Objective  Mechanism of aquaporins relating to the plasma membrane intrinsic proteins (PIPs) of Hippophae rhamnoides subsp. sinensis in response to salt stress was studied.

  Methods  Bioinformatics of HrPIP was analyzed. Physiological indexes and expressions of the gene in tissues of H. rhamnoides under normal and imposed salt stresses of 200, 400, 600, 800, or 1,000 mmol ·L⁻¹ NaCl were determined.

  Results   Located in the cell membrane, HrPIP encoded 110 amino acids. The hydrophobic protein had no signal peptide or transmembrane helix region. As salt stress intensified, the RWC decreased gradually, and the chlorophyll content declined initially followed by an incline. The permeability of the plasma membrane and the content of MDA changed slightly when the salt concentration was low but increased significantly when the concentration was high. The 1000 mmol·L⁻¹ salt stress induced declined MDA but continuously rising membrane permeability. The expressions of HrPIP in different organs varied by the increasing salt stress. In roots, it rose at lower salt concentrations then declined but rose again at high salt levels. In the leaves, the opposite trend was observed, whereas it was in an “M” pattern in the stems.

  Conclusion  H.rhamnoides subsp. sinensis was salt resistant to a certain degree. Under the stress, by altering the HrPIP expression to increase water absorption in roots, transport in stems, and retention in leaves the plant manipulated the cellular salt concentration to achieve an improved stress tolerance.