Application of GC7 to reduce hypusination via inhibiting deoxyhypusine synthase in Arabidopsis thaliana seedlings exposed salt stress

Salt stress is one of the most harmful stress types affecting our agriculture and food safety. Despite the extensive knowledge of plant responses induced by salt stress, the details of the regulation of metabolite-dependent posttranslational modifications occurring during salt stress have rarely been investigated. Hypusination is polyamine-dependent posttranslational modification of eukaryotic translation factor 5A (eIF5A), which is conserved in all living organisms. Some evidence suggests that this modification plays an important role in salt stress tolerance, but the significance of the enzymes participating in the synthesis of hypusine is unknown. GC7 (N1-guanyl-1,7-diaminoheptane) is a special compound which can inhibit the enzyme activity of deoxyhypusine synthase (DHS). In our study, we applied GC7 in order to examine the applicability and efficiency of this compound and to decipher the modulation of polyamine metabolism during salt stress in plants. Our results support the significance of DHS during salt stress and of GC7 as an efficient tool to study hypusination in plant species.