Wittek A, Dreyer I, Al-Rasheid KA, Sauer N, Hedrich R, Geiger D (2017)
Publication Language: English
Publication Status: Published
Publication Type: Journal article, Original article
Publication year: 2017
DOI: 10.1111/jipb.12535
Open Access Link: http://onlinelibrary.wiley.com/doi/10.1111/jipb.12535/abstract;jsessionid=6013841E5524A4CEA03EAC928C29DC49.f02t03
The biotrophic fungus Ustilago maydis causes the corn smut disease inducing tumor formation in its host Zea mays. Upon infection, the fungal hyphae invaginate the plasma membrane of infected maize cells establishing an interface where pathogen and host are separated only by their plasma membranes. At this interface the fungal and maize sucrose transporters, UmSrt1 and ZmSUT1, compete for extracellular sucrose in the corn smut/maize pathosystem. Here we biophysically characterized ZmSUT1 and UmSrt1 in Xenopus oocytes with respect to their voltage-, pH- and substrate-dependence and determined affinities towards protons and sucrose. In contrast to ZmSUT1, UmSrt1 has a high-affinity for sucrose and is relatively pH- and voltage-independent. Using these quantitative parameters, we developed a mathematical model to simulate the competition for extracellular sucrose at the contact zone between the fungus and the host plant. This approach revealed that UmSrt1 exploits the apoplastic sucrose resource, which forces the plant transporter into a sucrose export mode providing the fungus with sugar from the phloem. Importantly, the high sucrose concentration in the phloem appeared disadvantageous for the ZmSUT1, preventing sucrose recovery from the apoplastic space in the fungus/plant interface.
APA:
Wittek, A., Dreyer, I., Al-Rasheid, K.A., Sauer, N., Hedrich, R., & Geiger, D. (2017). The fungal UmSrt1 and maize ZmSUT1 sucrose transporters battle for plant sugar resources. Journal of integrative plant biology. https://doi.org/10.1111/jipb.12535
MLA:
Wittek, Anke, et al. "The fungal UmSrt1 and maize ZmSUT1 sucrose transporters battle for plant sugar resources." Journal of integrative plant biology (2017).
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