M.V. Rajam

My research uses transgenic and other molecular approaches like RNAi to address a wide range of fundamental questions in plant development and stress responses. We have developed several rice, eggplant and tomato transgenics, tolerant to abiotic and biotic stresses by over-expressing various stress-related genes, notably polyamine biosynthesis genes. We have also developed transgenic tomatoes for delayed fruit ripening for longer shelf-life and improved fruit quality by over-expressing polyamine biosynthetic genes during fruit development. These studies provide clues to basic molecular and cellular mechanisms underlying the plant development and stress responses, which we are actively persuing. Work is also undertaken to stack transgenes in transgenic eggplant and tomato for enhanced tolerance to abiotic and biotic stresses. For the past several years, I have been working on the molecular dissection of polyamine biosynthesis in crop plants, and also in a model organism Chamydomonas reinhardtii to decipher the roles of polyamines in various biological processes, and rigorous analysis of this important pathway has yielded insights into the molecular and cellular basis for plant development processes and stress tolerance, and is opening new opportunities for the improvement of crop plants.
 
The current major research interests of my laboratory is to use RNAi technology to unravel the functions of polyamine biosynthesis genes in various developmental processes, including fruit ripening, male sterility, senescence and stress responses as well as to develop transgenic tomato, eggplant and cotton plants for disease, insect and nematode resistance through plant RNAi- mediated silencing of vital genes of the target pathogens and pests. Besides, virus resistant sweet orange transgenics, male sterility transgenic tomato and marker-free transgenic tomato are being produced by using RNAi and other approaches. Silencing of vital gene of a fungal pathogen (Aspergillus nidulans) and insect pest (Helicoverpa armigera) by siRNAs for their control in vitro, development of marker-free and double transgenics of tomato for stress tolerance and slow ripening transgenic tomatoes are some of our recent significant achievements.
 
Major Research Findings
 
Prof. M. V. Rajam’s lab has developed several novel strategies, based on RNAi and artificial microRNA, for the control of viral and fungal pathogens, and insect pests in crops. They have demonstrated that engineered polyamine accumulation can confer abiotic stress tolerance in plants and that the polyamines are important determinants of plant regeneration and transformation. They have also developed improved regeneration and Agrobacterium-mediated transformation protocols for important crops and  Chlamydomonas (first report), and generated a battery of transgenic crops for stress tolerance, delayed ripening and other agronomic traits. 
 
Recent Publications 
  1. Roopali Pandey, Aarti Gupta, Anuj Chowdhary, Ram Krishna Pal & M. V. Rajam.2015. Over-expression of mouse ornithine decarboxylase gene under the control of fruit-specific promoter enhances fruit quality in tomato. Plant Mol. Biol. DOI10.1007/s11103-014-0273-y.
  2. Tengale Dipak Bhauso, Thankappan Radhakrishnan, Abhay Kumar, Gyan Prakash Mishra, Jentilal Ramjibhai Dobaria, Kirankumar Patel & Rajam MV. 2015. Overexpression of bacterial mtlD gene in peanut improves drought tolerance through accumulation of mannitol. Sci. World J. 2014: doi.org/10.1155/2014/125967.
  3. Deepali Singh, Annick Ambroise, Robert Haicour, Darasinh Sihachakr & Rajam MV. 2014. Increased resistance to fungal wilts in transgenic eggplant expressing alfalfa glucanase gene. Physiol. Mol. Biol. Plants    DOI: 10.1007/s12298-014-0225-7.
  4. Madhulatha P, Aarti Gupta, Saaraj Gupta, Anuj Kumar, Pal RK & Rajam MV. 2014. Fruit-specific over-expression of human S-adenosylmethionine decarboxylase gene results in polyamine accumulation and affects diverse aspects of tomato fruit development and quality. J. Plant Biochem. Biotechnol. 23: 151-160. DOI: 10.1007/s 13562-013-0194-x.
  5. Natarajaswamy K, Naorem A & Rajam MV. 2013. Targeting fungal genes by diced siRNAs: A rapid tool to decipher gene function in Aspergillus nidulans. PLoS ONE 8 (10): e75443.
  6. Ranjita Sinha & Rajam MV. 2013. RNAi silencing of three homologues of S-adenosylmethionine decarboxylase gene in tapetal tissue of tomato results in male sterility. Plant Mol. Biol. 82: 169-180.
  7. Aarti Gupta, Pal RK & Rajam MV. 2013. Delayed ripening and improved fruit processing quality in tomato by RNAi-mediated silencing of three homologs of ACC synthase gene. J. Plant Physiol. 170: 987-995.
  8. Hazarika P & Rajam MV. 2011. Biotic and abiotic stress tolerance in transgenic tomatoes by constitutive expression of S-adenosylmethionine decarboxylase gene. Physiol. Mol. Biol. Plants.  17: 115-128.
  9. Uma Ganesan, Suri SS, Rajasubramaniam S, Rajam MV & Dasgupta I. 2009. Transgenic expression of coat protein gene of Rice tungro bacilliform virus in rice reduces the accumulation of viral DNA in inoculated plants. Virus Genes, 39: 113-119.
  10. Kumar M, Gupta GP & Rajam MV. 2009. Silencing of acetylcholinesterase gene of Helicoverpa armigera by siRNA affects larval growth and its life cycle. J. Insect Physiol. 55:  273-278.

 

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