Arun K. Sharma

Professor 

E-mail: arun.sharma@south.du.ac.in
Phone: 9810538742
Specialization: Regulation of gene expression & Biotechnology
Research Interests: 
  • Improving quality of tomato fruits: Genes encoding several transcription factors have been overexpressed or silenced to improve quality of tomato fruits and delay their ripening. Some of these genes are LeMADS-RIN, a gene which codes for a MADS box containing transcription factor, LeEIL1 and LeEIL3, involved in ethylene signal transduction and genes encoding several Ethylene Responsive Factors (ERFs). Attempt has been made to increase accumulation of folates in tomato by fruit-specific overexpression of 2 genes encoding for Para amino benzoate Aminodeoxychorismate synthase and GTP cyclohydrolase. Several miRNAs with potential to improve folate accumulation have been identified. 
  •  Role of DNA methylation: Several methylated DNA binding proteins of Arabidopsis have been characterized. AtMBD6 has been found to have an essential role in maintenance of gene silencing. AtMBD4 has been found to have a role in phosphate starvation response and AtMBD1 has been found to have a role in controlling ABA responses. Homologs of genes encoding methylated DNA binding genes of Arabidopsis have been identified in tomato and their roles are being investigated. 
  • Sequencing of tomato genome: My group contributed in “Indian initiative on Tomato Genome Sequencing” where part of chromosome 5 of tomato was sequenced by BAC by BAC approach. 
  •  Genetic manipulation of tomato for cold resistance: Attempt has been made to engineer cold resistance in tomato using OSISAP1 gene of rice. Further transgenic plants over-expressing genes encoding for mitogen activated protein kinase 3 and alternative oxidase 1 have been produced. These plants are showing improved tolerance to various abiotic stresses.
  •  Expression of proteins of pharmaceutical importance in plants: The genes for B subunit (CTB) of cholera toxin, toxin co-regulated pillus (TCP) protein and accessory colonization factor (ACF) of Vibrio cholerae have been introduced into tomato. Further, chimeric antigens having CTB fused to immunogenic epitopes of TCP have also been expressed in tomato plants. Feeding of transgenic tomato expressing CTB to mice was found to elicit production of CTB-specific IgA antibodies. 
Select Publications
  1. Parida, A.P., Sharma, A. and Sharma, A.K. 2019. AtMBD4: A methylated DNA binding protein negatively regulates a subset of phosphate starvation genes. J. Biosci.  44:14.
  2. Parida, A.P., Raghuvanshi, U., Pareek, A., Singh, V., Kumar, R. and Sharma, A.K. (2018). Genome-wide analysis of genes encoding MBD domain-containing proteins from tomato suggest their role in fruit development and abiotic stress responses. Molecular Biol. Rep. 45:2653–2669.
  3. Parida, A.P., Sharma, A. and Sharma, A.K. (2017) AtMBD6, a methyl CpG binding domain protein, maintains gene silencing in Arabidopsis by interacting with RNA binding proteins. J. Biosci. 42:57-68.
  4. Agarwal, P., Kumar, R. Pareek, A. and Sharma, A.K. (2017) Fruit preferential activity of tomato RIP1 gene promoter in transgenic tomato and Arabidopsis. Mol. Gen. Genomics 292:145-156. 
  5. Kumar, R., Jiwani, G., Pareek, A., SravanKumar, T., Khurana, A. and Sharma, A.K. 2016. Evolutionary profiling of group II PLP-dependent decarboxylase gene family suggests expansion and functional diversification of histidine decarboxylases in tomato. The Plant Genome. 9:1-15.
  6. Kumar R., Agarwal P., Pareek A., Tyagi A.K. and Sharma A.K. (2015). Genomic Survey, Gene Expression, and Interaction Analysis Suggest Diverse Roles of ARF and Aux/IAA Proteins in Solanaceae. Plant Mol. Biol. Rep. 33:1552-1572.
  7. Kumar R, Khurana, A and Sharma A.K. (2014). Role of plant hormones and their interplay in development and ripening of fleshy fruits. J. Exp. Bot.  65:4561–4575.
  8. Tomato Genome Consortium (2012) The tomato genome sequence provides insights into fleshy fruit evolution. Nature, 485:635-641. Citations 639, Impact Factor 38.597.
  9. Sharma, M.K., Jani, D., Thungapathra, M., Gautam, J.K., Meena, L.S., Singh, Y, Ghosh, A, Tyagi, A. K. and Sharma, A.K. (2008). Expression of accessory colonization factor subunit A (ACFA) of Vibrio cholerae and ACFA fused to cholera toxin B subunit in transgenic tomato (Solanum lycopersicum). J. Biotechnology 135:22-27. Elsevier B.V.
  10. Jani, D., Meena, L.S., Haq, Q.M.R., Singh, Y., Sharma, A.K. and Tyagi, A.K. (2002). Expression of cholera toxin B subunit in transgenic tomato plants. Transgen. Res. 11:447-454. Publisher: Kluwer Academic Publishers, Netherlands.