Toward the functional analysis of the grape sugar transporter VvHT5: ectopic expression in Arabidopsis thaliana during Botrytis cinerea infection
Résumé
Understanding of plant defense mechanisms is essential for developing alternative solutions to fight against cryptogamic diseases. Among these mechanisms, increasing evidence indicate that sugar transporters and invertases play important roles in plant resistance[1]. We previously reported that the overexpression of PM-localized H+/ hexose symporters STP13 enhanced Arabidopsis basal resistance to the necrotrophic fungus B. cinerea, whereas STP13-deficiency resulted in an enhanced susceptibility indicating that STP13 may improve resistance by depriving the pathogen from resources and fueling the plant defense responses[2,3]. By contrast, STPs could also play a negative role in defense by promoting the proliferation of biotrophic fungi during infection[4]. Based on these studies, we now expand our research to plant of agricultural interest such as grapevine. To explore the functional role of VvHT5 (STP13 closest homolog from grapevine), we used a gain-of-function approach. Here, we present the phenotypic analysis of the ectopic expression of VvHT5 in A. thaliana during B. cinerea infection. Our results indicate that the control of apoplastic sugars by the activity of PM-localized hexose transporters may constitute a host-defense strategy that limits fungal proliferation.
1. Liu, Y.-H. et al. Sugar conundrum in plant–pathogen interactions: roles of invertase and sugar transporters depend on pathosystems. J. Exp. Bot. erab562 (2022).
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3. Veillet, F. et al. The molecular dialogue between Arabidopsis thaliana and the necrotrophic fungus Botrytis cinerea leads to major changes in host carbon metabolism. Sci. Rep. 7, 17121 (2017).
4. Moore, J. W. et al. A recently evolved hexose transporter variant confers resistance to multiple pathogens in wheat. Nat Genet 47, 1494–1498 (2015).