Operationalizing the C4 photosynthetic pathway – much energy efficient outside the ambient temperature window than C3 photosynthetic pathway – in major C3 crop plants especially rice and wheat is one of the major focus under agricultural research at global level to obtain improved yield for food security.  We have discovered the accomplishment of C4 photosynthetic pathway exclusively in developing wheat grains at grain filling stage.  This opens up the possibility of accomplishing the energy efficient C4 photosynthesis in leaves of Wheat and rice by understanding the regulatory mechanism through which it is selectively expressed in grains and its origin.  With yield improvement through genetic gain achieving its plateau, more focus on the improvement of photosynthetic efficiency to improve yield is the key alternate and also the need of the day.  

Role of polyamines in imparting abiotic stress tolerance, identification and characterization of genes regulating or imparting abiotic stress tolerance in crop plants. Especially, the role of polyamines and its biosynthetic pathway, genetic variability, its role in differential functionality and improved efficiency beyond optimal environments.  

Development of markers and fingerprinting profiles in order to make available the unique identity criteria for cultivars / germplasm of Vegetable Brassicas.  This is primarily focussed on the cultivars and landraces being cultivated in India and with secondary importance for the ones being procured from across the globe.  

Researcher biography

Parimalan Rangan, is a graduate from Tamil Nadu Agricultural University (TNAU), B. Sc. (Forestry); post-graduate in Agriculture with Plant Breeding and Genetics as specialization (TNAU); PG diploma in Bioinformatics from Bharathiar University; doctorate in Biotechnology from CSIR-Central Food Technological Research Institute under University of Mysore through CSIR-JRF-NET fellowship.  Underwent a Post-doctoral research on heat stress tolerance in wheat at Queensland Alliance for Agriculture and Food Innovation, The University of Queensland through Indo-Australian Career Boosting Gold Fellowship funded by Department of Biotechnology, Government of India.  In 2016, Parimalan Rangan was conferred with Honorary Senior Research Fellow for the discovery of C4 photosynthetic pathway in developing wheat grains.

Some of his earlier works include: effect of Frankia on Casuarina seedlings; genetic variability studies; tissue culture including somatic embryogenesis and genetic transformation in annatto plant; bixin (annatto dye) biosynthetic pathway; development of chemotaxonomic markers in identifying plants that produce higher annatto dye yield; screening of pomegranate germplasm; and development and standardization of detection and quantification protocols for genetically modified plants or plant products.  


  • Bachelor of Science, Tamil Nadu Agricultural University
  • Master of Science, Tamil Nadu Agricultural University
  • Doctor of Philosophy, University of Mysore


Variation in polyamine biosynthetic genes for abiotic stress tolerance 
(2013-2014) Young Scientist Award project, DST, Government of India

Heat stress tolerance in wheat
(2014-2016) Indo-Australian Career Boosting Gold Fellowship, DBT, Government of India

Available research projects

Variation in polyamine biosynthetic genes for abiotic stress tolerance

Polyamines are the key metabolites involved in normal developmental processes.  In plants, it is well known that these polyamines are differentially regulated under stressed environments.  With existing variation and diversity in rice germplasm with altered levels of tolerance for various abiotic stress environments, identifying variation for genes involving polyamine biosynthetic pathway is the key focus and linking the variation with tolerance levels.

Heat stress tolerance and grain quality in wheat

Wheat is one of the three major crops along with Maize and Rice that feed the whole globe.  Of which, Rice and Maize are tropical crop while wheat is of temperate to sub-tropical nature.  Due to which, wheat is most susceptible to heat stress.  Identifying the genes imparting tolerance for heat stress in tolerant genotypes will be of much help in transferring those genes into the high yielding cultivars for improved yield without compromising in quality.


Journal articles

Rangan, P., Furtado, A., Henry, R.  2016.  New evidence for grain specific C4 photosynthesis in wheat.  Sci Rep., 6: 31721; doi: 10.1038/srep31721

Rangan, P., Rajesh Bhoge, Randhawa, G.J., and Chitra Devi Pandey.  2015.  Assessment of transgene flow in eggplant germplasm conserved at National Genebank.  Indian J. Biotechnol., 14: 357-363.

Rangan, P., Mahendranath, G., and Giridhar, P.  2014.  Analysis of water soluble polysaccharides as a potential chemotaxonomic marker for landraces in Bixa orellana.  Indian J. Biochem. Biophys., 51: 81-86. 

Vikas, V.K., Sivasamy, M., Kumar, J., Jayaprakash, P., Sundeep, K., , Rangan, P., Arun,  K., Kalyani, S., Radhamani, J., Sherry, R.J., Mamata, Y., Jyotisna, R., Bisht, I.S., Bhandari, D.C., Sunil A., Dutta, M., Tyagi, R.K., and Bansal, K.C.  2014.  Stem and leaf rust resistance in wild relatives of wheat with D genome (Aegilops spp.).  Genet Resour Crop Evol., 61: 861-874; doi: 10.1007/s10722-014-0085-6

Rangan, P., Akshatha, V., Giridhar, P., and Ravishankar, G.A.  2011.  Somatic embryogenesis and Agrobacterium-mediated transformation in Bixa orellana L.  Plant Cell Tiss. Organ Cult., 105: 317-328; doi: 10.1007/s11240-010-9870-x

Rangan, P., Giridhar, P., and Ravishankar, G.A.  2011.  Enhanced shoot organogenesis in Bixa orellana L. in the presence of putrescine and silver nitrate.  Plant Cell Tiss. Organ Cult., 105: 285-290; doi: 10.1007/s11240-010-9865-7

Mahendranath, G., Akshatha, V., Rangan, P., Giridhar, P., and Ravishankar, G.A.  2011.  Annatto pigment production in root cultures of Achiote.  Plant Cell Tiss. Organ Cult., 106: 517-522; doi: 10.1007/s11240-011-9931-9

Review articles

Henry, R.J., Rangan, P., Furtado, A.  2016.  Functional cereals for production in new and variable climates.  Curr. Opin. Plant Biol., 30: 11-18; dx.doi.org/10.1016/j.pbi.2015.12.008 

Rangan, P., Rajkumar, S., Rajesh, K, Singh, A.K., and Singh R.  2014.  Recent advances in polyamine metabolism and abiotic stress tolerance.  BioMed Res. Intl., 2014:  ID239621; dx.doi.o0072g/10.1155/2014/239621

Book chapter

Rangan, P., Kandan, A., and Singh, M.C.  2013.  Biotechnological approaches for crop protection and improvement. In: Biotechnological approaches in crop protection (Prasad, D., and Ray, D.P., Eds), Biotech Books, New Delhi, pp: 512-527.

Areas of research