Two distinct families of protein kinases are required for plant growth under high external Mg2+ concentrations in Arabidopsis.

Protein phosphorylation events play key roles in maintaining cellular ion homeostasis in higher plants, and the regulatory roles of these events in Na(+) and K(+) transport have been studied extensively. However, the regulatory mechanisms governing Mg(2+) transport and homeostasis in higher plants remain poorly understood, despite the vital roles of Mg(2+) in cellular function. A member of subclass III sucrose nonfermenting-1-related protein kinase2 (SnRK2), SRK2D/SnRK2.

Early senescence of the oldest leaves of Fe-deficient barley plants may contribute to phytosiderophore release from the roots.

Barley (Hordeum vulgare), which tolerates iron (Fe) deficiency, secretes a large amount of phytosiderophores from its roots. However, how barley is able to allocate resources for phytosiderophore synthesis when the carbon assimilation rate is reduced by Fe deficiency is unknown. We previously suggested that the acceleration of senescence in older leaves triggered by Fe deficiency may allow the recycling of assimilates to contribute to phytosiderophore synthesis.