria tenuissima SP-07 isolated from the fresh root of Chinese herbal medicine Salvia przewalskii, along with the known solanapyrones (4-6) and benzopyrones (7-9). Solanapyrones P (1) and Q (2) possess an unprecedented nor-solanapyrone skeleton as natural products. Their structures were determined on the basis of NMR and HR-ESI-MS analysis. The plausible biosynthetic pathways to those unknown compounds were discussed. All the isolated compounds were evaluated for their antibacterial activities against six bacteria. PMID:25284429

Wang, Xiao-Zheng; Luo, Xiao-Hong; Xiao, Jie; Zhai, Ming-Ming; Yuan, Yun; Zhu, Ying; Crews, Phillip; Yuan, Cheng-Shan; Wu, Quan-Xiang

2014-12-01

212

Proteomic analysis of Alternaria alternata (Fr.) Keissler responds to COS fumigation.  

PubMed

Carbonyl sulfide (COS) is a new fumigant which has been a potential alternative to methyl bromide and phosphine in many applications. In this study, we investigated the fungitoxicity of COS towards the pathogen of pear black spot disease Alternaria alternata (Fr.) Keissler (A. alternata). Moreover, proteomic analysis and RT-PCR was performed and our results showed that during the fumigation, the regulation of 21 proteins in protein expression and mRNA accumulation levels is involved, which respond to growth inhibition caused by COS. These results provide new clues for the mechanism of the fungitoxicity of COS. PMID:20036892

Liu, Tao; Li, Li; Qu, Haixia; Zhan, Guoping; Liu, Bo; Wang, Yuejin

2010-01-01

213

Alternaria arborescens Infection in a Healthy Individual and Literature Review of Cutaneous Alternariosis.  

PubMed

A 28-year-old man presented at our clinic with 1-month history of an ulcer covered with crust on his left anterior tibia. Based on the morphological features and molecular identification, the patient was diagnosed as cutaneous alternariosis caused by Alternaria arborescens. He was successfully cured by oral itraconazole and topical use of 0.25 % liposomal amphotericin B. A review of published studies revealed 29 cases of cutaneous alternariosis. Most cases (90 %) occurred in immunosuppressed patients; itraconazole (59 %) and voriconazole (24 %) are the most effective treatments of choices. PMID:25370461

Hu, Wenying; Ran, Yuping; Zhuang, Kaiwen; Lama, Jebina; Zhang, Chaoliang

2015-02-01

214

Effect of vitamins on growth and sporulation of Alternaria alternata (Fr.) Keissler.  

PubMed

Alternaria alternata, a leaf spot pathogen of beet (Beta vulgaris), was found to be auxoautotrophic for thiamine. On the other hand, riboflavin, biotin, inositol, and pyridoxine were heterotrophically needed for its growth. Vigorous sporulation was prominent in response to the additions of riboflavin, d-biotin, and inositol. A curiously depressent effect on both the growth and sporulation of the pathogen was noticed in presence of 1-ascorbic acid, folic acid, and nicotinic acid. These substances also lowered the pH of the medium towards acidity. Separate additions of thiamine, riboflavin, pyridoxine, biotin, and inositol, however, increased the pH towards the neutral and alkaline range. PMID:7191607

Singh, J K; Shahdeo, S P; Lal, B B; Prasad, M

1980-01-01

215

Natural zinniol derivatives from Alternaria tagetica. Isolation, synthesis, and structure-activity correlation.  

PubMed

Two novel phytotoxins, 8-zinniol methyl ether (5) and 8-zinniol acetate (6), in addition to 6-(3',3'-dimethylallyloxy)-4-methoxy-5-methylphthalide (2), 5-(3',3'-dimethylallyloxy)-7-methoxy-6-methylphthalide (3), and the novel metabolites 8-zinniol 2-(phenyl)ethyl ether (4) and 7-zinniol acetate (7) have been identified as natural zinniol derivatives from the organic crude extract of Alternaria tagetica culture filtrates. Using zinniol as the starting material, phytotoxin 5 was synthesized, together with a number of synthetic intermediates (8-13). Both natural and synthetic zinniol derivatives were evaluated in the leaf-spot bioassay against marigold leaves (Tagetes erecta). PMID:11853479

Gamboa-Angulo, M Marcela; Escalante-Erosa, Fabiola; García-Sosa, Karlina; Alejos-González, Fátima; Delgado-Lamas, Guillermo; Peña-Rodríguez, Luis M

2002-02-27

216

Maculosin, a host-specific phytotoxin for spotted knapweed from Alternaria alternata  

PubMed Central

Several diketopiperazines have been isolated from liquid cultures of Alternaria alternata, the causal agent of black leaf blight of spotted knapweed, Centaurea maculosa Lam. One of these compounds, maculosin [the diketopiperazine cyclo(-L-Pro-L-Tyr-)], was active in the nicked-leaf bioassay at 10-5 M; synthetic maculosin possessed chemical and biological activities identical to those of the natural product. Other diketopiperazines isolated from the fungus possessed either less activity or none at all. In tests against 19 plant species, maculosin was phytotoxic only to spotted knapweed. Thus maculosin is a host-specific phytotoxin from a weed pathogen. PMID:16593989

Stierle, Andrea C.; Cardellina, John H.; Strobel, Gary A.

1988-01-01

217

Alternethanoxins A and B, polycyclic ethanones produced by Alternaria sonchi , potential mycoherbicides for Sonchus arvensis biocontrol.  

PubMed

Alternaria sonchi is a fungal pathogen isolated from Sonchus arvensis and proposed as a biocontrol agent of this noxious perennial weed. Different phytotoxic metabolites were isolated from solid culture of the fungus. Two new polycyclic ethanones, named alternethanoxins A and B, were characterized using essentially spectroscopic and chemical methods. Tested by leaf disk-puncture assay on the fungal host plant and a number of nonhost plants, alternethanoxins A and B were shown to be phytotoxic, whereas they did not possess antimicrobial activity tested at 100 microg/disk. Hence, alternethanoxins A and B have potential as nonselective natural herbicides. Some structure-activity relationship observations were also made. PMID:19594161

Evidente, Antonio; Punzo, Biancavaleria; Andolfi, Anna; Berestetskiy, Alexander; Motta, Andrea

2009-08-12

218

Maculosin, a host-specific phytotoxin for spotted knapweed from Alternaria alternata.  

PubMed

Several diketopiperazines have been isolated from liquid cultures of Alternaria alternata, the causal agent of black leaf blight of spotted knapweed, Centaurea maculosa Lam. One of these compounds, maculosin [the diketopiperazine cyclo(-L-Pro-L-Tyr-)], was active in the nicked-leaf bioassay at 10(-5) M; synthetic maculosin possessed chemical and biological activities identical to those of the natural product. Other diketopiperazines isolated from the fungus possessed either less activity or none at all. In tests against 19 plant species, maculosin was phytotoxic only to spotted knapweed. Thus maculosin is a host-specific phytotoxin from a weed pathogen. PMID:16593989

Stierle, A C; Cardellina, J H; Strobel, G A

1988-11-01

219

STEM Career  

NSDL National Science Digital Library

There are many groups and organizations in the United States working to encourage young people to enter STEM-related careers, and this website represents one of those endeavors. The STEM Career website was created by Professor Rich Feller of Colorado State University to help encourage young people to select just such a career path. The website contains updates on STEM career possibilities, and basic answers to questions like "Why STEM?" and "Why STEM Centric Career Development?" Visitors should also scan through the "STEM Disciplines" area on the homepage, as it contains resources about the job outlook for related STEM disciplines, such as biochemical engineering and engineering managers. Moving on, the site also features news updates from Professor Feller and his colleagues on subjects that include the ways in which corporations are promoting STEM education and women in STEM.

220

Conservation of the genes for HC-toxin biosynthesis in Alternaria jesenskae  

PubMed Central

Background HC-toxin, a cyclic tetrapeptide, is a virulence determinant for the plant pathogenic fungus Cochliobolus carbonum. It was recently discovered that another fungus, Alternaria jesenskae, also produces HC-toxin. Results The major genes (collectively known as AjTOX2) involved in the biosynthesis of HC-toxin were identified from A. jesenskae by genomic sequencing. The encoded orthologous proteins share 75-85% amino acid identity, and the genes for HC-toxin biosynthesis are duplicated in both fungi. The genomic organization of the genes in the two fungi show a similar but not identical partial clustering arrangement. A set of representative housekeeping proteins show a similar high level of amino acid identity between C. carbonum and A. jesenskae, which is consistent with the close relatedness of these two genera within the family Pleosporaceae (Dothideomycetes). Conclusions This is the first report that the plant virulence factor HC-toxin is made by an organism other than C. carbonum. The genes may have moved by horizontal transfer between the two species, but it cannot be excluded that they were present in a common ancestor and lost from other species of Alternaria and Cochliobolus. PMID:23865912

2013-01-01

221

Brenneria populi sp. nov., isolated from symptomatic bark of Populus×euramericana canker.  

PubMed

Five Gran-stain-negative, facultatively anaerobic, motile, bacterial strains were isolated from symptomatic bark tissue of Populus×euramericana canker. Strains grew at 4-41 °C, pH 4-10 and 0-6?% (w/v) salinity. They were positive with respect to catalase activity and negative for oxidase activity, nitrate reduction and the Voges-Proskauer reaction. Analysis of 16S rRNA gene sequences indicated that these five poplar isolates belong to the genus Brenneria, having highest sequence similarity of 95.98?% with Brenneria goodwinii LMG 26270(T). These five isolates formed a single cluster based on multilocus sequence analysis, indicating that they all belong to a single taxon within the genus Brenneria, which was confirmed by DNA-DNA hybridization. The DNA G+C content was 54.9-55.7 mol%, and the main fatty acids were C16?:?0, C18?:?1?7c, C17?:?0 cyclo and C16?:?1?7c/iso-C15?:?0 2-OH. Based on these results, we describe a novel species of the genus Brenneria with the proposed name Brenneria populi sp. nov. The type strain is D9-5(T) (?=?CFCC 11963(T)?=?KCTC 42088(T)). PMID:25385993

Li, Yong; Fang, Wei; Xue, Han; Liang, Wen-Xing; Wang, Lai-Fa; Tian, Guo-Zhong; Wang, Xi-Zhuo; Lin, Cai-Li; Li, Xia; Piao, Chun-Gen

2015-02-01

222

Population structure of the butternut canker fungus, Ophiognomonia clavigignenti-juglandacearum, in North American forests  

PubMed Central

The occurrence of multiple introduction events, or sudden emergence from a host jump, of forest pathogens may be an important factor in successful establishment in a novel environment or on a new host; however, few studies have focused on the introduction and emergence of fungal pathogens in forest ecosystems. While Ophiognomonia clavigignenti-juglandacearum (Oc-j), the butternut canker fungus, has caused range-wide mortality of butternut trees in North America since its first observation in 1967, the history of its emergence and spread across the United States and Canada remains unresolved. Using 17 single nucleotide polymorphic loci, we investigated the genetic population structure of 101 isolates of Oc-j from across North America. Clustering analysis revealed that the Oc-j population in North America is made up of three differentiated genetic clusters of isolates, and these genetic clusters were found to have a strong clonal structure. These results, in combination with the geographic distribution of the populations, suggest that Oc-j was introduced or has emerged in North America on more than one occasion, and these clonal lineages have since proliferated across much of the range of butternut. No evidence of genetic recombination was observed in the linkage analysis, and conservation of the distinct genetic clusters in regions where isolates from two or more genetic clusters are present, would indicate a very minimal or non-existent role of sexual recombination in populations of Oc-j in North America. PMID:23139872

Broders, K D; Boraks, A; Sanchez, A M; Boland, G J

2012-01-01

223

Effects of Alternaria destruens, Glyphosate, and Ammonium Sulfate Individually and Integrated for Control of Dodder (Cuscuta pentagona)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Dodder is a serious weed problem in several crops. Its minutely sized, easily dispersed, and highly viable seed makes it difficult to control. Alternaria destruens is the active ingredient in a registered bioherbicide for control of dodder species. In greenhouse studies, the following treatments ...

224

Molecular characterization and detection of mutations associated with resistance to succinate dehydrogenase inhibiting (SDHI) fungicides in Alternaria solani  

Technology Transfer Automated Retrieval System (TEKTRAN)

Early blight, caused by Alternaria solani, is an economically important foliar disease of potato in several production areas of the United States. Few potato cultivars possess resistance to early blight, therefore, the application of fungicides is a primary means of achieving disease control. Previo...

225

COLONIZATION BY FUSARIUM AND ALTERNARIA SPP. OF SORGHUM GRAIN OF NEAR ISOGENIC LINES VARYING IN PLANT COLOR AND PERICARP COLOR.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Colonization by Fusarium and Alternaria spp. of sorghum grain of near isogenic lines varying in plant color and pericarp color. Deanna L. Funnell and Jeffery F. Pedersen, Grain, Forage and Bioenergy Research, USDA-ARS; Departments of Plant Pathology (DLF) and Agronomy (JFP), University of Nebraska. ...

226

Nonhost-specific phytotoxicity of the polyketide-derived toxin solanapyrone A produced by Ascochyta rabiei and Alternaria solani  

Technology Transfer Automated Retrieval System (TEKTRAN)

Solanapyrone A is a polyketide-derived metabolite produced by Ascochyta rabiei and Alternaria solani, which are the most destructive necrotrophic pathogens of chickpea and potato/tomato, respectively. They belong to the Order Pleosporales within the Class Dothideomycetes, but are phylogenetically di...

227

First Report of a Leaf Spot Caused by Alternaria brassicae on the Invasive Weed Lepidium draba in North America  

Technology Transfer Automated Retrieval System (TEKTRAN)

A second leaf spot disease on the perennial invasive weed white top, aka hoary cress, was found in a stand of white top in south central Montana. The plant pathogen causing the lesions was identified as the fungus Alternaria brassicae. It was isolated, purified grown on a V-8 agar growth medium and ...

228

Effects of Leaf Maturity, Infection Site, and Application Rate of Alternaria cirsinoxia Conidia on Infection of Canada Thistle ( Cirsium arvense)  

Microsoft Academic Search

The effects of leaf maturity, infection site, and application rate of Alternaria cirsinoxia conidia on the pre- and postpenetration phases of infection of Canada thistle were studied. Leaf maturity had no effect on the germination of conidia, but appressoria formation was significantly higher on the oldest leaf than on the youngest leaf. There were no differences in the frequency of

S Green; K. L Bailey

2000-01-01

229

STEM Sell  

ERIC Educational Resources Information Center

Between 1994 and 2003, employment in science, technology, engineering and math (STEM) fields grew by a remarkable 23 percent, compared with 17 percent in non-STEM fields, according to federal data. The Bureau of Labor Statistics predicts continued strong growth in STEM job openings through 2014, with emphasis on life sciences, environmental…

Pantic, Zorica

2007-01-01

230

A framework to gauge the epidemic potential of plant pathogens in environmental reservoirs: the example of kiwifruit canker.  

PubMed

New economically important diseases on crops and forest trees emerge recurrently. An understanding of where new pathogenic lines come from and how they evolve is fundamental for the deployment of accurate surveillance methods. We used kiwifruit bacterial canker as a model to assess the importance of potential reservoirs of new pathogenic lineages. The current kiwifruit canker epidemic is at least the fourth outbreak of the disease on kiwifruit caused by Pseudomonas syringae in the mere 50 years in which this crop has been cultivated worldwide, with each outbreak being caused by different genetic lines of the bacterium. Here, we ask whether strains in natural (non-agricultural) environments could cause future epidemics of canker on kiwifruit. To answer this question, we evaluated the pathogenicity, endophytic colonization capacity and competitiveness on kiwifruit of P.?syringae strains genetically similar to epidemic strains and originally isolated from aquatic and subalpine habitats. All environmental strains possessing an operon involved in the degradation of aromatic compounds via the catechol pathway grew endophytically and caused symptoms in kiwifruit vascular tissue. Environmental and epidemic strains showed a wide host range, revealing their potential as future pathogens of a variety of hosts. Environmental strains co-existed endophytically with CFBP 7286, an epidemic strain, and shared about 20 virulence genes, but were missing six virulence genes found in all epidemic strains. By identifying the specific gene content in genetic backgrounds similar to known epidemic strains, we developed criteria to assess the epidemic potential and to survey for such strains as a means of forecasting and managing disease emergence. PMID:24986268

Bartoli, Claudia; Lamichhane, Jay Ram; Berge, Odile; Guilbaud, Caroline; Varvaro, Leonardo; Balestra, Giorgio M; Vinatzer, Boris A; Morris, Cindy E

2015-02-01

231

DNA Polymorphisms and Biocontrol of Bacillus Antagonistic to Citrus Bacterial Canker with Indication of the Interference of Phyllosphere Biofilms  

PubMed Central

Citrus bacterial canker caused by Xanthomonas axonopodis pv. citri is a devastating disease resulting in significant crop losses in various citrus cultivars worldwide. A biocontrol agent has not been recommended for this disease. To explore the potential of bacilli native to Taiwan to control this disease, Bacillus species with a broad spectrum of antagonistic activity against various phytopathogens were isolated from plant potting mixes, organic compost and the rhizosphere soil. Seven strains TKS1-1, OF3-16, SP4-17, HSP1, WG6-14, TLB7-7, and WP8-12 showing superior antagonistic activity were chosen for biopesticide development. The genetic identity based on 16S rDNA sequences indicated that all seven native strains were close relatives of the B. subtilis group and appeared to be discrete from the B. cereus group. DNA polymorphisms in strains WG6-14, SP4-17, TKS1-1, and WP8-12, as revealed by repetitive sequence-based PCR with the BOXA1R primers were similar to each other, but different from those of the respective Bacillus type strains. However, molecular typing of the strains using either tDNA-intergenic spacer regions or 16S–23S intergenic transcribed spacer regions was unable to differentiate the strains at the species level. Strains TKS1-1 and WG6-14 attenuated symptom development of citrus bacterial canker, which was found to be correlated with a reduction in colonization and biofilm formation by X. axonopodis pv. citri on leaf surfaces. The application of a Bacillus strain TKS1-1 endospore formulation to the leaf surfaces of citrus reduced the incidence of citrus bacterial canker and could prevent development of the disease. PMID:22848728

Huang, Tzu-Pi; Tzeng, Dean Der-Syh; Wong, Amy C. L.; Chen, Chun-Han; Lu, Kuan-Min; Lee, Ya-Huei; Huang, Wen-Di; Hwang, Bing-Fang; Tzeng, Kuo-Ching

2012-01-01

232

STEM crisis or STEM surplus?  

E-print Network

The science, technology, engineering, and mathematics (STEM) workforce is a crucial driver of the U.S. economy. Over the last decade, there has been significant concern regarding the adequacy of the supply of STEM workers ...

Xue, Yi, S.M. Massachusetts Institute of Technology

2014-01-01

233

Identification of putative TAL effector targets of the citrus canker pathogens shows functional convergence underlying disease development and defense response  

PubMed Central

Background Transcriptional activator-like (TAL) effectors, formerly known as the AvrBs3/PthA protein family, are DNA-binding effectors broadly found in Xanthomonas spp. that transactivate host genes upon injection via the bacterial type three-secretion system. Biologically relevant targets of TAL effectors, i.e. host genes whose induction is vital to establish a compatible interaction, have been reported for xanthomonads that colonize rice and pepper; however, citrus genes modulated by the TAL effectors PthA“s” and PthC“s” of the citrus canker bacteria Xanthomonas citri (Xc) and Xanthomonas aurantifolii pathotype C (XaC), respectively, are poorly characterized. Of particular interest, XaC causes canker disease in its host lemon (Citrus aurantifolia), but triggers a defense response in sweet orange. Results Based on, 1) the TAL effector-DNA binding code, 2) gene expression data of Xc and XaC-infiltrated sweet orange leaves, and 3) citrus hypocotyls transformed with PthA2, PthA4 or PthC1, we have identified a collection of Citrus sinensis genes potentially targeted by Xc and XaC TAL effectors. Our results suggest that similar with other strains of Xanthomonas TAL effectors, PthA2 and PthA4, and PthC1 to some extent, functionally converge. In particular, towards induction of genes involved in the auxin and gibberellin synthesis and response, cell division, and defense response. We also present evidence indicating that the TAL effectors act as transcriptional repressors and that the best scoring predicted DNA targets of PthA“s” and PthC“s” in citrus promoters predominantly overlap with or localize near to TATA boxes of core promoters, supporting the idea that TAL effectors interact with the host basal transcriptional machinery to recruit the RNA pol II and start transcription. Conclusions The identification of PthA“s” and PthC“s” targets, such as the LOB (LATERAL ORGAN BOUNDARY) and CCNBS genes that we report here, is key for the understanding of the canker symptoms development during host susceptibility, or the defenses of sweet orange against the canker bacteria. We have narrowed down candidate targets to a few, which pointed out the host metabolic pathways explored by the pathogens. PMID:24564253

2014-01-01

234

Lateral organ boundaries 1 is a disease susceptibility gene for citrus bacterial canker disease  

PubMed Central

Citrus bacterial canker (CBC) disease occurs worldwide and incurs considerable costs both from control measures and yield losses. Bacteria that cause CBC require one of six known type III transcription activator-like (TAL) effector genes for the characteristic pustule formation at the site of infection. Here, we show that Xanthomonas citri subspecies citri strain Xcc306, with the type III TAL effector gene pthA4 or with the distinct yet biologically equivalent gene pthAw from strain XccAw, induces two host genes, CsLOB1 and CsSWEET1, in a TAL effector-dependent manner. CsLOB1 is a member of the Lateral Organ Boundaries (LOB) gene family of transcription factors, and CsSWEET1 is a homolog of the SWEET sugar transporter and rice disease susceptibility gene. Both TAL effectors drive expression of CsLOB1 and CsSWEET1 promoter reporter gene fusions when coexpressed in citrus or Nicotiana benthamiana. Artificially designed TAL effectors directed to sequences in the CsLOB1 promoter region, but not the CsSWEET1 promoter, promoted pustule formation and higher bacterial leaf populations. Three additional distinct TAL effector genes, pthA*, pthB, and pthC, also direct pustule formation and expression of CsLOB1. Unlike pthA4 and pthAw, pthB and pthC do not promote the expression of CsSWEET1. CsLOB1 expression was associated with the expression of genes associated with cell expansion. The results indicate that CBC-inciting species of Xanthomonas exploit a single host disease susceptibility gene by altering the expression of an otherwise developmentally regulated gene using any one of a diverse set of TAL effector genes in the pathogen populations. PMID:24474801

Hu, Yang; Zhang, Junli; Jia, Hongge; Sosso, Davide; Li, Ting; Frommer, Wolf B.; Yang, Bing; White, Frank F.; Wang, Nian; Jones, Jeffrey B.

2014-01-01

235

Bayesian Analysis for Inference of an Emerging Epidemic: Citrus Canker in Urban Landscapes  

PubMed Central

Outbreaks of infectious diseases require a rapid response from policy makers. The choice of an adequate level of response relies upon available knowledge of the spatial and temporal parameters governing pathogen spread, affecting, amongst others, the predicted severity of the epidemic. Yet, when a new pathogen is introduced into an alien environment, such information is often lacking or of no use, and epidemiological parameters must be estimated from the first observations of the epidemic. This poses a challenge to epidemiologists: how quickly can the parameters of an emerging disease be estimated? How soon can the future progress of the epidemic be reliably predicted? We investigate these issues using a unique, spatially and temporally resolved dataset for the invasion of a plant disease, Asiatic citrus canker in urban Miami. We use epidemiological models, Bayesian Markov-chain Monte Carlo, and advanced spatial statistical methods to analyse rates and extent of spread of the disease. A rich and complex epidemic behaviour is revealed. The spatial scale of spread is approximately constant over time and can be estimated rapidly with great precision (although the evidence for long-range transmission is inconclusive). In contrast, the rate of infection is characterised by strong monthly fluctuations that we associate with extreme weather events. Uninformed predictions from the early stages of the epidemic, assuming complete ignorance of the future environmental drivers, fail because of the unpredictable variability of the infection rate. Conversely, predictions improve dramatically if we assume prior knowledge of either the main environmental trend, or the main environmental events. A contrast emerges between the high detail attained by modelling in the spatiotemporal description of the epidemic and the bottleneck imposed on epidemic prediction by the limits of meteorological predictability. We argue that identifying such bottlenecks will be a fundamental step in future modelling of weather-driven epidemics. PMID:24762851

Neri, Franco M.; Cook, Alex R.; Gibson, Gavin J.; Gottwald, Tim R.; Gilligan, Christopher A.

2014-01-01

236

Bayesian analysis for inference of an emerging epidemic: citrus canker in urban landscapes.  

PubMed

Outbreaks of infectious diseases require a rapid response from policy makers. The choice of an adequate level of response relies upon available knowledge of the spatial and temporal parameters governing pathogen spread, affecting, amongst others, the predicted severity of the epidemic. Yet, when a new pathogen is introduced into an alien environment, such information is often lacking or of no use, and epidemiological parameters must be estimated from the first observations of the epidemic. This poses a challenge to epidemiologists: how quickly can the parameters of an emerging disease be estimated? How soon can the future progress of the epidemic be reliably predicted? We investigate these issues using a unique, spatially and temporally resolved dataset for the invasion of a plant disease, Asiatic citrus canker in urban Miami. We use epidemiological models, Bayesian Markov-chain Monte Carlo, and advanced spatial statistical methods to analyse rates and extent of spread of the disease. A rich and complex epidemic behaviour is revealed. The spatial scale of spread is approximately constant over time and can be estimated rapidly with great precision (although the evidence for long-range transmission is inconclusive). In contrast, the rate of infection is characterised by strong monthly fluctuations that we associate with extreme weather events. Uninformed predictions from the early stages of the epidemic, assuming complete ignorance of the future environmental drivers, fail because of the unpredictable variability of the infection rate. Conversely, predictions improve dramatically if we assume prior knowledge of either the main environmental trend, or the main environmental events. A contrast emerges between the high detail attained by modelling in the spatiotemporal description of the epidemic and the bottleneck imposed on epidemic prediction by the limits of meteorological predictability. We argue that identifying such bottlenecks will be a fundamental step in future modelling of weather-driven epidemics. PMID:24762851

Neri, Franco M; Cook, Alex R; Gibson, Gavin J; Gottwald, Tim R; Gilligan, Christopher A

2014-04-01

237

Lateral organ boundaries 1 is a disease susceptibility gene for citrus bacterial canker disease.  

PubMed

Citrus bacterial canker (CBC) disease occurs worldwide and incurs considerable costs both from control measures and yield losses. Bacteria that cause CBC require one of six known type III transcription activator-like (TAL) effector genes for the characteristic pustule formation at the site of infection. Here, we show that Xanthomonas citri subspecies citri strain Xcc306, with the type III TAL effector gene pthA4 or with the distinct yet biologically equivalent gene pthAw from strain XccA(w), induces two host genes, CsLOB1 and CsSWEET1, in a TAL effector-dependent manner. CsLOB1 is a member of the Lateral Organ Boundaries (LOB) gene family of transcription factors, and CsSWEET1 is a homolog of the SWEET sugar transporter and rice disease susceptibility gene. Both TAL effectors drive expression of CsLOB1 and CsSWEET1 promoter reporter gene fusions when coexpressed in citrus or Nicotiana benthamiana. Artificially designed TAL effectors directed to sequences in the CsLOB1 promoter region, but not the CsSWEET1 promoter, promoted pustule formation and higher bacterial leaf populations. Three additional distinct TAL effector genes, pthA*, pthB, and pthC, also direct pustule formation and expression of CsLOB1. Unlike pthA4 and pthAw, pthB and pthC do not promote the expression of CsSWEET1. CsLOB1 expression was associated with the expression of genes associated with cell expansion. The results indicate that CBC-inciting species of Xanthomonas exploit a single host disease susceptibility gene by altering the expression of an otherwise developmentally regulated gene using any one of a diverse set of TAL effector genes in the pathogen populations. PMID:24474801

Hu, Yang; Zhang, Junli; Jia, Hongge; Sosso, Davide; Li, Ting; Frommer, Wolf B; Yang, Bing; White, Frank F; Wang, Nian; Jones, Jeffrey B

2014-01-28

238

Chemotactic signal transduction and phosphate metabolism as adaptive strategies during citrus canker induction by Xanthomonas citri.  

PubMed

The genome of Xanthomonas citri subsp. Citri strain 306 pathotype A (Xac) was completely sequenced more than 10 years; to date, few studies involving functional genomics Xac and its host compatible have been developed, specially related to adaptive events that allow the survival of Xac within the plant. Proteomic analysis of Xac showed that the processes of chemotactic signal transduction and phosphate metabolism are key adaptive strategies during the interaction of a pathogenic bacterium with its plant host. The results also indicate the importance of a group of proteins that may not be directly related to the classical virulence factors, but that are likely fundamental to the success of the initial stages of the infection, such as methyl-accepting chemotaxis protein (Mcp) and phosphate specific transport (Pst). Furthermore, the analysis of the mutant of the gene pstB which codifies to an ABC phosphate transporter subunit revealed a complete absence of citrus canker symptoms when inoculated in compatible hosts. We also conducted an in silico analysis which established the possible network of genes regulated by two-component systems PhoPQ and PhoBR (related to phosphate metabolism), and possible transcriptional factor binding site (TFBS) motifs of regulatory proteins PhoB and PhoP, detaching high degree of conservation of PhoB TFBS in 84 genes of Xac genome. This is the first time that chemotaxis signal transduction and phosphate metabolism were therefore indicated to be fundamental to the process of colonization of plant tissue during the induction of disease associated with Xanthomonas genus bacteria. PMID:25403594

Moreira, Leandro Marcio; Facincani, Agda Paula; Ferreira, Cristiano Barbalho; Ferreira, Rafael Marine; Ferro, Maria Inês Tiraboshi; Gozzo, Fabio Cesar; de Oliveira, Julio Cezar Franco; Ferro, Jesus Aparecido; Soares, Márcia Regina

2015-03-01

239

Stem Cell Basics  

MedlinePLUS

... Info Center Stem Cell Basics Stem Cell Basics Stem Cell Information Frequently Asked Questions What are stem cells? ... U.S. policy? More FAQs Links to related resources Stem Cell Research Center for Regenerative Medicine NIH Stem Cell ...

240

Differential expression profiles of Alternaria alternate genes in response to carbonyl sulfide fumigation.  

PubMed

Carbonyl sulfide (COS) is a new fumigant used in phytosanitary treatments. It was developed as a potential alternative to methyl bromide, which is being phased out because of its ozone-depletion properties. To understand the molecular and cellular mechanisms occurring in fungal pathogens in response to COS fumigation, we cloned 510 cDNA fragments of Alternaria alternata (Fr.) Keissler genes that are differentially expressed; these genes were cloned using suppression subtractive hybridization. Changes in the levels of transcripts of 79 fragments were confirmed by microarray analysis and qRT-PCR. Further homology search revealed that they are highly homologous to 41 genes of other fungi, which were related to general metabolism, growth and division, defense, cellular transport, and signal transduction. These results provide an overview of differential expression profiles of A. alternata genes following COS treatment and some new clues about the mechanism of COS fungitoxicity. PMID:20799090

Liu, Tao; Li, Li; Wang, Yuejin; Zhan, Guoping; Liu, Bo

2010-08-01

241

Induction of defense responses against Alternaria rot by different elicitors in harvested pear fruit.  

PubMed

Pear fruit (Pyrus pyrifolia L. cv. Yali) treated by different elicitors, such as salicylic acid (SA), oxalic acid, calcium chloride, and antagonistic yeast Cryptococcus laurentii, were investigated to determine the induction of defense responses. The possible mechanism by which elicitors induced the resistance of pear fruit against postharvest disease was also evaluated. The results indicated that all the elicitors could significantly enhance defense-related enzyme activities, such as beta-1,3-glucanase, phenylalanine ammonia lyase, peroxidase, and polyphenol oxidase activity, and reduce the disease incidence caused by Alternaria alternata in pear fruit (P=0.05). Among these different elicitors, SA treatment showed the best result in inducing the defense responses and reducing the decay in pear fruit. PMID:16158285

Tian, Shiping; Wan, Yakun; Qin, Guozheng; Xu, Yong

2006-05-01

242

First Report of Foliar Blight on Dendropanax morbifera Caused by Alternaria panax.  

PubMed

Leaf spot and blight disease was observed on two-year-old seedlings of Dendropanax morbifera (Korean name: Hwangchil tree) during July of 2008 in Jindo Island, Korea. Symptoms included yellow-brown to dark brown irregularly enlarged spots frequently located along the veins of leaves. The lesions were often surrounded by chlorotic haloes. Severe leaf blight and subsequent defoliation occurred when conditions favored disease outbreak. The causal organism of the disease was identified as Alternaria panax based on morphological characteristics and sequence analysis of the internal transcribed spacer region of rDNA. A. panax isolates induced leaf spots and blight symptoms not only on D. morbifera but also on the other members of Araliaceae tested. This is the first report of foliar blight caused by A. panax on D. morbifera. PMID:23956672

Deng, Jian Xin; Kim, Chang Sun; Oh, Eun Sung; Yu, Seung Hun

2010-12-01

243

Effect of Glucose and Adenosine Phosphates on Production of Extracellular Carbohydrases of Alternaria solani1  

PubMed Central

Production of carbohydrases by Alternaria solani is inhibited by glucose under low growth conditions. In an enriched medium, glucose has little effect on the production of polygalacturonase and cellulase while it still suppresses production of ?-glucosidase. Low levels of all three enzymes were produced in the absence of their respective substrates. Such regulation has been found with many organisms. However, far greater production of these carbohydrases occurred with additions of adenosine phosphates to the growth media. Highest stimulation of enzyme production was by adenosine 5?-phosphate. Adenosine 5?-triphosphate and cyclic 3?, 5?-adenosine monophosphate gave lesser amounts. Starvation appears to induce production of extracellular carbohydrases and adenosine 5?-phosphate may have a role in the starvation process. PMID:16658949

Sands, David C.; Lukens, Raymond J.

1974-01-01

244

Exogenous treatment with salicylic acid attenuates occurrence of citrus canker in susceptible navel orange (Citrus sinensis Osbeck).  

PubMed

Citrus canker caused by Xanthomonas axonopodis pv. citri (Xac) is a devastating bacterial disease threatening the citrus industry. Salicylic acid (SA) plays a key role in plant defense response to biotic stress, but information is scarce concerning the application of SA to enhancing Xac resistance. In the present research attempts were made to investigate how exogenous application of SA influenced canker disease outbreak in navel orange (Citrus sinensis). Exogenously applied SA at 0.25 mM significantly enhanced the endogenous free and bound SA, particularly the latter. Upon exposure to Xac, lower disease incidence rate and smaller lesion sites were observed in the samples pre-treated with SA, accompanied by repression of bacterial growth at the lesion sites. Concurrent with the augmented disease resistance, SA-treated leaves had higher H?O? level and smaller stomata apertures before or after Xac infection when compared with their counterparts pre-treated with water (control). SA treatment elevated the activities of phenylalanine ammonia-lyase and ?-1,3-glucanase, but only the latter was higher in the SA-treated samples after Xac infection. In addition, mRNA levels of two pathogenesis-related genes, CsCHI and CsPR4A, were higher in the SA-treated samples relative to the control. Taken together, our results strongly suggest that the exogenously applied SA has evoked a cascade of physiological and molecular events that function singly or in concert to confer resistance to Xac invasion. PMID:22658220

Wang, Yin; Liu, Ji-Hong

2012-08-15

245

The epidemiological significance of post-packinghouse survival of Xanthomonas citri ssp. citri for dissemination of Asiatic citrus canker via infected fruit  

Technology Transfer Automated Retrieval System (TEKTRAN)

The risk of introduction of Xanthomonas citri spp. citri (Xcc) to new, unaffected citrus producing areas is a major concern for those citrus industries attempting to remain free of citrus canker. Citrus fruit, as a potential pathway for Xcc to enter and become established in these areas, is assumed...

246

THE CHANGE IN QUANTITY OF BACTERIA OF XANTHOMONAS AXONOPODIS PV CITRI DISPERSED DOWN WIND FROM CANKER-INFECTED GRAPEFRUIT TREES DURING A WIND/RAIN EVENT  

Technology Transfer Automated Retrieval System (TEKTRAN)

The yield and marketability of citrus is limited in several tropical wet parts of the world by citrus canker (caused by Xanthomonas axonopodis pv. citri, Xac). The disease can cause severe epidemics and there are few options for control, although eradication has been favored (1). A thorough knowledg...

247

POST-HURRICANE ANALYSIS OF CITRUS CANKER SPREAD AND PROGRESS TOWARDS THE DEVELOPMENT OF A PREDICTIVE MODEL FOR FUTURE WEATHER RELATED SPREAD  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker, caused by Xanthomonas axonopodis pv. citri (Xac), has been introduced into the state of Florida multiple times since the early 1900’s. With each discovery, an eradication program has been put into place to eliminate the disease. The most recent program began in 1996 and is still in ...

248

SPATIAL PATTERN ANALYSIS OF CITRUS CANKER INFECTED PLANTINGS IN SÃO PAULO BRAZIL AND IMPLICATION OF THE ASIAN LEAFMINER ON THE POTENTIAL DISPERSAL PROCESSES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Eradication of Asiatic Citrus Canker (ACC) has become increasingly difficult over the last decade following the introduction of the Asian leafminer into Brazil and Florida, which lead to changes in the eradication protocols. The present study, undertaken in Brazil, was aimed at characterizing the s...

249

POST-HURRICANE ANALYSIS OF CITRUS CANKER II: PREDICTIVE MODEL ESTIMATION OF DISEASE SPREAD AND AREA POTENTIALLY IMPACTED BY VARIOUS ERADICATION PROTOCOLS FOLLOWING CATASTROPHIC WEATHER EVENTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The affect of 2005 Hurricane Wilma on the dissemination of Xanthomonas axonopodis pv. citri (Xac), the cause of Asiatic citrus canker (ACC), and subsequent disease development was examined and predictions for the areas into which Xac was likely to have spread from known sources of infection was deve...

250

Processes involved in the dispersal of Xanthomonas citri pv. citri from canker-infectd citrus canopies, and in the infection of citrus foliage  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus canker (Xanthomonas citri subsp. citri, Xcc) is now considered endemic in Florida, and epidemics result in yield loss and market penalties both in Florida, and elsewhere where the pathogen occurs, and susceptible citrus is cultivated. The bacterium is dispersed in rain splash, and storms wit...

251

Effects of Mefenoxam, Phosphonate, and Paclobutrazol on In Vitro Characteristics of Phytophthora cactorum and P. citricola and on Canker Size of European Beech  

Technology Transfer Automated Retrieval System (TEKTRAN)

Phytophthora citricola and P. cactorum cause bleeding cankers that lead to the death of mature European beech in the northeastern United States. Because of the economic value placed on these trees, experiments were conducted to investigate the effects of two fungicides and a plant growth regulator ...

252

Fusicoccum arbuti sp. nov. causing cankers on Pacific madrone in western North America with notes on Fusicoccum dimidiatum, the correct name for Scytalidium dimidiatum and Nattrassia mangiferae  

Microsoft Academic Search

Pacific madrone (Arbutus menziesii )i s a broadleaf evergreen tree native to western North America that has been in decline for the past 30 years. A fungus has been isolated and was verified as the cause of cankers on dying trees. It was deter- mined to belong in the genus Fusicoccum, an asexual state of Botryosphaeria. This genus in both

David F. Farr; Marianne Elliott; Amy Y. Rossman; Robert L. Edmonds

2005-01-01

253

Fusarium torreyae sp. nov., a pathogen causing canker disease of Florida torreya (Torreya taxifolia), a critically endangered conifer restricted to northern Florida and southwestern Georgia  

Technology Transfer Automated Retrieval System (TEKTRAN)

During a survey for pathogens of Florida torreya (Torreya taxifolia) conducted in 2009, a novel Fusarium species was isolated from cankers affecting this critically endangered conifer whose current range is restricted to northern Florida and southwestern Georgia. Published multilocus molecular phylo...

254

Wind speed effects on the quantity of Xanthomonas citri subsp. citri dispersed downwind from canopies of grapefruit trees infected with citrus canker  

Technology Transfer Automated Retrieval System (TEKTRAN)

The epidemic of citrus canker (Xanthomonas citri subsp. citri, Xcc) in Florida continues to expand since termination of the eradication program in 2006. Storms are known to be associated with disease spread, but little information exists on the interaction of fundamental physical and biological proc...

255

ESTIMATING THE INCREASE AND SPREAD OF CITRUS CANKER CAUSED BY THE INTERACTION OF PEDESTRIAN VERSUS CATASTROPHIC WEATHER EVENTS, HUMANS, AND BAD LUCK  

Technology Transfer Automated Retrieval System (TEKTRAN)

The bacteria, Xanthomonas axonopodis pv. citri (Xac), that causes Asiatic Citrus Canker (ACC) can move in any of a variety of modes in the presence of free moisture. From a meteorological point of view, gentle rain, rain with wind, rain storms, tropical storms, and hurricanes can all disperse Xac i...

256

SPATIAL PATTERN ANALYSIS OF CITRUS CANKER INFECTED PLANTINGS IN SAO PAULO BRAZIL AND IMPLICATION OF THE ASIAN LEAFMINER ON POTENTIAL DISPERSAL PROCESSES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Eradication of Asiatic Citrus Canker (ACC) has become increasingly difficult over the last decade following the introduction of the Asian leafminer into Brazil and Florida. This prompted epidemiological studies in both countries that resulted in changes in the eradication protocols. The objective ...

257

POST-HURRICANE ANALYSIS OF CITRUS CANKER SPREAD AND PROGRESS TOWARDS THE DEVELOPMENT OF A PREDICTIVE MODEL FOR FUTURE WEATHER RELATED SPREAD  

Technology Transfer Automated Retrieval System (TEKTRAN)

Asiatic citrus canker (Xanthonomas axonopodis pv. citri) has had a long history in Florida and has been introduced multiple times since the early 1900’s. With each introduction or discovery, eradication programs have been implemented to attempt to eliminate the disease. The most recent eradication...

258

PROGRESS TOWARDS THE DEVELOPMENT OF AN EFFECTIVE RISK ANALYSIS PROCESS FOR THE FLORIDA CITRUS NURSERY INDUSTRY TO MITIGATE THE IMPACT OF CITRUS CANKER AND HUANGLONGBING  

Technology Transfer Automated Retrieval System (TEKTRAN)

The citrus industry within the state of Florida is being directly impacted by two recently introduced bacterial diseases, citrus canker and huanglongbing. As the commercial citrus industry is trying to develop efficient strategies to eradicate, control, or manage the diseases, it is becoming readil...

259

Responsiveness of different citrus genotypes to the Xanthomonas citri ssp. citri-derived pathogen-associated molecular pattern (PAMP) flg22 correlates with resistance to citrus canker.  

PubMed

The bacterial agent of citrus canker disease (Xanthomonas citri ssp. citri, Xcc) has caused tremendous economic losses to the citrus industry around the world. Pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) is important to plant immunity. In this study, we compared the defence responses of citrus canker-resistant and citrus canker-susceptible genotypes to the Xcc-derived PAMP flg22 (Xflg22) by analysing the expression of 20 citrus defence-associated genes. We showed that, in the most resistant genotype, 'Nagami' kumquat, there was significant induction of several defence genes (EDS1, NDR1, PBS1, RAR1, SGT1, PAL1, NPR2 and NPR3) as early as 6?h and up to 72?h after Xflg22 treatment. At the other end of the spectrum, highly susceptible 'Duncan' grapefruit showed no induction of the same defence genes, even 120?h after treatment. Citrus genotypes with partial levels of resistance showed intermediate levels of transcriptional reprogramming that correlated with their resistance level. Xflg22 also triggered a rapid oxidative burst in all genotypes which was higher and accompanied by the induction of PTI marker genes (WRKY22 and GST1) only in the more resistant genotypes. Pretreatment with Xflg22 prior to Xcc inoculation inhibited bacterial growth in kumquat, but not in grapefruit. A flagellin-deficient Xcc strain (Xcc?fliC) showed greater growth increase relative to wild-type Xcc in kumquat than in grapefruit. Taken together, our results indicate that Xflg22 initiates strong PTI in canker-resistant genotypes, but not in susceptible ones, and that a robust induction of PTI is an important component of citrus resistance to canker. PMID:25231217

Shi, Qingchun; Febres, Vicente J; Jones, Jeffrey B; Moore, Gloria A

2014-09-18

260

Use of a climatic rule and fuzzy sets to model geographic distribution of climatic risk for European canker (Neonectria galligena) of apple.  

PubMed

A rule-based model was developed to assess climatic risk of European canker (Neonectria galligena), which is a major disease of apple in some temperate zones. A descriptive rule was derived from published observations on climatic conditions favorable for European canker development. Fuzzy set theory was used to evaluate the descriptive rule quantitatively. The amount and frequency of rainfall and the average number of hours between 11 and 16°C/day were used as input variables whose values were matched with terms in the rule, e.g., 'high' or 'low'. The degree of a term, e.g., the state of being high or low, to a given input value was determined using a membership function that converts an input value to a number between 0 and 1. The rule was evaluated by combining the degree of the terms associated with monthly climate data. Monthly risk index values derived using the rule were combined for pairs of consecutive months over 12 months. The annual risk of European canker development was represented by the maximum risk index value for 2 months combined. The membership function parameters were adjusted iteratively to achieve a specified level of risk at Talca (Chile), Loughgall (Northern Ireland), East Malling (UK), and Sebastopol (USA), where European canker risk was known. The rule-based model was validated with data collected from Canada, Ecuador, Denmark, Germany, Norway, Poland, Sweden, the Netherlands, New Zealand, and the Pacific Northwest (USA), where European canker has been reported to occur. In these validation areas, the model's risk prediction agreed with reports of disease occurrence. The rule-based model also predicted high risk areas more reliably than the climate matching model, CLIMEX, which relies on correlations between the spatial distribution of a species and climatic conditions. The combination of a climatic rule and fuzzy sets could be used for other applications where prediction of the geographic distribution of organisms is required for climatic risk assessment. PMID:21809979

Kim, Kwang Soo; Beresford, Robert M

2012-02-01

261

Geo-referenced spatiotemporal analysis of the urban citrus canker epidemic in Florida.  

PubMed

ABSTRACT Five areas in urban Miami were identified to study the spread of Xanthomonas axonopodis pv. citri to determine if the practice of removing exposed citrus trees within 38.1 m of trees affected by citrus canker was adequate to curtail further bacterial spread. To accomplish this, 18,769 trees in dooryards were surveyed, geo-referenced by differential global positioning systems (GPS), and assayed for disease severity, age of infection, citrus cultivar, location of infection in tree, and canopy size. For each tree, the date the tree became infected was estimated and used to separate trees into contiguous 30-day categories. For each area studied, distance measurements between focal trees and newly infected trees were calculated for various temporal periods of 30, 60, 90, and 120 days in duration, corresponding to intervals of inspection survey. A visual basic application was used to calculate the distances between each newly diseased tree and all prior focal trees. The nearest distance was used because it was considered the most conservative estimate possible. It is therefore likely to be an underestimate of spread but is a good estimate of the minimum possible distances of spread. For the first four 30-day periods among the five study areas, calculated maximum distances of spread ranged from 12 to 3,474 m, indicating a broad continuum of distance for bacterial spread was possible. Disease increased during the first two-thirds of the time studied and reached an asymptote due to dry conditions in the final one-third of the duration of the study. Cross correlation analysis indicated that disease was best visualized 107 days following rainstorms with wind. Analysis of regional spatial point patterns was performed temporally for each 30-day period via a modified Ripley's K-function. Spatiotemporal analyses between periods over areas larger than previously examined were accomplished via spatiotemporal semivariogram analysis. These methods in combination demonstrated rapid increases in range of spatial dependency and range of spatiotemporal dependency for all study sites. This corresponded to rapid spread of disease across the regions studied in response to rainstorms with wind followed by a "filling in" of disease on remaining noninfected susceptible trees through time by less intense rain events. A stochastic quadratization technique demonstrated that disease incidence and disease severity were not greatly affected by urban host density but were positively correlated to host susceptibility within local 0.25-km(2) quadrats. PMID:18942949

Gottwald, Tim R; Sun, Xiaoan; Riley, Tim; Graham, James H; Ferrandino, Frank; Taylor, Earl L

2002-04-01

262

Effect of climate change on Alternaria leaf spot of rocket salad and black spot of basil under controlled environment.  

PubMed

Plant responses to elevated CO2 and temperature have been much studied in recent years, but effects of climate change on pathological responses are still largely unknown. The pathosystems rocket (Eruca vesicaria subsp. sativa)--Alternaria leaf spot (Alternaria japonica) and basil (Ocimum basilicum)--black spot (Colletotrichum gloeosporioides) were chosen as models to assess the potential impact of increased CO2 and temperature on disease incidence and severity under controlled environment. Potted plants were grown in phytotrons under 4 different simulated climatic conditions: (1) standard temperature (ranging from 18 degrees to 22 degrees C) and standard CO2 concentration (400 ppm); (2) standard temperature and elevated CO2 concentration (800 ppm); (3) elevated temperature (ranging from 22 degrees to 26 degrees C, 4 degrees C higher than standard) and standard CO2 concentration; (4) elevated temperature and CO2 concentration. Each plant was inoculated with a spore suspension containing 1 x 10(5) cfu/ml of the pathogen. Disease incidence and severity were assessed 14 days after inoculation. Increasing CO2 to 800 ppm showed a clear increment in the percentage of Alternaria leaf spot on rocket leaves compared to standard conditions. Basil plants grown at 800 ppm of CO2 showed increased black spot symptoms compared to 400 ppm. Disease incidence and severity were always influenced by the combination of rising CO2 and increased temperature, compared to standard conditions (400 ppm of CO2 - 22 degrees C). Considering the rising concentrations of CO2 and global temperature, we can assume that this could increase the severity of Alternaria japonica on rocket and Colletotrichum gloeosporioides on basil. PMID:23878979

Pugliese, M; Cogliati, E; Gullino, M L; Garibaldi, A

2012-01-01

263

Alternaria sp. MG1, a resveratrol-producing fungus: isolation, identification, and optimal cultivation conditions for resveratrol production.  

PubMed

Due to its potential in preventing or slowing the occurrence of many diseases, resveratrol (3,5,4'-trihydroxystilbene) has attracted great research interest. The objective of this study was to identify microorganisms from selected plants that produce resveratrol and to optimize the conditions for resveratrol production. Endophytes from Merlot wine grapes (Vitis vinifera L. cv. Merlot), wild Vitis (Vitis quinquangularis Rehd.), and Japanese knotweed (Polygonum cuspidatum Siebold & Zucc.) were isolated, and their abilities to produce resveratrol were evaluated. A total of 65 isolates were obtained and 21 produced resveratrol (6-123 ?g/L) in liquid culture. The resveratrol-producing isolates belonged to seven genera, Botryosphaeria, Penicillium, Cephalosporium, Aspergillus, Geotrichum, Mucor, and Alternaria. The resveratrol-producing capability decreased or was completely lost in most isolates after three rounds of subculture. It was found that only the strain Alternaria sp. MG1 (isolated from cob of Merlot using GA1 medium) had stable and high resveratrol-producing capability in all subcultures. During liquid cultivation of Alternaria sp. MG1 in potato dextrose medium, the synthesis of resveratrol began on the first day, increased to peak levels on day 7, and then decreased sharply thereafter. Cell growth increased during cultivation and reached a stable and high level of biomass after 5 days. The best fermentation conditions for resveratrol production in liquid cultures of Alternaria sp. MG1 were an inoculum size of 6 %, a medium volume of 125 mL in a 250-mL flask, a rotation speed of 101 rpm, and a temperature of 27 °C. PMID:22526800

Shi, Junling; Zeng, Qin; Liu, Yanlin; Pan, Zhongli

2012-07-01

264

Specific PCR-based detection of Alternaria helianthi: the cause of blight and leaf spot in sunflower.  

PubMed

Alternaria helianthi is an important seed-borne pathogenic fungus responsible for blight disease in sunflower. The current detection methods, which are based on culture and morphological identification, are time-consuming, laborious and are not always reliable. A PCR-based diagnostic method was developed with species-specific primers designed based on the sequence data of a region consisting of the 5.8S RNA gene and internal transcribed spacers-ITS 1 and ITS 2 of nuclear ribosomal RNA gene (rDNA) repeats of A. helianthi. The specificity of the primer pairs AhN1F and AhN1R designed was verified by PCR analysis of DNA from 18 Alternaria helianthi strains isolated from India, 14 non-target Alternaria spp. and 11 fungal isolates of other genera. A single amplification product of 357-bp was detected from DNA of A. helianthi isolates. No cross-reaction was observed with any of the other isolates tested. The detection limit of the PCR method was of 10 pg from template DNA. The primers could also detect the pathogen in infected sunflower seed. This species-specific PCR method provides a quick, simple, powerful and reliable alternative to conventional methods in the detection and identification of A. helianthi. This is the first report of an A. helianthi-specific primer set. PMID:22722684

Udayashankar, A C; Chandra Nayaka, S; Archana, B; Anjana, G; Niranjana, S R; Mortensen, C N; Lund, Ole S; Prakash, H S

2012-11-01

265

STEM Thinking!  

ERIC Educational Resources Information Center

Science, Technology, Engineering, and Mathematics (STEM) is a term seen almost daily in the news. In 2009, President Obama launched the Educate to Innovate initiative to move American students from the middle to the top of the pack in science and math achievement over the next decade (The White House, n.d.). Learning about the attributes of STEM

Reeve, Edward M.

2015-01-01

266

Similar and distinct roles of NADPH oxidase components in the tangerine pathotype of Alternaria alternata.  

PubMed

The fungal nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox) complex, which has been implicated in the production of low-level reactive oxygen species (ROS), contains mainly NoxA, NoxB (gp91(phox) homologues) and NoxR (p67(phox) homologue). Here, we report the developmental and pathological functions of NoxB and NoxR in the tangerine pathotype of Alternaria alternata. Loss-of-function genetics revealed that all three Nox components are required for the accumulation of cellular hydrogen peroxide (H?O?). Alternaria alternata strains lacking NoxA, NoxB or NoxR also displayed an increased sensitivity to H?O? and many ROS-generating oxidants. These phenotypes are highly similar to those previously seen for the ?yap1 mutant lacking a YAP1 transcriptional regulator and for the ?hog1 mutant lacking a HOG1 mitogen-activated protein (MAP) kinase, implicating a possible link among them. A fungal strain carrying a NoxA NoxB or NoxA NoxR double mutation was more sensitive to the test compounds than the strain mutated at a single gene, implicating a synergistic function among Nox components. The ?noxB mutant strain failed to produce any conidia; both ?noxA and ?noxR mutant strains showed a severe reduction in sporulation. Mutant strains carrying defective NoxB had higher chitin content than the wild-type and were insensitive to calcofluor white, Congo red and the fungicides vinclozolin and fludioxonil. Virulence assays revealed that all three Nox components are required for the elaboration of the penetration process. The inability to penetrate the citrus host, observed for ?nox mutants, could be overcome by wounding and by reacquiring a dominant Nox gene. The A.?alternata?NoxR did not influence the expression of NoxB, but negatively regulated NoxA. Importantly, the expression of both YAP1 and HOG1 genes, whose products are involved in resistance to ROS, was down-regulated in fungi carrying defective NoxA, NoxB or NoxR. Our results highlight the requirement of Nox in ROS resistance and provide insights into its critical role in regulating both YAP1 and HOG1 in A.?alternata. PMID:23527595

Yang, Siwy Ling; Chung, Kuang-Ren

2013-08-01

267

Stem Cells and Diseases  

MedlinePLUS

... Center Can Stem Cells Help my Medical Condition? Stem Cell Information Frequently Asked Questions What are stem cells? ... U.S. policy? More FAQs Links to related resources Stem Cell Research Center for Regenerative Medicine NIH Stem Cell ...

268

Visceral phaeohyphomycosis caused by Alternaria alternata offering a diagnostic as well as a therapeutic challenge.  

PubMed

Phaeohyphomycosis is a heterogeneous group of opportunistic infections caused by dematiaceous molds, which are distributed worldwide as plant pathogens but rarely cause human diseases. However, due to the growing populations of immunocompromised patients, these fungi are frequently recognized as important human pathogens. We are reporting this very rare, unique case for the first time from Islamabad, Pakistan, describing the association of visceral Phaeohyphomycosis caused by the opportunistic fungus Alternaria alternata, affecting the left kidney, with the immunocompromised state in a young incidentally detected patient with insulin-dependent type I diabetes. The case was diagnosed on the basis of a high index of clinical suspicion, microbial cultures, microscopy, imaging studies and endourological procedures. The patient did not respond well to the highly sensitive Amphotericin B, resulting in loss of the kidney. Therefore, we suggest that clinicians involved in treating immunocompromised patients should have a high degree of clinical suspicion for such opportunistic pathogens to allow timely initiation of the correct diagnostic and therapeutic work-up. PMID:25758886

Raza, H; Khan, R U; Anwar, K; Muhammad, K

2015-01-01

269

Stress Response and Pathogenicity of the Necrotrophic Fungal Pathogen Alternaria alternata  

PubMed Central

The production of host-selective toxins by the necrotrophic fungus Alternaria alternata is essential for the pathogenesis. A. alternata infection in citrus leaves induces rapid lipid peroxidation, accumulation of hydrogen peroxide (H2O2), and cell death. The mechanisms by which A. alternata avoids killing by reactive oxygen species (ROS) after invasion have begun to be elucidated. The ability to coordinate of signaling pathways is essential for the detoxification of cellular stresses induced by ROS and for pathogenicity in A. alternata. A low level of H2O2, produced by the NADPH oxidase (NOX) complex, modulates ROS resistance and triggers conidiation partially via regulating the redox-responsive regulators (YAP1 and SKN7) and the mitogen-activated protein (MAP) kinase (HOG1) mediated pathways, which subsequently regulate the genes required for the biosynthesis of siderophore, an iron-chelating compound. Siderophore-mediated iron acquisition plays a key role in ROS detoxification because of the requirement of iron for the activities of antioxidants (e.g., catalase and SOD). Fungal strains impaired for the ROS-detoxifying system severely reduce the virulence on susceptible citrus cultivars. This paper summarizes the current state of knowledge of signaling pathways associated with cellular responses to multidrugs, oxidative and osmotic stress, and fungicides, as well as the pathogenicity/virulence in the tangerine pathotype of A. alternata. PMID:24278721

Chung, Kuang-Ren

2012-01-01

270

Changes in concentration of Alternaria and Cladosporium spores during summer storms  

NASA Astrophysics Data System (ADS)

Fungal spores are known to cause allergic sensitization. Recent studies reported a strong association between asthma symptoms and thunderstorms that could be explained by an increase in airborne fungal spore concentrations. Just before and during thunderstorms the values of meteorological parameters rapidly change. Therefore, the goal of this study was to create a predictive model for hourly concentrations of atmospheric Alternaria and Cladosporium spores on days with summer storms in Szczecin (Poland) based on meteorological conditions. For this study we have chosen all days of June, July and August (2004-2009) with convective thunderstorms. There were statistically significant relationships between spore concentration and meteorological parameters: positive for air temperature and ozone content while negative for relative humidity. In general, before a thunderstorm, air temperature and ozone concentration increased, which was accompanied by a considerable increase in spore concentration. During and after a storm, relative humidity increased while both air temperature ozone concentration along with spore concentrations decreased. Artificial neural networks (ANN) were used to assess forecasting possibilities. Good performance of ANN models in this study suggest that it is possible to predict spore concentrations from meteorological variables 2 h in advance and, thus, warn people with spore-related asthma symptoms about the increasing abundance of airborne fungi on days with storms.

Grinn-Gofro?, Agnieszka; Strzelczak, Agnieszka

2013-09-01

271

Heterologous expression, characterization and site-directed mutagenesis of cutinase CUTAB1 from Alternaria brassicicola.  

PubMed

The cutinase CUTAB1 was cloned from a cutin induced culture of Alternaria brassicicola and heterologously expressed in Pichia pastoris under the control of the methanol-inducible AOX1 promoter. From a 400-ml culture, 36 mg of purified recombinant enzyme were obtained. Biochemical characterization revealed highest catalytic activity of the enzyme at 40 degrees C and pH 7-9 using p-nitrophenyl palmitate (p-NPP) as substrate. Among several fatty acid methyl and ethyl esters, glycerol esters and p-nitrophenyl esters tested, CUTAB1 showed highest activity towards tributyrin (3,302 +/- 160 U mg(-1)) and the activity decreased with increase in chain length of the investigated esters. Lowest activity was found for p-NPP. Replacing Leu80, Leu181 and Ile183, respectively, by the smaller alanine in the hydrophobic binding loop of CUTAB1, drastically reduced the overall activity of the enzyme. On the other hand, mutation A84F located in the small helical flap of CUTAB1 significantly increased the activity of the enzyme towards longer chain substrates like p-NPP. PMID:20306187

Koschorreck, Katja; Liu, Danni; Kazenwadel, Christian; Schmid, Rolf D; Hauer, Bernhard

2010-07-01

272

Oxidative in vitro metabolism of the Alternaria toxins altenuene and isoaltenuene.  

PubMed

The mycotoxins altenuene (ALT) and isoaltenuene (iALT) frequently occur in food and feed items infested by fungi of the genus Alternaria, but nothing is known about their oxidative metabolism in mammals. We have therefore incubated ALT and iALT with microsomes from rat liver in the presence of a nicotinamide adenine dinucleotide phosphate (NADPH)-generating system and analyzed the extracted metabolites with HPLC and GC-MS after trimethylsilylation. Both toxins formed a major metabolite, which was tentatively identified as the 8-hydroxylation product by GC-MS analysis and by its methylation by the enzyme catechol-O-methyltransferase. Three minor metabolites were tentatively identified as 10-hydroxy- and two stereoisomers of 4-hydroxy-ALT and -iALT. The same metabolic pattern was observed in microsomes from different rat strains and from pigs and humans. Moreover, incubation of ALT with rat liver slices provided evidence that the same oxidative metabolites were formed under in vivo-like conditions. Thus, ALT and iALT exhibit a considerable propensity for undergoing metabolic hydroxylation reactions, and the toxicological properties of the oxidative metabolites should now be studied. PMID:19065583

Pfeiffer, Erika; Herrmann, Carina; Altemöller, Martina; Podlech, Joachim; Metzler, Manfred

2009-04-01

273

Antifungal activity of diketopiperazines extracted from Alternaria alternata against Plasmopara viticola: an ultrastructural study.  

PubMed

Three dipeptides, belonging to the family of diketopiperazines (DKPs), were extracted from broth culture of the grapevine endophyte Alternaria alternata, and were tested against Plasmopara viticola on leaves of grapevine plants grown in greenhouse. DKPs, used at different concentrations (10(-3), 10(-4), 10(-5) and 10(-6)M) both singularly and in mixtures, demonstrated real effectiveness in inhibiting P. viticola sporulation when applied 2 or 24h after pathogen inoculation. Moreover, no necrotic lesions or other phytotoxicity symptoms were observed on DKP-treated grapevine leaf tissues. Ultrastructural analysis performed on grapevine leaf tissues revealed that the DKPs used singularly and in mixture, at above reported concentrations, did not cause leaf tissue damages. By contrast, hyphae of P. viticola exhibited marked structural changes, similar to those induced by the endophyte A. alternata. This demonstrates the involvement of these metabolites in the relationship of P. viticola and the endophyte. Further experimental trials will be carried out in the next future in order to test the effectiveness of these molecules also under field conditions, and to better understand the mechanism of action involved in the pathogen inhibition. PMID:17071094

Musetti, R; Polizzotto, R; Vecchione, A; Borselli, S; Zulini, L; D'Ambrosio, M; di Toppi, L Sanità; Pertot, I

2007-01-01

274

Alternaria brassicae produces a host-specific protein toxin from germinating spores on host leaves.  

PubMed

Spore suspensions of Alternaria brassicae, the causal agent of gray leaf spot in Brassica plants, were incubated on the leaves of cabbage (B. oleracea) and spore germination fluid (SGF) was collected after 48 h. A high molecular weight (HMW) fraction (>10 kDa) was separated from the SGF by ultrafiltration. In a detached leaf assay, the HMW fraction induced visible symptoms only on host leaves and the toxicity was lost by treatment with proteinase K or heat at 60 degrees C for 15 min, indicating the presence of host-specific protein toxin(s). A protein toxin in the HMW fraction was purified by several chromatography steps. The toxin induced water-soaked symptoms followed by chlorosis at concentrations of 0.5 to 1 microg/ml on host leaves, but not on nonhost leaves even at 50 microg/ml. The toxin also had infection-inducing activity when added to spore suspension of a nonpathogenic isolate of A. alternata, causing symptoms similar to the infection of A. brassicae only on host leaves. These results indicate that a new host-specific protein toxin named ABR-toxin is released from germinating spores of A. brassicae on host leaves. ABR-toxin migrated as a protein of 27.5 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The isoelectric point of ABR-toxin was estimated to be approximately 7.0 and 21 N-terminal amino acid residues were sequenced. PMID:18944195

Parada, R Y; Sakuno, E; Mori, N; Oka, K; Egusa, M; Kodama, M; Otani, H

2008-04-01

275

Changes in the leaf proteome profile of Mentha arvensis in response to Alternaria alternata infection.  

PubMed

Plant pathogenic fungi cause important yield losses in crops. A proteomic approach was used to study the changes in the leaf proteome profile of the plant Mentha arvensis infected with a necrotrophic fungus, Alternaria alternata. High-resolution two-dimensional gel electrophoresis (2-DE) followed by colloidal Coomassie staining and mass spectrometric analysis was used to identify highly abundant proteins differentially expressed in response to fungal infection. From a total of 210 reproducibly detected and analyzed spots, the intensity of sixty-seven spots was altered, and forty-five of them were successfully identified by matrix assisted laser desorption/ionization time of flight-mass spectrometry (MALDI TOF/TOF MS/MS). Fifty-six percent of the identified proteins belonged to energy and metabolism whereas 29% were stress and defense related. Taken together, the results allow to assess changes at the proteomic level in the host due to the defense response. Results show an initial defense response, not strong enough to overcome the pathogenesis, which may be similar to other susceptible plant-pathogen interactions; however, cross-talks between various defense pathways, regulatory networks and physiological conditions are other important aspects to be considered. PMID:21111074

Sinha, Ragini; Chattopadhyay, Sharmila

2011-03-01

276

Changes in concentration of Alternaria and Cladosporium spores during summer storms.  

PubMed

Fungal spores are known to cause allergic sensitization. Recent studies reported a strong association between asthma symptoms and thunderstorms that could be explained by an increase in airborne fungal spore concentrations. Just before and during thunderstorms the values of meteorological parameters rapidly change. Therefore, the goal of this study was to create a predictive model for hourly concentrations of atmospheric Alternaria and Cladosporium spores on days with summer storms in Szczecin (Poland) based on meteorological conditions. For this study we have chosen all days of June, July and August (2004-2009) with convective thunderstorms. There were statistically significant relationships between spore concentration and meteorological parameters: positive for air temperature and ozone content while negative for relative humidity. In general, before a thunderstorm, air temperature and ozone concentration increased, which was accompanied by a considerable increase in spore concentration. During and after a storm, relative humidity increased while both air temperature ozone concentration along with spore concentrations decreased. Artificial neural networks (ANN) were used to assess forecasting possibilities. Good performance of ANN models in this study suggest that it is possible to predict spore concentrations from meteorological variables 2 h in advance and, thus, warn people with spore-related asthma symptoms about the increasing abundance of airborne fungi on days with storms. PMID:23161270

Grinn-Gofro?, Agnieszka; Strzelczak, Agnieszka

2013-09-01

277

Fungicidal activity of volatile oil from eucalyptus Citriodora Hook. against Alternaria triticina.  

PubMed

Use of plant products for the management of phytopathogenic fungi is fast becoming an important component of Integrated Disease Management (I.D.M.) programme. The natural plant products are bio-degradable and thus eco-friendly, are catching the attention of the scientist worldwide. Such products from higher plants are relatively broad spectrum, bio-efficacious, economical and environmentally safe. Among these essential oils from higher plants because of their greater inhibitory action are being explored preferably worldwide. In this context, a study was undertaken to explore the effect of volatile oil from Eucalyptus citriodora against Alternaria triticina. The radial growth, dry weight and spore germination of pathogen were drastically reduced in response to the different concentrations of volatile oil. A complete inhibition of radial growth, dry weight and spore germination were observed at 1500, 1000 and 100 ppm, respectively. In contrast, similar complete inhibition of test pathogen was observed at very high concentration (6500, 6500 and 1000 ppm) of mancozeb--a commercially available synthetic fungicide. Based on these observations, it was therefore concluded that eucalypt volatile oil has potential to suppress the phytopathogenic fungi. PMID:17390838

Ramezani, Hesamedin

2006-01-01

278

Multiple phytohormone signalling pathways modulate susceptibility of tomato plants to Alternaria alternata f. sp. lycopersici  

PubMed Central

Three phytohormone molecules – ethylene (ET), jasmonic acid (JA) and salicylic acid (SA) – play key roles in mediating disease response to necrotrophic fungal pathogens. This study investigated the roles of the ET, JA, and SA pathways as well as their crosstalk during the interaction between tomato (Solanum lycopersicum) plants and a necrotrophic fungal pathogen Alternaria alternata f. sp. lycopersici (AAL). Both the ET and JASMONIC ACID INSENSITIVE1 (JAI1) receptor-dependent JA signalling pathways are necessary for susceptibility, while SA response promotes resistance to AAL infection. In addition, the role of JA in susceptibility to AAL is partly dependent on ET biosynthesis and perception, while the SA pathway enhances resistance to AAL and antagonizes the ET response. Based on these results, it is proposed that ET, JA, and SA each on their own can influence the susceptibility of tomato to AAL. Furthermore, the functions of JA and SA in susceptibility to the pathogen are correlated with the enhanced or decreased action of ET, respectively. This study has revealed the functional relationship among the three key hormone pathways in tomato defence against AAL. PMID:23264518

Jia, Chengguo; Zhang, Liping; Wang, Qiaomei

2013-01-01

279

Modifications of Xanthomonas axonopodis pv. citri Lipopolysaccharide Affect the Basal Response and the Virulence Process during Citrus Canker  

PubMed Central

Xanthomonas axonopodis pv. citri (Xac) is the phytopathogen responsible for citrus canker, one of the most devastating citrus diseases in the world. A broad range of pathogens is recognized by plants through so-called pathogen-associated molecular patterns (PAMPs), which are highly conserved fragments of pathogenic molecules. In plant pathogenic bacteria, lipopolisaccharyde (LPS) is considered a virulence factor and it is being recognized as a PAMP. The study of the participation of Xac LPS in citrus canker establishment could help to understand the molecular bases of this disease. In the present work we investigated the role of Xac LPS in bacterial virulence and in basal defense during the interaction with host and non host plants. We analyzed physiological features of Xac mutants in LPS biosynthesis genes (wzt and rfb303) and the effect of these mutations on the interaction with orange and tobacco plants. Xac mutants showed an increased sensitivity to external stresses and differences in bacterial motilities, in vivo and in vitro adhesion and biofilm formation. Changes in the expression levels of the LPS biosynthesis genes were observed in a medium that mimics the plant environment. Xacwzt exhibited reduced virulence in host plants compared to Xac wild-type and Xacrfb303. However, both mutant strains produced a lower increase in the expression levels of host plant defense-related genes respect to the parental strain. In addition, Xac LPS mutants were not able to generate HR during the incompatible interaction with tobacco plants. Our findings indicate that the structural modifications of Xac LPS impinge on other physiological attributes and lead to a reduction in bacterial virulence. On the other hand, Xac LPS has a role in the activation of basal defense in host and non host plants. PMID:22792211

Petrocelli, Silvana; Tondo, María Laura; Daurelio, Lucas D.; Orellano, Elena G.

2012-01-01

280

Efficacy of heat treatment for the thousand cankers disease vector and pathogen in small black walnut logs.  

PubMed

Thousand cankers disease, caused by the walnut twig beetle (Pityophthorus juglandis Blackman) and an associated fungal pathogen (Geosmithia morbida M. Kolarík, E. Freeland, C. Utley, and N. Tisserat), threatens the health and commercial use of eastern black walnut (Juglans nigra L.), one of the most economically valuable tree species in the United States. Effective phytosanitary measures are needed to reduce the possibility of spreading this insect and pathogen through wood movement. This study evaluated the efficacy of heat treatments and debarking to eliminate P. juglandis and C. morbida in J. nigra logs 4-18 cm in diameter and 30 cm in length. Infested logs were steam heated until various outer sapwood temperatures (60, 65, and 70 degrees C in 2011; 36, 42, 48, 52, and 56 degrees C in 2012) were maintained or exceeded for 30-40 min. In 2011, all heat treatments eliminated G. morbida from the bark, but logs were insufficiently colonized by P. juglandis to draw conclusions about treatment effects on the beetle. Debarking did not ensure elimination of the pathogen from the sapwood surface. In 2012, there was a negative effect of increasing temperature on P. juglandis emergence and G. morbida recovery. G. morbida did not survive in logs exposed to treatments in which minimum temperatures were 48 degrees C or higher, and mean P. juglandis emergence decreased steadily to zero as treatment minimum temperature increased from 36 to 52 degrees C. A minimum outer sapwood temperature of 56 degrees C maintained for 40 min is effective for eliminating the thousand cankers disease vector and pathogen from walnut logs, and the current heat treatment schedule for the emerald ash borer (60 degrees C core temperature for 60 min) is more than adequate for treating P. juglandis and G. morbida in walnut firewood. PMID:24665700

Mayfield, A E; Fraedrich, S W; Taylor, A; Merten, P; Myers, S W

2014-02-01

281

Invasive Plants, Species and Conditions Fact Sheets: Cheatgrass Brome, Bamboo Reed, Butternut Canker, Dutch Elm, Chestnut Blight, Asian Cycad Scale, Crazy Ant, Red Fox  

NSDL National Science Digital Library

This resource from ATEEC provides a number of fact sheets on invasive plants, species and conditions which may be printed out or used as presentation material. The plants, species and conditions described here are cheatgrass brome, bamboo reed, butternut canker, dutch elm disease, chestnut blight, Asian cycad scale, crazy ant and red fox. The lesson plan is available for download as a PDF; users must create a free, quick login with ATEEC to access the materials.

282

Quantitative Association of Bark Beetles with Pitch Canker Fungus and Effects of Verbenone on Their Semiochemical Communication in Monterey Pine Forests in Northern Spain  

Microsoft Academic Search

The association between 11 species of bark beetles (Coleoptera: Scolytinae) and one weevil (Coleoptera: Entiminae) with the pitch canker fungus, Fusarium circinatum Nirenberg and OÕDonnell, was determined by crushing beetles on selective medium and histone H3 gene sequencing. Pityophthorus pubescens (Marsham) (25.00%), Hylurgops palliatus (Gyllenhal) (11.96%), Ips sexden- tatus (Borner) (8.57%), Hypothenemus eruditus Westwood (7.89%), Hylastes attenuatus Erichson (7.40%), and

Pedro Romón; Juan Carlos Iturrondobeitia; Ken Gibson; B. Staffan Lindgren; Arturo Goldarazena

2007-01-01

283

First case of disseminated phaeohyphomycosis in an immunocompetent individual due to Alternaria malorum.  

PubMed

A 27-year-old Iranian, previously healthy male presented with sub-cutaneous necrotic lesions with a localized dermatosis affecting the anterior chest, neck and face. These lesions consisted of singular, well-defined verrucous plaques which gradually developed and disseminated over time. The dermatosis was followed by the development of necrotic swollen lesions localized on the hard palate. The patient did not recall any history of trauma or puncture at any of the sites of infection. While histopathological examination of periodic acid-Schiff (PAS) stained material revealed irregular, unbranched, septate hyphae, direct examination (KOH 10%) of lesion samples demonstrated the presence of septate indistinct brownish hyphae. Alternaria malorum was isolated (CBS 126589) and its identity was confirmed by sequencing of the internal transcribed spacer (ITS rDNA). Since the palate lesion reoccurred after 10 years and the patient's condition did not improve with amphotericin B combination therapy, the lesion was surgical excised and he underwent antifungal therapy with amphotericin B and itraconazole. There was no dehiscence or fistula formation or any evidence of relapse of fungal infection during a one year follow-up and the patient was successfully cured. In vitro antifungal susceptibility tests revealed that the MIC values for those antifungals employed in this case were amphotericin B (0.125 ?g/ml), fluconazole (32 ?g/ml), itraconazole (0.125 ?g/ml), voriconazole (1 ?g/ml), and posaconazole (0.063 ?g/ml). The MECs for caspofungin and anidulafungin were 0.25 ?g/ml and 0.016 ?g/ml, respectively. However, treatment of A. malorum infections with the latter agents remains to be evaluated. PMID:22871097

Mirhendi, Hossein; Fatemi, Mohammad Javad; Bateni, Hamid; Hajabdolbaghi, Mahboubeh; Geramishoar, Mohsen; Ahmadi, Bahram; Badali, Hamid

2013-02-01

284

Elevated Atmospheric Carbon Dioxide Concentrations Amplify Alternaria alternata Sporulation and Total Antigen Production  

PubMed Central

Background Although the effect of elevated carbon dioxide (CO2) concentration on pollen production has been established in some plant species, impacts on fungal sporulation and antigen production have not been elucidated. Objective Our purpose was to examine the effects of rising atmospheric CO2 concentrations on the quantity and quality of fungal spores produced on timothy (Phleum pratense) leaves. Methods Timothy plants were grown at four CO2 concentrations (300, 400, 500, and 600 ?mol/mol). Leaves were used as growth substrate for Alternaria alternata and Cladosporium phlei. The spore abundance produced by both fungi, as well as the size (microscopy) and antigenic protein content (ELISA) of A. alternata, were quantified. Results Leaf carbon-to-nitrogen ratio was greater at 500 and 600 ?mol/mol, and leaf biomass was greater at 600 ?mol/mol than at the lower CO2 concentrations. Leaf carbon-to-nitrogen ratio was positively correlated with A. alternata spore production per gram of leaf but negatively correlated with antigenic protein content per spore. At 500 and 600 ?mol/mol CO2 concentrations, A. alternata produced nearly three times the number of spores and more than twice the total antigenic protein per plant than at lower concentrations. C. phlei spore production was positively correlated with leaf carbon-to-nitrogen ratio, but overall spore production was much lower than in A. alternata, and total per-plant production did not vary among CO2 concentrations. Conclusions Elevated CO2 concentrations often increase plant leaf biomass and carbon-to-nitrogen ratio. Here we demonstrate for the first time that these leaf changes are associated with increased spore production by A. alternata, a ubiquitous allergenic fungus. This response may contribute to the increasing prevalence of allergies and asthma. PMID:20462828

Wolf, Julie; O’Neill, Nichole R.; Rogers, Christine A.; Muilenberg, Michael L.; Ziska, Lewis H.

2010-01-01

285

Modulation of Alternaria infectoria Cell Wall Chitin and Glucan Synthesis by Cell Wall Synthase Inhibitors  

PubMed Central

The present work reports the effects of caspofungin, a ?-1,3-glucan synthase inhibitor, and nikkomycin Z, an inhibitor of chitin synthases, on two strains of Alternaria infectoria, a melanized fungus involved in opportunistic human infections and respiratory allergies. One of the strains tested, IMF006, bore phenotypic traits that conferred advantages in resisting antifungal treatment. First, the resting cell wall chitin content was higher and in response to caspofungin, the chitin level remained constant. In the other strain, IMF001, the chitin content increased upon caspofungin treatment to values similar to basal IMF006 levels. Moreover, upon caspofungin treatment, the FKS1 gene was upregulated in IMF006 and downregulated in IMF001. In addition, the resting ?-glucan content was also different in both strains, with higher levels in IMF001 than in IMF006. However, this did not provide any advantage with respect to echinocandin resistance. We identified eight different chitin synthase genes and studied relative gene expression when the fungus was exposed to the antifungals under study. In both strains, exposure to caspofungin and nikkomycin Z led to modulation of the expression of class V and VII chitin synthase genes, suggesting its importance in the robustness of A. infectoria. The pattern of A. infectoria phagocytosis and activation of murine macrophages by spores was not affected by caspofungin. Monotherapy with nikkomycin Z and caspofungin provided only fungistatic inhibition, while a combination of both led to fungal cell lysis, revealing a strong synergistic action between the chitin synthase inhibitor and the ?-glucan synthase inhibitor against this fungus. PMID:24614372

Fernandes, Chantal; Anjos, Jorge; Walker, Louise A.; Silva, Branca M. A.; Cortes, Luísa; Mota, Marta; Munro, Carol A.; Gow, Neil A. R.

2014-01-01

286

Transcription Factor Amr1 Induces Melanin Biosynthesis and Suppresses Virulence in Alternaria brassicicola  

SciTech Connect

Alternaria brassicicola is a successful saprophyte and necrotrophic plant pathogen. Several A. brassicicola genes have been characterized as affecting pathogenesis of Brassica species. To study regulatory mechanisms of pathogenesis, we mined 421 genes in silico encoding putative transcription factors in a machine-annotated, draft genome sequence of A. brassicicola. In this study, targeted gene disruption mutants for 117 of the transcription factor genes were produced and screened. Three of these genes were associated with pathogenesis. Disruption mutants of one gene (AbPacC) were nonpathogenic and another gene (AbVf8) caused lesions less than half the diameter of wild-type lesions. Unexpectedly, mutants of the third gene, Amr1, caused lesions with a two-fold larger diameter than the wild type and complementation mutants. Amr1 is a homolog of Cmr1, a transcription factor that regulates melanin biosynthesis in several fungi. We created gene deletion mutants of ?amr1 and characterized their phenotypes. The ?amr1 mutants used pectin as a carbon source more efficiently than the wild type, were melanin-deficient, and more sensitive to UV light and glucanase digestion. The AMR1 protein was localized in the nuclei of hyphae and in highly melanized conidia during the late stage of plant pathogenesis. RNA-seq analysis revealed that three genes in the melanin biosynthesis pathway, along with the deleted Amr1 gene, were expressed at low levels in the mutants. In contrast, many hydrolytic enzyme-coding genes were expressed at higher levels in the mutants than in the wild type during pathogenesis. The results of this study suggested that a gene important for survival in nature negatively affected virulence, probably by a less efficient use of plant cell-wall materials. We speculate that the functions of the Amr1 gene are important to the success of A. brassicicola as a competitive saprophyte and plant parasite.

Cho, Yangrae; Srivastava, Akhil; Ohm, Robin A.; Lawrence, Christopher B.; Wang, Koon-Hui; Grigoriev, Igor V.; Marahatta, Sharadchandra P.

2012-05-01

287

Scopoletin is a phytoalexin against Alternaria alternata in wild tobacco dependent on jasmonate signalling  

PubMed Central

Alternaria alternata (tobacco pathotype) is a necrotrophic fungus causing severe losses in Nicotiana species by infection of mature leaves. Similar to what has been observed in cultivated tobacco, N. tabacum, young leaves of wild tobacco, N. attenuata, were more resistant to A. alternata than mature leaves, and this was correlated with stronger blue fluorescence induced after infection. However, the nature of the fluorescence-emitting compound, its role in defence, and its regulation were not clear. Silencing feruloyl-CoA 6?-hydroxylase 1 (F6?H1), the gene encoding the key enzyme for scopoletin biosynthesis, by virus-induced gene silencing (VIGS) revealed that the blue fluorescence was mainly emitted by scopoletin and its ?-glycoside form, scopolin. Further analysis showed that scopoletin exhibited strong antifungal activity against A. alternata in vitro and in vivo. Importantly, jasmonic acid (JA) levels were highly elicited in young leaves but much less in mature leaves after infection; and fungus-elicited scopoletin was absent in JA-deficient plants, but was largely restored with methyl jasmonate treatments. Consistent with this, plants strongly impaired in JA biosynthesis and perception were highly susceptible to A. alternata in the same way scopoletin/scopolin-depleted VIGS F6?H1 plants. Furthermore, silencing MYC2, a master regulator of most JA responses, reduced A. alternata-induced NaF6?H1 transcripts and scopoletin. Thus, it is concluded that JA signalling is activated in N. attenuata leaves after infection, which subsequently regulates scopoletin biosynthesis for the defence against A. alternata partly through MYC2, and higher levels of scopoletin accumulated in young leaves account for their strong resistance. PMID:24821958

Sun, Huanhuan; Wang, Lei; Zhang, Baoqin; Ma, Junhong; Hettenhausen, Christian; Cao, Guoyan; Sun, Guiling; Wu, Jianqiang; Wu, Jinsong

2014-01-01

288

Alternaria alternata serine proteases induce lung inflammation and airway epithelial cell activation via PAR2  

PubMed Central

Allergens are diverse proteins from mammals, birds, arthropods, plants, and fungi. Allergens associated with asthma (asthmagens) share a common protease activity that may directly impact respiratory epithelial biology and lead to symptoms of asthma. Alternaria alternata is a strong asthmagen in semiarid regions. We examined the impact of proteases from A. alternata on lung inflammation in vivo and on cleaving protease-activated receptor-2 (PAR2) in vitro. A. alternata filtrate applied to the airway in nonsensitized Balb/c mice induced a protease-dependent lung inflammation. Moreover, A. alternata filtrate applied to human bronchial epithelial cells (16HBE14o-) induced changes in intracellular Ca2+ concentration ([Ca2+]i), consistent with PAR2 activation. These effects were blocked by heat inactivation or by serine protease inhibition of A. alternata filtrates, and mimicked by PAR2 specific ligands SLIGRL-NH2 or 2-furoyl-LIGRLO-NH2, but not the PAR1-specific ligand TFLLR-NH2. Desensitization of PAR2 in 16HBE14o- cells with 2-furoyl-LIGRLO-NH2 or trypsin prevented A. alternata-induced [Ca2+]i changes while desensitization of PAR1, PAR3, and PAR4 with thrombin had no effect on A. alternata-induced Ca2+ responses. Furthermore, the Ca2+ response to A. alternata filtrates was dependent on PAR2 expression in stably transfected HeLa cell models. These data demonstrate that A. alternata proteases act through PAR2 to induce rapid increases in human airway epithelial [Ca2+]i in vitro and cell recruitment in vivo. These responses are likely critical early steps in the development of allergic asthma. PMID:21296894

Flynn, Andrea N.; Sherwood, Cara L.; Schulz, Stephanie M.; Hoffman, Justin; Gruzinova, Irina; Daines, Michael O.

2011-01-01

289

Efficacy of a pyrimidine derivative to control spot disease on Solanum melongena caused by Alternaria alternata.  

PubMed

The pyrimidine derivative (4,6-dimethyl-N-phenyldiethyl pyrimidine, DPDP) was tested as a foliar spray fungicide at 50 mg l(-1) for protection of eggplant (Solanum melongena) from spot disease caused by Alternaria alternata. Varied concentrations of DPDP (10-50 mg l(-1)) differentially inhibited mycelial growth, conidial count and conidial germination of A. alternata growth in vitro; the magnitude of inhibition increased with increasing concentration. In vivo, an experiment was conducted in pots using a complete block randomized design and repeated twice with three replications and four treatments (control, A. alternata alone, DPDP alone and combination of DPDP and A. alternata) for 5 weeks (1 plant in pot × 3 pots per set (3 replications per treatment) × 4 sets (4 treatments) × 5 weeks × 2 experimental repetitions = 120 pots). In this experiment, 10-day-old eggplant seedlings were transplanted in pots and then inoculated with A. alternata, DPDP or their combination 1 week later. Leaves of the A. alternata-infected eggplant suffered from chlorosis, necrosis and brown spots during the subsequent 5 weeks. Disease intensity was obvious in infected leaves but withdrawn by DPDP. There were relationships between incidence and severity, greater in plant leaves infected A. alternata alone and diminished with the presence of DPDP. Moreover, the infection resulted in reductions in growth, decreases in contents of anthocyanins, chlorophylls, carotenoids and thiols as well as inhibitions in activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and glutathione-S-transferase (GST). Nonetheless, the application of DPDP at 50 mg led to a recovery of the infected eggplant; the infection-induced deleterious effects were mostly reversed by DPDP. However, treatment with DPDP alone seemed with no significant impacts. Due to its safe use to host and the inhibition for the pathogen, DPDP could be suggested as an efficient fungicide for protection of eggplant to control A. alternata spot disease. PMID:25685445

Hassan, Nemat M; Abu-Doubara, Mohamed I; Waly, Mohamed A; Nemat Alla, Mamdouh M

2013-07-01

290

Contribution of peroxisomes to secondary metabolism and pathogenicity in the fungal plant pathogen Alternaria alternata.  

PubMed

The filamentous fungus Alternaria alternata includes seven pathogenic variants (pathotypes) which produce different host-selective toxins and cause diseases on different plants. The Japanese pear pathotype produces the host-selective AK-toxin, an epoxy-decatrienoic acid ester, and causes black spot of Japanese pear. Previously, we identified four genes, AKT1, AKT2, AKT3, and AKTR, involved in AK toxin biosynthesis. AKT1, AKT2, and AKT3 encode enzyme proteins with peroxisomal targeting signal type 1 (PTS1)-like tripeptides, SKI, SKL, and PKL, respectively, at the C-terminal ends. In this study, we verified the peroxisome localization of Akt1, Akt2, and Akt3 by using strains expressing N-terminal green fluorescent protein (GFP)-tagged versions of the proteins. To assess the role of peroxisome function in AK-toxin production, we isolated AaPEX6, which encodes a peroxin protein essential for peroxisome biogenesis, from the Japanese pear pathotype and made AaPEX6 disruption-containing transformants from a GFP-Akt1-expressing strain. The DeltaAaPEX6 mutant strains did not grow on fatty acid media because of a defect in fatty acid beta oxidation. The import of GFP-Akt1 into peroxisomes was impaired in the DeltaAaPEX6 mutant strains. These strains completely lost AK toxin production and pathogenicity on susceptible pear leaves. These data show that peroxisomes are essential for AK-toxin biosynthesis. The DeltaAaPEX6 mutant strains showed a marked reduction in the ability to cause lesions on leaves of a resistant pear cultivar with defense responses compromised by heat shock. This result suggests that peroxisome function is also required for plant invasion and tissue colonization in A. alternata. We also observed that mutation of AaPEX6 caused a marked reduction of conidiation. PMID:20348386

Imazaki, Ai; Tanaka, Aiko; Harimoto, Yoshiaki; Yamamoto, Mikihiro; Akimitsu, Kazuya; Park, Pyoyun; Tsuge, Takashi

2010-05-01

291

Modulation of Alternaria infectoria cell wall chitin and glucan synthesis by cell wall synthase inhibitors.  

PubMed

The present work reports the effects of caspofungin, a ?-1,3-glucan synthase inhibitor, and nikkomycin Z, an inhibitor of chitin synthases, on two strains of Alternaria infectoria, a melanized fungus involved in opportunistic human infections and respiratory allergies. One of the strains tested, IMF006, bore phenotypic traits that conferred advantages in resisting antifungal treatment. First, the resting cell wall chitin content was higher and in response to caspofungin, the chitin level remained constant. In the other strain, IMF001, the chitin content increased upon caspofungin treatment to values similar to basal IMF006 levels. Moreover, upon caspofungin treatment, the FKS1 gene was upregulated in IMF006 and downregulated in IMF001. In addition, the resting ?-glucan content was also different in both strains, with higher levels in IMF001 than in IMF006. However, this did not provide any advantage with respect to echinocandin resistance. We identified eight different chitin synthase genes and studied relative gene expression when the fungus was exposed to the antifungals under study. In both strains, exposure to caspofungin and nikkomycin Z led to modulation of the expression of class V and VII chitin synthase genes, suggesting its importance in the robustness of A. infectoria. The pattern of A. infectoria phagocytosis and activation of murine macrophages by spores was not affected by caspofungin. Monotherapy with nikkomycin Z and caspofungin provided only fungistatic inhibition, while a combination of both led to fungal cell lysis, revealing a strong synergistic action between the chitin synthase inhibitor and the ?-glucan synthase inhibitor against this fungus. PMID:24614372

Fernandes, Chantal; Anjos, Jorge; Walker, Louise A; Silva, Branca M A; Cortes, Luísa; Mota, Marta; Munro, Carol A; Gow, Neil A R; Gonçalves, Teresa

2014-05-01

292

Efficacy of a pyrimidine derivative to control spot disease on Solanum melongena caused by Alternaria alternata  

PubMed Central

The pyrimidine derivative (4,6-dimethyl-N-phenyldiethyl pyrimidine, DPDP) was tested as a foliar spray fungicide at 50 mg l?1 for protection of eggplant (Solanum melongena) from spot disease caused by Alternaria alternata. Varied concentrations of DPDP (10–50 mg l?1) differentially inhibited mycelial growth, conidial count and conidial germination of A. alternata growth in vitro; the magnitude of inhibition increased with increasing concentration. In vivo, an experiment was conducted in pots using a complete block randomized design and repeated twice with three replications and four treatments (control, A. alternata alone, DPDP alone and combination of DPDP and A. alternata) for 5 weeks (1 plant in pot × 3 pots per set (3 replications per treatment) × 4 sets (4 treatments) × 5 weeks × 2 experimental repetitions = 120 pots). In this experiment, 10-day-old eggplant seedlings were transplanted in pots and then inoculated with A. alternata, DPDP or their combination 1 week later. Leaves of the A. alternata-infected eggplant suffered from chlorosis, necrosis and brown spots during the subsequent 5 weeks. Disease intensity was obvious in infected leaves but withdrawn by DPDP. There were relationships between incidence and severity, greater in plant leaves infected A. alternata alone and diminished with the presence of DPDP. Moreover, the infection resulted in reductions in growth, decreases in contents of anthocyanins, chlorophylls, carotenoids and thiols as well as inhibitions in activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and glutathione-S-transferase (GST). Nonetheless, the application of DPDP at 50 mg led to a recovery of the infected eggplant; the infection-induced deleterious effects were mostly reversed by DPDP. However, treatment with DPDP alone seemed with no significant impacts. Due to its safe use to host and the inhibition for the pathogen, DPDP could be suggested as an efficient fungicide for protection of eggplant to control A. alternata spot disease. PMID:25685445

Hassan, Nemat M.; Abu-Doubara, Mohamed I.; Waly, Mohamed A.; Nemat Alla, Mamdouh M.

2012-01-01

293

Transcription Factor Amr1 Induces Melanin Biosynthesis and Suppresses Virulence in Alternaria brassicicola  

PubMed Central

Alternaria brassicicola is a successful saprophyte and necrotrophic plant pathogen. Several A. brassicicola genes have been characterized as affecting pathogenesis of Brassica species. To study regulatory mechanisms of pathogenesis, we mined 421 genes in silico encoding putative transcription factors in a machine-annotated, draft genome sequence of A. brassicicola. In this study, targeted gene disruption mutants for 117 of the transcription factor genes were produced and screened. Three of these genes were associated with pathogenesis. Disruption mutants of one gene (AbPacC) were nonpathogenic and another gene (AbVf8) caused lesions less than half the diameter of wild-type lesions. Unexpectedly, mutants of the third gene, Amr1, caused lesions with a two-fold larger diameter than the wild type and complementation mutants. Amr1 is a homolog of Cmr1, a transcription factor that regulates melanin biosynthesis in several fungi. We created gene deletion mutants of ?amr1 and characterized their phenotypes. The ?amr1 mutants used pectin as a carbon source more efficiently than the wild type, were melanin-deficient, and more sensitive to UV light and glucanase digestion. The AMR1 protein was localized in the nuclei of hyphae and in highly melanized conidia during the late stage of plant pathogenesis. RNA-seq analysis revealed that three genes in the melanin biosynthesis pathway, along with the deleted Amr1 gene, were expressed at low levels in the mutants. In contrast, many hydrolytic enzyme-coding genes were expressed at higher levels in the mutants than in the wild type during pathogenesis. The results of this study suggested that a gene important for survival in nature negatively affected virulence, probably by a less efficient use of plant cell-wall materials. We speculate that the functions of the Amr1 gene are important to the success of A. brassicicola as a competitive saprophyte and plant parasite. PMID:23133370

Cho, Yangrae; Srivastava, Akhil; Ohm, Robin A.; Lawrence, Christopher B.; Wang, Koon-Hui; Grigoriev, Igor V.; Marahatta, Sharadchandra P.

2012-01-01

294

Contrasting Codon Usage Patterns and Purifying Selection at the Mating Locus in Putatively Asexual Alternaria Fungal Species  

PubMed Central

Sexual reproduction in heterothallic ascomycete fungi is controlled by a single mating-type locus called MAT1 with two alternate alleles or idiomorphs, MAT1-1 and MAT1-2. These alleles lack sequence similarity and encode different transcriptional regulators. A large number of phytopathogenic fungi including Alternaria spp. are considered asexual, yet still carry expressed MAT1 genes. The molecular evolution of Alternaria MAT1 was explored using nucleotide diversity, nonsynonymous vs. synonymous substitution (dn/ds) ratios and codon usage statistics. Likelihood ratio tests of site-branch models failed to detect positive selection on MAT1-1-1 or MAT1-2-1. Codon-site models demonstrated that both MAT1-1-1 and MAT1-2-1 are under purifying selection and significant differences in codon usage were observed between MAT1-1-1 and MAT1-2-1. Mean GC content at the third position (GC3) and effective codon usage (ENC) were significantly different between MAT1-1-1 and MAT1-2-1 with values of 0.57 and 48 for MAT1-1-1 and 0.62 and 46 for MAT1-2-1, respectively. In contrast, codon usage of Pleospora spp. (anamorph Stemphylium), a closely related Dothideomycete genus, was not significantly different between MAT1-1-1 and MAT1-2-1. The purifying selection and biased codon usage detected at the MAT1 locus in Alternaria spp. suggest a recent sexual past, cryptic sexual present and/or that MAT1 plays important cellular role(s) in addition to mating. PMID:21625561

Stewart, Jane E.; Kawabe, Masato; Abdo, Zaid; Arie, Tsutomu; Peever, Tobin L.

2011-01-01

295

Environmental Factors Affecting Production, Release, and Field Populations of Conidia of Alternaria alternata, the Cause of Brown Spot of Citrus.  

PubMed

ABSTRACT Alternaria brown spot, caused by Alternaria alternata pv. citri, affects many tangerines and their hybrids, causing loss of immature leaves and fruit and reducing the marketability of the remaining fruit. Conidial production of A. alternata was greatest on mature leaves moistened and maintained at near 100% relative humidity (RH) for 24 h, whereas leaves that had been soaked or maintained at moderate RH produced few conidia. Conidial release from filter paper cultures and infected leaves was studied in a computer-controlled environmental chamber. Release of large numbers of conidia was triggered from both substrates by sudden drops in RH or by simulated rainfall events. Vibration induced release of low numbers of conidia, but red/infrared irradiation had no effect. In field studies from 1994 to 1996, air sampling with a 7-day recording volumetric spore trap indicated that conidia were present throughout the year with periodic large peaks. The number of conidia captured was not closely related to rainfall amounts or average wind speed, but was weakly related to the duration of leaf wetness. Likewise, disease severity on trap plants placed in the field weekly during 1995 to 1996 was not closely related to conidial numbers or rainfall amounts, but was weakly related to leaf wetness duration. Sufficient inoculum appears to be available to allow infection to occur throughout the year whenever susceptible host tissue and moisture are available. PMID:18944857

Timmer, L W; Solel, Z; Gottwald, T R; Ibañez, A M; Zitko, S E

1998-11-01

296

Involvement of an extracellular fungus laccase in the flavonoid metabolism in Citrus fruits inoculated with Alternaria alternata.  

PubMed

Fungi of the genus Alternaria are responsible for substantial pre-harvest losses in Citrus. In this study a degradative metabolism of flavonoids (flavanones, flavones and polymethoxyflavones) was observed when 'Fortune' mandarin, Citrus limon and Citrus paradisi, fruits were inoculated with Alternaria alternata, a pre-harvest pathogenic fungus. Associated to this flavonic metabolism the de novo synthesis of the phytoalexin scoparone was detected. This metabolism of flavonoids is caused by an extracellular fungus laccase. The kinetic characterisation of this enzyme revealed that the activity was induced by Citrus flavonoids and was dependent on flavonoid concentrations. The enzyme exhibited a Km of 1.9 mM using ABTS as substrate with an optimum pH of 3.5 in citrate buffer 100 mM. The enzyme is active between 15 and 45 °C, the optimum temperature being around 35 °C, although 50% of the initial activity is lost after 45 min at 35 °C. The A. alternata laccase was inhibited by 0.5 mM l-cysteine and by caffeic acid. Study of the substrate specificity of this enzyme revealed that Citrus flavonoids are substrates of A. alternata laccase. These results suggest that the laccase enzyme could be involved in the pathogenesis of A. alternata in Citrus. PMID:25686700

Díaz, Licinio; Del Río, José Antonio; Pérez-Gilabert, Manuela; Ortuño, Ana

2015-04-01

297

The major allergen of Alternaria alternata (Alt a 1) is expressed in other members of the Pleosporaceae family.  

PubMed

There is general consensus regarding the scarce cross-reactivity existing between Alternaria alternata and other allergenic moulds such as Aspergillus fumigatus, Penicillium notatum or Cladosporium herbarum. However, A. alternata has been shown to have a very significant level of allergenic cross-reactivity with other fungi belonging to the Pleosporaceae family. To date, no biological identity or homologies with other proteins have been described for Alt a 1, and it remains unclear whether the major allergen Alt a 1 contributes to the cross-reactivity shown for these moulds. Specific quantification of Alt a 1 in culture filtrates of Stemphylium botryosum, Ulocladium botrytis, Curvularia lunata, Alternaria tenuissima, C. herbarum, Penicillium chrysogenum and Asp. fumigatus, and immunoblotting using culture filtrate extracts from the above-mentioned moulds and rabbit serum anti-recombinant Alt a 1 have shown significant amounts of Alt a 1 in culture filtrates as well as antigenic components ranging from 14 to 20 kDa that strongly react with the specific serum for all taxonomically related species (Pleosporaceae family). No reactions were revealed in culture filtrates of Cladosporium, Penicillium and Aspergillus. These results restrict the cross-reactivity phenomenon due to Alt a 1 to the scope of the taxonomical term of family. PMID:16466440

Sáenz-de-Santamaría, M; Postigo, I; Gutierrez-Rodríguez, A; Cardona, G; Guisantes, J A; Asturias, J; Martínez, J

2006-03-01

298

Stem cells, cancer, and cancer stem cells  

Microsoft Academic Search

Stem cell biology has come of age. Unequivocal proof that stem cells exist in the haematopoietic system has given way to the prospective isolation of several tissue-specific stem and progenitor cells, the initial delineation of their properties and expressed genetic programmes, and the beginnings of their utility in regenerative medicine. Perhaps the most important and useful property of stem cells

Tannishtha Reya; Sean J. Morrison; Michael F. Clarke; Irving L. Weissman

2001-01-01

299

Genetic differentiation and spatial structure of Geosmithia morbida, the causal agent of thousand cankers disease in black walnut (Juglans nigra).  

PubMed

The main objectives of this study were to evaluate genetic composition of Geosmithia morbida populations in the native range of black walnut and provide a better understanding regarding demography of the pathogen. The fungus G. morbida, and the walnut twig beetle, Pityophthorus juglandis, have been associated with a disease complex of black walnut (Juglans nigra) known as thousand cankers disease (TCD). The disease is manifested as branch dieback and canopy loss, eventually resulting in tree death. In 2010, the disease was detected in black walnut in Tennessee, and subsequently in Virginia and Pennsylvania in 2011 and North Carolina in 2012. These were the first incidences of TCD east of Colorado, where the disease has been established for more than a decade on indigenous walnut species. A genetic diversity and population structure study of 62 G. morbida isolates from Tennessee, Pennsylvania, North Carolina and Oregon was completed using 15 polymorphic microsatellite loci. The results revealed high haploid genetic diversity among seven G. morbida populations with evidence of gene flow, and significant differentiation among two identified genetic clusters. There was a significant correlation between geographic and genetic distance. Understanding the genetic composition and demography of G. morbida can provide valuable insight into recognizing factors affecting the persistence and spread of an invasive pathogen, disease progression, and future infestation predictions. Overall, these data support the hypotheses of two separate, highly diverse pathogen introductions into the native range of black walnut. PMID:24177436

Hadziabdic, Denita; Vito, Lisa M; Windham, Mark T; Pscheidt, Jay W; Trigiano, Robert N; Kolarik, Miroslav

2014-05-01

300

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

PubMed

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. PMID:22713076

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

2012-09-01

301

Identification of QTLs for early blight ( Alternaria solani ) resistance in tomato using backcross populations of a Lycopersicon esculentum × L. hirsutum cross  

Microsoft Academic Search

Most commercial cultivars of tomato, Lycopersicon esculentum Mill., are susceptible to early blight (EB), a devastating fungal (Alternaria solani Sorauer) disease of tomato in the northern and eastern parts of the U.S. and elsewhere in the world. The disease causes plant defoliation, which reduces yield and fruit quality, and contributes to significant crop loss. Sources of resistance have been identified

M. R. Foolad; L. Zhang; A. A. Khan; D. Niño-Liu; G. Lin

2002-01-01

302

SHARED ITS DNA SUBSTITUTIONS IN ISOLATES OF OPPOSITE MATING TYPE REVEAL A RECOMBIING HISTORY FOR THREE PRESUMED ASEXUAL SPECIES IN THE FILAMENTOUS ASCOMYCETE GENUS ALTERNARIA  

Technology Transfer Automated Retrieval System (TEKTRAN)

About 15,000 species of ascomycete fungi lack a known sexual state. For fungi with asexual states in the form genera Embellisia, Ulocladium and Alternaria, six species have known sexual states but more than 50 species do not. In sexual filamentous ascomycetes, opposite mating type information at t...

303

Expression of ß-1,3-glucanase and ß-1,4-glucanase in two potato cultivars following challenge by the fungal pathogen Alternaria solani  

Technology Transfer Automated Retrieval System (TEKTRAN)

Early blight of potato, caused by Alternaria solani, is a ubiquitous disease in many countries around the world. We have previously found that variation in resistance phenotypes exist between two different Iranian cultivars of potato. Cultivar ‘Diamond’ is more resistant to multiple isolates of A. s...

304

Alternaria toxin-induced resistance against rose aphids and olfactory response of aphids to toxin-induced volatiles of rose plants*  

PubMed Central

The search for active toxins for managing weeds or plant diseases is believed to be a promising avenue of investigation. However, the effects of Alternaria toxins on insects have just begun to be investigated. Bioactivities of toxins from four strains of Alternaria alternata on Rosa chinensis and rose aphid Macrosiphum rosivorum were tested in the present study. At a concentration of 50.0 ?g/ml, the crude extract (toxin) of strain 7484 was found not to be harmful to rose plants with excised leaf-puncture method (P?0.079), and rose plants showed enhanced resistance to rose aphids when this Alternaria toxin was sprayed on the plants (P?0.001). However, this toxin caused no detrimental effects on aphids in insecticidal bioassay at a concentration of 10.0 to 160.0 ?g/ml (P?0.096). Therefore, the Alternaria toxin had significantly induced the resistance of rose plants against rose aphids, demonstrating that the resistance mechanism triggered by the Alternaria toxin in the rose plant may also be used by the plant to defend itself against insects. Further bioassays aimed to discover the olfactory responses of aphids to the toxin-induced volatiles of host plants. The aphids were significantly more attracted to both volatiles emitted and collected from control rose plants than to both volatiles emitted and collected from the toxin-treated rose plants (P?0.014). This result showed that the toxin-induced resistance related to the volatile changes of host plants. PMID:22302426

Yang, Fa-zhong; Li, Li; Yang, Bin

2012-01-01

305

Diamine and polyamine levels in cotton (Gossypium sp.), under stresses by potassium and Alternaria macrospora Zimm.  

E-print Network

is higher than in the resistant cultivar. Putrescine titer is closely associated with potassium deficiency and with the development of leaf chlorosis and necrosis. The increased titer of putrescine caused by a potassium deficency decreases...). Distribution of putrescine in barley leaves parallels the activity of ADC. Thus, the first leaf has lower ADC activity (120 picokatals/g FW), than fully expanded leaves in the lower half of the stem (338 picokatals/g FW). The activity of ADC declines...

Bolanos Vasquez, Jose Isnain

1989-01-01

306

Capsaicin production by Alternaria alternata, an endophytic fungus from Capsicum annum; LC-ESI-MS/MS analysis.  

PubMed

Alternaria alternata, an endophytic fungus capable of producing capsaicin (1) was isolated from Capsicum annum. The endophyte was found to produce capsaicin upto three generations. Upscaling of the fermentation broth led to the isolation of one known and one compound characterized as 2,4-di-tert-butyl phenol (2) and alternariol-10-methyl ether (3) respectively. Compound 1 and 3 were identified and quantified using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) system through multiple reaction monitoring (MRM). Furthermore, compound 3 displayed a range of cytotoxicity against a panel of human cancer cell lines and was found to induce apoptosis evidenced by Hoechst staining and loss of mitochondrial-membrane potential in HL-60 cells. PMID:24378219

Devari, Shekaraiah; Jaglan, Sundeep; Kumar, Manjeet; Deshidi, Ramesh; Guru, Santosh; Bhushan, Shashi; Kushwaha, Manoj; Gupta, Ajai P; Gandhi, Sumit G; Sharma, Jai P; Taneja, Subhash C; Vishwakarma, Ram A; Shah, Bhahwal Ali

2014-02-01

307

Alterporriol-Type Dimers from the Mangrove Endophytic Fungus, Alternaria sp. (SK11), and Their MptpB Inhibitions  

PubMed Central

A new alterporriol-type anthranoid dimer, alterporriol S (1), along with seven known anthraquinone derivatives, (+)-aS-alterporriol C (2), hydroxybostrycin (3), halorosellinia A (4), tetrahydrobostrycin (5), 9?-hydroxydihydrodesoxybostrycin (6), austrocortinin (7) and 6-methylquinizarin (8), were isolated from the culture broth of the mangrove fungus, Alternaria sp. (SK11), from the South China Sea. Their structures and the relative configurations were elucidated using comprehensive spectroscopic methods, including 1D and 2D NMR spectra. The absolute configurations of 1 and the axial configuration of 2 were defined by experimental and theoretical ECD spectroscopy. 1 was identified as the first member of alterporriols consisting of a unique C-10?C-2? linkage. Atropisomer 2 exhibited strong inhibitory activity against Mycobacterium tuberculosis protein tyrosine phosphatase B (MptpB) with an IC50 value 8.70 ?M. PMID:24840716

Xia, Guoping; Li, Jia; Li, Hanxiang; Long, Yuhua; Lin, Shao’e; Lu, Yongjun; He, Lei; Lin, Yongcheng; Liu, Lan; She, Zhigang

2014-01-01

308

Stem Cell Transplants  

MedlinePLUS

What Are Stem Cells? As you probably remember from biology class, every living thing is made up of cells — including the human ... cells can become new cells like this. Blood Stem Cells When you hear about stem cell transplants, they ...

309

Dual Roles of Reactive Oxygen Species and NADPH Oxidase RBOHD in an Arabidopsis-Alternaria Pathosystem1[W  

PubMed Central

Arabidopsis (Arabidopsis thaliana) NADPH oxidases have been reported to suppress the spread of pathogen- and salicylic acid-induced cell death. Here, we present dual roles of RBOHD (for respiratory burst oxidase homolog D) in an Arabidopsis-Alternaria pathosystem, suggesting either initiation or prevention of cell death dependent on the distance from pathogen attack. Our data demonstrate that a rbohD knockout mutant exhibits increased spread of cell death at the macroscopic level upon inoculation with the fungus Alternaria brassicicola. However, the cellular patterns of reactive oxygen species accumulation and cell death are fundamentally different in the AtrbohD mutant compared with the wild type. Functional RBOHD causes marked extracellular hydrogen peroxide accumulation as well as cell death in distinct, single cells of A. brassicicola-infected wild-type plants. This single cell response is missing in the AtrbohD mutant, where infection triggers spreading-type necrosis preceded by less distinct chloroplastic hydrogen peroxide accumulation in large clusters of cells. While the salicylic acid analog benzothiadiazole induces the action of RBOHD and the development of cell death in infected tissues, the ethylene inhibitor aminoethoxyvinylglycine inhibits cell death, indicating that both salicylic acid and ethylene positively regulate RBOHD and cell death. Moreover, A. brassicicola-infected AtrbohD plants hyperaccumulate ethylene and free salicylic acid compared with the wild type, suggesting negative feedback regulation of salicylic acid and ethylene by RBOHD. We propose that functional RBOHD triggers death in cells that are damaged by fungal infection but simultaneously inhibits death in neighboring cells through the suppression of free salicylic acid and ethylene levels. PMID:19726575

Pogány, Miklós; von Rad, Uta; Grün, Sebastian; Dongó, Anita; Pintye, Alexandra; Simoneau, Philippe; Bahnweg, Günther; Kiss, Levente; Barna, Balázs; Durner, Jörg

2009-01-01

310

Partial Resistance of Carrot to Alternaria dauci Correlates with In Vitro Cultured Carrot Cell Resistance to Fungal Exudates  

PubMed Central

Although different mechanisms have been proposed in the recent years, plant pathogen partial resistance is still poorly understood. Components of the chemical warfare, including the production of plant defense compounds and plant resistance to pathogen-produced toxins, are likely to play a role. Toxins are indeed recognized as important determinants of pathogenicity in necrotrophic fungi. Partial resistance based on quantitative resistance loci and linked to a pathogen-produced toxin has never been fully described. We tested this hypothesis using the Alternaria dauci – carrot pathosystem. Alternaria dauci, causing carrot leaf blight, is a necrotrophic fungus known to produce zinniol, a compound described as a non-host selective toxin. Embryogenic cellular cultures from carrot genotypes varying in resistance against A. dauci were confronted with zinniol at different concentrations or to fungal exudates (raw, organic or aqueous extracts). The plant response was analyzed through the measurement of cytoplasmic esterase activity, as a marker of cell viability, and the differentiation of somatic embryos in cellular cultures. A differential response to toxicity was demonstrated between susceptible and partially resistant genotypes, with a good correlation noted between the resistance to the fungus at the whole plant level and resistance at the cellular level to fungal exudates from raw and organic extracts. No toxic reaction of embryogenic cultures was observed after treatment with the aqueous extract or zinniol used at physiological concentration. Moreover, we did not detect zinniol in toxic fungal extracts by UHPLC analysis. These results suggest that strong phytotoxic compounds are present in the organic extract and remain to be characterized. Our results clearly show that carrot tolerance to A. dauci toxins is one component of its partial resistance. PMID:24983469

Voisine, Linda; Gatto, Julia; Hélesbeux, Jean-Jacques; Séraphin, Denis; Peña-Rodriguez, Luis M.; Richomme, Pascal; Boedo, Cora; Yovanopoulos, Claire; Gyomlai, Melvina; Briard, Mathilde; Simoneau, Philippe; Poupard, Pascal; Berruyer, Romain

2014-01-01

311

Phylogeography of the Walnut Twig Beetle, Pityophthorus juglandis, the Vector of Thousand Cankers Disease in North American Walnut Trees  

PubMed Central

Thousand cankers disease (TCD) of walnut trees (Juglans spp.) results from aggressive feeding in the phloem by the walnut twig beetle (WTB), Pityophthorus juglandis, accompanied by inoculation of its galleries with a pathogenic fungus, Geosmithia morbida. In 1960, WTB was only known from four U.S. counties (in Arizona, California, and New Mexico), but the species has now (2014) invaded over 115 counties, representing much of the western USA, and at least six states in the eastern USA. The eastern expansion places TCD in direct proximity to highly valuable (> $500 billion) native timber stands of eastern black walnut, Juglans nigra. Using mitochondrial DNA sequences, from nearly 1100 individuals, we examined variation among 77 samples of WTB populations across its extended range in the USA, revealing high levels of polymorphism and evidence of two divergent lineages. The highest level of genetic diversity for the different lineages was found in the neighboring Madrean Sky Island and Western New Mexico regions, respectively. Despite their proximity, there was little evidence of mixing between these regions, with only a single migrant detected among 179 beetles tested. Indeed, geographic overlap of the two lineages was only common in parts of Colorado and Utah. Just two haplotypes, from the same lineage, predominated over the vast majority of the recently expanded range. Tests for Wolbachia proved negative suggesting it plays no role in "driving" the spread of particular haplotypes, or in maintaining deep levels of intraspecific divergence in WTB. Genotyping of ribosomal RNA corroborated the mitochondrial lineages, but also revealed evidence of hybridization between them. Hybridization was particularly prevalent in the sympatric areas, also apparent in all invaded areas, but absent from the most haplotype-rich area of each mitochondrial lineage. Hypotheses about the specific status of WTB, its recent expansion, and potential evolutionary origins of TCD are discussed. PMID:25695760

Rugman-Jones, Paul F.; Seybold, Steven J.; Graves, Andrew D.; Stouthamer, Richard

2015-01-01

312

Population Structure of Geosmithia morbida, the Causal Agent of Thousand Cankers Disease of Walnut Trees in the United States  

PubMed Central

The ascomycete Geosmithia morbida and the walnut twig beetle Pityophthorus juglandis are associated with thousand cankers disease of Juglans (walnut) and Pterocarya (wingnut). The disease was first reported in the western United States (USA) on several Juglans species, but has been found more recently in the eastern USA in the native range of the highly susceptible Juglans nigra. We performed a comprehensive population genetic study of 209 G. morbida isolates collected from Juglans and Pterocarya from 17 geographic regions distributed across 12 U.S. states. The study was based on sequence typing of 27 single nucleotide polymorphisms from three genomic regions and genotyping with ten microsatellite primer pairs. Using multilocus sequence-typing data, 197 G. morbida isolates were placed into one of 57 haplotypes. In some instances, multiple haplotypes were recovered from isolates collected on the same tree. Twenty-four of the haplotypes (42%) were recovered from more than one isolate; the two most frequently occurring haplotypes (H02 and H03) represented 36% of all isolates. These two haplotypes were abundant in California, but were not recovered from Arizona or New Mexico. G. morbida population structure was best explained by four genetically distinct groups that clustered into three geographic regions. Most of the haplotypes isolated from the native range of J. major (Arizona and New Mexico) were found in those states only or present in distinct genetic clusters. There was no evidence of sexual reproduction or genetic recombination in any population. The scattered distribution of the genetic clusters indicated that G. morbida was likely disseminated to different regions at several times and from several sources. The large number of haplotypes observed and the genetic complexity of G. morbida indicate that it evolved in association with at least one Juglans spp. and the walnut twig beetle long before the first reports of the disease. PMID:25393300

Graves, Andrew D.; Hartel, Colleen; Pscheidt, Jay W.; Tonos, Jadelys; Broders, Kirk; Cranshaw, Whitney; Seybold, Steven J.; Tisserat, Ned

2014-01-01

313

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

PubMed Central

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

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

2012-01-01

314

Population structure of Geosmithia morbida, the causal agent of thousand cankers disease of walnut trees in the United States.  

PubMed

The ascomycete Geosmithia morbida and the walnut twig beetle Pityophthorus juglandis are associated with thousand cankers disease of Juglans (walnut) and Pterocarya (wingnut). The disease was first reported in the western United States (USA) on several Juglans species, but has been found more recently in the eastern USA in the native range of the highly susceptible Juglans nigra. We performed a comprehensive population genetic study of 209 G. morbida isolates collected from Juglans and Pterocarya from 17 geographic regions distributed across 12 U.S. states. The study was based on sequence typing of 27 single nucleotide polymorphisms from three genomic regions and genotyping with ten microsatellite primer pairs. Using multilocus sequence-typing data, 197 G. morbida isolates were placed into one of 57 haplotypes. In some instances, multiple haplotypes were recovered from isolates collected on the same tree. Twenty-four of the haplotypes (42%) were recovered from more than one isolate; the two most frequently occurring haplotypes (H02 and H03) represented 36% of all isolates. These two haplotypes were abundant in California, but were not recovered from Arizona or New Mexico. G. morbida population structure was best explained by four genetically distinct groups that clustered into three geographic regions. Most of the haplotypes isolated from the native range of J. major (Arizona and New Mexico) were found in those states only or present in distinct genetic clusters. There was no evidence of sexual reproduction or genetic recombination in any population. The scattered distribution of the genetic clusters indicated that G. morbida was likely disseminated to different regions at several times and from several sources. The large number of haplotypes observed and the genetic complexity of G. morbida indicate that it evolved in association with at least one Juglans spp. and the walnut twig beetle long before the first reports of the disease. PMID:25393300

Zerillo, Marcelo M; Ibarra Caballero, Jorge; Woeste, Keith; Graves, Andrew D; Hartel, Colleen; Pscheidt, Jay W; Tonos, Jadelys; Broders, Kirk; Cranshaw, Whitney; Seybold, Steven J; Tisserat, Ned

2014-01-01

315

Phylogeography of the Walnut Twig Beetle, Pityophthorus juglandis, the Vector of Thousand Cankers Disease in North American Walnut Trees.  

PubMed

Thousand cankers disease (TCD) of walnut trees (Juglans spp.) results from aggressive feeding in the phloem by the walnut twig beetle (WTB), Pityophthorus juglandis, accompanied by inoculation of its galleries with a pathogenic fungus, Geosmithia morbida. In 1960, WTB was only known from four U.S. counties (in Arizona, California, and New Mexico), but the species has now (2014) invaded over 115 counties, representing much of the western USA, and at least six states in the eastern USA. The eastern expansion places TCD in direct proximity to highly valuable (> $500 billion) native timber stands of eastern black walnut, Juglans nigra. Using mitochondrial DNA sequences, from nearly 1100 individuals, we examined variation among 77 samples of WTB populations across its extended range in the USA, revealing high levels of polymorphism and evidence of two divergent lineages. The highest level of genetic diversity for the different lineages was found in the neighboring Madrean Sky Island and Western New Mexico regions, respectively. Despite their proximity, there was little evidence of mixing between these regions, with only a single migrant detected among 179 beetles tested. Indeed, geographic overlap of the two lineages was only common in parts of Colorado and Utah. Just two haplotypes, from the same lineage, predominated over the vast majority of the recently expanded range. Tests for Wolbachia proved negative suggesting it plays no role in "driving" the spread of particular haplotypes, or in maintaining deep levels of intraspecific divergence in WTB. Genotyping of ribosomal RNA corroborated the mitochondrial lineages, but also revealed evidence of hybridization between them. Hybridization was particularly prevalent in the sympatric areas, also apparent in all invaded areas, but absent from the most haplotype-rich area of each mitochondrial lineage. Hypotheses about the specific status of WTB, its recent expansion, and potential evolutionary origins of TCD are discussed. PMID:25695760

Rugman-Jones, Paul F; Seybold, Steven J; Graves, Andrew D; Stouthamer, Richard

2015-01-01

316

Stem Up  

NSDL National Science Digital Library

Stem Up is a pilot program to aid the disadvantaged youth of Boyle Heights in Los Angeles. The intent of the program was to integrate STEM career pathways into schools and local communities. Visitors will find the K-12 Students tab near the top of the page to be filled with almost two dozen links for all levels of student learning about science and technology. Some of the sites include "Arrick Robotics", for 9-12 graders, "Extreme Science", for all ages, and "Fun Engineering" for kids aged 10-14. The "Boyle Heights" link is a great resource for residents of the LA neighborhood, as well as informative for those visitors unfamiliar with it. There is full contact information for the city and state representatives of the neighborhood, the Police Activities League, and a live theatre that performs outreach through theatre, and classical plays. The "Parents" link also provides a number of science and technology links that parents and kids can visit together.

317

Rotatable stem and lock  

DOEpatents

A valve stem and lock include a housing surrounding a valve stem, a solenoid affixed to an interior wall of the housing, an armature affixed to the valve stem and a locking device for coupling the armature to the housing body. When the solenoid is energized, the solenoid moves away from the housing body, permitting rotation of the valve stem.

Deveney, Joseph E. (Albuquerque, NM); Sanderson, Stephen N. (Albuquerque, NM)

1984-01-01

318

Rotatable stem and lock  

DOEpatents

A valve stem and lock is disclosed which includes a housing surrounding a valve stem, a solenoid affixed to an interior wall of the housing, an armature affixed to the valve stem and a locking device for coupling the armature to the housing body. When the solenoid is energized, the solenoid moves away from the housing body, permitting rotation of the valve stem.

Deveney, J.E.; Sanderson, S.N.

1981-10-27

319

Cell Stem Cell Perspective  

E-print Network

Cell Stem Cell Perspective Genetic and Epigenetic Variations in iPSCs: Potential Causes Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA 5Harvard Stem Cell Institute, WAB-149G, 200.1016/j.stem.2013.07.001 The ability to reprogram somatic cells to induced pluripotent stem cells (i

Zhang, Yi

320

Cell Stem Cell Perspective  

E-print Network

Cell Stem Cell Perspective Identifying the Stem Cell of the Intestinal Crypt: Strategies.clevers@hubrecht.eu http://dx.doi.org/10.1016/j.stem.2012.09.009 Decades ago, two nonoverlapping crypt stem cell populations were proposed: Leblond's Crypt Base Columnar (CBC) cell and Potten's +4 cell. The identification

van Oudenaarden, Alexander

321

Stem cells in urology  

Microsoft Academic Search

The shortage of donors for organ transplantation has stimulated research on stem cells as a potential resource for cell-based therapy in all human tissues. Stem cells have been used for regenerative medicine applications in many organ systems, including the genitourinary system. The potential applications for stem cell therapy have, however, been restricted by the ethical issues associated with embryonic stem

Tamer Aboushwareb; Anthony Atala

2008-01-01

322

Stem Cell 101 What is a stem cell?  

E-print Network

Stem Cell 101 What is a stem cell? A stem cell is a parent cell in the body that has two specific into all types of tissue in the body ­ this is called differentiation. Where are stem cells found? There are two types of stem cells: embryonic stem cells, found in embryos, and adult stem cells, which can

Minnesota, University of

323

An Isolate of Alternaria alternata That Is Pathogenic to Both Tangerines and Rough Lemon and Produces Two Host-Selective Toxins, ACT- and ACR-Toxins.  

PubMed

ABSTRACT Two different pathotypes of Alternaria alternata cause Alternaria brown spot of tangerines and Alternaria leaf spot of rough lemon. The former produces the host-selective ACT-toxin and the latter produces ACR-toxin. Both pathogens induce similar symptoms on leaves or young fruits of their respective hosts, but the host ranges of these pathogens are distinct and one pathogen can be easily distinguished from another by comparing host ranges. We isolated strain BC3-5-1-OS2A from a leaf spot on rough lemon in Florida, and this isolate is pathogenic on both cv. Iyokan tangor and rough lemon and also produces both ACT-toxin and ACR-toxin. Isolate BC3-5-1-OS2A carries both genomic regions, one of which was known only to be present in ACT-toxin producers and the other was known to exist only in ACR-toxin producers. Each of the genomic regions is present on distinct small chromosomes, one of 1.05 Mb and the other of 2.0 Mb. Alternaria species have no known sexual or parasexual cycle in nature and populations of A. alternata on citrus are clonal. Therefore, the ability to produce both toxins was not likely acquired through meiotic or mitotic recombination. We hypothesize that a dispensable chromosome carrying the gene cluster controlling biosynthesis of one of the host-selective toxins was transferred horizontally and rearranged by duplication or translocation in another isolate of the fungus carrying genes for biosynthesis of the other host-selective toxin. PMID:18943116

Masunaka, A; Ohtani, K; Peever, T L; Timmer, L W; Tsuge, T; Yamamoto, M; Yamamoto, H; Akimitsu, K

2005-03-01

324

Inheritance of resistance to blackmold ( Alternaria alternata (Fr.) Keissler) in two interspecific crosses of tomato ( Lycopersicon esculentum × L. cheesmanii f. typicum )  

Microsoft Academic Search

Inheritance of resistance to blackmold, a disease of ripe tomato fruit caused byAlternaria alternata, was studied in two interspecific crosses. The parents, F1 and F2 generations of a cross between the susceptibleLycopersicon esculentum Mill. cultivar ‘Hunt 100’ and the resistantL. Cheesmanii f.typicum Riley accession LA 422, and the parents, F1, F2, F3, and BC1 P2 generations of a cross between

T. Cassol; D. A. St. Clair

1994-01-01

325

Stable integration and expression of wasabi defensin gene in “Egusi” melon ( Colocynthis citrullus L.) confers resistance to Fusarium wilt and Alternaria leaf spot  

Microsoft Academic Search

Production of “Egusi” melon (Colocynthis citrullus L.) in West Africa is limited by fungal diseases, such as Alternaria leaf spot and Fusarium wilt. In order to engineer “Egusi”\\u000a resistant to these diseases, cotyledonary explants of two “Egusi” genotypes, ‘Ejagham’ and NHC1-130, were transformed with\\u000a Agrobacterium tumefaciens strain EHA101 harbouring wasabi defensin gene (isolated from Wasabia japonica L.) in a binary

Valentine Otang Ntui; Gunaratnam Thirukkumaran; Pejman Azadi; Raham Sher Khan; Ikuo Nakamura; Masahiro Mii

2010-01-01

326

Effects of Alternaria triticina and foliar fly ash deposition on growth, yield, photosynthetic pigments, protein and lysine contents of three cultivars of wheat  

Microsoft Academic Search

A greenhouse experiment was conducted to study the effects of Alternaria triticina with and without foliar dusting of fly ash (0.0, 2.5, 5.0, 7.5 gplant?1\\/day?1) on the growth, yield, photosynthetic pigments, protein and lysine contents of three cultivars of wheat, Triticum aestivum. Dusting of 2.5 and 5.0 g fly ash caused a significant increase in growth, yield, photosynthetic pigments, protein

Lamabam P Singh; Zaki A Siddiqui

2003-01-01

327

Functional Analyses of the Diels-Alderase Gene sol5 of Ascochyta rabiei and Alternaria solani Indicate that the Solanapyrone Phytotoxins Are Not Required for Pathogenicity.  

PubMed

Ascochyta rabiei and Alternaria solani, the causal agents of Ascochyta blight of chickpea (Cicer arietinum) and early blight of potato (Solanum tuberosum), respectively, produce a set of phytotoxic compounds including solanapyrones A, B, and C. Although both the phytotoxicity of solanapyrones and their universal production among field isolates have been documented, the role of solanapyrones in pathogenicity is not well understood. Here, we report the functional characterization of the sol5 gene, which encodes a Diels-Alderase that catalyzes the final step of solanapyrone biosynthesis. Deletion of sol5 in both Ascochyta rabiei and Alternaria solani completely prevented production of solanapyrones and led to accumulation of the immediate precursor compound, prosolanapyrone II-diol, which is not toxic to plants. Deletion of sol5 did not negatively affect growth rate or spore production in vitro, and led to overexpression of the other solanapyrone biosynthesis genes, suggesting a possible feedback regulation mechanism. Phytotoxicity tests showed that solanapyrone A is highly toxic to several legume species and Arabidopsis thaliana. Despite the apparent phytotoxicity of solanapyrone A, pathogenicity tests showed that solanapyrone-minus mutants of Ascochyta rabiei and Alternaria solani were equally virulent as their corresponding wild-type progenitors, suggesting that solanapyrones are not required for pathogenicity. PMID:25372118

Kim, Wonyong; Park, Chung-Min; Park, Jeong-Jin; Akamatsu, Hajime O; Peever, Tobin L; Xian, Ming; Gang, David R; Vandemark, George; Chen, Weidong

2015-04-01

328

Induction of resistance in host against the infection of leaf blight pathogen (Alternaria palandui) in onion (Allium cepa var aggregatum).  

PubMed

The Pseudomonas fluorescens isolate Pfl was found to inhibit the growth of pathogen Alternaria palandui, in vitro. In the present study, foliar application of a talc-based formulation of Pfl significantly reduced the incidence of leaf blight of onion, caused by A. palandui. Induction of defense-related proteins viz., chitinase, beta-1,3 glucanase, peroxidase (PO) and polyphenol oxidase (PPO) by application of Pfl, was studied against A. palandui infection in resistant (IHR 56) and susceptible (MDUI) onion cultivars. Chitinase in both cultivars, with or without challenge-inoculation of A. palandui revealed changes in the isoform pattern. The Native-PAGE of PO showed induction of PO2 isoform in both the cultivars, in response to inoculation of pathogen. Isoform analysis of PPO also exhibited induction in the Pfl-treated plants challenged with pathogen. Similarly, the activity of beta-1,3-glucanase was greatly induced in Pfl-treated plants, challenged with pathogen as compared to controls. Thus, the P. fluorescens-treated plants showed significant increase in the levels of the defense enzymes, in comparison to the plants challenged with the pathogen. PMID:16955738

Karthikeyan, M; Jayakumar, V; Radhika, K; Bhaskaran, R; Velazhahan, R; Alice, D

2005-12-01

329

Decolorization and biodegradation of congo red dye by a novel white rot fungus Alternaria alternata CMERI F6.  

PubMed

A novel white rot fungus Alternaria alternata CMERI F6 decolorized 99.99% of 600 mg/L congo red within 48 h in yeast extract-glucose medium at 25 °C, pH 5 and 150 rpm. Physicochemical parameters like carbon and nitrogen sources, temperature, pH and aeration were optimized to develop faster decolorization process. Dye decolorization rate was maximal (20.21 mg/L h) at 25 °C, pH 5, 150 rpm and 800 mg/L dye, giving 78% final decolorization efficiency. Scanning electron microscopy and X-ray Diffraction analysis revealed that the fungus become amorphous after dye adsorption. HPLC and FTIR analysis of the extracted metabolites suggested that the decolorization occurred through biosorption and biodegradation. Thermogravimetric analysis (TGA), differential thermal analysis (DTA) and acid-alkali and 70% ethanol treatment revealed the efficient dye retention capability of the fungus. The foregoing results justify the applicability of the strain in removal of congo red from textile wastewaters and their safe disposal. PMID:24034987

Chakraborty, Samayita; Basak, Bikram; Dutta, Subhasish; Bhunia, Biswanath; Dey, Apurba

2013-11-01

330

Host-Specific Effects of Toxin from the Rough Lemon Pathotype of Alternaria alternata on Mitochondria 1  

PubMed Central

Host-specific toxin from the rough lemon (Citrus jambhiri Lush) pathotype of Alternaria alternata (ACR toxin) was tested for effects on mitochondria isolated from several citrus species. The toxin caused uncoupling of oxidative phosphorylation and changes in membrane potential in mitochondria from leaves of the susceptible host (rough lemon); the effects differed from those of carbonylcyanide-m-chlorophenylhydrazone, a typical protonophore. ACR toxin also inhibited malate oxidation, apparently because of lack of NAD+ in the matrix. In contrast, the toxin had no effect on mitochondria from citrus species (Dancy tangerine and Emperor mandarin [Citrus reticulata Blanco], and grapefruit [Citrus paradisi Macf.]) that are not hosts of the fungus. The effects of the toxin on mitochondria from rough lemon are similar to the effects of a host-specific toxin from Helminthosporium maydis (HMT) on mitochondria from T-cytoplasm maize. Both ACR and HMT toxins are highly selective for the respective host plants. HMT toxin and methomyl had no effect (toxic or protective) on the activity of ACR toxin against mitochondria from rough lemon. PMID:16666643

Akimitsu, Kazuya; Kohmoto, Keisuke; Otani, Hiroshi; Nishimura, Syoyo

1989-01-01

331

Nonpathogenic Binucleate Rhizoctonia spp. and Benzothiadiazole Protect Cotton Seedlings Against Rhizoctonia Damping-Off and Alternaria Leaf Spot in Cotton.  

PubMed

ABSTRACT Recent reports have shown induction of resistance to Rhizoctonia root rot using nonpathogenic strains of binucleate Rhizoctonia spp. (np-BNR). This study evaluates the biocontrol ability of several np-BNR isolates against root and foliar diseases of cotton in greenhouse trials, provides evidence for induced systemic resistance (ISR) as a mechanism in this biocontrol, and compares the disease control provided by np-BNR with that provided by the chemical inducer benzothiadiazole (BTH). Pretreatment of cotton seedlings with np-BNR isolates provided good protection against pre- and post-emergence damping-off caused by a virulent strain of Rhizoctonia solani (AG-4). Seedling stand of protected cotton was significantly higher (P < 0.05) than that of nonprotected seedlings. Several np-BNR isolates significantly reduced disease severity. The combination of BTH and np-BNR provided significant protection against seedling rot and leaf spot in cotton; however, the degree of disease reduction was comparable to that obtained with np-BNR treatment alone. Significant reduction in leaf spot symptoms caused by Alternaria macrospora occurred on cotyledons pretreated with np-BNR or sprayed with BTH, and the np- BNR-treated seedlings had significantly less leaf spot than BTH-treated seedlings. The results demonstrate that np-BNR isolates can protect cotton from infections caused by both root and leaf pathogens and that disease control was superior to that observed with a chemical inducer. PMID:18943300

Jabaji-Hare, Suha; Neate, Stephen M

2005-09-01

332

The phytoalexin camalexin induces fundamental changes in the proteome of Alternaria brassicicola different from those caused by brassinin.  

PubMed

Camalexin is the major phytoalexin produced by Alternaria thaliana, but is absent in Brassica species that usually produce phytoalexin blends containing brassinin and derivatives. The protein profiles of A. brassicicola treated with camalexin were evaluated using proteomics and metabolic analyses and compared with those treated with brassinin. Conidial germination and mycelial growth of A. brassicicola in liquid media amended with camalexin and brassinin showed that fungal growth was substantially slower in presence of camalexin than brassinin; chemical analyses revealed that A. brassicicola detoxified camalexin at much slower rate than brassinin. Two-dimensional gel electrophoresis (2-DE) followed by tryptic digestion and capillary liquid chromatography-mass spectrometric analyses identified 158 different proteins, of which 45 were up-regulated and 113 were down-regulated relative to controls. Venn diagram analyses of differentially expressed proteins in cultures of A. brassicicola incubated with camalexin and brassinin indicated clear differences in the effect of each phytoalexin, with camalexin causing down-regulation of a larger number of proteins than brassinin. Overall, results of this work suggest that each phytoalexin has several different targets in the cells of A. brassicicola, and that camalexin appears to have greater potential to protect cultivated Brassica species against A. brassicicola than brassinin. PMID:24433679

Pedras, M Soledade C; Minic, Zoran; Abdoli, Abbas

2014-01-01

333

Selection and differentiation of Bacillus spp. Antagonistic to Fusarium oxysporum f.sp. lycopersici and Alternaria solani infecting Tomato.  

PubMed

Antagonistic Bacillus spp. displaying in vitro production of siderophore, chitinase, and ?-1,3-glucanase were identified from dual culture assays. In independent greenhouse studies, seed bacterization and soil application of Bacillus atrophaeus S2BC-2 challenge inoculated with Fusarium oxysporum f.sp. lycopersici (FOL) and Alternaria solani (AS) recorded low percent disease index of 25.3 and 28.7, respectively, over nonbacterised pathogen control (44.3 and 56.4). The low disease incidence corroborated with tomato growth promotion with high vigor index (8,041.2) and fresh plant weight (82.5 g) on challenge inoculation with FOL. Analysis of root and leaf samples in rhizobacterial treatment challenged with FOL and AS revealed maximum induction of chitinase (1.9 and 1.7 U/mg of protein, respectively) and ?-1,3-glucanase (23.5 and 19.2 U/mg of protein, respectively). In native gel activity assays, the rhizobacterial treatment on challenge inoculation strongly expressed three high intensity PO isoforms along with one low intensity isoform. In studies on genetic diversity of the Bacillus strains by repetitive extragenomic palindromic-polymerase chain reaction (REP-PCR) and amplified rDNA restriction analysis (ARDRA) patterns, ARDRA was more highly discriminant than REP-PCR and allowed grouping of the strains and differentiation of the antagonistic strains from other isolates. PMID:21503737

Shanmugam, Veerubommu; Atri, Kamini; Gupta, Samriti; Kanoujia, Nandina; Naruka, Digvijay Singh

2011-03-01

334

The LOV Protein of Xanthomonas citri subsp. citri Plays a Significant Role in the Counteraction of Plant Immune Responses during Citrus Canker  

PubMed Central

Pathogens interaction with a host plant starts a set of immune responses that result in complex changes in gene expression and plant physiology. Light is an important modulator of plant defense response and recent studies have evidenced the novel influence of this environmental stimulus in the virulence of several bacterial pathogens. Xanthomonas citri subsp. citri is the bacterium responsible for citrus canker disease, which affects most citrus cultivars. The ability of this bacterium to colonize host plants is influenced by bacterial blue-light sensing through a LOV-domain protein and disease symptoms are considerably altered upon deletion of this protein. In this work we aimed to unravel the role of this photoreceptor during the bacterial counteraction of plant immune responses leading to citrus canker development. We performed a transcriptomic analysis in Citrus sinensis leaves inoculated with the wild type X. citri subsp. citri and with a mutant strain lacking the LOV protein by a cDNA microarray and evaluated the differentially regulated genes corresponding to specific biological processes. A down-regulation of photosynthesis-related genes (together with a corresponding decrease in photosynthesis rates) was observed upon bacterial infection, this effect being more pronounced in plants infected with the lov-mutant bacterial strain. Infection with this strain was also accompanied with the up-regulation of several secondary metabolism- and defense response-related genes. Moreover, we found that relevant plant physiological alterations triggered by pathogen attack such as cell wall fortification and tissue disruption were amplified during the lov-mutant strain infection. These results suggest the participation of the LOV-domain protein from X. citri subsp. citri in the bacterial counteraction of host plant defense response, contributing in this way to disease development. PMID:24260514

Kraiselburd, Ivana; Daurelio, Lucas D.; Tondo, María Laura; Merelo, Paz; Cortadi, Adriana A.; Talón, Manuel; Tadeo, Francisco R.; Orellano, Elena G.

2013-01-01

335

Choosing a STEM Career  

NSDL National Science Digital Library

Students will view video clips about graduate and middle school students with interests in STEM careers and compare technologies from yesterday with today. They will explore careers on-line before writing about their futures as STEM professionals.

WPSU

2009-11-10

336

STEM Club Participation and STEM Schooling Outcomes  

ERIC Educational Resources Information Center

To develop a more robust understanding of the relationship between non-formal, school-based STEM activities and students' success and persistence in STEM fields, this study evaluates how math club participation influences math GPA and how science club participation influences science GPA. Additionally, this study evaluates how math or science…

Gottfried, Michael A.; Williams, Darryl N.

2013-01-01

337

Umbilical Cord Stem Cells  

Microsoft Academic Search

The two most basic properties of stem cells are the capacities to self-renew and to differentiate into multiple cell or tissue\\u000a types (1–3). Generally, stem cells are categorized as one of three types: embryonic stem cells (ES), embryonic germ cells (EG), or adult\\u000a stem cells. ES cells are derived from the inner cell mass of the blastula (Fig. 1). They

Kathy E. Mitchell

338

STEM Education Resource Center  

NSDL National Science Digital Library

This website houses the PBS collection of educational resources for science, technology, engineering and mathematics (STEM). A brief video introduces the idea that anyone who works and studies hard can have a successful career in a STEM field. Webinars and other forms of professional development are available, as well as links to other STEM websites.

2009-01-01

339

Hair Follicle Stem Cells  

Microsoft Academic Search

The workshop on Hair Follicle Stem Cells brought together investigators who have used a variety of approaches to try to understand the biology of follicular epithelial stem cells, and the role that these cells play in regulating the hair cycle. One of the main concepts to emerge from this workshop is that follicular epithelial stem cells are multipotent, capable of

Robert M. Lavker; Tung-Tien Sun; Hideo Oshima; Yann Barrandon; Masashi Akiyama; Corinne Ferraris; Genevieve Chevalier; Bertrand Favier; Colin A. B. Jahoda; Danielle Dhouailly; Andrei A. Panteleyev; Angela M. Christiano

2003-01-01

340

Understanding Embryonic Stem Cells  

NSDL National Science Digital Library

This indexed webcast video along with synchronized lecture slides is from Howard Hughes Medical Institute's 2006 Holiday LecturesPotent Biology: Stem Cells, Cloning, and Regeneration. Douglas A. Melton presents an introduction to stem cells, as well as answers to questions about the role of stem cells in the human body. This video requires RealPlayer 10.

Douglas A. Melton, Ph.D. (Howard Hughes Medical Institute; )

2008-04-10

341

Stem cell culture engineering  

Microsoft Academic Search

Stem cells have the capacity for self renewal and undergo multilineage differentiation. Stem cells isolated from both blastocysts and adult tissues represent valuable sources of cells for applications in cell therapy, drug screening and tissue engineering. While expanding stem cells in culture, it is critical to maintain their self?renewal and differentiation capacity. In generating particular cell types for specific applications,

Gargi Seth; Catherine M. Verfaillie

2005-01-01

342

Understanding STEM: Current Perceptions  

ERIC Educational Resources Information Center

In many ways, the push for STEM (science, technology, engineering, and mathematics) education appears to have grown from a concern for the low number of future professionals to fill STEM jobs and careers and economic and educational competitiveness. The proponents of STEM education believe that by increasing math and science requirements in…

Brown, Ryan; Brown, Joshua; Reardon, Kristin; Merrill, Chris

2011-01-01

343

Canker Sore (Aphthous Ulcer)  

MedlinePLUS

... 2006-2013 Logical Images, Inc. All rights reserved. Advertising Notice This Site and third parties who place ... would like to obtain more information about these advertising practices and to make choices about online behavioral ...

344

Canker Sores: Treatment  

MedlinePLUS

... RAS fall roughly into four categories: occlusives, anesthetics, cleansing agents / antiseptics, and other. OTC products often combine ... with hypersensitivity. Many OTC anesthetic products are available. Cleansing agents/ Antiseptics can cleanse the area and decrease ...

345

Stem Cell Quick Guide: Stem Cell Basics What is a Stem Cell?  

E-print Network

Stem Cell Quick Guide: Stem Cell Basics What is a Stem Cell? Stem cells are the starting point from to line blood vessels. All of these highly specialized cells have to grow from unspecialized stem cells. Stem cells produce new cells by dividing. In the right conditions, these new cells can then continue

Schladow, S. Geoffrey

346

Testing of selected South African Pinus hybrids and families for tolerance to the pitch canker pathogen, Fusarium circinatum  

Microsoft Academic Search

Plantations of Pinus spp. constitute approximately 50% of the South African forestry industry. The first aim of this study was to develop a reliable\\u000a inoculation technique to screen Pinus spp., for tolerance to infection by F. circinatum, which threatens pine forestry in South Africa. Inoculation of branches was compared with stem inoculations and we considered\\u000a the number of branches or

J. Roux; B. Eisenberg; A. Kanzler; A. Nel; V. Coetzee; E. Kietzka; M. J. Wingfield

2007-01-01

347

Systemic jasmonic acid modulation in mycorrhizal tomato plants and its role in induced resistance against Alternaria alternata.  

PubMed

Tomato plants colonised with the arbuscular mycorrhizal (AM) fungus Glomus fasciculatum show systemic induced resistance to the foliar pathogen Alternaria alternata, as observed in interactions of other AM-colonised plants with a range of pathogens. The role of jasmonic (JA) and salicylic (SA) acid in expression of this mycorrhiza-induced resistance (MIR) against A. alternata was studied by measuring: (i) activity of enzymes reported to be involved in their biosynthesis, namely lipoxygenase (LOX) and phenylammonia lyase (PAL); and (ii) levels of methyl jasmonate (MeJA) and SA. Transcript abundance of some defence genes associated with JA and SA response pathways were also studied. Both LOX and PAL activity increased twofold in response to pathogen application to control plants. AM-colonised plants had three-fold higher LOX activity compared to control plants, but unlike controls, this did not increase further in response to pathogen application. Higher LOX activity in AM-colonised plants correlated with four-fold higher MeJA in leaves of AM-colonised plants compared to controls. Treatment of plants with the JA biosynthesis inhibitor salicylhydroxamic acid (SHAM) led to 50% lower MeJA in both control and AM-colonised plants and correlated with increased susceptibility to A. alternata, suggesting a causal role for JA in expression of MIR against the pathogen. Genes involved in JA biosynthesis (OPR3) and response (COI1) showed six- and 42-fold higher expression, respectively, in leaves of AM-colonised plants compared to controls. AM-colonised plants also showed increased expression of the SA response gene PR1 and that of the wound-inducible polypeptide prosystemin. Our results suggest that the systemic increase in JA in response to AM colonisation plays a key role in expression of MIR against A. alternata. PMID:25327848

Nair, A; Kolet, S P; Thulasiram, H V; Bhargava, S

2015-05-01

348

Alternaria toxin-induced resistance in rose plants against rose aphid (Macrosiphum rosivorum): effect of tenuazonic acid*  

PubMed Central

Many different types of toxins are produced by the fungus, Alternaria alternata (Fr.) Keissler. Little is known, however, regarding the influence of these toxins on insects. In this study, we investigated the toxin-induced inhibitory effects of the toxin produced by A. alternata on the rose aphid, Macrosiphum rosivorum, when the toxin was applied to leaves of the rose, Rosa chinensis. The results demonstrated that the purified crude toxin was non-harmful to rose plants and rose aphids, but had an intensive inhibitory effect on the multiplication of aphids. The inhibitory index against rose aphids reached 87.99% when rose plants were sprayed with the toxin solution at a low concentration. Further results from bioassays with aphids and high performance liquid chromatography (HPLC) analyses demonstrated that tenuazonic acid (TeA) was one of the most important resistance-related active components in the crude toxin. The content of TeA was 0.1199% in the crude toxin under the HPLC method. Similar to the crude toxin, the inhibitory index of pure TeA reached 83.60% 15 d after the rose plants were sprayed with pure TeA solution at the lower concentration of 0.060 ?g/ml, while the contents of residual TeA on the surface and in the inner portion of the rose plants were only 0.04 and 0.00 ng/g fresh weight of TeA-treated rose twigs, respectively, 7 d after the treatment. Our results show that TeA, an active component in the A. alternata toxin, can induce the indirect plant-mediated responses in rose plants to intensively enhance the plant’s resistances against rose aphids, and the results are very helpful to understand the plant-mediated interaction between fungi and insects on their shared host plants. PMID:25845360

Yang, Fa-zhong; Yang, Bin; Li, Bei-bei; Xiao, Chun

2015-01-01

349

Inducible and constitutive expression of an elicitor gene Hrip1 from Alternaria tenuissima enhances stress tolerance in Arabidopsis.  

PubMed

Hrip1 is a novel hypersensitive response-inducing protein secreted by Alternaria tenuissima that activates defense responses and systemic acquired resistance in tobacco. This study investigates the role that Hrip1 plays in responses to abiotic and biotic stress using transgenic Arabidopsis thaliana expressing the Hrip1 gene under the control of the stress-inducible rd29A promoter or constitutive cauliflower mosaic virus 35S promoter. Bioassays showed that inducible Hrip1 expression in rd29A?Hrip1 transgenic lines had a significantly higher effect on plant height, silique length, plant dry weight, seed germination and root length under salt and drought stress compared to expression in 35S?Hrip1 lines and wild type plants. The level of enhancement of resistance to Botrytis cinerea by the 35S?Hrip1 lines was higher than in the rd29A?Hrip1 lines. Moreover, stress-related gene expression in the transgenic Arabidopsis lines was significantly increased by 200 mM NaCl and 200 mM mannitol treatments, and defense genes in the jasmonic acid and ethylene signaling pathway were significantly up-regulated after Botrytis inoculation in the Hrip1 transgenic plants. Furthermore, the activity of some antioxidant enzymes, such as peroxidase and catalase increased after salt and drought stress and Botrytis infection. These results suggested that the Hrip1 protein contributes to abiotic and biotic resistance in transgenic Arabidopsis and may be used as a useful gene for resistance breeding in crops. Although the constitutive expression of Hrip1 is suitable for biotic resistance, inducible Hrip1 expression is more responsive for abiotic resistance. PMID:25120219

Peng, Xue-Cong; Qiu, De-Wen; Zeng, Hong-Mei; Guo, Li-Hua; Yang, Xiu-Fen; Liu, Zheng

2015-02-01

350

A compatible interaction of Alternaria brassicicola with Arabidopsis thaliana ecotype DiG: evidence for a specific transcriptional signature  

PubMed Central

Background The interaction of Arabidopsis with Alternaria brassicicola provides a model for disease caused by necrotrophs, but a drawback has been the lack of a compatible pathosystem. Infection of most ecotypes, including the widely-studied line Col-0, with this pathogen generally leads to a lesion that does not expand beyond the inoculated area. This study examines an ecotype, Dijon G (DiG), which is considered sensitive to A. brassicicola. Results We show that the interaction has the characteristics of a compatible one, with expanding rather than limited lesions. To ask whether DiG is merely more sensitive to the pathogen or, rather, interacts in distinct manner, we identified genes whose regulation differs between Col-0 and DiG challenged with A. brassicicola. Suppression subtractive hybridization was used to identify differentially expressed genes, and their expression was verified using semi-quantitative PCR. We also tested a set of known defense-related genes for differential regulation in the two plant-pathogen interactions. Several known pathogenesis-related (PR) genes are up-regulated in both interactions. PR1, and a monooxygenase gene identified in this study, MO1, are preferentially up-regulated in the compatible interaction. In contrast, GLIP1, which encodes a secreted lipase, and DIOX1, a pathogen-response related dioxygenase, are preferentially up-regulated in the incompatible interaction. Conclusion The results show that DiG is not only more susceptible, but demonstrate that its interaction with A. brassicicola has a specific transcriptional signature. PMID:19296849

Mukherjee, Arup K; Lev, Sophie; Gepstein, Shimon; Horwitz, Benjamin A

2009-01-01

351

Alternaria toxin-induced resistance in rose plants against rose aphid (Macrosiphum rosivorum): effect of tenuazonic acid.  

PubMed

Many different types of toxins are produced by the fungus, Alternaria alternata (Fr.) Keissler. Little is known, however, regarding the influence of these toxins on insects. In this study, we investigated the toxin-induced inhibitory effects of the toxin produced by A. alternata on the rose aphid, Macrosiphum rosivorum, when the toxin was applied to leaves of the rose, Rosa chinensis. The results demonstrated that the purified crude toxin was non-harmful to rose plants and rose aphids, but had an intensive inhibitory effect on the multiplication of aphids. The inhibitory index against rose aphids reached 87.99% when rose plants were sprayed with the toxin solution at a low concentration. Further results from bioassays with aphids and high performance liquid chromatography (HPLC) analyses demonstrated that tenuazonic acid (TeA) was one of the most important resistance-related active components in the crude toxin. The content of TeA was 0.1199% in the crude toxin under the HPLC method. Similar to the crude toxin, the inhibitory index of pure TeA reached 83.60% 15 d after the rose plants were sprayed with pure TeA solution at the lower concentration of 0.060 ?g/ml, while the contents of residual TeA on the surface and in the inner portion of the rose plants were only 0.04 and 0.00 ng/g fresh weight of TeA-treated rose twigs, respectively, 7 d after the treatment. Our results show that TeA, an active component in the A. alternata toxin, can induce the indirect plant-mediated responses in rose plants to intensively enhance the plant's resistances against rose aphids, and the results are very helpful to understand the plant-mediated interaction between fungi and insects on their shared host plants. PMID:25845360

Yang, Fa-Zhong; Yang, Bin; Li, Bei-Bei; Xiao, Chun

2015-04-01

352

Inhibitory activity of Indian spice plant Cinnamomum zeylanicum extracts against Alternaria solani and Curvularia lunata, the pathogenic dematiaceous moulds  

PubMed Central

Background Dematiaceous moulds are pathogenic microorganisms and act as etiological agents of mycoses with different degrees of severity in humans and animals. These moulds also cause loss of food crops and storage food products. The information regarding antimicrobial efficacy of the plant preparations on these moulds is scanty. The present study reveals phytochemical characterization and the effect of bark and leaf extracts of Indian spice plant, Cinnamomum zeylanicum (Cz), against the growth of two species of dematiaceous moulds, Alternaria solani and Curvularia lunata. Methods Cz bark and leaf samples were sequentially extracted in different solvents using Soxhlet apparatus. Phytochemical analyses of extracts were done as per standard protocols. The antifungal bioassay of extracts was done by hanging drop technique. The inhibition of fungal spore germination was monitored under influence of three different concentrations of extracts. Results The lowest test concentration (50 ?g/ml) of extracts of Cz bark prepared into acetone and that of Cz leaf into petroleum ether and ethanol exhibited complete inhibition (100%) of spore germination in both the moulds. At 100 ?g/ml concentration all the extracts showed about 50 to 100% inhibition. However, the treatment of the spores of the two fungal species with highest concentration (500 ?g/ml) of bark and leaf extracts in all the solvents showed 100% fungicidal activity as it completely arrested the germination of spores. Relatively lower activity of aqueous extracts at 50 and 100 ?g/ml concentrations suggests that the antifungal ingredients present in Cz bark and leaf are more soluble in organic solvents than water. Conclusion The results demonstrated that the Cz bark and leaves contain certain fungicidal constituents exhibiting potential antimould activity against A. solani and C. lunata. PMID:19267932

Mishra, Ajay K; Mishra, Amita; Kehri, HK; Sharma, Bechan; Pandey, Abhay K

2009-01-01

353

RNA-Seq derived identification of differential transcription in the chrysanthemum leaf following inoculation with Alternaria tenuissima  

PubMed Central

Background A major production constraint on the important ornamental species chrysanthemum is black spot which is caused by the necrotrophic fungus Alternaria tenuissima. The molecular basis of host resistance to A. tenuissima has not been studied as yet in any detail. Here, high throughput sequencing was taken to characterize the transcriptomic response of the chrysanthemum leaf to A. tenuissima inoculation. Results The transcriptomic data was acquired using RNA-Seq technology, based on the Illumina HiSeq™ 2000 platform. Four different libraries derived from two sets of leaves harvested from either inoculated or mock-inoculated plants were characterized. Over seven million clean reads were generated from each library, each corresponding to a coverage of >350,000 nt. About 70% of the reads could be mapped to a set of chrysanthemum unigenes. Read frequency was used as a measure of transcript abundance and therefore as an identifier of differential transcription in the four libraries. The differentially transcribed genes identified were involved in photosynthesis, pathogen recognition, reactive oxygen species generation, cell wall modification and phytohormone signalling; in addition, a number of varied transcription factors were identified. A selection of 23 of the genes was transcription-profiled using quantitative RT-PCR to validate the RNA-Seq output. Conclusions A substantial body of chrysanthemum transcriptomic sequence was generated, which led to a number of insights into the molecular basis of the host response to A. tenuissima infection. Although most of the differentially transcribed genes were up-regulated by the presence of the pathogen, those involved in photosynthesis were down-regulated. PMID:24387266

2014-01-01

354

Effect of water activity and temperature on mycotoxin production by Alternaria alternata in culture and on wheat grain.  

PubMed Central

Both water activity (aW) and temperature affected the production of altenuene (AE), alternariol (AOH), and alternariol monomethyl ether (AME) by Alternaria alternata on wheat extract agar and wheat grain. Greatest production of all three mycotoxins occurred at 0.98 aW and 25 degrees C on both substrates. At 0.98 aW and 25 degrees C, a single colony of A. alternata grown on wheat extract agar produced 807 micrograms of AOH, 603 micrograms of AME, and 169 micrograms of AE ml in 30 days. However, production of all three mycotoxins at 0.95 aW was less than 40% of these amounts. Little toxin was produced at 0.90 aW. Changing temperature and aW altered the relative amounts of the different toxins produced on agar. At 15 degrees C and 0.98 aW, maxima of 52 micrograms of AOH and 25 micrograms of AME per ml were produced after 15 and 30 days, respectively, whereas AE continued to increase and reached 57 micrograms/ml after 40 days. At 15 degrees C and 0.95 aW, production was, respectively, 62, 10, and 5 micrograms/ml after 40 days. All three metabolites were produced at 5 degrees C and 0.98 to 0.95 aW and at 30 degrees C and 0.98 to 0.90 aW. On wheat grain at 25 degrees C and 0.98 to 0.95 aW, more AME was produced than AOH or AE, but at 15 degrees C there was less AME than AOH or AE. Only trace amounts of AE, AOH, and AME were found at 15 to 25 degrees C and 0.90 aW, but production of AME was inhibited at 30 degrees C and 0.95 aW or less. PMID:6540067

Magan, N; Cayley, G R; Lacey, J

1984-01-01

355

The involvement of jasmonates and ethylene in Alternaria alternata f. sp. lycopersici toxin-induced tomato cell death  

PubMed Central

Previous studies have shown that an ethylene (ET)-dependent pathway is involved in the cell death signalling triggered by Alternaria alternata f. sp. lycopersici (AAL) toxin in detached tomato (Solanum lycopersicum) leaves. In this study, the role of jasmonic acid (JA) signalling in programmed cell death (PCD) induced by AAL toxin was analysed using a 35S::prosystemin transgenic line (35S::prosys), a JA-deficient mutant spr2, and a JA-insensitive mutant jai1. The results indicated that JA biosynthesis and signalling play a positive role in the AAL toxin-induced PCD process. In addition, treatment with the exogenous ET action inhibitor silver thiosulphate (STS) greatly suppressed necrotic lesions in 35S::prosys leaves, although 35S::prosys leaflets co-treated with AAL toxin and STS still have a significant high relative conductivity. Application of 1-aminocyclopropane-1-carboxylic acid (ACC) markedly enhanced the sensitivity of spr2 and jai1 mutants to the toxin. However, compared with AAL toxin treatment alone, exogenous application of JA to the ET-insensitive mutant Never ripe (Nr) did not alter AAL toxin-induced cell death. In addition, the reduced ET-mediated gene expression in jai1 leaves was restored by co-treatment with ACC and AAL toxin. Furthermore, JA treatment restored the decreased expression of ET biosynthetic genes but not ET-responsive genes in the Nr mutant compared with the toxin treatment alone. Based on these results, it is proposed that both JA and ET promote the AAL toxin-induced cell death alone, and the JAI1 receptor-dependent JA pathway also acts upstream of ET biosynthesis in AAL toxin-triggered PCD. PMID:21865178

Zhang, Liping; Jia, Chengguo; Liu, Lihong; Zhang, Zhiming; Li, Chuanyou; Wang, Qiaomei

2011-01-01

356

Biosynthesis of seven carbon-13 labeled Alternaria toxins including altertoxins, alternariol, and alternariol methyl ether, and their application to a multiple stable isotope dilution assay.  

PubMed

An unprecedented stable isotope dilution assay for the genotoxic altertoxins along with exposure data of consumers is presented to enable a first risk assessment of these Alternaria toxins in foods. Altertoxins were produced as the most abundant Alternaria toxins in a modified Czapek-Dox medium with a low level of glucose as the carbon source and ammonium sulfate as the sole nitrogen source. Labeled altertoxins were synthesized in the same way using [(13)C6]glucose. Moreover, labeled alternariol, alternariol methyl ether, altenuene, and alternuisol were biosynthesized in another modified medium containing [(13)C6]glucose and sodium [(13)C2]acetate. A stable isotope dilution LC-MS/MS method was developed and used for food analysis. For altertoxin I, altertoxin II, alterperylenol, alternariol, and alternariol methyl ether, the limits of detection ranged from 0.09 to 0.53 ?g kg(-1). The inter-/intra-day (n?=?3?×?6) relative standard deviations of the method were below 13 %, and the recoveries ranged between 96 and 109 %. Among the various commercial food samples, some of the organic whole grains revealed low-level contamination with altertoxin I and alterperylenol, and paprika powder, which was heavily loaded with alternariol, alternariol methyl ether, and tentoxin, showed higher contamination level of altertoxin I and alterperylenol. Altertoxin II and III and stemphyltoxin III were not detectable. In addition, if the food was contaminated with altertoxins, it was likely to be co-contaminated with the other Alternaria toxins, but not necessarily vice versa. Maximum concentrations of altertoxin I and alterperylenol were detected in sorghum feed samples containing 43 and 58 ?g kg(-1), respectively. This was significantly higher than that in the measured food samples. PMID:25577349

Liu, Yang; Rychlik, Michael

2015-02-01

357

Minor contribution of alternariol, alternariol monomethyl ether and tenuazonic acid to the genotoxic properties of extracts from Alternaria alternata infested rice.  

PubMed

Alternaria spp. are known to form a spectrum of secondary metabolites with alternariol (AOH), alternariol monomethyl ether (AME), altenuene (ALT) and tenuazonic acid (TA) as the major mycotoxins with respect to quantity. In the present study we investigated the contribution of these compounds for the DNA damaging properties of complex extracts of Alternaria spp. infested rice. Five different Alternaria strains were cultured on rice and analyzed for their production of AOH, AME, ALT and TA. The extracts of two strains with distinctly different toxin profiles were selected for further toxicological analysis. An extract from A. alternata DSM 1102 infested rice, found to contain predominantly TA, exhibited substantial DNA strand breaking properties in cultured human colon carcinoma cells in the comet assay, whereas TA as a single compound did not affect DNA integrity up to 200?M. An extract of A. alternata DSM 12633 infested rice, containing in comparable proportions AOH, AME and TA, exceeded by far the DNA damaging properties of the single compounds. In contrast to AOH, AME and TA, both selected extracts induced an increase of DNA modifications sensitive to the bacterial repair enzyme formamidopyrimidine DNA glycosylase (FPG) in the comet assay, indicative for oxidative DNA damage. Toxicity-guided fractionation of the DSM 12633 extract confirmed that these effects were not caused by AOH, AME or TA. Taken together, the mycotoxins AOH, AME and TA, representing the major mycotoxins with respect to quantity in A. alternata infested food, play only a subordinate role for the genotoxic properties of complex extracts and appear not to be involved in the induction of FPG sensitive sites. PMID:22906495

Schwarz, Christoph; Kreutzer, Martin; Marko, Doris

2012-10-01

358

Stable integration and expression of wasabi defensin gene in "Egusi" melon (Colocynthis citrullus L.) confers resistance to Fusarium wilt and Alternaria leaf spot.  

PubMed

Production of "Egusi" melon (Colocynthis citrullus L.) in West Africa is limited by fungal diseases, such as Alternaria leaf spot and Fusarium wilt. In order to engineer "Egusi" resistant to these diseases, cotyledonary explants of two "Egusi" genotypes, 'Ejagham' and NHC1-130, were transformed with Agrobacterium tumefaciens strain EHA101 harbouring wasabi defensin gene (isolated from Wasabia japonica L.) in a binary vector pEKH1. After co-cultivation for 3 days, infected explants were transferred to MS medium containing 100 mg l(-l) kanamycin to select transformed tissues. After 3 weeks of culture, adventitious shoots appeared directly along the edges of the explants. As much as 19 out of 52 (36.5%) and 25 out of 71 (35.2%) of the explants in genotype NHC1-130 and 'Ejagham', respectively, formed shoots after 6 weeks of culture. As much as 74% (14 out of 19) of the shoots regenerated in genotype NHC1-130 and 72% (18 out of 25) of those produced in genotype 'Ejagham' were transgenic. A DNA fragment corresponding to the wasabi defensin gene or the selection marker nptII was amplified by PCR from the genomic DNA of all regenerated plant clones rooted on hormone-free MS medium under the same selection pressure, suggesting their transgenic nature. Southern blot analysis confirmed successful integration of 1-5 copies of the transgene. RT-PCR, northern and western blot analyses revealed that wasabi defensin gene was expressed in transgenic lines. Transgenic lines showed increased levels of resistance to Alternaria solani, which causes Alternaria leaf spot and Fusarium oxysporum, which causes Fusarium wilt, as compared to that of untransformed plants. PMID:20552202

Ntui, Valentine Otang; Thirukkumaran, Gunaratnam; Azadi, Pejman; Khan, Raham Sher; Nakamura, Ikuo; Mii, Masahiro

2010-09-01

359

Plant stem cell niches.  

PubMed

Multicellular organisms possess pluripotent stem cells to form new organs, replenish the daily loss of cells, or regenerate organs after injury. Stem cells are maintained in specific environments, the stem cell niches, that provide signals to block differentiation. In plants, stem cell niches are situated in the shoot, root, and vascular meristems-self-perpetuating units of organ formation. Plants' lifelong activity-which, as in the case of trees, can extend over more than a thousand years-requires that a robust regulatory network keep the balance between pluripotent stem cells and differentiating descendants. In this review, we focus on current models in plant stem cell research elaborated during the past two decades, mainly in the model plant Arabidopsis thaliana. We address the roles of mobile signals on transcriptional modules involved in balancing cell fates. In addition, we discuss shared features of and differences between the distinct stem cell niches of Arabidopsis. PMID:22404469

Aichinger, Ernst; Kornet, Noortje; Friedrich, Thomas; Laux, Thomas

2012-01-01

360

Cell Stem Cell Dear Student: Stem Cell Scientists' Advice  

E-print Network

Cell Stem Cell Forum Dear Student: Stem Cell Scientists' Advice to the Next Generation Emily L on Stem Cells in Society, Stanford, CA 94305, USA 2Department of Family Practice, University of British@stanford.edu (C.T.S.) http://dx.doi.org/10.1016/j.stem.2013.05.007 For the field of pluripotent stem cell biology

361

A polyketide synthase gene, ACRTS2, is responsible for biosynthesis of host-selective ACR-toxin in the rough lemon pathotype of Alternaria alternata.  

PubMed

The rough lemon pathotype of Alternaria alternata produces host-selective ACR-toxin and causes Alternaria leaf spot disease of rough lemon (Citrus jambhiri). The structure of ACR-toxin I (MW = 496) consists of a polyketide with an ?-dihydropyrone ring in a 19-carbon polyalcohol. Genes responsible for toxin production were localized to a 1.5-Mb chromosome in the genome of the rough lemon pathotype. Sequence analysis of this chromosome revealed an 8,338-bp open reading frame, ACRTS2, that was present only in the genomes of ACR-toxin-producing isolates. ACRTS2 is predicted to encode a putative polyketide synthase of 2,513 amino acids and belongs to the fungal reducing type I polyketide synthases. Typical polyketide functional domains were identified in the predicted amino acid sequence, including ?-ketoacyl synthase, acyl transferase, methyl transferase, dehydratase, ?-ketoreductase, and phosphopantetheine attachment site domains. Combined use of homologous recombination-mediated gene disruption and RNA silencing allowed examination of the functional role of multiple paralogs in ACR-toxin production. ACRTS2 was found to be essential for ACR-toxin production and pathogenicity of the rough lemon pathotype of A. alternata. PMID:22835272

Izumi, Y; Ohtani, K; Miyamoto, Y; Masunaka, A; Fukumoto, T; Gomi, K; Tada, Y; Ichimura, K; Peever, T L; Akimitsu, K

2012-11-01

362

Gastrointestinal Stem Cells  

Microsoft Academic Search

\\u000a Stem cell research is advancing at an incredible pace, with new ­discoveries and clinical applications being reported from\\u000a all over the world. Stem cells are functionally defined by their ability to self-renew and to differentiate into the cell\\u000a lineages of their tissue of origin. Stem cells are self-sustaining and can ­replicate themselves for long periods of time.\\u000a These characteristics make

N. Parveen; Aleem A. Khan; M. Aejaz Habeeb; C. M. Habibullah

363

Stem Cell Transplants  

NSDL National Science Digital Library

Transplanting embryonic stem cells from embryo into adult as a means of rejuvenating diseased cells, tissues, and organs poses ethical and moral challenges. In recent years, stem cell-derived nerve and glandular tissue has been transplanted into the brains and pancreas of Parkinson's disease and diabetes patients, respectively, with mixed results. This chapter provides background information on stem cell research, the future treatment of Parkinson's disease, and the controversy surrounding this sensitive issue.

Irwin Slesnick

2004-01-01

364

Cardiac stem cell therapy  

Microsoft Academic Search

In cardiac stem cell therapy, the past decade has been interesting with respect to preclinical and clinical research. The\\u000a high diversity of applied stem cell populations and evaluation methods represent a challenge to fully understand the impact\\u000a of stem cell administration, leaving uncertain answers to the questions that have been dealt with thus far. In the present\\u000a work, registered studies

C. Nesselmann; A. Kaminski; G. Steinhoff

2011-01-01

365

Embryonic Stem Cells  

Microsoft Academic Search

Stem cells, which have a great capacity for self-renewal and can differentiate into at least one committed cell type, exist\\u000a in embryonic and adult organisms of many phyla. Although stem cells of various types from mice and other lower organisms have\\u000a been studied for many years, it was not until the derivation of stem cell lines from human embryos in

Victoria L. Browning; Jon S. Odorico

366

Embryonic Stem Cell Course  

NSDL National Science Digital Library

This "Course-in-a-Box" from Bio-Link is a good starting point for instructors to develop a course on embryonic stem cells. If a full course on stem cells is not appropriate for a particular curriculum "individual lectures and activity modules are well-suited for integration into existing bioscience or biotechnology courses." Materials include laboratory protocols for both mouse and human embryonic stem cells, lectures, activities, and assessments. A free login is required to access the materials.

367

Stress and stem cells  

PubMed Central

The unique properties and functions of stem cells make them particularly susceptible to stresses and also lead to their regulation by stress. Stem cell division must respond to the demand to replenish cells during normal tissue turnover as well as in response to damage. Oxidative stress, mechanical stress, growth factors, and cytokines signal stem cell division and differentiation. Many of the conserved pathways regulating stem cell self-renewal and differentiation are also stress-response pathways. The long life span and division potential of stem cells create a propensity for transformation (cancer) and specific stress responses such as apoptosis and senescence act as antitumor mechanisms. Quiescence regulated by CDK inhibitors and a hypoxic niche regulated by FOXO transcription factor function to reduce stress for several types of stem cells to facilitate long-term maintenance. Aging is a particularly relevant stress for stem cells, because repeated demands on stem cell function over the life span can have cumulative cell-autonomous effects including epigenetic dysregulation, mutations, and telomere erosion. In addition, aging of the organism impairs function of the stem cell niche and systemic signals, including chronic inflammation and oxidative stress. PMID:23799624

Tower, John

2013-01-01

368

Stem Cell Resources  

NSDL National Science Digital Library

The mission of the Stem Cell Resources website is "to provide timely, reliable, high-quality and scientifically credible stem cell information for the educational community worldwide." The website is a division of Bioscience Network which publishes online science education materials. On the site, visitors will find a stem cell image library, a multimedia area, and a special section titled "For Educators". In the "For Educators" area, visitors will find links to a primer on stem cells and links to educational resources on stem cells from curriculum to case studies to lesson plans from such trusted sources as the Australian Stem Cell Centre and the National Institutes of Health. Moving on, the "Multimedia" area includes videos that show how embryonic stem cell lines are made, along with other animations and graphics on the topic. Additionally, the site's "SCR Library" area includes the link to the Stem Cell Image Library, which provides dozens of photos of stem cells taken from researchers at the University of Cambridge and other institutions.

369

Donating Peripheral Blood Stem Cells  

MedlinePLUS

... this page Print this page Donating peripheral blood stem cells Peripheral blood stem cell (PBSC) donation is a nonsurgical procedure to collect ... PBSC Donating bone marrow Donor experiences Peripheral blood stem cell (PBSC) donation is one of two methods of ...

370

Lock For Valve Stem  

NASA Technical Reports Server (NTRS)

Simple, cheap device locks valve stem so its setting cannot be changed by unauthorized people. Device covers valve stem; cover locked in place with standard padlock. Valve lock made of PVC pipe and packing band. Shears, drill or punch, and forming rod only tools needed.

Burley, Richard K.; Guirguis, Kamal S.

1991-01-01

371

Skeletal muscle stem cells  

Microsoft Academic Search

Satellite cells are myogenic stem cells responsible for the post-natal growth, repair and maintenance of skeletal muscle. This review focuses on the basic biology of the satellite cell with emphasis on its role in muscle repair and parallels between embryonic myogenesis and muscle regeneration. Recent advances have altered the long-standing view of the satellite cell as a committed myogenic stem

Jennifer CJ Chen; David J Goldhamer

2003-01-01

372

Optimizing stem cell culture  

PubMed Central

Stem cells always balance between self-renewal and differentiation. Hence, stem cell culture parameters are critical and need to be continuously refined according to progress in our stem cell biology understanding and the latest technological developments. This led to the progressive replacement of ill-defined additives such as serum or feeder cell layers by recombinant cytokines or growth factors. Another example is the control of the oxygen pressure. For many years cell cultures have been done under atmospheric oxygen pressure which is much higher than the one experienced by stem cells in vivo. A consequence of cell metabolism is that cell culture conditions are constantly changing. Therefore, the development of high sensitive monitoring processes and control algorithms is required for ensuring cell culture medium homeostasis. Stem cells also sense the physical constraints of their microenvironment. Rigidity, stiffness and geometry of the culture substrate influence stem cell fate. Hence, nanotopography is probably as important as medium formulation in the optimization of stem cell culture conditions. Recent advances include the development of synthetic bioinformative substrates designed at the micro- and nanoscale level. On going research in many different fields including stem cell biology, nanotechnology, and bioengineering suggest that our current way to culture cells in Petri dish or flasks will soon be outdated as flying across the Atlantic Ocean in the Lindbergh’s plane. PMID:20803548

Van Der Sanden, Boudewijn; Dhobb, Mehdi; Berger, François; Wion, Didier

2010-01-01

373

Circulating Skeletal Stem Cells  

Microsoft Academic Search

We report the isolation of adherent, clono- genic, fibroblast-like cells with osteogenic and adipogenic potential from the blood of four mammalian species. These cells phenotypically resemble but are distinguish- able from skeletal stem cells found in bone marrow (stromal stem cells, \\

Sergei A. Kuznetsov; Mahesh H. Mankani; Stan Gronthos; Kazuhito Satomura; Paolo Bianco; Pamela Gehron Robey

2001-01-01

374

Bioreactors Stem Cells  

E-print Network

Keywords Bioreactors Stem Cells Regenerative Medicine Tissue Engineering Pharmacology » Prof. M.; yeZhelyev, M.; eMMrich, F.; o'regan, r.; bader, a. Quantum dots for human mesenchymal stem cells and mechanical forces mediated to the cells by the matrix. The in vivo extracellular matrix constitutes

Schüler, Axel

375

Bringing STEM to Life  

ERIC Educational Resources Information Center

The interdisciplinary approach that science, technology, engineering and mathematics (STEM) projects inspire in both teachers and students "brings to light a larger picture that promotes real-world scientific applications, which has in turn been shown to increase undergraduate persistence in STEM." The high school students have been warned…

Berkeihiser, Mike; Ray, Dori

2013-01-01

376

The filamentous phage XacF1 causes loss of virulence in Xanthomonas axonopodis pv. citri, the causative agent of citrus canker disease.  

PubMed

In this study, filamentous phage XacF1, which can infect Xanthomonas axonopodis pv. citri (Xac) strains, was isolated and characterized. Electron microscopy showed that XacF1 is a member of the family Inoviridae and is about 600 nm long. The genome of XacF1 is 7325 nucleotides in size, containing 13 predicted open reading frames (ORFs), some of which showed significant homology to Ff-like phage proteins such as ORF1 (pII), ORF2 (pV), ORF6 (pIII), and ORF8 (pVI). XacF1 showed a relatively wide host range, infecting seven out of 11 strains tested in this study. Frequently, XacF1 was found to be integrated into the genome of Xac strains. This integration occurred at the host dif site (attB) and was mediated by the host XerC/D recombination system. The attP sequence was identical to that of Xanthomonas phage Cf1c. Interestingly, infection by XacF1 phage caused several physiological changes to the bacterial host cells, including lower levels of extracellular polysaccharide production, reduced motility, slower growth rate, and a dramatic reduction in virulence. In particular, the reduction in virulence suggested possible utilization of XacF1 as a biological control agent against citrus canker disease. PMID:25071734

Ahmad, Abdelmonim Ali; Askora, Ahmed; Kawasaki, Takeru; Fujie, Makoto; Yamada, Takashi

2014-01-01

377

The filamentous phage XacF1 causes loss of virulence in Xanthomonas axonopodis pv. citri, the causative agent of citrus canker disease  

PubMed Central

In this study, filamentous phage XacF1, which can infect Xanthomonas axonopodis pv. citri (Xac) strains, was isolated and characterized. Electron microscopy showed that XacF1 is a member of the family Inoviridae and is about 600 nm long. The genome of XacF1 is 7325 nucleotides in size, containing 13 predicted open reading frames (ORFs), some of which showed significant homology to Ff-like phage proteins such as ORF1 (pII), ORF2 (pV), ORF6 (pIII), and ORF8 (pVI). XacF1 showed a relatively wide host range, infecting seven out of 11 strains tested in this study. Frequently, XacF1 was found to be integrated into the genome of Xac strains. This integration occurred at the host dif site (attB) and was mediated by the host XerC/D recombination system. The attP sequence was identical to that of Xanthomonas phage Cf1c. Interestingly, infection by XacF1 phage caused several physiological changes to the bacterial host cells, including lower levels of extracellular polysaccharide production, reduced motility, slower growth rate, and a dramatic reduction in virulence. In particular, the reduction in virulence suggested possible utilization of XacF1 as a biological control agent against citrus canker disease. PMID:25071734

Ahmad, Abdelmonim Ali; Askora, Ahmed; Kawasaki, Takeru; Fujie, Makoto; Yamada, Takashi

2014-01-01

378

STEM Education Coalition  

NSDL National Science Digital Library

The Science Technology Engineering and Mathematics (STEM) Education Coalition is an educational lobbying group that promotes "policies to improve STEM education at all levels." A coalition consisting of 500 organizations, it aims to educate policymakers about the importance of STEM education in keeping the U.S. competitive in the global marketplace. Visitors can find testimony and letters from the Coalition to various lawmakers in the "Positions and Activities" tab, including Secretary of Education Arne Duncan, the President's Council of Advisors on Science and Technology, and President Obama himself. The "STEM Resources" tab has multiple links to fact sheets, report cards, and various reports that indicate the state of STEM education in the U.S. Visitors will also find an extensive number of panel discussions, commissions, and reports, beginning with a report from September 1996 on teaching and America's future to a more recent report titled "Tapping America's Potential: Gaining Momentum, Losing Ground."

379

Cell Stem Cell From Stem Cells to Grandmother Cells  

E-print Network

how learning enhances the survival of neural stem/progenitor cell progeny and what these new neuronsCell Stem Cell Commentary From Stem Cells to Grandmother Cells: How Neurogenesis Relates@rutgers.edu DOI 10.1016/j.stem.2008.08.010 Neurogenesis contributes thousands of new neurons each day

Shors, Tracey J.

380

Cell Stem Cell Molecular Analysis of Stem Cells and Their  

E-print Network

mediterranea provide an interesting model for studying both stem cell function and line- age commitment duringCell Stem Cell Article Molecular Analysis of Stem Cells and Their Descendants during Cell Turnover@neuro.utah.edu DOI 10.1016/j.stem.2008.07.002 SUMMARY In adult planarians, the replacement of cells lost

Alvarado, Alejandro Sánchez

381

``Stemness'': Transcriptional Profiling of Embryonic and Adult Stem Cells  

Microsoft Academic Search

The transcriptional profiles of mouse embryonic, neural, and hematopoietic stem cells were compared to define a genetic program for stem cells. A total of 216 genes are enriched in all three types of stem cells, and several of these genes are clustered in the genome. When compared to differentiated cell types, stem cells express a significantly higher number of genes

Miguel Ramalho-Santos; Soonsang Yoon; Yumi Matsuzaki; Richard C. Mulligan; Douglas A. Melton

2002-01-01

382

Cell Stem Cell Control of Stem Cell Fate by Physical  

E-print Network

Cell Stem Cell Review Control of Stem Cell Fate by Physical Interactions with the Extracellular, Philadelphia, PA 19104, USA 5Stem Cell Laboratory, Pennington Biomedical Research Center, Louisiana State.06.016 A diverse array of environmental factors contributes to the overall control of stem cell activity

Chen, Christopher S.

383

Cell Stem Cell Stem Cell Epigenetics: Looking Forward  

E-print Network

Cell Stem Cell Voices Stem Cell Epigenetics: Looking Forward Epigenetics in Adult SCs The integrity of tissues is maintained by adult stem cells during adulthood. How- ever, recent work indicates that tissues often contain more than one population of stem cells that are located at distinct niches and display

Sander, Maike

384

Mesenchymal stem cells.  

PubMed

Stem cells have two features: the ability to differentiate along different lineages and the ability of self-renewal. Two major types of stem cells have been described, namely, embryonic stem cells and adult stem cells. Embryonic stem cells (ESC) are obtained from the inner cell mass of the blastocyst and are associated with tumorigenesis, and the use of human ESCs involves ethical and legal considerations. The use of adult mesenchymal stem cells is less problematic with regard to these issues. Mesenchymal stem cells (MSCs) are stromal cells that have the ability to self-renew and also exhibit multilineage differentiation. MSCs can be isolated from a variety of tissues, such as umbilical cord, endometrial polyps, menses blood, bone marrow, adipose tissue, etc. This is because the ease of harvest and quantity obtained make these sources most practical for experimental and possible clinical applications. Recently, MSCs have been found in new sources, such as menstrual blood and endometrium. There are likely more sources of MSCs waiting to be discovered, and MSCs may be a good candidate for future experimental or clinical applications. One of the major challenges is to elucidate the mechanisms of differentiation, mobilization, and homing of MSCs, which are highly complex. The multipotent properties of MSCs make them an attractive choice for possible development of clinical applications. Future studies should explore the role of MSCs in differentiation, transplantation, and immune response in various diseases. PMID:21396235

Ding, Dah-Ching; Shyu, Woei-Cherng; Lin, Shinn-Zong

2011-01-01

385

Stem Cell Differentiation Game  

NSDL National Science Digital Library

This game uses a modified Uno deck to review concepts related to stem cell research and diabetes. Specifically, it covers material in the "Pulse-Chase Primer," "Pancreatic Beta Cells," and "Microarrays and Stem Cells" activities from the same resource which may or may not be necessary to complete prior to this activity (depending on learner's prior knowledge). Learners accumulate points and answer questions about stem cells, development, and microarrays so that they can be the first to differentiate into a pancreatic beta (?) cell. This activity is recommended for learners studying Biology at the High School (honors, IB and AP) or Undergraduate level.

2013-07-30

386

Bone marrow stem cells.  

PubMed

The "mesenchymal stem cells (MSCs)" are cells adherent in the bone marrow, which can be isolated to induce differentiation. In contrast to the "embryonic stem cells" whose goal is to develop a new organism, the "MSC adult stem cells" can participate in tissue growth and repair throughout postnatal life. Addition of 5-azacytidine to MSCs in vitro induces the gradual increase in cellular size and begins spontaneous beatings, thereafter differentiating into cardiomyocytes. The "Methods" and "Protocols" to induce structural and functional maturations of MSCs, thus to achieve "Cellular Cardiomyoplasty," are described. With appropriate media, differentiations of MSCs to various kinds of cells such as chondrocytes, osteocytes, and adipocytes are also achievable. PMID:23807784

Duong, Minh Ngoc; Ma, Yu-Ting; Chiu, Ray C J

2013-01-01

387

Stem Cell Task Force  

NSDL National Science Digital Library

This Web site from the National Institutes of Health (NIH) provides an overview of the activities of an NIH task force established to move the stem cell research agenda forward. The section titled Scientific Research may be of particular interest to researchers in this area. It provides links to the Web sites of stem cell-related research at a number of NIH institutes, as well as an extensive information index, a FAQs page about stem cell research, information on funding opportunities, and much more.

388

Cardiac stem cell niches.  

PubMed

The critical role that stem cell niches have in cardiac homeostasis and myocardial repair following injury is the focus of this review. Cardiac niches represent specialized microdomains where the quiescent and activated state of resident stem cells is regulated. Alterations in niche function with aging and cardiac diseases result in abnormal sites of cardiomyogenesis and inadequate myocyte formation. The relevance of Notch1 signaling, gap-junction formation, HIF-1? and metabolic state in the regulation of stem cell growth and differentiation within the cardiac niches are discussed. PMID:25267073

Leri, Annarosa; Rota, Marcello; Hosoda, Toru; Goichberg, Polina; Anversa, Piero

2014-11-01

389

LESSON PLAN Stem Cell Discussion  

E-print Network

LESSON PLAN Stem Cell Discussion Learning objectives Students will: · consider the implications of stem cell research · research the current research situation · debate the future of stem cell of the Wellcome Trust, discusses why stem cells have the potential to treat many debilitating diseases, and why

Rambaut, Andrew

390

Information on Stem Cell Research  

MedlinePLUS

Information on Stem Cell Research Research @ NINDS Stem Cell Highlights Submit a hESC line for NIH review (9/21/09) NIH Opens ... found here: Human Induced Pluripotent Stem Cells NINDS Stem Cell Research on Campus The Intramural Research Program of ...

391

Cell Stem Cell Clinical Progress  

E-print Network

Cell Stem Cell Clinical Progress Rapid Expansion of Human Hematopoietic Stem Cells by Automated implementations of hematopoietic stem cells (HSCs) and their deriva- tives further increase interest in strategies the marked improvements that control of feed- back signaling can offer primary stem cell culture

Zandstra, Peter W.

392

The advantages of hair follicle pluripotent stem cells over embryonic stem cells and induced pluripotent stem cells for regenerative medicine  

Microsoft Academic Search

Multipotent adult stem cells have many potential therapeutic applications. Our recent findings suggest that hair follicles are a promising source of easily accessible multipotent stem cells. Stem cells in the hair follicle area express the neural stem cell marker nestin, suggesting that hair-follicle stem cells and neural stem cells have common features. Nestin-expressing hair follicle stem cells can form neurons

Yasuyuki Amoh; Kensei Katsuoka; Robert M. Hoffman

2010-01-01

393

STEM Careers Grad Students  

NSDL National Science Digital Library

This brief video from WPSU introduces a diverse group of graduate students with interests in STEM careers. From deep sea diving to creating video games, each graduate student is pursuing activities beyond the stereotypical view of a nerdy scientist.

2009-11-09

394

STEM Careers Middle School  

NSDL National Science Digital Library

This brief video from WPSU introduces a diverse group of middle school students with interests in STEM careers. Whether creating robots or designing solar cars, each student dreams of activities beyond the stereotypical view of a nerdy scientist.

WPSU

2009-11-10

395

Editor's Note: STEM Careers  

NSDL National Science Digital Library

There is a new impetus for encouraging students to become more knowledgeable about science, technology, engineering, and mathematics (STEM) and perhaps encourage them to choose a career in science-related fields. Several groups and individuals, including

Linda Froschauer

2010-03-01

396

Clonal interrogation of stem cells  

Microsoft Academic Search

Individual stem cells are functionally defined by their self-renewal and differentiation potential. Methods for clonal analysis are essential for understanding stem cells, particularly given the increasing evidence for stem-cell heterogeneity. Stem cells reside within complex microenvironments, making single-cell analysis particularly challenging. Furthermore, simultaneous molecular and functional characterization of single stem cells is not trivial. Here we explore clonal assays applied

Kristin Hope; Mickie Bhatia

2011-01-01

397

Control of Stemness by Fibroblast Growth Factor Signaling in Stem Cells and Cancer Stem Cells  

Microsoft Academic Search

Since the discovery of stem cells, scientists have invested tremendous effort in establishing in vitro culture conditions in order to maintain the self-renewal and efficient proliferative capabilities of stem cells by manipulating a va- riety of growth factors. Fibroblast growth factor (FGF) is one of the most common growth factors used to expand stem cells, including human embryonic stem (hES)

Noriko Gotoh

2009-01-01

398

Study of rhizosphere and phyllosphere bacterial community and resistance to bacterial canker in genetically engineered phytochrome A cherry plants.  

PubMed

The cherry rootstock 'Colt' line was transformed with a phytochrome A rice gene with the aim of altering light perception. Three transgenic events were chosen because of a modified developmental behavior. When red enriched light was supplied horizontally to stems, the PD3 transgenic line showed an increased rate of phytomer formation associated to a superior rate of plant growth compared to wild type (WT). Under the same light conditions, the PO1 and PA lines were less altered in morphology and development. When far-red enriched light was supplied, all transgenic lines had a reduced rate of growth, with the PD3 line being the most similar to the WT. The influence of the alien gene on root and leaf-associated bacteria was studied for a duration of 1 year. Significantly more culturable bacteria were recovered from PA lines than from PO1, PD3 and WT lines. On average, significantly more fluorescent pseudomonads were recovered from the rhizosphere of PA and PO1 lines than from PD3 and WT. No significant differences were detected in the number of bacteria recovered from the phyllosphere of transgenic and WT plant lines. A total of 143 Pseudomonas fluorescens strains isolated from rhizosphere of transgenic and WT lines were tested for their antagonistic activity against Phytophthora nicotianae and differences between bacteria derived from transgenic and WT were not detected. Fluorescent pseudomonads strains isolated from phyllosphere of PA and PO1 lines showed antagonistic activity against P. syringae pv. syringae, whereas no difference among the transgenic and WT lines was detected when fluorescent Pseudomonas strains were tested against P. syringae pv. mors-prunorum. Pathogenicity tests were conducted on rooted and micropropagated plants with P. s. pv. syringae and P. s. pv. mors-prunorum: in all assays, the PO1 lines were the most tolerant to P. s. pv. Syringae, and the PO1 and PD3 were tolerant to P. s. pv. mors-prunorum. PMID:18439710

Cirvilleri, Gabriella; Spina, Stefania; Iacona, Calogero; Catara, Antonino; Muleo, Rosario

2008-07-01

399

Stem Cell Niche  

Microsoft Academic Search

\\u000a The adult stem cells are essential for maintaining tissue homeostasis and commonly reside in specific local microenvironment\\u000a named niche. The niche keeps stem cells in multipotent state, prevents them from precocious differentiation and positions\\u000a them to undergo asymmetric division to produce differentiated ­progenies for tissue regeneration. The niches employ a variety\\u000a of factors including cell adhesion molecules, extra cellular matrix,

Pei Wen; Pei Sun; Rongwen Xi

400

Skeletal muscle stem cells.  

PubMed

Skeletal muscle satellite cells (myoblasts) are the primary stem cells of skeletal muscle which contribute to growth, maintenance, and repair of the muscles. Satellite cells are the first stem cells used for cellular cardiomyoplasty more than 20 years ago. The isolation, culture, labeling, and identification of satellite cells are described in detail here. The implantation and outcomes of cellular cardiomyoplasty using satellite cells have been summarized in the previous chapter (Chapter 1). PMID:23807783

Kao, Grace W; Lamb, Elizabeth K; Kao, Race L

2013-01-01

401

Valve stem and packing assembly  

DOEpatents

A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

Wordin, John J. (Bingham County, ID)

1991-01-01

402

Valve stem and packing assembly  

DOEpatents

A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents over tightening of the retaining nut and the resulting excessive friction between stem and stem packing. 2 figures.

Wordin, J.J.

1991-09-03

403

Colon cancer stem cells.  

PubMed

Colorectal cancer (CRC) is the third most common form of cancer and the second cause of cancer-related death in the Western world, leading to 655,000 deaths worldwide per year (Jemal et al. in CA Cancer J Clin 56:106-130, 2006). Despite the emergence of new targeted agents and the use of various therapeutic combinations, none of the treatment options available is curative in patients with advanced cancer. A growing body of evidence is increasingly supporting the idea that human cancers can be considered as a stem cell disease. According to the cancer stem cell model, malignancies originate from a small fraction of cancer cells that show self-renewal and pluripotency and are capable of initiating and sustaining tumor growth (Boman and Wicha in J Clin Oncol 26:2795-2799, 2008). The cancer-initiating cells or "cancer stem cells" were first identified in hematologic malignancies and most recently in several solid tumors, including CRC. The hypothesis of stem cell-driven tumorigenesis in colon cancer raises questions as to whether current treatments are able to efficiently target the tumorigenic cell population that is responsible for tumor growth and maintenance. This review will focus on the different aspects of stem cell biology in the context of CRC, which might help to understand the mechanisms that give rise to tumor development and resistance to therapy. First, we will briefly revise the knowledge available on normal intestinal stem cells and recent advances in understanding crypt biology, which have led to new theory on the origins of colon adenomas and cancers. Then, we will summarize the evidence and current status on colon cancer stem cells, focusing on their relevance and promises for the treatment of colorectal carcinoma. PMID:19727638

Ricci-Vitiani, Lucia; Fabrizi, Eros; Palio, Elisabetta; De Maria, Ruggero

2009-11-01

404

Fifth Annual Stem Cell Summit.  

PubMed

The Fifth Annual Stem Cell Summit, held in New York, included topics covering new commercial developments in the research field of stem cell-based therapies. This conference report highlights selected presentations on embryonic and adult stem cells, stem cell-based therapies for the treatment of orthopedic and cardiovascular indications and inflammatory diseases, as well as technologies for processing and storing stem cells. Investigational therapies discussed include placental expanded (PLX) cells (Pluristem Therapeutics Inc), StemEx (Gamida-Teva Joint Venture/Teva Pharmaceutical Industries Ltd) and remestemcel-L (Osiris Therapeutics Inc/Genzyme Corp/JCR Pharmaceuticals Co Ltd/ Mochida Pharmaceutical Co Ltd). PMID:20373251

Knowlton, Daniel

2010-04-01

405

STEM Guitar Project  

NSDL National Science Digital Library

This ATE professional development project is a collaboration between STEM faculty teams from Butler County Community College (Butler, PA), Purdue University (West Lafayette, IN), Sinclair Community College (Dayton, OH), Ventura College (Ventura, CA), College of the Redwoods (Eureka, Ca.), as well as high school STEM faculty in each of the states involved. Faculty teams at the respective locations are working together to design, build, and analyze solid body electric guitars as a means of learning applied concepts of science, technology, engineering, mathematics, and as a means of understanding product lifecycle management. This experience is providing teachers and students an accurate simulation of the collaborative design and rapid manufacturing processes routinely used in business and industry. Over 150 STEM faculty members from high schools and community colleges are participating in an intense five-day Summer Professional Development Program and are having extensive academic year follow-up activities. The teacher participants are using these processes and simulations in their classrooms to enhance the STEM laboratory learning experience. Nearly 5000 students are learning about cross-disciplinary STEM problem solving that is becoming increasingly important for new design technicians to experience.On the site, visitors can find curriculum materials including classroom tools and information on guitar fabrication. There are also details of upcoming workshops and professional development opportunities. In the Storefront section, visitors can learn about how to purchase a guitar kit.

406

Overexpression of the Tomato Asc1 Gene Mediates High Insensitivity to AAL Toxins and Fumonisin B1 in Tomato Hairy Roots and Confers Resistance to Alternaria alternata f. sp. lycopersici in Nicotiana umbratica Plants  

Microsoft Academic Search

The sphinganine-analog mycotoxins (SAMs) fumonisin B1 and AAL toxins are inhibitors of eukaryotic sphinganine N- acyltransferase in vitro. Treatment of eukaryotes with SAMs generally results in an accumulation of sphingoid base precursors and a depletion of complex sphingolipids. The asc,asc genotypes of tomato (Lycopersicon esculentum) and Nicotiana umbratica are sensitive to SAMs and host of the AAL toxin-producing fungus Alternaria

Bas F. Brandwagt; J. A. Kneppers; John J. Nijkamp; Jacques Hille

407

Overexpression of the Tomato Asc1 Gene Mediates High Insensitivity to AAL Toxins and Fumonisin B1 in Tomato Hairy Roots and Confers Resistance to Alternaria alternata f. sp. lycopersici in Nicotiana umbratica Plants  

Microsoft Academic Search

The sphinganine-analog mycotoxins (SAMs) fumonisin B1 and AAL toxins are inhibitors of eukaryotic sphinganine N-acyltransferase in vitro. Treatment of eukaryotes with SAMs generally results in an accumulation of sphingoid base precursors and a depletion of complex sphingolipids. The asc,asc genotypes of tomato (Lycopersicon esculentum) and Nicotiana umbratica are sensitive to SAMs and host of the AAL toxin-producing fungus Alternaria alternata

Bas F. Brandwagt; Tarcies J. A. Kneppers; H. John J. Nijkamp; Jacques Hille

2002-01-01

408

Microarrays and Stem Cells  

NSDL National Science Digital Library

In this activity, learners use microarray technology to determine which genes are turned on and off at various points in the differentiation of pluripotent stem cells on their way to becoming pancreatic ? cells. An introductory PowerPoint, reading, video clip and an animation provide learners with background information needed to interpret the results of a paper microarray simulation. Learners will position cDNA strips on mini-microarrays to discover which genes are expressing, to what degree they are expressing, and which are not. They use these findings to trace the differentiation of embryonic stem cells that give rise to pancreatic ? cells and other cell types. The role of growth factors and proximity of other cell types is central to learners understanding how researchers may direct the ultimate fate of stem cells. The value of this in treating diabetes is also discussed. This activity is recommended for learners studying Biology at the High School (honors, IB and AP) or Undergraduate level.

Mary Colvard

2010-01-01

409

Intestinal stem cells.  

PubMed

Self-renewal in the intestinal epithelia is fueled by a population of undifferentiated intestinal stem cells (ISCs) that give rise to daughter or progenitor cells, which can subsequently differentiate into the mature cell types required for normal gut function. The cellular signals that regulate self-renewal are poorly understood and the factors that mediate the transition from a stem cell to a progenitor cell in the gut are unknown. Recent studies have suggested that ISCs are located either at the crypt base interspersed between the Paneth cells (eg, Lgr-5+ve cells) or at or near position 4 within the intestinal crypt (eg, DCAMKL-1 or Bmi-1+ve cells). This raises the possibility that distinct stem cell regions exist in the crypts and that ISC's state of activation will determine how the self-renewal is regulated in the intestinal tract. PMID:20683682

Umar, Shahid

2010-10-01

410

Cancer stem cells and “stemness” genes in neuro-oncology  

Microsoft Academic Search

The main properties of stem cells include long-term self-renewal and the capacity to give rise to one or more types of differentiated progeny. Recently, much evidence was provided that leukemia and tumor maintenance and growth are sustained by a small proportion of cells exhibiting stem cell properties. In neural tumors, stem cells have been detected in glioblastoma, medulloblastoma and ependymoma.

Silvia K. Nicolis

2007-01-01

411

Stem Cells Branch Out  

NSDL National Science Digital Library

Heals all manner of ailments, unlimited quantities, tailor-made for you. â?¦ No, it's not an advertisement for snake oil but may represent the promise of stem cellsâ??cells that have the potential to produce various cell types that make up the body and might therefore provide replacements for tissues damaged by age, trauma, or disease. But the work raises numerous questions as well: Can such promise be true? What is the ethical cost of such developments? Who will fund the necessary R&D? This article introduces a special issue on stem cells.

Pamela Hines (AAAS; )

2000-02-25

412

GIS in STEM Education  

E-print Network

GIS in STEM Education? GIS Day 2014 – University of Kansas? November 19, 2014 Esri Education Manager Adjunct Researcher, Center for STEM Learning University of Kansas @trbaker? tbaker@esri.com? Thomas R. Baker? Images used... in this presentation:? gps.gov; esri.com; gis.com; garmin.com; popularmechaics.com ? GeoSpatial Tech? What is GIS? ? http://arcgis.com ? http://connectED.esri.com? Learning? A Tool for Thinkers? ? •? Think about a topic or a place ... •? Ask a question about...

Baker, Michael

2014-11-19

413

STEM on the radio  

NASA Astrophysics Data System (ADS)

Looking for an Internet radio station focusing on programing about science, technology, engineering, and math (STEM)? The U.S. National Science Foundation (NSF) announced on 26 September the launch of Science360 Radio, which it says is the first Internet radio stream dedicated to STEM programing. Science360 includes more than 100 radio shows and podcasts that are available on the Web as well as on iPhone and Android devices. The shows originate from a variety of sources, including NSF, other U.S. government agencies, science organizations, universities, and media outlets. For more information, see http://science360.gov/files/.

Showstack, Randy

2011-10-01

414

Cell Fusion and Stem Cells  

Microsoft Academic Search

\\u000a Differentiation, self-renewal and the ability to readily undergo cell fusion are properties of adult and embryonic stem cells.\\u000a Spontaneous fusion between stem cells, and fusion of stem cells with various differentiated cell types, has been observed\\u000a in many in vitro and in vivo contexts. Stem cell fusion is implicated in many crucial functions during normal development\\u000a and is increasingly being

Alain Silk; Anne E. Powell; Paige S. Davies; Melissa H. Wong

415

Laser biomodulation on stem cells  

NASA Astrophysics Data System (ADS)

Stem cells are views from the perspectives of their function, evolution, development, and cause. Counterintuitively, most stem cells may arise late in development, to act principally in tissue renewal, thus ensuring an organisms long-term survival. Surprisingly, recent reports suggest that tissue-specific adult stem cells have the potential to contribute to replenishment of multiple adult tissues. Stem cells are currently in the news for two reasons: the successful cultivation of human embryonic stem cell lines and reports that adult stem cells can differentiate into developmentally unrelated cell types, such as nerve cells into blood cells. The spotlight on stem cells has revealed gaps in our knowledge that must be filled if we are to take advantage of their full potential for treating devastating degenerative diseases such as Parkinsons's disease and muscular dystrophy. We need to know more about the intrinsic controls that keep stem cells as stem cells or direct them along particular differentiation pathways. Such intrinsic regulators are, in turn, sensitive to the influences of the microenvironment, or niche, where stem cells normally reside. Both intrinsic and extrinsic signals regular stem cell fate and some of these signals have now been identified. Vacek et al and Wang et al have studied the effect of low intensity laser on the haemopoietic stem cells in vitro. There experiments show there is indeed the effect of low intensity laser on the haemopoietic stem cells in vitro, and the present effect is the promotion of haemopoietic stem cells proliferation. In other words, low intensity laser irradiation can act as an extrinsic signal regulating stem cell fate. In this paper, we study how low intensity laser can be used to regulate stem cell fate from the viewpoint of collective phototransduction.

Liu, Timon C.; Duan, Rui; Li, Yan; Li, Xue-Feng; Tan, Li-Ling; Liu, Songhao

2001-08-01

416

STEM--Beyond the Acronym  

ERIC Educational Resources Information Center

When most educators think of STEM education, they think of fully integrated projects seamlessly combining all four disciplines--science, technology, engineering, and mathematics. Although such transdisciplinary STEM units are ideal, writes Vasquez, they are not the only way to give students valuable STEM experiences. She gives examples of two…

Vasquez, Jo Anne

2015-01-01

417

Cell Stem Cell Protocol Review  

E-print Network

neurons might be re- placed. As the identity of ``true'' CNS stem cells, defined as being capableCell Stem Cell Protocol Review Everything that Glitters Isn't Gold: A Critical Review of Postnatal School and Massachusetts General Hospital, Boston, MA 02114, USA 6Department of Stem Cell

418

Once Upon a Stem Cell  

MedlinePLUS

... Science > Once Upon a Stem Cell Inside Life Science View All Articles | Inside Life Science Home Page Once Upon a Stem Cell By ... Do Geometry Sticky Stem Cells This Inside Life Science article also appears on LiveScience . Learn about related ...

419

The River of Stem Cells  

PubMed Central

In this issue of Cell Stem Cell, Greco et al. (2009) characterize the hair germ as a novel stop between bulge stem cell and transient amplifying cells during hair regeneration. The work implies stem cell states can be regulated to form different numbers of intermediate stops, depending on physiological requirements. PMID:19200797

Chuong, Cheng-Ming; Widelitz, Randall Bruce

2015-01-01

420

Embryonic Stem Cells from Parthenotes  

Microsoft Academic Search

While human embryonic stem cells (hESCs) hold tremendous therapeutic potential, they also create societal and ethical dilemmas. Adult and placental stem cells represent two alternatives to the hESC, but may have technical limitations. An additional alternative is the stem cell derived from parthenogenesis. Parthenogenesis is a reproductive mechanism that is common in lower organisms and produces a live birth from

Jose B. Cibelli; Kerrianne Cunniff; Kent E. Vrana

2006-01-01

421

Haute Culture: Tailoring stem cells  

E-print Network

research projects and its faculty have founded five stem cell-related startup companies and serveHaute Culture: Tailoring stem cells to make us well Tuesday, April 24, 2012 6:00-7:30 p;Haute Culture: Tailoring stem cells to make us well Moderator Brock Reeve, MPhil, MBA Executive Director

Chou, James

422

Cell Stem Cell Brief Report  

E-print Network

Cell Stem Cell Brief Report Reprogramming of T Cells from Human Peripheral Blood Yuin-Han Loh,1,2,5,9,10,* 1Stem Cell Transplantation Program, Division of Pediatric Hematology Oncology, Children's Hospital, Harvard Medical School, Boston, MA 02115, USA 2Harvard Stem Cell Institute, Cambridge, MA 02138, USA 3

Church, George M.

423

Spring black stem  

Technology Transfer Automated Retrieval System (TEKTRAN)

Spring black stem is the most destructive alfalfa diseases in temperate regions of the U.S., Canada, Australia, and countries of Europe, Asia, and South America. The disease causes serious yield losses by reducing canopy dry matter and also decreases seed weight and crown and root mass. Forage qua...

424

Botryosphaeria Stem Blight  

Technology Transfer Automated Retrieval System (TEKTRAN)

Stem blight, commonly referred to as dieback, is a destructive disease of highbush and rabbiteye blueberry primarily in the southeastern United States extending north into New Jersey. Losses are most severe in young fields where plants often become infected and die in the first two years. In older...

425

"Excellence" in STEM Education  

ERIC Educational Resources Information Center

So what does it take to achieve excellence in STEM education? That is the title of the author's presentation delivered at International Technology and Engineering Educators Association's (ITEEA's) FTEE "Spirit of Excellence" Breakfast on March 16, 2012, in Long Beach, California. In preparation for this presentation, the author went back and read…

Clark, Aaron C.

2012-01-01

426

SMOOTH MUSCLE STEM CELLS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Vascular smooth muscle cells (SMCs) originate from multiple types of progenitor cells. In the embryo, the most well-studied SMC progenitor is the cardiac neural crest stem cell. Smooth muscle differentiation in the neural crest lineage is controlled by a combination of cell intrinsic factors, includ...

427

Embryonic Stem Cells  

NSDL National Science Digital Library

BioEd Online is an "educational resource for educators, students, and parents" from the Baylor College of Medicine. This is an excellent place to find educational materials and current information in the field of biology. The "Hot Topics" section of this site focus on current events and issues in biology that are "receiving national attention." The controversy surrounding embryonic stem cells, and coverage it receives in news and research publications in the United States and around the world definitely warrants a closer look at this issue. This "Hot Topic" compiled by Joseph Marx, PhD, Nancy Moreno, PhD, and Deanne Erdmann, MS, contains a brief discussion of the stem cell debate, and includes references and links for further reading. Related news articles can be found as well. Be sure to check out the related slide sets for both embryonic stem cells and stem cells. These slide shows are an excellent resource to use in the classroom. Just add the slides you wish to use to your tray and then view or download your slide tray for an instant visual resource.

Erdmann, Deanne

2006-07-20

428

A Problem with STEM  

ERIC Educational Resources Information Center

Striking differences between physics and biology have important implications for interdisciplinary science, technology, engineering, and mathematics (STEM) education. The author is a physicist with interdisciplinary connections. The research group in which he works, the Center for Nonlinear Dynamics at the University of Texas at Austin, is…

Marder, Michael

2013-01-01

429

STEM At Work  

NSDL National Science Digital Library

STEM (Science Technology Engineering & Math) at work, presented by the Florida Advanced Technological Education Center, includes a number of educational puzzles for use in the classroom. Puzzles include an energy audit exercise, measurement of air bag movement, and diesel fuel additive volatility.

430

Siemens Stem Academy  

NSDL National Science Digital Library

This website hosts resources for K-12 educators looking to access and share ideas for STEM (science, technology, engineering and mathematics) education. Monthly webinars (archived), lessons, videos, a blog, posters and other materials are available. Professional development opportunities are posted. Some resources require a free registration.

2012-01-01

431

Advancing Diversity in STEM  

ERIC Educational Resources Information Center

Although progress has been made, greater efforts are needed to promote faculty diversity at the college and university levels, especially in STEM fields. Thus, it is important to elucidate best practices both for increasing awareness of diversity issues pertaining to higher education and for implementing change. This article focuses on the…

Hill, Paul L.; Shaw, Rose A.; Taylor, Jan R.; Hallar, Brittan L.

2011-01-01

432

Helping STEM Take Root  

ERIC Educational Resources Information Center

STEM--the catchy shorthand for "science, technology, engineering and mathematics"--has been part of the school improvement discussion for more than a decade, as educational leaders and policy makers have underscored the importance of these areas in preparing students for an internationally competitive, 21st-century economy. But while the acronym…

Schachter, Ron

2011-01-01

433

STEMMING the Gap  

ERIC Educational Resources Information Center

America has a gap when it comes to youth pursuing science and technology careers. In an effort to improve the knowledge and application of science, technology, engineering, and math (STEM), after-school programs can work in conjunction with formal in-school curriculum to improve science education. One organization that actively addresses this…

Kahler, Jim; Valentine, Nancy

2011-01-01

434

Global STEM Navigators  

ERIC Educational Resources Information Center

In the STEM classroom, students can work in collaborative teams to build those essential skills needed for the 21st-century world. In project-based learning (PBL), teams of four to six students are often randomly selected to describe a realistic situation that may occur in today's workplace; this may be done by counting off in fours, fives,…

Dalimonte, Cathy

2013-01-01

435

Education research Making STEM  

E-print Network

on these disciplines in a collaborative way. Schools were given the freedom to develop projects that were suitable of the project. This report, Working Together, explores the importance of STEM education, the impacts to schools elsewhere. The report is structured as follows: · What did Camden schools do? · The importance

Rambaut, Andrew

436

Epithelial Cells Stem Cells  

E-print Network

Keywords Epithelial Cells Keratins Stem Cells » Prof. Thomas M. Magin Epithelia protect the body, altered cell adhesion and signal- ling. As no molecular therapy for these conditions is available, one that the co-chaperone CHIP can remove mutant aggregated keratins in a cell culture model of EBS, leading

Schüler, Axel

437

STEM Sense and Nonsense  

ERIC Educational Resources Information Center

If you can believe the daily flood of mass media stories, journal articles, and white papers, the United States is facing a STEM worker crisis. Business leaders and politicians warn that the nation is falling hopelessly behind in the global economic race because our students are unprepared for and uninterested in science, technology, engineering,…

Charette, Robert N.

2015-01-01

438

Stem cell mobilization.  

PubMed

Successful blood and marrow transplant (BMT), both autologous and allogeneic, requires the infusion of a sufficient number of hematopoietic progenitor/stem cells (HPCs) capable of homing to the marrow cavity and regenerating a full array of hematopoietic cell lineages in a timely fashion. At present, the most commonly used surrogate marker for HPCs is the cell surface marker CD34, identified in the clinical laboratory by flow cytometry. Clinical studies have shown that infusion of at least 2 x 10(6) CD34(+) cells/kg recipient body weight results in reliable engraftment as measured by recovery of adequate neutrophil and platelet counts approximately 14 days after transplant. Recruitment of HPCs from the marrow into the blood is termed mobilization, or, more commonly, stem cell mobilization. In Section I, Dr. Tsvee Lapidot and colleagues review the wide range of factors influencing stem cell mobilization. Our current understanding focuses on chemokines, proteolytic enzymes, adhesion molecules, cytokines and stromal cell-stem cell interactions. On the basis of this understanding, new approaches to mobilization have been designed and are now starting to undergo clinical testing. In Section II, Dr. Michele Cottler-Fox describes factors predicting the ability to mobilize the older patient with myeloma. In addition, clinical approaches to improving collection by individualizing the timing of apheresis and adjusting the volume of blood processed to achieve a desired product are discussed. Key to this process is the daily enumeration of blood CD34(+) cells. Newer methods of enumerating and mobilizing autologous blood HPCs are discussed. In Section III, Dr. John DiPersio and colleagues provide data on clinical results of mobilizing allogeneic donors with G-CSF, GM-CSF and the combination of both as relates to the number and type of cells collected by apheresis. Newer methods of stem cell mobilization as well as the relationship of graft composition on immune reconstitution and GVHD are discussed. PMID:14633793

Cottler-Fox, Michele H; Lapidot, Tsvee; Petit, Isabelle; Kollet, Orit; DiPersio, John F; Link, Dan; Devine, Steven

2003-01-01

439

Short stem shoulder replacement  

PubMed Central

Context: It is agreed that it is important to anatomically reproduce the proximal humeral anatomy when performing a prosthetic shoulder replacement. This can be difficult with a long stemmed prosthesis, in particular if there is little relationship of the metaphysis to the humeral shaft. The ‘short stem’ prosthesis can deal with this problem. Aims: A prospective study assessed the results of total shoulder arthroplasty using a short stem humeral prosthesis, a ceramic humeral head, and a pegged cemented polyethylene glenoid. Materials and methods: Patients with primary shoulder osteoarthritis were recruited into this prospective trial and pre-operatively had the ASES, Constant, SPADI, and DASH scores recorded. The patients were clinically reviewed at the two weeks, eight weeks, one year, and two year mark with completion of a data form. Radiological evaluation was at the eight week, one year and two year follow-up. At the one and two year follow-up the satisfaction rating, the range of passive and active motion, Constant, ASES, SPADI, DASH and pain results were recorded and analysed with SPPS 20. Results: During the study period 97 short stem, ceramic head total shoulder replacements were carried out. At the time of follow-up 12 were two years from operation and 38 one year from operation. Active elevation was overall mean 160 degrees. Constant scores were 76 at 1 year, and 86 at 2 years, ASES 88 and 93, and satisfaction 96% and 98% respectively at one and 2 year follow up. There were no problems during insertion of the humeral prosthesis, or any radiolucent lines or movement of the prosthesis on later radiographs. Conclusion: The short stem prosthesis had no complications, and on follow up radiographs good bone fixation. These fairly short term clinical results were overall good. PMID:25258497

Bell, Simon N.; Coghlan, Jennifer A.

2014-01-01

440

Gravitropism in Leafy Dicot Stems  

NASA Technical Reports Server (NTRS)

A polarizing research microscope with rotating stage and associated camera equipment were ordered, and techniques of fixation and preparation of specimens were perfected for studying possible changes in orientation of cellulose microfibrils in cell walls of gravistimulated dicot stems. Acid ethephon solutions or acid without ethephon caused elongation of stem tissues where they were applied; stems bent away from the side of application. Acid solutions applied to the bottom of horizontal stems greatly delayed bending. Research in tissue sensitivity changes during gravitropic bending of soybean hypocotyls while immersed in auxin and in castor bean stems is also reported.

Salisbury, F. B.

1985-01-01

441

FTIR spectroscopic evaluation of changes in the cellular biochemical composition of the phytopathogenic fungus Alternaria alternata induced by extracts of some Greek medicinal and aromatic plants  

NASA Astrophysics Data System (ADS)

In this study, the biological activity of aquatic extracts of selected Greek medicinal and aromatic plants to the phytopathogenic fungus Alternaria alternata was investigated. Lamiaceae species (Hyssopus officinalis L., Melissa officinalis L., Origanum dictamnus L., Origanum vulgare L. and Salvia officinalis L.) were found to enhance significantly the mycelium growth whereas Crocus sativus appears to inhibit it slightly. M. officinalis and S. officinalis caused the highest stimulation in mycelium growth (+97%) and conidia production (+65%) respectively. In order to further investigate the bioactivity of plant extracts to A. alternata, we employed Fourier Transform Infrared Spectroscopy (FTIR). Differences of original spectra were assigned mainly to amides of proteins. The second derivative transformation of spectra revealed changes in spectral regions corresponding to absorptions of the major cellular constituents such as cell membrane and proteins. Principal component analysis of the second derivative transformed spectra confirmed that fatty acids of the cell membranes, amides of proteins and polysaccharides of the cell wall had the major contribution to data variation. FTIR band area ratios were found to correlate with fungal mycelium growth.

Skotti, Efstathia; Kountouri, Sophia; Bouchagier, Pavlos; Tsitsigiannis, Dimitrios I.; Polissiou, Moschos; Tarantilis, Petros A.

2014-06-01

442

FTIR spectroscopic evaluation of changes in the cellular biochemical composition of the phytopathogenic fungus Alternaria alternata induced by extracts of some Greek medicinal and aromatic plants.  

PubMed

In this study, the biological activity of aquatic extracts of selected Greek medicinal and aromatic plants to the phytopathogenic fungus Alternaria alternata was investigated. Lamiaceae species (Hyssopus officinalis L., Melissa officinalis L., Origanum dictamnus L., Origanum vulgare L. and Salvia officinalis L.) were found to enhance significantly the mycelium growth whereas Crocus sativus appears to inhibit it slightly. M. officinalis and S. officinalis caused the highest stimulation in mycelium growth (+97%) and conidia production (+65%) respectively. In order to further investigate the bioactivity of plant extracts to A. alternata, we employed Fourier Transform Infrared Spectroscopy (FTIR). Differences of original spectra were assigned mainly to amides of proteins. The second derivative transformation of spectra revealed changes in spectral regions corresponding to absorptions of the major cellular constituents such as cell membrane and proteins. Principal component analysis of the second derivative transformed spectra confirmed that fatty acids of the cell membranes, amides of proteins and polysaccharides of the cell wall had the major contribution to data variation. FTIR band area ratios were found to correlate with fungal mycelium growth. PMID:24657421

Skotti, Efstathia; Kountouri, Sophia; Bouchagier, Pavlos; Tsitsigiannis, Dimitrios I; Polissiou, Moschos; Tarantilis, Petros A

2014-06-01

443

Appressorium-localized NADPH oxidase B is essential for aggressiveness and pathogenicity in the host-specific, toxin-producing fungus Alternaria alternata?Japanese pear pathotype.  

PubMed

Black spot disease, Alternaria alternata?Japanese pear pathotype, produces the host-specific toxin AK-toxin, an important pathogenicity factor. Previously, we have found that hydrogen peroxide is produced in the hyphal cell wall at the plant-pathogen interaction site, suggesting that the fungal reactive oxygen species (ROS) generation machinery is important for pathogenicity. In this study, we identified two NADPH oxidase (NoxA and NoxB) genes and produced nox disruption mutants. ?noxA and ?noxB disruption mutants showed increased hyphal branching and spore production per unit area. Surprisingly, only the ?noxB disruption mutant compromised disease symptoms. A fluorescent protein reporter assay revealed that only NoxB localized at the appressoria during pear leaf infection. In contrast, both NoxA and NoxB were highly expressed on the cellulose membrane, and these Nox proteins were also localized at the appressoria. In the ?noxB disruption mutant, we could not detect any necrotic lesions caused by AK-toxin. Moreover, the ?noxB disruption mutant did not induce papilla formation on pear leaves. Ultrastructural analysis revealed that the ?noxB disruption mutant also did not penetrate the cuticle layer. Moreover, ROS generation was not essential for penetration, suggesting that NoxB may have an unknown function in penetration. Taken together, our results suggest that NoxB is essential for aggressiveness and basal pathogenicity in A.?alternata. PMID:23279187

Morita, Yuichi; Hyon, Gang-Su; Hosogi, Naoki; Miyata, Nao; Nakayashiki, Hitoshi; Muranaka, Yoshinori; Inada, Noriko; Park, Pyoyun; Ikeda, Kenichi

2013-05-01

444

Ultrastructural changes and oxidative stress markers in wild and cultivar Sesamum orientale L. following Alternaria sesami (Kawamura) Mohanty and Behera. inoculation.  

PubMed

Alternaria sesami causes leaf spot disease in Sesamum orientale. Conidium germination, inoculation, penetration and colonization of the pathogen on the plant surfaces were studied using scanning electron microscopy. Electron microscopy analysis revealed multiple germ tubes from conidium that spread in all direction across the leaf surfaces. Penetration in the plant surface occured, directly through the epidermis or via stomata with or without the appressoria formation. Hyphal penetration continued through the substomata cavity and some of hyphal branches grew in the intercellular space of mesophyll tissue. Hyphal toxin, caused cell and cell wall damages. Changes in different biochemical parameters in the diseased sesame plants (both in wild and cultivar) were compared to control. Transmission electron microscopy showed structural changes in the chloroplast of diseased plants. Isozyme pattern and assays of different enzymes, namely catalase, acid phosphatase and peroxidase expressed varied level of activities. Meanwhile, esterase, polyphenol oxidase and superoxide dismutase in diseased plants showed remarkable levels compared to control. Due to the infection, chlorophyll content, carbohydrates and total soluble protein decreased whereas free amino acid, proline, phenols and disease-related proteins increased in the host plants. Differential SDS-PAGE band profiling of total soluble proteins were also observed in plants due to the infection. PMID:24228391

Lubaina, A S; Murugan, K

2013-08-01

445

Combination of Trichoderma harzianum endochitinase and a membrane-affecting fungicide on control of Alternaria leaf spot in transgenic broccoli plants.  

PubMed

Progeny from transgenic broccoli (cv. Green Comet) expressing a Trichoderma harzianum endochitinase gene were used to assess the interaction between endochitinase and the fungicide Bayleton in the control of Alternaria brassicicola. In vitro assays have shown synergistic effects of endochitinase and fungicides on fungal pathogens. Our study examined the in planta effects of endochitinase and Bayleton, individually and in combination. Two month old transgenic and non-transgenic plants were sprayed with ED50 levels of Bayleton and/or inoculated with an A. brassicicola spore suspension. Disease levels in non-sprayed transgenic plants were not statistically different from sprayed transgenic plants nor from sprayed non-transgenic controls. Thus endochitinase-transgenic plants alone provided a significant reduction of disease severity, comparable to the protection by fungicide on non-transgenic plants. Comparison of the expected additive and observed effects revealed no synergism between endochitinase and Bayleton (at ED50 level), and usually less than an additive effect. Some transgenic lines sprayed with fungicide at doses higher than ED50 showed resistance similar to the non-sprayed transgenic lines, again suggesting no synergistic effect. Lack of synergism may be due to incomplete digestion of the cell wall by endochitinase, so that the effect of Bayleton at the cell membrane is not enhanced. PMID:11341311

Mora, A; Earle, E D

2001-04-01

446

Role of the Alternaria alternata Blue-Light Receptor LreA (White-Collar 1) in Spore Formation and Secondary Metabolism  

PubMed Central

Alternaria alternata is a filamentous fungus that causes considerable loss of crops of economically important feed and food worldwide. It produces more than 60 different secondary metabolites, among which alternariol (AOH) and altertoxin (ATX) are the most important mycotoxins. We found that mycotoxin production and spore formation are regulated by light in opposite ways. Whereas spore formation was largely decreased under light conditions, the production of AOH was stimulated 2- to 3-fold. ATX production was even strictly dependent on light. All light effects observed could be triggered by blue light, whereas red light had only a minor effect. Inhibition of spore formation by light was reversible after 1 day of incubation in the dark. We identified orthologues of genes encoding the Neurospora crassa blue-light-perceiving white-collar proteins, a cryptochrome, a phytochrome, and an opsin-related protein in the genome of A. alternata. Deletion of the white-collar 1 (WC-1) gene (lreA) resulted in derepression of spore formation in dark and in light. ATX formation was strongly induced in the dark in the lreA mutant, suggesting a repressing function of LreA, which appears to be released in the wild type after blue-light exposure. In addition, light induction of AOH formation was partially dependent on LreA, suggesting also an activating function. A. alternata ?lreA was still able to partially respond to blue light, indicating the action of another blue-light receptor system. PMID:24532063

Pruß, Sonja; Fetzner, Ramona; Seither, Kristin; Herr, Andreas; Pfeiffer, Erika; Metzler, Manfred; Lawrence, Christopher B.

2014-01-01

447

Examination of fungi in domestic interiors by using factor analysis: Correlations and associations with home factors. [Cladosporium, Alternaria, Epicoccum, Aureobasidium, Aspergillus; Penicillium  

SciTech Connect

Factor analysis was utilized to investigate correlations among airborne microorganisms collected with Andersen samplers from homes in Topeka, Kans., during the winter of 1987 to 1988. The factors derived were used to relate microbial concentrations with categorical, questionnaire-derived descriptions of housing conditions. This approach successfully identified groups of common aboveground decay fungi including Cladosporium, Alternaria, Epicoccum, and Aureobasidium spp. The common soil fungi Aspergillus and Penicillium spp. were also separated as a group. These previously known ecological groupings were confirmed with air sampling data by a quantitative evaluation technique. The above ground decay fungi sampled indoors in winter were present at relatively high concentrations in homes with gas stoves for cooking, suggesting a possible association between these fungi and increased humidity from the combustion process. Elevated concentrations of the soil fungi were significantly associated with the dirt floor, crawl-space type of basement. Elevated concentrations of water-requiring fungi, such as Fusarium spp., were shown to be associated with water collection in domestic interiors. Also, elevated mean concentrations for the group of fungi including Cladosporium, Epicoccum, Aureobasidium, and yeast spp. were found to be associated with symptoms reported on a health questionnaire. This finding was consistent with the authors previous study of associations between respiratory health and airborne microorganisms by univariate logistic regression analysis.

Su, H.J.; Rotnitzky, A.; Spengler, J.D. (Harvard Univ., Boston, MA (United States)); Burge, H.A. (Univ. of Michigan, Ann Arbor (United States))

1992-01-01

448

Effects of Alternaria triticina and foliar fly ash deposition on growth, yield, photosynthetic pigments, protein and lysine contents of three cultivars of wheat.  

PubMed

A greenhouse experiment was conducted to study the effects of Alternaria triticina with and without foliar dusting of fly ash (0.0, 2.5, 5.0, 7.5 g plant(-1)/day(-1)) on the growth, yield, photosynthetic pigments, protein and lysine contents of three cultivars of wheat, Triticum aestivum. Dusting of 2.5 and 5.0 g fly ash caused a significant increase in growth, yield, photosynthetic pigments, protein and lysine contents of all the three cultivars. Dusting of 5.0 g fly ash caused a higher increase in the parameters than the 2.5 g dusting. However, dusting of 7.5 g fly ash had an adverse effect on growth, yield, photosynthetic pigments, protein and lysine contents. Cultivar HD-2009 suffered highest reductions in growth and yield and showed greater infected leaf area and disease symptoms from A. triticina followed by HD-2329 and Lok-1. Inoculation of A. triticina to plants dusted with 2.5/5.0 g fly ash gave higher reduction in growth and yield than did plants inoculated with A. triticina without fly ash. Cultivar Lok-1 showed highest growth, yield, photosynthetic pigments, protein and lysine contents followed by HD-2329 and HD-2009. PMID:12653286

Singh, Lamabam P; Siddiqui, Zaki A

2003-01-01

449

Stem cells: research tools and clinical treatments.  

PubMed

The term 'stem cell' most commonly refers to embryonic stem cells, particularly in the lay media; however, it also describes other cell types. A stem cell represents a cell of multi-lineage potential with the ability for self-renewal. It is now clear that the plasticity and immortality of a given stem cell will depend on what type of stem cell it is, whether an embryonic stem cell, a fetal-placental stem cell or an adult stem cell. Stem cells offer great promise as cell-based therapies for the future. With evolving technology, much of the socio-political debate regarding stem cells can now be avoided. PMID:21951457

Fahey, Michael C; Wallace, Euan M

2011-09-01

450

Materials as stem cell regulators  

PubMed Central

The stem cell/material interface is a complex, dynamic microenvironment in which the cell and the material cooperatively dictate one another's fate: the cell by remodelling its surroundings, and the material through its inherent properties (such as adhesivity, stiffness, nanostructure or degradability). Stem cells in contact with materials are able to sense their properties, integrate cues via signal propagation and ultimately translate parallel signalling information into cell fate decisions. However, discovering the mechanisms by which stem cells respond to inherent material characteristics is challenging because of the highly complex, multicomponent signalling milieu present in the stem cell environment. In this Review, we discuss recent evidence that shows that inherent material properties may be engineered to dictate stem cell fate decisions, and overview a subset of the operative signal transduction mechanisms that have begun to emerge. Further developments in stem cell engineering and mechanotransduction are poised to have substantial implications for stem cell biology and regenerative medicine. PMID:24845994

Murphy, William L.; McDevitt, Todd C.; Engler, Adam J.

2014-01-01

451

Perinatal sources of stem cells.  

PubMed

Recently, stem cell biology has become an interesting topic. Several varieties of human stem cells have been isolated and identified in vivo and in vitro. Successful application of hematopoietic stem cells in hematology has led to the search for other sources of stem cells and expanding the scale of their application. Perinatal stem cells are a versatile cell population, and they are interesting for both scientific and practical objectives. Stem cells from perinatal tissue may be particularly useful in the clinic for autologous transplantation for fetuses and newborns, and after banking in later stages of life, as well as for in utero transplantation in the case of genetic disorders. In this review paper we focus on the extraction and therapeutic potential of stem cells derived from perinatal tissues such as the placenta, the amnion, amniotic fluid, umbilical cord blood and Wharton's jelly. PMID:25748624

Piskorska-Jasiulewicz, Magdalena Maria; Witkowska-Zimny, Ma?gorzata

2015-01-01

452

Characterization of rhizosphere bacteria for control of phytopathogenic fungi of tomato.  

PubMed

Fluorescent Pseudomonas spp., isolated from rhizosphere soil of tomato and pepper plants, were evaluated in vitro as potential antagonists of fungal pathogens. Strains were characterized using the API 20NE biochemical system, and tested against the causal agents of stem canker and leaf blight (Alternaria alternata f. sp. lycopersici), southern blight (Sclerotium rolfsii Sacc.), and root rot (Fusarium solani). To this end, dual culture antagonism assays were carried out on 25% Tryptic Soy Agar, King B medium, and Potato Dextrose Agar to determine the effect of the strains on mycelial growth of the pathogens. The effect of two concentrations of FeCl(3) on antagonism against Alternaria alternata f. sp. lycopersici was also tested. In addition, strains were screened for ability to produce exoenzymes and siderophores. Finally, the selected Pseudomonas strain, PCI2, was evaluated for effect on tomato seedling development and as a potential candidate for controlling tomato damping-off caused by Sclerotium rolfsii Sacc., under growth chamber conditions. All strains significantly inhibited Alternaria alternata f. sp. lycopersici, particularly in 25% TSA medium. Antagonistic effect on Sclerotium rolfsii Sacc. and Fusarium solani was greater on King B medium. Protease was produced by 30% of the strains, but no strains produced cellulase or chitinase. Growth chamber studies resulted in significant increases in plant stand as well as in root dry weight. PCI2 was able to establish and survive in tomato plants rhizosphere after 40 days following planting of bacterized seeds. PMID:21507555

Pastor, Nicolás; Carlier, Evelin; Andrés, Javier; Rosas, Susana B; Rovera, Marisa

2012-03-01

453

STEM Equity Pipeline  

NSDL National Science Digital Library

As a past president of the National Academy of Engineering put it, "A consequence of lack of diversity...[is that] we pay an opportunity cost, a cost in designs not thought of, in solutions not produced." Thus, in an effort to increase the diversity of the Science, Technology, Engineering and Mathematics (STEM) workforce, STEM Equity Pipeline was developed. The "Online Resources" section of their website offers visitors a wide variety of resources, including "pamphlets/brochures", "posters", "scholarships" and "videos". The "Curriculum" resource is particularly rich and it offers over 50 websites that contain single activities, whole lesson plans or hands-on explorations. Some of the titles visitors might find valuable are "Some Disassembly Required", which employs reverse engineering (or taking things apart) to learn how they work, "Teaching Tool for Introductory Programming Concepts", to teach students computer programming in a 3D environment, and "Home Science Adventures", science lessons and plans for home- schoolers.

454

Brain cancer stem cells  

Microsoft Academic Search

Cancers comprise heterogeneous cells, ranging from highly proliferative immature precursors to more differentiated cell lineages.\\u000a In the last decade, several groups have demonstrated the existence of cancer stem cells in both nonsolid solid tumors, including\\u000a some of the brain: glioblastoma multiforme (GBM), medulloblastoma, and ependymoma. These cells, like their normal counterpart\\u000a in homologous tissues, are multipotent, undifferentiated, self-sustaining, yet transformed

Sara G. M. Piccirillo; Elena Binda; Roberta Fiocco; Angelo L. Vescovi; Khalid Shah

2009-01-01

455

Melanoma Stem Cells  

Microsoft Academic Search

\\u000a The hypothesis that tumor initiation and growth are driven by a subpopulation of malignant cells, that is, cancer stem cells\\u000a (CSCs), has received considerable attention. The CSC concept predicts that the design of novel therapies that ablate CSCs\\u000a or target CSC-specific protumorigenic signaling pathways might result in more durable therapeutic responses in cancer patients\\u000a than those achieved by therapeutic approaches

Tobias Schatton; Markus H. Frank

456

Cancer Stem Cells  

Microsoft Academic Search

\\u000a Far from being a new concept, the belief that cancer might originate from stem cells dates back to the mid-19th century when\\u000a Rudolf Virchow proposed that cancer arises from embryo-like cells, based on the histologic similarity between embryonic and\\u000a cancer tissues. This hypothesis was later extended by Cohnheim and Durante, who postulated that adult tissues contain embryonic\\u000a remnants that usually

Marcello Maugeri Saccà; Vito D’Andrea; Angelo Pulcini; Ruggero Maria

457

AccessSTEM  

NSDL National Science Digital Library

The University of Washington's award-winning DO-IT Center (Disabilities, Opportunities, Internetworking and Technology) collaborates with AccessSTEM, which has been funded by the National Science Foundation since 2002. AccessSTEM, aims to "broaden participation in STEM fields and improve those fields with the perspectives and expertise of people with disabilities." Visitors to the site who are disabled students, faculty, employees, or just the interested public will find much to peruse or read in-depth. There is the longitudinal transition study link in the "For Faculty and Employees" section that tracks the college and career paths of students with disabilities who used the DO-IT program. Visitors will find the "Promising Practices" section, also in the Faculty and Employees section, to be filled with useful articles and innovations. There is "A Smart Board in the Classroom: A Promising Practice for Engaging Students", which addresses how the use of a Smart Board can aid students with attention deficits, visual impairments, and other disabling conditions without bringing the whole class' attention to them.

458

TPCP: Cryphonectria canker of Eucalyptus CRYPHONECTRIA CANKER OF  

E-print Network

in various parts of the world such as Brazil and India. The disease was discovered in South Africa in 1988 and has already resulted in the elimination of a number of valuable Eucalyptus clones. Cracked tree crown of the world such as Brazil. Sexual spores of Cryphonectria cubensis. MANAGEMENT STRATEGIES The most effective

459

EMBRYONIC STEM CELLS/INDUCED PLURIPOTENT STEM CELLS Long-Term, Stable Differentiation of Human Embryonic Stem  

E-print Network

EMBRYONIC STEM CELLS/INDUCED PLURIPOTENT STEM CELLS Long-Term, Stable Differentiation of Human Embryonic Stem Cell-Derived Neural Precursors Grafted into the Adult Mammalian Neostriatum IGOR NASONKIN Words. Cellular therapy · Embryonic stem cells · Neural differentiation · Neural induction · Neural stem

Ryugo, David K.

460

Biomaterials as Stem Cell Niche: Cardiovascular Stem Cells  

Microsoft Academic Search

\\u000a A tissue-specific stem cell niche functions to direct either self-renewal or differentiation. The niche comprises all local\\u000a cues that can be sensed by the cell including soluble and insoluble signals, physical forces and cell–cell contacts. Approximating\\u000a the stem cell niche through the utilization of biomaterials may give rise to a greater understanding of the biology of the\\u000a stem cell niche

Ge Zhang; Laura J. Suggs

461

STEM CELLS 2014;00:0000 www.StemCells.com AlphaMed Press 2014 EMBRYONIC STEM CELLS/INDUCED PLURIPOTENT STEM CELLS  

E-print Network

reduced in induced pluripotent stem cell (iPSC)derived TH + or TH neurons from PD patients neurons by stabilizing microtubules. STEM CELLS 2014; 00:000­000 INTRODUCTION The locomotorSTEM CELLS 2014;00:0000 www.StemCells.com ©AlphaMed Press 2014 EMBRYONIC STEM CELLS

Feng, Jian

462

Background Information 1. What are stem cells?  

E-print Network

Background Information 1. What are stem cells? 2. What might stem cell research achieve? 3. Why we need to continue research using embryonic stem cells? 4. Time taken for discoveries 5. Examples of stem cell therapies in clinical trials 6. Patentability of human embryonic stem cell therapies 7. Creation

Rambaut, Andrew

463

Stem cells in gastroenterology and hepatology  

Microsoft Academic Search

Cellular and tissue regeneration in the gastrointestinal tract and liver depends on stem cells with properties of longevity, self-renewal and multipotency. Progress in stem cell research and the identification of potential esophageal, gastric, intestinal, colonic, hepatic and pancreatic stem cells provides hope for the use of stem cells in regenerative medicine and treatments for disease. Embryonic stem cells and induced

Michael Quante; Timothy C. Wang

2009-01-01

464

Embryonic Stem Cells Cell Signalling Course  

E-print Network

Embryonic Stem Cells Cell Signalling Course Ceské Budjovice January 2013 #12;Pluripotent (stem(s) of differentiation ·Symmetric/asymmetric division ? ? ? ? #12;Where can we find the origins of stem cell research;1981 Lines of pluripotent cells were established for the first time from mouse embryo ­ Embryonic Stem Cells

South Bohemia, University of

465

Embryonic Stem Cells Cell Signalling Course  

E-print Network

Embryonic Stem Cells Cell Signalling Course Ceské Budjovice November 2013 #12;Pluripotent (stem(s) of differentiation ·Symmetric/asymmetric division ? ? ? ? #12;Where can we find the origins of stem cell research;1981 Lines of pluripotent cells were established for the first time from mouse embryo ­ Embryonic Stem Cells

South Bohemia, University of

466

Stem Cell Basics About this document  

E-print Network

1 Stem Cell Basics About this document This primer on stem cells is intended for anyone who wishes to learn more about the biological properties of stem cells, the important questions about stem cells that are the focus of scientific research, and the potential use of stem cells in research and in treating disease

Bandettini, Peter A.

467

Stem Cell Plasticity, Beyond Alchemy  

Microsoft Academic Search

Cell plasticity is a central issue in stem cell biology. Differentiated somatic nuclei have the flexibility to dedifferentiate\\u000a when transferred into oocytes or when fused to pluripotent embryonic stem cells. Recent publications also claim that somatic\\u000a stem cells can convert into developmentally unrelated cell types both in vivo and ex vivo without such drastic cell manipulations.\\u000a Some of these claims

Michael S. Rutenberg; Takashi Hamazaki; Amar M. Singh; Naohiro Terada

2004-01-01

468

Stem cells—meet immunity  

Microsoft Academic Search

The ability of stem cells to differentiate into various different cell types holds great promise for the treatment of irreversible\\u000a tissue damage that occurs in many debilitating conditions. With stem cell research advancing at a tremendous pace, it is becoming\\u000a clear that one of the greatest hurdles to successful stem cell-derived therapies is overcoming immune rejection of the transplant.\\u000a Although

Tracy S. P. Heng; Jarrod A. Dudakov; Danika M. P. Khong; Ann P. Chidgey; Richard L. Boyd

2009-01-01

469

Stem cells in veterinary medicine  

Microsoft Academic Search

The stem cell field in veterinary medicine continues to evolve rapidly both experimentally and clinically. Stem cells are\\u000a most commonly used in clinical veterinary medicine in therapeutic applications for the treatment of musculoskeletal injuries\\u000a in horses and dogs. New technologies of assisted reproduction are being developed to apply the properties of spermatogonial\\u000a stem cells to preserve endangered animal species. The

Lisa A Fortier; Alexander J Travis

2011-01-01

470

Stem Cell Transplants at Childbirth  

Microsoft Academic Search

Autologous transplantation of stem cells is a natural phenomenon at birth in mammals via the umbilical cord. Here, we discuss\\u000a that a delay in the cord clamping may increase stem cell supply to the baby, thereby allowing an innate stem cell therapy\\u000a that can render acute benefits in the case of neonatal disease, as well as long-term benefits against age-related

Paul R. Sanberg; Dong-Hyuk Park; Cesar V. Borlongan

2010-01-01

471

Thousand Cankers of Black Walnut  

E-print Network

spread of TCD. Take the wood to a local landfill Take wood to an approved storage site in your city or county Small diameter trees may be chipped, but chips must be disposed of in a landfill or approved storage site DO NOT TRANSPORT, SAVE OR SELL LOGS OF BLACK WALNUT FOR FIREWOOD, LUMBER OR OTHER USES! Trees

472

Mechanotransduction: Tuning Stem Cells Fate  

PubMed Central

It is a general concern that the success of regenerative medicine-based applications is based on the ability to recapitulate the molecular events that allow stem cells to repair the damaged tissue/organ. To this end biomaterials are designed to display properties that, in a precise and physiological-like fashion, could drive stem cell fate both in vitro and in vivo. The rationale is that stem cells are highly sensitive to forces and that they may convert mechanical stimuli into a chemical response. In this review, we describe novelties on stem cells and biomaterials interactions with more focus on the implication of the mechanical stimulation named mechanotransduction. PMID:24956164

D'Angelo, Francesco; Tiribuzi, Roberto; Armentano, Ilaria; Kenny, Josè Maria; Martino, Sabata; Orlacchio, Aldo

2011-01-01

473

iSeek: STEM Careers  

NSDL National Science Digital Library

Minnesota's iSeek website "works with the state's workforce development and education authorities to develop and inform policy and to strategize services for career planning, education and e-learning, and workforce development." But the resources on the STEM Careers and Skills section of the site aren't just for those people living in Minnesota; this section provides all visitors the opportunity to explore STEM career skills that can be helpful no matter what state they live in. Visitors interested in learning what STEM skills are, should check out the link "Understanding STEM Skills". Here key STEM skills are outlined, such as analytical skills, science skills, technical, and math skills. The site also goes on to outline some of the soft skills that those in STEM careers should have, such as leadership, organization, communication, and creative skills. Visitors can take a free 5-10 minute "Skills Assessment" to determine which of their interests and skills match up with STEM careers. The "STEM Careers" link has a list of high-demand STEM careers, average hourly wage, and typical education requirements.

474

Characterization of amniotic stem cells.  

PubMed

The amnion membrane is developed from embryo-derived cells, and amniotic cells have been shown to exhibit multidifferentiation potential. These cells represent a desirable source for stem cells for a variety of reasons. However, to date very few molecular analyses of amnion-derived cells have been reported, and efficient markers for isolating the stem cells remain unclear. This paper assesses the characterization of amnion-derived cells as stem cells by examining stemness marker expressions for amnion-derived epithelial cells and mesenchymal cells by flow cytometry, immunocytochemistry, and quantitative PCR. Flow cytometry revealed that amnion epithelial cells expressed CD133, CD 271, and TRA-1-60, whereas mecenchymal cells expressed CD44, CD73, CD90, and CD105. Immunohistochemistry showed that both cells expressed the stemness markers Oct3/4, Sox2, Klf4, and SSEA4. Stemness genes' expression in amnion epithelial cells, mesenchymal cells, fibroblast, bone marrow-derived mesenchymal stem cells (MSCs), and induced pluripotent stem cells (iPSCs) was compared by quantitative reverse-transcription polymerase chain reaction (RT-PCR). Amnion-derived epithelial cells and mesenchymal cells expressed Oct3/4, Nanog, and Klf4 more than bone marrow-derived MSCs. The sorted TRA1-60-positive cells expressed Oct3/4, Nanog, and Klf4 more than unsorted cells or TRA1-60-negative cells. TRA1-60 can be a marker for isolating amnion epithelial stem cells. PMID:25068631

Koike, Chika; Zhou, Kaixuan; Takeda, Yuji; Fathy, Moustafa; Ok