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Elizabeth D Earle - One of the best experts on this subject based on the ideXlab platform.

  • somatic hybrids between brassica oleracea l and sinapis alba l with resistance to Alternaria brassicae berk sacc
    Theoretical and Applied Genetics, 1997
    Co-Authors: L N Hansen, Elizabeth D Earle
    Abstract:

    Somatic Hybrids between Sinapis alba and rapid-cycling Brassica oleracea were generated for transferring of resistance to Alternaria brassicae to B. oleracea. A. brassicae causes the significant disease black spot in cruciferous crops. A total of 27 plants were regenerated from protoplast fusion using 0, 5, 10, 20 and 30 krad γ-irradiation of the resistance donor and iodoacetate treatment of B. oleracea. All plants showed intermediate morphology with partially divided leaves and some trichomes on stems and leaves. Flow cytometry and banding patterns of the enzymes leucine amino peptidase (LAP) and phosphoglucose isomerase (PGI) confirmed the hybrid status of the regenerated plants. Some of the plants obtained from cuttings from the somatic hybrids showed a resistance to A. brassicae that was similar to that found in S. alba. The flowers of the somatic hybrids had reduced anthers with little pollen production.

Philippe Simoneau - One of the best experts on this subject based on the ideXlab platform.

  • First Report of an Alternaria Leaf Spot Caused by Alternaria brassicae on Crambe abyssinicia in Australia.
    Plant disease, 2005
    Co-Authors: Ming Pei You, Philippe Simoneau, Martin J. Barbetti, Anita Dongo, Krishnapillai Sivasithamparam
    Abstract:

    Crambe abyssinicia Hochst. is grown sporadically worldwide for its value as a source of high erucic acid industrial oils and secondary commercial products. While there is increasing interest in cropping C. abyssinicia in Australia, for these potentials and also as a source of oil for biodiesel production, currently, there have been no commercial crops of this species. In September 2004, inspection of a small experimental field crop in Beverley, Western Australia indicated the presence of significant leaf spotting just prior to commencement of flowering. The symptoms of this disease included as many as 10 to 15 spot lesions per leaf that were generally rounded and varied between 0.5 to 11 mm in diameter. Clusters of these lesions were often associated with chlorosis of the region of leaves where they occurred. More than 95% of plants inspected showed these symptoms. When affected leaves were incubated in moist chambers, typical conidia of Alternaria brassicae (Berk.) Sacc. were observed. The description of...

  • Analysis of a nonribosomal peptide synthetase gene from Alternaria brassicae and flanking genomic sequences
    Current Genetics, 2004
    Co-Authors: Thomas Guillemette, Adnane Sellam, Philippe Simoneau
    Abstract:

    Very little information is currently available concerning the pathogenic determinants produced by Alternaria brassicae, the causal agent of the blackspot disease of crucifers. We screened a genomic library of this fungus and identified a nonribosomal peptide synthetase (NRPS) gene named AbrePsy1. The complete coding sequence is 22 kbp long and encodes a large protein (792 kDa) showing typical NRPS modular organization. Structural analysis of AbrePsy1 revealed four complete elongation modules, two of which have epimerization domains. In the vicinity of AbrePsy1, a second gene (named AbreAtr1), which encodes an ATP-binding cassette transporter was identified. Increased expression of AbrePsy1 and AbreAtr1 was observed during host-plant infection. However, while physically linked, these two genes are probably not functionally clustered, as their expression patterns differed.

  • Conventional and Real-Time PCR-Based Assay for Detecting Pathogenic Alternaria brassicae in Cruciferous Seed
    Plant disease, 2004
    Co-Authors: Thomas Guillemette, Béatrice Iacomi-vasilescu, Philippe Simoneau
    Abstract:

    Alternaria brassicae is an important seedborne pathogenic fungus responsible for the black spot disease of crucifers. Sanitary control of commercial seed is necessary to limit the spread of this pathogen. Current detection methods, based on culture and morphological identification of the fungus, are time consuming, laborious, and not always reliable. Therefore, a polymerase chain reaction (PCR)-based assay was developed with A. brassicae-specific primers designed on the basis of the sequence of two clustered genes potentially involved in pathogenicity. Two sets of primers were selected for conventional and real-time PCR, respectively. In both cases, A. brassicae was specifically detected using DNA extracted from seed. The real-time PCR-based method presented here can be automated easily and preliminary results indicate that it is efficient for quantitative estimation of seed infection.

L N Hansen - One of the best experts on this subject based on the ideXlab platform.

  • somatic hybrids between brassica oleracea l and sinapis alba l with resistance to Alternaria brassicae berk sacc
    Theoretical and Applied Genetics, 1997
    Co-Authors: L N Hansen, Elizabeth D Earle
    Abstract:

    Somatic Hybrids between Sinapis alba and rapid-cycling Brassica oleracea were generated for transferring of resistance to Alternaria brassicae to B. oleracea. A. brassicae causes the significant disease black spot in cruciferous crops. A total of 27 plants were regenerated from protoplast fusion using 0, 5, 10, 20 and 30 krad γ-irradiation of the resistance donor and iodoacetate treatment of B. oleracea. All plants showed intermediate morphology with partially divided leaves and some trichomes on stems and leaves. Flow cytometry and banding patterns of the enzymes leucine amino peptidase (LAP) and phosphoglucose isomerase (PGI) confirmed the hybrid status of the regenerated plants. Some of the plants obtained from cuttings from the somatic hybrids showed a resistance to A. brassicae that was similar to that found in S. alba. The flowers of the somatic hybrids had reduced anthers with little pollen production.

Lan Liu - One of the best experts on this subject based on the ideXlab platform.

  • A new Secondary metabolites of the crinoid (Comanthina schlegeli) associated fungus Alternaria brassicae 93.
    Natural product research, 2016
    Co-Authors: Liu-hong Zhang, Hong-wei Wang, Xu Jiayi, Lan Liu
    Abstract:

    Fungus Alternaria brassicae 93 isolated from crinoid (Comanthina schlegeli), which was collected from the South China Sea. Six compounds were isolated from A. brassicae 93, including one new compound (1), along with five known compounds, ochratoxin A methyl ester (2), cis-4-hydroxym-ellein (3), (R)-7-hydroxymellein (4), trans-2-anhydromevalonic (5) and protocatechuic acid (6). Their structures were determined by spectroscopic methods and comparison with reported data. Cytotoxicity against two human cancer cell lines and antibacterial activity against twelve aquatic bacteria of compound 1 were also tested.

  • A new Secondary metabolites of the crinoid (Comanthina schlegeli) associated fungus Alternaria brassicae 93
    2016
    Co-Authors: Liu-hong Zhang, Hong-wei Wang, Lan Liu
    Abstract:

    Fungus Alternaria brassicae 93 isolated from crinoid (Comanthina schlegeli), which was collected from the South China Sea. Six compounds were isolated from A. brassicae 93, including one new compound (1), along with five known compounds, ochratoxin A methyl ester (2), cis-4-hydroxym-ellein (3), (R)-7-hydroxymellein (4), trans-2-anhydromevalonic (5) and protocatechuic acid (6). Their structures were determined by spectroscopic methods and comparison with reported data. Cytotoxicity against two human cancer cell lines and antibacterial activity against twelve aquatic bacteria of compound 1 were also tested. The fungus Alternaria brassicae 93 separated from crinoid (Comanthina schlegeli) produced one new compound (1).

S. C. Chatterjee - One of the best experts on this subject based on the ideXlab platform.

  • Transgenic Indian mustard (Brassica juncea) expressing tomato glucanase leads to arrested growth of Alternaria brassicae
    Plant cell reports, 2006
    Co-Authors: Kalyan K. Mondal, R. C. Bhattacharya, K. R. Koundal, S. C. Chatterjee
    Abstract:

    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.