Co-expression of AtbHLH17 and AtWRKY28 Improves Abiotic Stress Resistance in Arabidopsis

Scientists control stress adaptation in plants by altering the expression of specific genes involved in complex signaling pathways. Researcher K.C. Babitha and colleagues at the University of Agricultural Sciences in India expressed AtbHLH17 (AtAIB) and AtWRKY28, transcription factors (TFs) which are known to be upregulated under drought and oxidative stress, respectively in Arabidopsis. They developed multigene expression cassette with the two genes andreported gene GUS employing a modifies gateway cloning technique.This multigene casette was successfully intergrated as shown in the results of the GUS assay and expression analysis of transgenes in GM plants.

Under mannitol stress condition, significantly higher root growth was observed in the GM plants. Growth under stress and recovery growth was significantly higher in GM plants exposed to gradual long term desiccation stress conditions.Furthermore, the researchers reported expression of several downstream target genes under various stress conditions. A few genes having either WRKY or bHLH cis elements in their promoter regions exhibited higher transcript levels than wild type. However, the genes which did not have either of the motifs did not differ in their expression levels in stress conditions compared to wild type plants.

Based on the findings, co-expressing two or more TFs may lead to upregulation of many downstream target genes and enhance the stress tolerance of the plants.

Read the abstract at http://link.springer.com/article/10.1007/s11248-012-9645-8.