Coupled expression of Cu/Zn-superoxide dismutase and catalase in cassava improves tolerance against cold and drought stresses

Abstract

Recently we reported that the joint expression of cassava Cu/Zn superoxide dismutase (MeCu/ZnSOD) and catalase (MeCAT1) prolonged the shelf life of cassava storage-roots by the stabilization of reactive oxygen species (ROS) homeostasis after harvest. Since oxidative damage is a major feature of plants exposed to environmental stresses, transgenic cassava showing increased expression of the cytosolic MeCu/ZnSOD and the peroxisomal MeCAT1 should have improved resistance against other abiotic stresses. After cold treatment, the transgenic cassava maintained higher SOD and CAT activities and lower malendialdehyde content than those of wild type plants (WT). Detached leaves of transgenic cassava also showed slower transpirational water loss than those of WT. When plants were not watered for 30 d, transgenic lines exhibited a significant increase in water retention ability, accumulated 13% more proline and 12% less malendialdehyde than WT’s, and showed enhanced activity of SOD and CAT. These results imply that manipulation of the antioxidative mechanism allows the development of staple crops with improved tolerance to abiotic stresses.

Keywords: :

• ROS scavenging
• cassava
• superoxide dismutase
• catalase
• abiotic stress resistance

Disclosure of Potential Conflicts of Interest

The authors indicated no potential conflicts of interest.

Acknowledgments

This work was supported by grants from the National Basic Research Program (2010CB126605), the National Natural Science Foundation of China (31271775), the National High Technology Research and Development Program of China (2012AA101204), the Earmarked Fund for China Agriculture Research System (CARS-12) and Shanghai Municipal Afforestation and City Appearance and Environmental Sanitation Administration (G102410, F132427) to J.X., X.D., J.Y. and P.Z. The study was partially funded by a grant from the Bill and Melinda Gates Foundation (BioCassava Plus program) to J.R.B. and P.Z.