A comparative analysis of the heterotrimeric G-protein Gα, Gβ and Gγ subunits in the wheat pathogen Stagonospora nodorum

BMC Microbiology

Research Article

Richard P Oliver¹  Peter S Solomon²  Joel P A Gummer³  Robert D Trengove³ 

[1]Australian Centre for Necrotrophic Fungal Pathogens, Curtin University, 6102, Bentley, WA, Australia

[2]Plant Science Division, Research School of Biology, The Australian National University, 0200, Acton, ACT, Australia

[3]Separation Science Laboratory, Murdoch University, 6150, Perth, WA, Australia

[4]Metabolomics Australia, Murdoch University, 6150, Perth, WA, Australia

关键词: G-protein;    cAMP-independent signal transduction;    Fungal wheat pathogen;    Asexual sporulation;   

DOI  :  10.1186/1471-2180-12-131

 received in 2012-02-27, accepted in 2012-06-07,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundIt has been well established that the Gα subunit of the heterotrimeric G-protein in the wheat pathogen Stagonospora nodorum is required for a variety of phenotypes including pathogenicity, melanisation and asexual differentiation. The roles though of the Gγ and Gβ subunits though were unclear. The objective of this study was to identify and understand the role of these subunits and assess their requirement for pathogenicity and development.ResultsG-protein Gγ and Gβ subunits, named Gga1 and Gba1 respectively, were identified in the Stagonospora nodorum genome by comparative analysis with known fungal orthologues. A reverse genetics technique was used to study the role of these and revealed that the mutant strains displayed altered in vitro growth including a differential response to a variety of exogenous carbon sources. Pathogenicity assays showed that Stagonospora nodorum strains lacking Gba1 were essentially non-pathogenic whilst Gga1- impaired strains displayed significantly slower growth in planta. Subsequent sporulation assays showed that like the previously described Gα subunit mutants, both Gba1 and Gga1 were required for asexual sporulation with neither mutant strain being able to differentiate either pycnidia nor pycnidiospores under normal growth conditions. Continued incubation at 4°C was found to complement the mutation in each of the G-protein subunits with nearly wild-type levels of pycnidia recovered.ConclusionThis study provides further evidence on the significance of cAMP-dependent signal transduction for many aspects of fungal development and pathogenicity. The observation that cold temperatures can complement the G-protein sporulation defect now provides an ideal tool by which asexual differentiation can now be dissected.

【 授权许可】

Unknown   
© Gummer et al.; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.