ZmSKIP, a homologue of SKIP in maize, is involved in response to abiotic stress in tobacco

摘要

Maize is one of the most important agricultural crops in the world. Abiotic stresses are major limiting factors for crop productivity. To improve maize tolerance to abiotic stresses, identification of stress tolerance-associated genes is of great importance. In this study, a maize homologue of human ski-interacting protein (SKIP) gene, named as ZmSKIP, was identified and characterized. Findings indicated that the ZmSKIP protein was targeted to the nucleus, and that it was induced at the transcriptional level by various abiotic stresses including drought, high salinity, and abscisic acid (ABA) in maize. Transgenic tobacco plants expressing β-glucuronidase (GUS) reporter gene under the control of the ZmSKIP promoter exhibited GUS activity in all tested tissues and GUS expression was induced by NaCl, mannitol, polyethylene glycol and ABA. Compared to wild type plants, transgenic tobacco plants overexpression ZmSKIP displayed higher antioxidant enzymes, such as superoxide dismutase, peroxidase and catalase (CAT) activities and lower malondialdehyde content and electrical conductivity under drought, NaCl and ABA treatments. The root growth was less inhibited and the plants displayed more tolerance under mannitol, NaCl and ABA treatments. Quantitative real-time PCR analysis showed that overexpression of ZmSKIP in tobacco plants altered the expression of CAT, APX and PR5. These data suggest that overexpression of ZmSKIP in tobacco can enhance tolerance to drought, NaCl and ABA abiotic stresses, and ZmSKIP acts as a positive regulator of abiotic stress tolerance in plants.