Pestalotiopsis biciliata, a new leaf pathogen ofEucalyptusspp. recorded in Italy

2019 ◽  
Vol 49 (2) ◽  
pp. e12492 ◽  
Author(s):  
Carmen Morales-Rodríguez ◽  
Matteo Dalla Valle ◽  
MariaPia Aleandri ◽  
Andrea Vannini
Keyword(s):  
Leaf Pathogen

Catalase released from beneficial and plant-pathogenic pseudomonads by water and chloroform treatments

1994 ◽  
Vol 40 (8) ◽  
pp. 630-636
Author(s):  
J. I. Pounder ◽  
A. J. Anderson
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Water Treatment ◽  
Pseudomonas Syringae ◽  
Small Proportion ◽  
Plant Colonization ◽  
Periplasmic Proteins ◽  
Specific Activities ◽  
Leaf Pathogen ◽  
Glucose 6 Phosphate Dehydrogenase

Survival of pseudomonads during plant colonization may involve bacterial catalases to degrade the hydrogen peroxide produced by the plant. The specific activities of catalases in lysates from two saprophytic isolates of Pseudomonas putida and Pseudomonas fluorescens and three races of Pseudomonas syringae pv. glycinea were similar. To explore the location of the bacterial catalases, cells of the pathogenic and saprophytic pseudomonads were treated with chloroform, which is reported to release periplasmic proteins. Although catalase was released by chloroform treatment, the cytoplasmic enzymes isocitrate dehydrogenase, superoxide dismutase, and glucose-6-phosphate dehydrogenase were also detected. These proteins may have come from lysis of a small proportion of the cells rather than the periplasm. Water treatment of cells also released amounts of protein similar to those derived from chloroform treatment. Similar responses were found from both pathogenic and saprophytic strains. The release of catalase and proteins from the leaf pathogen P. syringae pv. glycinea race 0 and the root-associated saprophyte P. putida decreased as the cultures aged. With P. putida and P. syringae pv. glycinea race 0, the single isozyme of catalase released by water and chloroform treatment also was detected in lysates. Additional catalase isozymes were present in lysates as the cultures aged.Key words: periplasmic proteins, survival.

Morphological and molecular identification of Colletotrichum siamense , a novel leaf pathogen associated with Sterculia lanceolata recorded in China

2020 ◽  
Vol 168 (7-8) ◽  
pp. 451-459 ◽  
Author(s):  
Yaowen Zhang ◽  
Di Long ◽  
Jiawen Wang ◽  
Qiqin Li ◽  
Zhongwen Wang ◽  
...  
Keyword(s):  
Molecular Identification ◽  
Colletotrichum Siamense ◽  
Leaf Pathogen

The effects of a stem gall fly and a leaf pathogen on the reproductive output of Crofton weed, Ageratina adenophora (Asteraceae), in greenhouse and field trials

2021 ◽  
Vol 152 ◽  
pp. 104453
Author(s):  
Lisa Buccellato ◽  
Jolene T. Fisher ◽  
Ed T.F. Witkowski ◽  
Marcus J. Byrne
Keyword(s):  
Reproductive Output ◽  
Field Trials ◽  
Crofton Weed ◽  
Ageratina Adenophora ◽  
Stem Gall ◽  
Leaf Pathogen

scholarly journals First Report of Leaf Blight Caused by Nigrospora sphaerica on Curcuma in China

Plant Disease ◽  
2011 ◽  
Vol 95 (9) ◽  
pp. 1190-1190
Author(s):  
L. X. Zhang ◽  
J. H. Song ◽  
G. J. Tan ◽  
S. S. Li
Keyword(s):  
Disease Incidence ◽  
Its Region ◽  
Leaf Blight ◽  
Morphological Data ◽  
Future Research ◽  
Leaf Margin ◽  
Academic Press ◽  
First Report ◽  
Pathogenicity Tests ◽  
Leaf Pathogen

Curcuma (family Zingiberaceae) is commonly cultivated for the use of rhizomes within traditional Chinese medicines. In October 2009 and 2010, severe leaf blight was observed on Curcuma wenyujin Y.H. Chen & C. Ling (4) in fields located in Ruian, China. The area of cultivation in Ruian encompasses 90% of the production in Zhejiang Province. Disease incidence was approximately 90% of plants observed in affected fields. Early symptoms were yellow-to-brown, irregular-shaped lesions on the leaf margin or tip. After several days, lesions expanded along the mid-vein until the entire leaf was destroyed. Blighted leaves turned grayish to dark brown and withered, and severely affected plants died. Eight fungal isolates were recovered from symptomatic C. wenyujin leaves, collected from eight different fields, on potato dextrose agar (PDA). These fungal colonies were initially white, becoming light to dark gray and produced black, spherical to subspherical, single-celled conidia (14 to 17 × 12 to 15 μm), which were borne on a hyaline vesicle at the tip of the conidiophores. On the basis of these morphological features, the isolates appeared to be similar to Nigrospora sphaerica (2). Strain ZJW-1 was selected as a representative for molecular identification. Genomic DNA was extracted from the isolate, and the internal transcribed spacer (ITS) region of the ribosomal DNA (ITS1-5.8S-ITS2) was amplified using ITS1 (5′-TCCGTAGGTGAACCTGCGG-3′) and ITS4 (5′-TCCTCCGCTTATTGATATGC-3′) primers (3). The ITS region was further cloned and sequenced (GenBank Accession No. JF738028) and was 99% identical to N. sphaerica (GenBank Accession No. FJ478134.1). On the basis of morphological data and the ITS rDNA sequence, the isolate was determined to be N. sphaerica. Pathogenicity tests were conducted on four leaves of four C. wenyujin plants by placing agar pieces (5 mm in diameter) from 8-day-old cultures on pushpin-wounded leaves. An equal number of control plants were wounded and inoculated with noncolonized PDA agar pieces. Plants were placed in moist chambers at 25°C with a 12-h photoperiod. Brown-to-black lesions were observed on wounded leaves after 3 days and expanded to an average of 56 × 40 mm 15 days after inoculation. No symptoms developed on the control leaves. The pathogen was reisolated from the margins of necrotic tissues but not from the controls. The pathogen has been reported as a leaf pathogen on several hosts worldwide (1). To our knowledge, this is the first report of N. sphaerica as a leaf pathogen of C. wenyujin in China. Future research will focus primarily on management of this disease. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases, Systematic Mycology and Microbiology Laboratory, USDA-ARS, Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , March 31, 2011. (2) E. W. Mason. Trans. Brit. Mycol. Soc. 12:152, 1927. (3) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990. (4) J. Zhao et al. Molecules 15:7547, 2010.

scholarly journals First Report of Nigrospora Leaf Blight on Sesame Caused by Nigrospora sphaerica in China

Plant Disease ◽  
2014 ◽  
Vol 98 (6) ◽  
pp. 842-842 ◽  
Author(s):  
H. Zhao ◽  
H. Y. Liu ◽  
X. S. Yang ◽  
Y. X. Liu ◽  
Y. X. Ni ◽  
...  
Keyword(s):  
Morphological Characteristics ◽  
Leaf Blight ◽  
Morphological Data ◽  
Its2 Region ◽  
Oilseed Crop ◽  
Conidial Suspension ◽  
First Report ◽  
Initial Symptoms ◽  
Central Regions ◽  
Leaf Pathogen

Sesame (Sesamum indicum L.) is an important oilseed crop widely grown in the central regions of China. A new leaf blight has increasingly been observed in sesame fields in Anhui, Hubei, and Henan provinces since 2010. Approximately 30 to 40% of the plants were symptomatic in the affected fields. Initial symptoms were yellow to brown, irregularly shaped lesions. Lesions later expanded and the affected leaves tuned grayish to dark brown and wilted, with a layer of whitish mycelial growth on the underside. Severe blighting caused the center of lesions to fall out, leaving holes in the leaves. Sections of symptomatic leaf tissues were surface-sterilized in 75% ethanol for 30 s, then in 1% HgCl2 for 30 s, rinsed three times in sterile distilled water, and plated onto potato dextrose agar (PDA). The resulting fungal colonies were initially white, and then became grayish-brown with sporulation. Conidia were single-celled, black, smooth, spherical, 14.2 to 19.8 μm (average 17.1 μm) in diameter, and borne on a hyaline vesicle at the tip of each conidiophore. Morphological characteristics of the isolates were similar to those of Nigrospora sphaerica (1). To verify the identification based on morphological features, the ITS1-5.8S-ITS2 region of the ribosomal RNA was amplified using ITS1 (5′-TCCGTAGGTGAACCTGCGG-3′) and ITS4 (5′-TCCTCCGCTTATTGATATGC-3′) primers (3), and then sequenced and compared to the GenBank database through a BLAST search. Comparison of the sequence revealed 100% similarity to N. sphaerica (GenBank Accession No. JF817271.1). On the basis of morphological data and the ITS rDNA sequence, the isolate was determined to be N. sphaerica. Pathogenicity tests were conducted using fresh and healthy sesame leaves of 10 plants. A conidial suspension (106 conidia/ml) collected from a 7-day-old culture on PDA was used for inoculation. Leaves of 10 plants were spray-inoculated with the spore suspension at the 6-week-old growth stage, and an additional 10 plants were sprayed with sterile water. Inoculated plants were covered with polyethylene bags to maintain high humidity. Plants were kept at 28°C and observed for symptom every day. Ten to 15 days after inoculation, inoculated leaves developed blight symptoms similar to those observed on naturally infected leaves. No symptoms were observed on the control leaves. N. sphaerica was re-isolated from the inoculated leaves, thus fulfilling Koch's postulates. N. sphaerica has been reported as a leaf pathogen on several hosts worldwide (2). To our knowledge, this is the first report of Nigrospora leaf blight on sesame caused by N. sphaerica in China. References: (1) M. B. Ellis. Dematiaceous Hyphomycetes. CMI, Kew, Surrey, UK, 1971. (2) D. F. Farr and A. Y. Rossman. Fungal Databases, Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ . July 01, 2013. (3) M. A. Innis et al. PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990.

scholarly journals Omics approaches revealed how arbuscular mycorrhizal symbiosis enhances yield and resistance to leaf pathogen in wheat

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Valentina Fiorilli ◽  
Candida Vannini ◽  
Francesca Ortolani ◽  
Daniel Garcia-Seco ◽  
Marco Chiapello ◽  
...  
Keyword(s):  
Arbuscular Mycorrhizal ◽  
Arbuscular Mycorrhizal Symbiosis ◽  
Mycorrhizal Symbiosis ◽  
Leaf Pathogen

scholarly journals Multiple introductions from multiple sources: invasion patterns for an important E ucalyptus leaf pathogen

2015 ◽  
Vol 5 (18) ◽  
pp. 4210-4220 ◽  
Author(s):  
Matsepo Taole ◽  
Wubetu Bihon ◽  
Brenda D. Wingfield ◽  
Michael J. Wingfield ◽  
Treena I. Burgess
Keyword(s):  
Multiple Sources ◽  
Multiple Introductions ◽  
Leaf Pathogen ◽  
Invasion Patterns

scholarly journals Barley Leaf Transcriptome and Metabolite Analysis Reveals New Aspects of Compatibility and Piriformospora indica–Mediated Systemic Induced Resistance to Powdery Mildew

2011 ◽  
Vol 24 (12) ◽  
pp. 1427-1439 ◽  
Author(s):  
Alexandra Molitor ◽  
Doreen Zajic ◽  
Lars M. Voll ◽  
Jörn Pons-Kühnemann ◽  
Birgit Samans ◽  
...  
Keyword(s):  
Systemic Disease ◽  
Piriformospora Indica ◽  
Systemic Resistance ◽  
Specific Gene ◽  
Gene Sets ◽  
Leaf Transcriptome ◽  
Genes Encoding ◽  
Sucrose Biosynthesis ◽  
Leaf Pathogen ◽  
Shock Proteins

Colonization of barley roots with the basidiomycete fungus Piriformospora indica (Sebacinales) induces systemic resistance against the biotrophic leaf pathogen Blumeria graminis f. sp. hordei (B. graminis). To identify genes involved in this mycorrhiza-induced systemic resistance, we compared the leaf transcriptome of P. indica-colonized and noncolonized barley plants 12, 24, and 96 h after challenge with a virulent race of B. graminis. The leaf pathogen induced specific gene sets (e.g., LRR receptor kinases and WRKY transcription factors) at 12 h postinoculation (hpi) (prepenetration phase) and vesicle-localized gene products 24 hpi (haustorium establishment). Metabolic analysis revealed a progressing shift of steady state contents of the intermediates glucose-1-phosphate, uridinediphosphate-glucose, and phosphoenolpyruvate 24 and 96 hpi, indicating that B. graminis shifts central carbohydrate metabolism in favor of sucrose biosynthesis. Both B. graminis and P. indica increased glutamine and alanine contents, whereas substrates for starch and nitrogen assimilation (adenosinediphosphate- glucose and oxoglutarate) decreased. In plants that were more B. graminis resistant due to P. indica root colonization, 22 transcripts, including those of pathogenesis-related genes and genes encoding heat-shock proteins, were differentially expressed ≥twofold in leaves after B. graminis inoculation compared with non-mycorrhized plants. Detailed expression analysis revealed a faster induction after B. graminis inoculation between 8 and 16 hpi, suggesting that priming of these genes is an important mechanism of P. indica-induced systemic disease resistance.

The intercellular biotrophic leaf pathogen Cymadothea trifolii locally degrades pectins, but not cellulose or xyloglucan in cell walls of Trifolium repens

2004 ◽  
Vol 165 (1) ◽  
pp. 243-260 ◽  
Author(s):  
Uwe K. Simon ◽  
Robert Bauer ◽  
Danny Rioux ◽  
Marie Simard ◽  
Franz Oberwinkler
Keyword(s):  
Trifolium Repens ◽  
Cell Walls ◽  
Leaf Pathogen
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