RETRACTED: WRKY71 and TGA1a physically interact and synergistically regulate the activity of a novel promoter isolated from Petunia vein-clearing virus.
Caulimoviral promoters have become excellent tools for efficient transgene expression in plants. However, the transcriptional framework controlling their systematic regulation is poorly understood. To understand this regulatory mechanism, we extensively studied a novel caulimoviral promoter, PV8 (-163 to +138, 301 bp), isolated from Petunia vein-clearing virus (PVCV). PVCV was found to be Salicylic acid (SA)-inducible and 2.5-3.0 times stronger than the widely used CaMV35S promoter. In silico analysis of the PV8 sequence revealed a unique clustering of two stress-responsive cis-elements, namely, as-11 and W-box1-2, located within a span of 31 bp (-74 to -47) that bound to the TGA1a and WRKY71 plant transcription factors (TFs), respectively. We found that as-1 (TTACG) and W-box (TGAC) elements occupied both TGA1a and WRKY71 on the PV8 backbone. Mutational studies demonstrated that the combinatorial influence of as-1 (-57) and W-box1-2 (-74 and -47) on the PV8 promoter sequence largely modulated its activity. TGA1a and WRKY71 physically interacted and cooperatively enhanced the transcriptional activity of the PV8 promoter. Biotic stress stimuli induced PV8 promoter activity by ~1.5 times. We also established the possible pathogen-elicitor function of AtWRKY71 and NtabWRKY71 TFs. Altogether, this study elucidates the interplay between TFs, biotic stress and caulimoviral promoter function.
['Shrestha|Ankita|A|', 'Khan|Ahamed|A|', 'Mishra|Dipti Ranjan|DR|', 'Bhuyan|Kashyap|K|', 'Sahoo|Bhabani|B|', 'Maiti|Indu B|IB|', 'Dey|Nrisingha|N|']
D017360:Arabidopsis D029681:Arabidopsis Proteins D050976:Basic-Leucine Zipper Transcription Factors D017796:Caulimovirus D018506:Gene Expression Regulation, Plant D032306:Petunia D018515:Plant Leaves D010940:Plant Proteins D030821:Plants, Genetically Modified D011401:Promoter Regions, Genetic D011485:Protein Binding D011523:Protoplasts D044224:Pseudomonas syringae D020156:Salicylic Acid D014026:Tobacco D014157:Transcription Factors
WRKY71 TGA1a PVCV Caulimovirus Transcriptional regulation