Overexpression of the ZmSAMDC Enhances Cold Tolerance in Transgenic Maize (Zea Mays L.)

Abstract

Maize (Zea mays L.) is a food crop sensitive to low temperatures. Low temperature, as one of the abiotic stress hazards, seriously affects the yield of corn. However, the genetic basis of low-temperature adaptation in maize is still poorly understood. In this study, maize S-adenosylmethionine decarboxylase (SAMDC) was localized on the nucleus. We introduced the SAMDC gene into the excellent maize inbred line variety GSH9901 and used Agrobacterium-mediated transformation to produce cold-tolerant transgenic maize lines. After a 3-year single-location field trial, the contents of polyamine (PA), proline, malondialdehyde, an antioxidant enzyme, and APX in the leaves of transgenic maize plants overexpressing SAMDC were significantly increased, and the introduction of the SAMDC gene was significantly increased the expression of CBFs and cold-related genes.The agronomic traits of overexpression maize changed and the yield traits were significantly improved, but no significant changes were found in plant height, ear length, and shaft thickness.Thus, engineering the SAMDC enzyme is an effective strategy to improve the cold tolerance and value of maize.