Abstract:

In plant, basic leucine zipper (bZIP) transcription factors play various roles in developmental processes and in response to biotic and abiotic stimuli. In the present study, a novel bZIP gene, designated as TabZIP, was isolated from wheat leaves infected by Puccinia striiformis f. sp. tritici using in silico cloning and reverse transcription PCR approaches. TabZIP was predicted to encode a 356 amino-acid protein, which contained a bZIP transcription factor basic domain signature and a leucine zipper motif. Multiple alignment analysis based on the amino acids encoded by different bZIP genes from rice (Oryza sativa), maize (Zea mays), Arabidopsis thaliana, indicated that TabZIP was conserved among the three species of plants with highly sequence similarity. The transcript level of TabZIP was relatively high in root, but low in stem and leaf. Real-time PCR analysis revealed that TabZIP gene was rapidly and dramatically induced during incompatible interaction, whereas there was no significant effect in compatible interaction. Meanwhile, the expression of TabZIP was also induced by exogenous methyl jasmonate and ethephon. On the basis of these results, we postulate that the transcription factor encoded by gene TabZIP may be involved in wheat defense response to stripe rust fungus infection through ethylene- or jasmonic acid-dependent signal transduction pathways.

Key words: Wheat, Stripe rust fungus, bZIP transcription factor, In-silico cloning, Gene expression