Overexpression of the Jojoba Aquaporin Gene, ScPIP1, Enhances Drought and Salt Tolerance in Transgenic Arabidopsis

Plasma membrane intrinsic proteins (PIPs) are a subfamily of aquaporin proteins located on plasma membranes where they facilitate the transport of water and small uncharged solutes. PIPs play an important role throughout plant development, and in response to abiotic stresses. Jojoba (Simmondsia chinensis (Link) Schneider), as a typical desert plant, tolerates drought, salinity and nutrient-poor soils. In this study, a PIP1 gene (ScPIP1) was cloned from jojoba and overexpressed in Arabidopsis thaliana. The expression of ScPIP1 at the transcriptional level was induced by polyethylene glycol (PEG) treatment. ScPIP1 overexpressed Arabidopsis plants exhibited higher germination rates, longer roots and higher survival rates compared to the wild-type plants under drought and salt stresses. The results of malonaldehyde (MDA), ion leakage (IL) and proline content measurements indicated that the improved drought and salt tolerance conferred by ScPIP1 was correlated with decreased membrane damage and improved osmotic adjustment. We assume that ScPIP1 may be applied to genetic engineering to improve plant tolerance based on the resistance effect in transgenic Arabidopsis overexpressing ScPIP1.