Abstract
ROPs (also called RACs) are RHO-like monomeric G-proteins of plants, well-known as molecular switches in plant signal transduction processes, which are involved in plant development and a variety of biotic and abiotic stress responses. The barley (Hordeum vulgare) ROPs RACB, RAC1 and RAC3 have been shown to be involved in cellular growth, polarity and in susceptibility to the biotrophic barley powdery mildew fungus Blumeria graminis f.sp. hordei. We produced transgenic tobacco (Nicotiana tabacum) plants expressing constitutively activated (CA) mutants of the barley ROPs RACB and RAC3 to monitor the impact of heterologous ROP expression on cell polarity and disease susceptibility of tobacco. CA HvROPs influenced leaf texture, disturbed root hair polarity and induced cell expansion in tobacco. Both barley ROPs induced super-susceptibility to the compatible powdery mildew fungus Golovinomyces cichoracearum but only CA HvRAC3 induced super-susceptibility to the bacterial leaf pathogen Pseudomonas syringae pv. tabaci. Data suggest involvements of ROPs in tobacco cell expansion, polar growth and in response to bacterial and fungal leaf pathogens.
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Abbreviations
- Bgh :
-
Blumeria graminis f.sp. hordei
- CA:
-
constitutively-activated
- DN:
-
dominant-negative
- Pst :
-
Pseudomonas syringae pv. tabaci
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Acknowledgements
We are grateful to Jörg Vogelsberg (University of Giessen) for support of the tissue culture growth of plant material, to Caroline Hoefle (Technische Universität München) for help with statistical data analysis and to Holger Schultheiss (University of Giessen) for plant genotyping. This work was supported by the German Research Foundation (FOR666, HU886/1), the University of Agricultural and Natural Resources, College of Agriculture, Department of Plant Protection, Sari, Iran and by the German Academic Exchange Service.
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Pathuri, I.P., Imani, J., Babaeizad, V. et al. Ectopic expression of barley constitutively activated ROPs supports susceptibility to powdery mildew and bacterial wildfire in tobacco. Eur J Plant Pathol 125, 317–327 (2009). https://doi.org/10.1007/s10658-009-9484-5
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DOI: https://doi.org/10.1007/s10658-009-9484-5