We are glad to announce that Ramakrishna Mission Vivekananda Educational and Research Institute (RKMVERI) will be conducting a special colloquium on “Development and characterization of plant synthetic promoters from Horseradish Latent Virus (HRLV)” on 14 Dec 2023, 12 noon at Seminar Hall, Narendrapur Campus.
Speaker : Dr. Nrisingha Dey, ILS, Bhubaneswar
Co-ordinator: Prof. Abhijit Chakrabarti
Abstract
The basics of molecular biology and structure of plant promoters will be discussed. Plant pararetroviruses are a rich source of novel plant promoters widely used for biotechnological applications. Here, we comprehensively characterized a unique sub-genomic transcript (Sgt) promoter of Horseradish Latent Virus (HRLV) and identified a fragment (HS4; -340 to +11; 351bp) that showed the highest expression of reporter genes in both transient and transgenic assays as evidenced by biochemical, histochemical GUS reporter assay and transcript analysis of uidA gene by qRT-PCR. We found that the as-1 element and W-box played an important role in the transcriptional activity of the HS4 promoter. Alongside, we enhanced the activity of the HS4 promoter by coupling the enhancer region from Figwort Mosaic Virus (FMV) promoter (FUAS; 195bp; -249 to -54) to the upstream region of it. This hybrid synthetic promoter FHS4 was around 1.1 times stronger than the most commonly used promoter, 35S (CaMV), and was efficient in driving reporter genes in both dicot and monocot plants. Subsequently, transgenic tobacco plants expressing the BrLTP2.1 gene, under the control of the FHS4 promoter, were developed which manifested increased resistance against an important plant fungal pathogen, Alternaria alternata. The Horseradish Latent Virus (HRLV) also possesses a peculiar full-length transcript (HRLV-Flt) promoter which is strong, constitutive and multi-stress responsive. We developed plethora of synthetic promoter using this HRLV-Flt in combination with other pararetroviral promoters by rationally designing different domains. A highly efficient promoter was discovered which showed strong gene expression efficiency in both tobacco leaves and rice seedling as suggested from transient assay of GUS and GFP reporter gene.
References:
- Shrestha A, Khan A, Dey N. cis-trans engineering: Advances and Perspectives on Customized Transcriptional Regulation in Plants. Mol Plant. 2018 Jul 2;11(7):886-898. doi: 10.1016/j.molp.2018.05.008. Epub
2018 May 30. PMID: 29859265. - Khan A, Shrestha A, Bhuyan K, Maiti IB, Dey N. Structural characterization of a novel full-length transcript promoter from Horseradish Latent Virus (HRLV) and its transcriptional regulation by multiple stress responsive transcription factors. Plant Mol Biol. 2018 Jan;96(1-2):179-196. doi: 10.1007/s11103-017-0693-6. Epub 2018 Jan 11. PMID: 29327227.
- Sherpa T, Jha DK, Kumari K, Chanwala J, Dey N. Synthetic sub-genomic transcript promoter from Horseradish Latent Virus (HRLV). Planta. 2023 Jan 18;257(2):40. doi: 10.1007/s00425-023-04066-7. PMID:
36653682.