Regulation of Na+ fluxes in plants

摘要

When exposed to salt, every plant takes up Na⁺ from the environment. Once in the symplast, Na⁺ is distributed within cells and between different tissues and organs. There it can help to lower the cellular water potential but also exert potentially toxic effects. Control of Na⁺ fluxes is therefore crucial and indeed, research shows that the divergence between salt tolerant and salt sensitive plants is not due to a variation in transporter types but rather originates in the control of uptake and internal Na⁺ fluxes. A number of regulatory mechanisms has been identified based on signaling of Ca²⁺, cyclic nucleotides, reactive oxygen species, hormones, or on transcriptional and post translational changes of gene and protein expression. This review will give an overview of intra- and intercellular movement of Na⁺ in plants and will summarize our current ideas of how these fluxes are controlled and regulated in the early stages of salt stress.