Effect of elevated ammonium on biotic and abiotic stress defense responses and expression of related genes in cucumber (Cucumis sativus L.) plants.

Ammonium (NH) enhances plant defense mechanisms but can be phytotoxic as the sole nitrogen source. To investigate the impact of a balanced NH and NO ratio on plant defense parameters without adverse effects, cucumber plants (Cucumis sativus L.) were grown under control (14 mM NO + 2 mM NH) and elevated level of NH (eNH, 8 mM NO+ 8 mM NH).

The arbuscular mycorrhizal mycelium from barley differentially influences various defense parameters in the non-host sugar beet under co-cultivation.

The interactions between arbuscular mycorrhizal fungi (AMF) and non-host species are poorly studied. Particularly scarce is information on members of the Amaranthaceae/Chenopodiaceae family. Sugar beet (Beta vulgaris) plants were co-cultivated with a host species (Hordeum vulgare) in the presence (+AMF) or absence of Rhizophagus intraradices to explore the hypothesis that the presence of an active, pre-established AMF mycelium induces defense responses in the non-host species.