Proteomic Analysis: Explosive Salt Accumulation in Leaves of Morus alba L. under Salt Stress

The salt tolerance of glycophytes is thought to be related to their ability to restrict sodium access to their aboveground parts. A previous study on the mulberry (Morus alba L.) revealed a phenomenon of explosive salt accumulation in the leaves after exceeding a certain treatment concentration. Here, we aim to observe the internal state of mulberry seedlings under salt stress by the proteomic method and to identify the possible inducements associated with salt bursts. In this study, the target treatments for TMT-label free quantitative analyses were determined by measuring the sodium content in the roots and leaves. The results showed that the expressions of proteins classified as “plant hormones”, “ion channels”, “REDOX homeostasis”, “cytoskeleton” and “cell wall” changed significantly after salt bursts. This phenotype is associated with the destruction of the apoplast, in which the assembly of the Casparian strip may be affected by the inhibition of some key proteins, indirectly increasing the rate of ion migration through the endodermis into the shoots.