Mg deficiency affects leaf Mg remobilization and the proteome in Brassica napus

•Mg deficiency decreases Brassica napus growth and modifies nutrient uptakes.•Zn and Mn uptakes were significantly increased in Mg-depleted plants.•In Mg-depleted plants, Mg was mobilized from oldest leaves to youngest tissues.•Mg deficiency induces leaf proteome modifications.

In order to cope with variable mineral nutrient availability, higher plants have developed numerous strategies including the remobilization of nutrients from source to sink tissues. However, such processes remain relatively unknown for magnesium (Mg), which is the third most important cation in plant tissues. Using Mg depletion of Brassica napus, we have demonstrated that Mg is remobilized from old leaves to young shoot tissues. Moreover, this study showed that Mg depletion induces modification of nutrient uptake, especially Zn and Mn. Finally, comparative proteomic analysis of old leaves (source of Mg) revealed amongst other results that some proteins requiring Mg for their functionality (isocitrate dehydrogenase for example) were up-regulated. Moreover, down-regulation of proteases suggested that mobilization of Mg from old leaves was not associated with senescence.