Genetic transformation is a powerful method for studying the functions and regulatory mechanisms of genes involved in various physiological and biochemical processes. Furthermore, transient gene expression systems complement stable transformation and provide novel experimental tools for physiological and localization studies, and for generating gene products.

The researchers, by optimizing the transient transformation method, developed a system for characterizing gene function in response to stress tolerance. Basing on the seedlings of Tamarix hispida cultured and carrying out plasmid construction, transformation, physiological measurements and real-time PCR analysis, the researchers studied the efficiency of the transient transformation system in different plant species.

The results of real-time PCR showed that the expression of ThbZIP1 was highly up- and down-regulated in the plants with overexpression and RNAi-silenced expression of ThbZIP1, respectively, when compared with control plants (transiently transformed with empty pROK2). A physiological study showed that ThbZIP1 can enhance the activities of both peroxidase (POD) and superoxide dismutase (SOD), and decrease electrolyte leakage rate and levels of reactive oxygen species (ROS) and malondialdehyde (MDA) under salt stress conditions. Furthermore, ThbZIP1 is found to mediate stress tolerance by regulating the expression of SOD and POD genes.

The results confirmed that this method is reliable and powerful in determining the function of a gene in response to abiotic stresses. The study was published in Plant Molecular Biology Reporter in June 2014.