Profile

Research

Publications

Team

Alumni

George Thomas, PhD

Scientist F

+91-471-2529464

gthomas@rgcb.res.in

george
george

George Thomas, PhD

Scientist F

+91-471-2529464

gthomas@rgcb.res.in

  • Profile

    • PhD Life Sciences (University of Hyderabad)
    • MPhil Plant Physiology and Biochemistry (Mangalore University)
    • MSc Genetics and Plant Breeding (University of Kerala)
    • January 2015: Scientist – F, RGCB
    • April 2009: Scientist E-II, RGCB
    • April 2005 - April 2009: Scientist E-I, RGCB
    • April 2000 – April 2005: Scientist C, RGCB
    • February 1997- April 2000: Scientist B, RGCB
  • Research

    Research Interests

    The research in my lab focuses on deciphering the gene net-work governing Pythium resistance in Zingiber zerumbet and to translate the information gathered in improving soft rot resistance in cultivated ginger (Zingiber officinale Rosc.), which is a major spice crop in India. Major hurdle in ginger production is the soft rot disease caused by the soil-borne necrotrophic oomycete Pythium spp. Improving disease resistance in ginger is really challenging. Because, all ginger cultivars available today for farmer's cultivation are susceptible to Pythium and any breeding methods involving sexual hybridization is ineffective as ginger is obligatory asexual, propagated exclusively through rhizomes. Earlier we identified Pythium resistance in certain accessions of Zingiber zerumbet (L.) Smith, a wild congener of cultivated ginger, and prospected the resistant accessions using different genomics tools. We identified robust expression reprogramming of certain key defense related pathways in Z. zerumbet. A comparative genomics approach further helped us to identify pathways that are differently modulated in cultivated ginger as compared to Z. zerumbet. We are now interested in pathway targeted priming of cultivated ginger and evaluate the extent and durability of such priming in managing soft disease in ginger.

    We are also interested in understanding the phylogenetic position and biochemical profile of the ancient Indian medicinal and health rice njavara (Oryza sativa landrace Njavara). Njavara (shashtika in Sanskrit), which is mentioned in ancient Ayurveda treatises like Charakasamhita, is used in several Ayurveda preparations and health food formulations since time immemorial. Our interest on Njavara is twofold. Its ancientness renders it as a suitable material to study crop domestication events and on farm evolutionary dynamics. Traditional claims on the medicinal and nutritive attributes of Njavara prompt to prospects its grains for novel traits for the nutritional improvements of rice. We developed a gene bank of Njavara and characterized the genetic structure and elucidated its phylogenetic position in global rice gene pool. We now focus on high throughput metabolomics and proteomics of Njavara grains.

    1. De novo transcriptome sequencing, microarray development and elucidation of Pythium responsive defense pathways in Zingiber zerumbet  (L.) Smith, Council of Scientific and Industrial Research, Government of India (Rs. 23 lakhs; 2015-2017)
    2. Development of rice varieties for Kerala with pyramided genes for resistance to BLB by marker assisted selection, Department of Biotechnology, Government of India (Rs. 18.824 lakhs; 2013 – 2018)
    3. Prospecting Zingiber zerumbet for molecular resources, Department of Biotechnology, Government of India (Rs. 89.95 lakhs; 2010 – 2013)
    4. DNA barcoding of the selected genera of family Zingiberaceae: Alpinia, Zingiber and Globba, Department of Biotechnology, Government of India (Rs. 46.06 lakhs, 2007- 2010)
    5. Circumscription of medicinal rice njavara from other traditional rice in Kerala following microsatellite assisted fingerprinting, Kerala State Council for Science Technology and Environment (Rs. 8.196 lakhs, 2008 – 2011)
    6. DNA fingerprinting and evaluation of wild Zingiber spp. from Western ghats, a valuable source of horticultural traits and medicine , Kerala Forest Department (Rs. 7.82 lakhs,  2005-2008)
    7. Gene bank of traditional medicinal rice strains from Western ghats: collection and DNA finger printing, WGDP , Government of Kerala (Rs. 4.3 lakhs, 2005 – 2008)
    8. Improvement of selected spices through biotechnology tools: black pepper, cardamom, ginger, vanilla , Department of Biotechnology (Rs. 30.25 lakhs, 2001-2005)
    9. Identification and evaluation of bioactive peptides: A biotechnological approach towards controlling fungal pathogen of quick wilt disease of black pepper , Indian Council of Agricultural Research (Rs. 8.23 lakhs, 2001-2004)
    10. Molecular marker assisted genotyping and genetic structural studies of genetic resource collections in njavara, a traditionally used medicinal rice (Oryza sativa L.) in Kerala, India , International Foundation for Science, Sweden (Rs. 4.63 lakhs, 2004-2007)
    11. Clonal seed orchard management for higher seed productivity , Kerala Forest Department (Rs. 2.14 lakhs, 2000-2002)
    1. Prof. M. Sabu, Department of Botany, University of Calicut, Calicut University PO, Kerala, PIN- 673 635
    2. Dr. V. G. Jayalekshmy, Associate Professor, Plant Breeding and Genetics, College of Agriculture, Kerala Agricultural University, Thiruvananthapuram - 695 522
  • Publications

    1. Aswati Nair, R and Thomas, G. 2007. Isolation, characterization and expression studies of resistance gene candidates (RGCs) from Zingiber spp. Theoretical and Applied Genetics 116:123-134.
    2. Aswati Nair, R and Thomas, G. 2007. Evaluation of resistance gene (R-gene) specific primet sets and characterization of resistance gene candidates in ginger (Zingiber officinale Rosc.). Current Science 93: 61 –66
    3. Kavitha, P. G and Thomas, G.2008. Defence transcriptome profiling of Zingiber zerumbet (L.) Smith by mRNA differential display. Journal of Biosciences 33: 81–90
    4. Kavitha, P. G. and Thomas, G. 2008. Population genetic structure of the clonal plant Zingier zerumbet (L.) Smith (Zingiberaceae), a wild relative of cultivated ginger, and its response to Pythium aphanidermatum. Euphytica 160:89-100
    5. Kavitha, P. G. and Thomas, G. 2008. Expression analysis of defense-related genes in Zingiber (Zingiberaceae) species with different levels of compatibility to the soft pathogen Pythium aphanidermatum. Plant Cell Reports 27:1767-1776
    6. Joseph, L., Kuriachan, P. and Thomas, G. 2008 Is Oryza malampuzhaensis Krish. et Chand. (Poaceae) a valid species? Evidence from morphological and molecular analyses. Plant Systematics and Evolution 270: 75–94.
    7. Aswati Nair, R., Kiran, A. G., Sivakumar, K. C. and Thomas, G. 2010. Molecular characterization of an oomycete-responsive PR-5 protein gene from Zingiber zerumbet. Plant Molecular Biology Reporter. 28:128–135
    8. Dinesh Raj, R., Kiran, A. G. and Thomas, G. 2010. Population genetic structure and conservation priorities of Oryza rufipogon Griff. populations in Kerala, India. Current Science 98:65-68.
    9. Kavitha, P. G., Kiran, A. G., Dinesh Raj, R., Sabu, M. and Thomas, G. 2010. Amplified fragment length polymorphism (AFLP) analyses unravel a striking difference in the intraspecific genetic diversity of four species of genus Zingiber Boehm. from the Western Ghats, south India. Current Science 98:242-247
    10. Sreejayan, Suresh Kumar, U., Varghese, G., Jacob, T. M.  and Thomas, G. 2011. Stratification and population structure of the genetic resources of ancient medicinal rice (Oryza sativa L.) landrace Njavara. Genetic Resources and Crop Evolution 58:697–711
    11. Aswati Nair, R. and Thomas, G. 2012. Functional genetic diversity at nucleotide binding site (NBS) loci: Comparisons among soft rot resistant and susceptible Zingiber taxa.Biochemical Systematics and Ecology 44:  196–201
    12. Aswati Nair, R. and Thomas, G. 2013. Molecular characterization of ZzR1 resistance gene from Zingiber zerumbet with potential for imparting Pythium aphanidermatum resistance in ginger. Gene516: 58-65
    13. Sobhan, P. K., Seervi, M., Deb, L., Varghese, S., Soman, A., Joseph, J.,  Mathew, K.A., Raghu, G., Thomas, G., Sreekumar, E., Manjula, S. and Santosh Kumar T. R. 2013. Calpain and Reactive Oxygen Species Targets Bax for Mitochondrial Permeabilisation and Caspase Activation in Zerumbone Induced Apoptosis. PLoS ONE 8(4): e59350. doi:10.1371/journal.pone.0059350
    14. Kiran, A.G., Augustine, L., Smini, V.  and  Thomas, G. 2013. Incompatible response of Zingiber zerumbet (L) Smith. to the necrotrophic pathogen Pythium sp. involves hypersensitive response  and salicylic acid signalling. Acta Phytopathologica Sinica 43 (Suppl.): 338 -339.
    15. Augustine, L., Kiran, A.G. and  Thomas, G. 2013. Differential defense response towards Pythium myriotylum in resistant and susceptible Zingiber spp. revealed by comparative whole genome RNA-Seq analysis. Acta Phytopathologica Sinica 43 (Suppl.): 338.
    16. Vinitha, M. R., Suresh Kumar, U., Aishwarya, K., Sabu, M. and Thomas, G. 2014. Prospects for discriminating Zingiberaceae species in India using DNA barcodes. Journal of Integrative Plant Biology 56 (8): 760-773
    17. Varghese, G., Jose, M., Dinesh Raj, R., Bocianowski, J., Thomas, G. and   Omanakumari, N. 2014. Quantitative and molecular analyses reveal a deep genetic divergence between the ancient medicinal rice (Oryza sativa) Njavara and syntopic traditional cultivars. Annals of Applied Biology 164: 95–106.
    18. Mahadevan, C., Jaleel, A., Deb, L., Thomas, G. and Sakuntala, M. 2015. Development of an efficient virus induced gene silencing strategy in the non-model wild ginger-Zingiber zerumbet and investigation of associated proteome changes. PLoS ONE 10(4): e0124518. doi:10.1371/journal.pone.0124518
    19. Aishwarya, K., Vinitha, M., Thomas, G. and Sabu, M. 2015. A new species of Boesenbergia and rediscovery of B. rotunda (Zingiberaceae) from India. Phytotaxa 197 : (3): 186–196 
  • Team


    Geethu Elizabath Thomas, PhD student

    Genome evolution in Zingiber species with contrasting breeding system

    Genus Zingiber offer an interesting system to study the effect of breeding system on genetic diversity and pathogen resistance as this genus consists of obligatory asexual species (Z. officinale, cultivated ginger), predominantly sexual species (Z. neesanum) and species that follow mixed breeding system (Z. zerumbet). Ms. Geethu is examining the relationships between seed set, genetic diversity and pathogen (Pythium) response in Zingiber species that follow contrasting breeding system.

    geethu
    geethu

    Geethu Elizabath Thomas, PhD student

    Genome evolution in Zingiber species with contrasting breeding system

    Genus Zingiber offer an interesting system to study the effect of breeding system on genetic diversity and pathogen resistance as this genus consists of obligatory asexual species (Z. officinale, cultivated ginger), predominantly sexual species (Z. neesanum) and species that follow mixed breeding system (Z. zerumbet). Ms. Geethu is examining the relationships between seed set, genetic diversity and pathogen (Pythium) response in Zingiber species that follow contrasting breeding system.

    Smini Varghese, PhD student

    Molecular genetics of Pythium resistance in Z. zerumbet populations

    Z. zerumbet shows spatial variation in response to Pythium, with resistance in some populations and susceptibility in other. Ms. Smini is interested in examining this spatial difference of Pythium response in Z. zerumbet in conjunction with their seed set and genetic diversity.

    smini
    smini

    Smini Varghese, PhD student

    Molecular genetics of Pythium resistance in Z. zerumbet populations

    Z. zerumbet shows spatial variation in response to Pythium, with resistance in some populations and susceptibility in other. Ms. Smini is interested in examining this spatial difference of Pythium response in Z. zerumbet in conjunction with their seed set and genetic diversity.

    Lesly Augustine, PhD student

    The role of phenylpropanoids in Pythium resistance in Z. zerumbet

    Phenylpropanoids have crucial role in deciding resistance reactions in plants against invading pathogens. The role of phenylpropanoid biosynthesis in controlling Pythium resistance in Z. zerumbet is the primary interest of Mr. Lesly Augustine.

    lesly
    lesly

    Lesly Augustine, PhD student

    The role of phenylpropanoids in Pythium resistance in Z. zerumbet

    Phenylpropanoids have crucial role in deciding resistance reactions in plants against invading pathogens. The role of phenylpropanoid biosynthesis in controlling Pythium resistance in Z. zerumbet is the primary interest of Mr. Lesly Augustine.

    George Varghese, Senior Manager (Technical Services)

    In addition to the regular laboratory management, Mr. George Varghese is involved in the development and characterization of intraspecific hybrids between medicinal rice njavara and other cultivars.

    varghese
    varghese

    George Varghese, Senior Manager (Technical Services)

    In addition to the regular laboratory management, Mr. George Varghese is involved in the development and characterization of intraspecific hybrids between medicinal rice njavara and other cultivars.

    Vinitha M R, Research Assistant

    Ms. Vinitha provides technical support to the ongoing programmes in the laboratory. Besides, she is also involved in developing DNA barcodes in members of family Zingiberaceae.

    vinitha
    vinitha

    Vinitha M R, Research Assistant

    Ms. Vinitha provides technical support to the ongoing programmes in the laboratory. Besides, she is also involved in developing DNA barcodes in members of family Zingiberaceae.

    Remya Madhu, Junior Research Fellow

    De novo transcriptome sequencing, microarray development and elucidation of Pythium responsive defense pathways in Zingiber zerumbet (L.) Smith

    Remya Madhu
    Remya Madhu

    Remya Madhu, Junior Research Fellow

    De novo transcriptome sequencing, microarray development and elucidation of Pythium responsive defense pathways in Zingiber zerumbet (L.) Smith

    Neethu Mathew, Junior Research Fellow

    Development of rice varieties for Kerala with pyramided genes for resistance to BLB by marker assisted selection,

    Neethu_Mathew
    Neethu_Mathew

    Neethu Mathew, Junior Research Fellow

    Development of rice varieties for Kerala with pyramided genes for resistance to BLB by marker assisted selection,

  • Alumni


    Dr. Sreejayan

    Email : sreejayan.nambiar@lifetech.com
    Thesis: 'Molecular characterization and varietal identification in 'njavara', a traditional medicinal rice (Oryza sativa L.) in Kerala, India' (2006)
    Current Position: Field Application Scientist, Ion Torrent Systems, Life Technologies, Bangalore - 560 066, India.

    sreejayan
    sreejayan

    Dr. Sreejayan

    Email : sreejayan.nambiar@lifetech.com
    Thesis: 'Molecular characterization and varietal identification in 'njavara', a traditional medicinal rice (Oryza sativa L.) in Kerala, India' (2006)
    Current Position: Field Application Scientist, Ion Torrent Systems, Life Technologies, Bangalore - 560 066, India.

    Dr. R Aswati Nair

    Email : aswati@nitc.ac.in
    Thesis: 'Resistance gene candidates from Zingiber spp.: Isolation, characterization and expression analysis' (2006)
    Current Position: Assistant Professor, School of Biotechnology, NIT Calicut- 673 601, India

    aswathy nair
    aswathy nair

    Dr. R Aswati Nair

    Email : aswati@nitc.ac.in
    Thesis: 'Resistance gene candidates from Zingiber spp.: Isolation, characterization and expression analysis' (2006)
    Current Position: Assistant Professor, School of Biotechnology, NIT Calicut- 673 601, India

    Dr. P G Kavitha

    Email : kavitha_pg@jubilantbiosis.com
    Thesis: 'Genetic variation in wild gingers (Zingiberaceae) for resistance to Pythium infection and analysis of differentially expressed transcripts in hosts with different levels of pathogen response' (2008)
    Current Position: Senior Research Scientist A, Jubilant Biosis, Bangalore, India.

    kavitha
    kavitha

    Dr. P G Kavitha

    Email : kavitha_pg@jubilantbiosis.com
    Thesis: 'Genetic variation in wild gingers (Zingiberaceae) for resistance to Pythium infection and analysis of differentially expressed transcripts in hosts with different levels of pathogen response' (2008)
    Current Position: Senior Research Scientist A, Jubilant Biosis, Bangalore, India.

    Dr. Dinesh Raj R

    Email: dineshrajr@gmail.com
    Thesis: 'Genetic structure of cultivated rice (Oryza sativa L.) and its progenitor Oryza rufipogon Griff. in India '
    Current Position: : Assistant Professor, Department of Botany, Bishop Moore College, Mavelikara, Kerala, India

    Dinesh Raj
    Dinesh Raj

    Dr. Dinesh Raj R

    Email: dineshrajr@gmail.com
    Thesis: Genetic structure of cultivated rice (Oryza sativa L.) and its progenitor Oryza rufipogon Griff. in India
    Current Position: : Assistant Professor, Department of Botany, Bishop Moore College, Mavelikara, Kerala, India

    Dr. Mariet Jose

    Email : marietjos@gmail.com
    Thesis: DNA fingerprinting and discrimination of the traditional medicinal rice 'Njavara' from other traditional rice strains

    Mariet Jose
    Mariet Jose

    Dr. Mariet Jose

    Email : marietjos@gmail.com
    Thesis: DNA fingerprinting and discrimination of the traditional medicinal rice 'Njavara' from other traditional rice strains

    Krian A G

    Email : kiran@rgcb.res.in
    Thesis: Molecular characterization of incompatible response of Zingiber zerumbet Smith to the soft rot pathogen Pythium myriotylum Drechsler

    kiran1
    kiran1

    Krian A G

    Email : kiran@rgcb.res.in
    Thesis: Molecular characterization of incompatible response of Zingiber zerumbet Smith to the soft rot pathogen Pythium myriotylum Drechsler