Effect of a Cell-Wall-Degrading Enzyme Complex on Starch Recovery and Steeping Requirements of Sorghum and Maize

Alternaria citri, the cause of Alternaria black rot, and Alternaria alternata rough lemon pathotype, the cause of Alternaria brown spot, are morphologically indistinguishable pathogens of citrus: one causes rot by macerating tissues and the other causes necrotic spots by producing a host-selective toxin. To evaluate the role of endopolygalacturonase (endoPG) in pathogenicity of these two Alternaria spp. pathogens, their genes for endoPG were mutated by gene targeting. The endoPGs produced by these fungi have similar biochemical properties, and the genes are highly similar (99.6% nucleotide identity). The phenotypes of the mutants, however, are completely different. An endoPG mutant of A. citri was significantly reduced in its ability to cause black rot symptoms on citrus as well as in the maceration of potato tissue and could not colonize citrus peel segments. In contrast, an endoPG mutant of A. alternata was unchanged in pathogenicity. The results indicate that a cell wall-degrading enzyme can play different roles in the pathogenicity of fungal pathogens. The role of a cell wall-degrading enzyme depends upon the type of disease but not the taxonomy of the fungus.

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Biochemical studies on lysin, a cell wall degrading enzyme released during fertilization in Chlamydomonas

Experimental Cell Research ◽

10.1016/0014-4827(88)90357-6 ◽

1988 ◽

Vol 179 (1) ◽

pp. 181-193 ◽

Cited By ~ 16

Author(s):

Marty J. Buchanan ◽

William J. Snell

Keyword(s):

Cell Wall ◽

Degrading Enzyme ◽

Cell Wall Degrading Enzyme ◽

Biochemical Studies ◽

A Cell

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Effect of Adding a Cell Wall Degrading Enzyme to a Total Mixed Ration for Lactating Cows1

The Professional Animal Scientist ◽

10.15232/s1080-7446(15)32494-3 ◽

1996 ◽

Vol 12 (2) ◽

pp. 81-85 ◽

Cited By ~ 7

Author(s):

G.E. Higginbotham ◽

E.J. Depeters ◽

S.L. Berry ◽

A. Ahmadi

Keyword(s):

Cell Wall ◽

Total Mixed Ration ◽

Degrading Enzyme ◽

Cell Wall Degrading Enzyme ◽

A Cell

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Hyphal fusions in the wood-rotting fungusSchizophyllum commune: I. The effects of incompatibility factors

Genetics Research ◽

10.1017/s0016672300001336 ◽

1970 ◽

Vol 15 (1) ◽

pp. 19-28 ◽

Cited By ~ 18

Author(s):

Sayed S. Ahmad ◽

Philip G. Miles

Keyword(s):

Cell Wall ◽

Mating Type ◽

Schizophyllum Commune ◽

Mating Types ◽

Hyphal Fusion ◽

Fusion Frequency ◽

Degrading Enzyme ◽

Cell Wall Degrading Enzyme ◽

Incompatibility Factor ◽

A Cell

SUMMARYEffects of the incompatibility factors inSchizophyllum communeFries on the process of hyphal fusion are described. A role for the A incompatibility factor in hyphal fusion is indicated. Matings between strains with different mating types have higher fusion frequencies than matings between strains with the same mating types. Evidence is presented that the differences in fusion frequencies are not due to genetical factors other than mating types. When two strains of different mating types are grown in the same culture plate, but separated by a cellophane membrane, the strains are altered in some unexplained manner in such a way that even matings between strains of the same mating type have a higher fusion frequency than occurs in matings between compatible strains not so treated. Matings leading to the formation of common-B and dikaryotic mycelia have comparable fusion frequencies while those leading to the formation of common-A mycelia have a far lower frequency of fusions. It has been demonstrated that high fusion frequency is associated with heterozygosity at the A locus. It is suggested that a repression–derepression mechanism involving a cell wall degrading enzyme or enzymes may be involved in the regulation of hyphal fusion.

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