Cloning and characterization of a bZIP transcription factor gene in wheat and its expression in response to stripe rust pathogen infection and abiotic stresses

In plant, basic leucine zipper (bZIP) transcription factors play various roles in response to biotic and abiotic stimuli, as well as in developmental processes. In the present study, a novel bZIP gene, designated as TabZIP1, was isolated from wheat leaves infected by Puccinia striiformis f. sp. tritici using in silico cloning and reverse transcription PCR (RT-PCR) approaches. TabZIP1 was predicted to encode a 388 amino acid protein that contained a bZIP transcription factor basic domain signature and a leucine zipper motif. In transient assays with a TabZIP1–GFP construct, green fluorescent signals were specifically localized to the nucleus. Quantitative real-time PCR (qRT-PCR) analyses revealed that the transcription level of TabZIP1 was relatively higher in root than that in stem and leaf tissues. TabZIP1 transcripts were rapidly and highly induced during incompatible interactions, and by exogenously applied methyl jasmonate (MeJA) and ethylene (ET). However, salicylic acid (SA) treatment had no obvious effect on TabZIP1 expression. The transcription level of TabZIP1 was also induced by wounding and environmental stimuli, including low temperature and high salinity. These results suggested that the transcription factor encoded by the TabZIP1 gene may be involved in stress tolerance and defense response to stripe rust pathogen infection through the ET/MeJA-dependent signal transduction pathways.