IDG

Indranil Dasgupta

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Specialization: Molecular biology of plant viruses and

plant-virus interactions

Research Interests

Rice tungro bacilliform virus (RTBV) and Rice tungro spherical virus (RTSV) jointly cause the tungro disease of rice. We have analyzed the genomic DNA of two isolates of RTBV from India and shown them to be significantly different from the virus isolates from Southeast Asia. Similar work is also being carried out for RTSV. PCR-RFLP analysis has shown that they exist as collections of microvariants in the field. To obtain new promoters for heterologous gene expression in rice, we have modified the native RTBV promoter of one of the Indian isolates and they show tissue- and development-specific expression patterns in transgenic rice plants, the levels of expression being comparable to maize ubi promoter. To engineer pathogen-derived resistance in rice against tungro, we have developed several independent transgenic rice lines containing a number of RTBV and RTSV genes, designed to express the respective proteins and/or anti-sense or double-stranded RNA. Some of them show a certain degree of resistance against RTBV/RTSV. As an additional tool for functional genomic studies in rice, we are working on developing a RTBV-based gene silencing vector, based on Agrobacterium – mediated inoculation of rice plants. Our work on the virus responsible for a devastating viral disease of cassava (Manihot esculenta ) Cassava mosaic virus has shown for the first time that Sri Lankan cassava mosaic virus (SLCMV), earlier reported only from Sri Lanka is also widely present in India We have also shown that it is the second virus responsible for cassava mosaic disease in India. The biodiversity of SLCMV and Indian cassava mosaic virus (ICMV) in three states of southern India was also investigated by PCR and was shown by PCR-RFLP to display high variability. The two genes of SLCMV required for the viral movement were functionally analyzed by GFP fusions followed by biolistic introduction to tobacco leaves. Fluorescence microscopic studies have indicated distinct nuclear- and plasmodesmal-targeting domains in the above viral proteins.

Select Publications

1. Patil, B. L., Rajasubramaniam, S., Bagchi, C. and Dasgupta, I. (2005) Both Indian cassava mosaic virus and Sri Lankan cassava mosaic virus are found in India and exhibit high variability as assessed by PCR-RFLP. Archives of Virology 150(2); 389-397.

2. Joshi, R., Kumar, V. and Dasgupta, I. (2003) Detection of molecular variability in rice tungro bacilliform viruses from India, using polymerase chain reaction-restriction fragment length polymorphism. Journal of Virological Methods 109; 89-93.

3. Dasgupta, I., Malathi, V. G. and Mukherjee, S. K. (2003) Genetic engineering for virus resistance. Current Science 84(3); 341-354.

4. Nath, N., Mathur, S. and Dasgupta, I. (2002) Molecular analysis of two complete rice tungro bacilliform virus sequences from India. Archives of Virology 147; 1173-1187.

5. Joshi, R. and Dasgupta, I. (2001) Cloning and molecular analysis of DNA of rice tungro bacilliform virus from different rice growing regions of India. Indian Phytopathology 54(4); 469-475.

6. Varma, A., Niazi, F. R., Dasgupta, I., Singh, J., Cheema, S. S. and Sokhi, S. S. (1999) Alarming epidemic of rice tungro disease in North-West India. Indian Phytopathology 52; 71-74.

7. Dasgupta, I., Das, B. K., Nath, P. S., Mukhopadhyay, S., Niazi, F. R. and Varma, A. (1996) Detection of rice tungro bacilliform virus in field and glasshouse samples from India using polymerase chain reaction. Journal of Virological Methods 58; 53-58.

8. Fan, Z., Dahal, G., Dasgupta, I., Hay, J. and Hull, R. (1996) Variation in the genome of rice tungro bacilliform virus: molecular characterization of six isolates. Journal of General Virology 77; 847-854.

9. Futterer, J., Potrykus, I., Valles-Brau, M. P., Dasgupta, I., Hull, R. and Hohn, T. (1994). Splicing in a plant pararetrovirus. Virology 198(2); 663-670.

10. Dasgupta, I., Hull, R., Eastop, S., Poggi-pollini, C., Blakebrough, M., Boulton, M. I. and Davies, J. W. (1991) Rice tungro bacilliform virus DNA independently infects rice after Agrobacterium-mediated transfer. Journal of General Virology 72; 1215-1221.