Construction of a Constitutively Activated Gα Mutant in the Maize Pathogen Cochliobolus heterostrophus


Conserved eukaryotic signaling proteins participate in development and disease in plant pathogenic fungi. Mutants in CGA1, a heterotrimeric G protein Ga subunit gene of the maize pathogen Cochliobolus heterostrophus, are defective in several developmental pathways. Conidia from CGA1 mutants germinate as abnormal, straight-growing germ tubes that form few appressoria, and the mutants are female-sterile. The CGA1, Gα subunit, is also thought to act as a down regulator of hydrophobin expression and secretion in this fungus and in related Ascomycete species. Although cga1 mutants can cause normal lesions on plants there are host physiology conditions under which full virulence requires signal transduction through CGA1-mediated pathways. A Gα activated mutant, cga1Q204L was created to help establish the role of CGA1 in growth and development, and in mediating hydrophobin secretion and expression. The activated Gα allele was transformed into a cga1 mutant strain. The transgenic lines showed phenotypes resembling the null mutant in development, sporulation and hydrophobicity, indicating a possible role for CGA1 as a stabilizer of these traits.

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O. Degani, "Construction of a Constitutively Activated Gα Mutant in the Maize Pathogen Cochliobolus heterostrophus," American Journal of Plant Sciences, Vol. 4 No. 12, 2013, pp. 2394-2399. doi: 10.4236/ajps.2013.412296.

Conflicts of Interest

The authors declare no conflicts of interest.


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