Specialization: Molecular biology of plant viruses and plant-virus interactions
Our lab is interested in studying the genomes of viruses infecting crops, their interactions with plant hosts and their use in the expression and silencing of plant genes. Our studies with viruses infecting rice have shown that out of the two viruses causing the Rice tungro disease, Rice tungro bacilliform virus (RTBV) exists as a distinct sub-group in India when compared with Southeast Asia (Nath et al., 2002), whereas Rice tungro spherical virus (RTSV), the second virus, is highly similar between India and Southeast Asian regions (Verma and Dasgupta, 2007). We have developed a number of rice lines containing genes derived from RTBV and RTSV with a view to engineer resistance against this dreaded disease. Some of the selected lines are being taken forward for back-crossing the desired genes to elite varieties of rice suited to different agro-ecological zones of India by research collaborators based in Tamilnadu and West Bengal. The use of novel plant lectins to control rice pests and the viral diseases vectored by them have been recently shown by us in collaboration with scientists at Bose Institute, Kolkata (Saha et al., 2006). Our work on the promoter of RTBV has shown the existence of tissue-specific control elements which can be used to drive gene expression in a defined manner and which are also influenced by the developmental stage the plant is passing through. To develop RTBV-based gene-silencing vectors for rice, we have generated a deleted version of the viral DNA, which can be introduced into rice plants through Agrobacterium, following which it is capable of independent replication and spread without causing detectable symptoms in the plant. Our studies with viruses infecting cassava (Manihot esculenta) has shown that, in addition to the Indian cassava mosaic virus known to be causing the Cassava mosaic disease, another virus, Sri Lankan cassava mosaic virus is also a causative agent in India (Dutt et al., 2005) and was already widespread in Kerala and Tamilnadu (Patil et al., 2005). In collaboration with European scientists, we have shown significant genomic recombination occurring in these viruses (Rothenstein et al., 2006) and the generation of defective DNA species as a result of such recombinations (Patil et al., 2007).
- Verma V & Dasgupta I 2007. Sequence analysis of the complete genomes of two Rice tungro spherical virus isolates from India.Archives of Virology 152: 645-648.
- Patil BL, Dutt N, Briddon RW, Bull SE, Rothenstein D, Borah BK, Dasgupta I, Stanley J & Jeske H. 2007. Deletion and recombination events between the DNA-A and DNA-B components of Indian cassava-infecting geminiviruses generate defective molecules in Nicotiana benthamiana. Virus Research 124: 59-67.
- Saha P, Dasgupta I & Das S 2006. A novel approach for developing resistance in rice against phloem limited viruses by antagonizing the phloem feeding hemipteran vectors. Plant Molecular Biology 62: 735-752.
- Patil B & Dasgupta I Defective Interfering DNAs of Plant Viruses 2006. Critical Reviews in Plant Sciences
- Rothenstein D, Haible D, Dasgupta I, Dutt N, Patil BL & Jeske H 2006 Biodiversity and recombination of cassava-infecting begomoviruses from southern India. Archives of Virology 151: 55-69.
- Dutt N, Briddon RW & Dasgupta I 2005. Identification of a second begomovirus, Sri Lankan cassava mosaic virus, causing cassava mosaic disease in India. Archives of Virology 150: 2101-2108.
- Patil BL, Rajasubramaniam S, Bagchi C. & 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
- Joshi R, Kumar V & 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.
- Dasgupta I, Malathi VG & Mukherjee SK 2003. Genetic engineering for virus resistance. Current Science 84: 341-354.
- Nath N, Mathur S & Dasgupta I 2002 Molecular analysis of two complete rice tungro bacilliform virus sequences from India. Archives of Virology 147: 1173-1187.