Overexpression of SIZ1 enhances tolerance to cold and salt stresses and attenuates response to abscisic acid in Arabidopsis thaliana

Abstract

Sumoylation is a post-translational modification to control several cellular functions, including responses to environmental stresses and hormones in plants, and SIZ1 is a SUMO (small ubiquitin-related modifier) E3 ligase that plays an important role in sumoylation. In this study, we produced transgenic Arabidopsis thaliana plants with a moderately higher expression of SIZ1. Compared to wild type, the transgenic plants, with or without cold acclimation, were tolerant to freezing stress when subjected to freezing temperatures. The transgenic plants exhibited enhanced performance associated with robust shoot and root growth under salinity stress, whereas the wild type exhibited necrosis in the leaves with salt treatment. Furthermore, SIZ1 overexpression attenuated the root growth inhibition caused by abscisic acid. These results suggest that SIZ1 has the potential to genetically improve plant responses to abiotic stresses. © 2014 The Japanese Society for Plant Cell and Molecular Biology.