Genetic regulation of host-selective toxin production: Characterization of a necrosis minus mutant of Pyrenophora tritici-repentis (died.) Drech. which has lost the ability to produce host-selective toxins in wheat
Material type:
TextLanguage: English Publication details: Columbia, MO (USA) : University of Missouri-Columbia, 1989Description: 128 pagesSubject(s): Summary: Pyrenophora tritici-repentis (Died.) Drech. strain mok1 (wild type) produces typical tan-spot symptoms on wheat (Triticum aestivum L. em Thell.) leaves. Strain mok2 (a naturally occurring mutant) was isolated from fleck type symptoms on wheat leaves infected with mok1. The two strains are easily distinguished by colony appearance, growth and sporulation on eight different media. Filtrates from cultures of the two strains contain chromatographically indistinguishable toxic components which cause the host-selective formation of tan-spot symptoms on wheat leaves. Quantitative leaf necrosis, ion leakage and E. coli inhibition assays indicate that approximately the same amount of toxin is formed in culture by both strains. Extracts of wheat leaf infected with mok1 (but not mok2) contain the same toxic component(s) found in culture filtrates. Strain mok2 is not an auxotrophic mutant and grows as well or better than strain mok1 in leaves of a susceptible cultivar of wheat (TAM 107). It appears that strain mok2 has retained the genes for synthesis of the host selective toxin but has lost genetic information necessary for toxin gene expression in host tissue.
| Item type | Current library | Collection | Call number | Copy number | Status | Barcode | |
|---|---|---|---|---|---|---|---|
| Thesis | CIMMYT Knowledge Center: John Woolston Library | Thesis Collection | Look under author name (Browse shelf(Opens below)) | 1 | Available | 622508 | |
| Thesis | CIMMYT Knowledge Center: John Woolston Library | Thesis Collection | Look under author name (Browse shelf(Opens below)) | 2 | Available | 634421 |
Thesis (Ph. D)
Pyrenophora tritici-repentis (Died.) Drech. strain mok1 (wild type) produces typical tan-spot symptoms on wheat (Triticum aestivum L. em Thell.) leaves. Strain mok2 (a naturally occurring mutant) was isolated from fleck type symptoms on wheat leaves infected with mok1. The two strains are easily distinguished by colony appearance, growth and sporulation on eight different media. Filtrates from cultures of the two strains contain chromatographically indistinguishable toxic components which cause the host-selective formation of tan-spot symptoms on wheat leaves. Quantitative leaf necrosis, ion leakage and E. coli inhibition assays indicate that approximately the same amount of toxin is formed in culture by both strains. Extracts of wheat leaf infected with mok1 (but not mok2) contain the same toxic component(s) found in culture filtrates. Strain mok2 is not an auxotrophic mutant and grows as well or better than strain mok1 in leaves of a susceptible cultivar of wheat (TAM 107). It appears that strain mok2 has retained the genes for synthesis of the host selective toxin but has lost genetic information necessary for toxin gene expression in host tissue.
English
Thesis Collection
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