Dhirendra Kumar, Ph.D.
Assistant Professor
Department of Biological Sciences,
Box 70703,
East Tennessee State University, Johnson city, TN 37614-1710
Phone : (423) 439-6928 Fax: (423) 439-5958
email : kumard@etsu.edu
RESEARCH
Our lab is interested in studying the salicylic acid (SA) mediated defense signaling in plants. SA) mediated pathway is one of the major pathways by which plants defend themselves. Plants resisting pathogen attack produce high amounts of salicylic acid which leads to activation of defense pathways. How the SA activates defense signaling pathways? is unclear. Using biochemical approach we identified a 29 kDa protein, salicylic acid binding protein 2 (SABP2) which binds SA with high affinity (KD=~90 nM). SABP2 is a esterase which converts the inactive methyl salicylate (MeSA) to the active salicylic acid. High levels of MeSA is produced in the plants resisting pathogen attack. Three dimensional structure analysis of SABP2 in complex with SA shows that SA binds in the active site of the SABP2. This binding inhibits the enzymatic activity of SABP2 which stops the conversion of MeSA to SA. Plants continue to make MeSA which is not only travels to other parts of the plant but also to neighboring plants. SABP2 in the healthy parts of the plant catalyzes the conversion of MeSA into SA which turns on the defense pathway and plant exhibits systemic acquired resistance (SAR). RNAi-mediated silencing of SABP2 in tobacco rendered the plant more susceptible to pathogen attack and it lost its ability to mount the systemic acquired resistance (SAR) response. These RNAi plants were also compromised in expression of defense genes. Our recent studies suggest that methyl salicylate is the long sought mobile signal for plant innate immunity which the scientists have been searching for more that five decades (http://www.sciencemag.org/cgi/content/summary/sci;318/5847/31a).
Publications
Vlot, Corina., Liu, Po-Pu, Cameron, R.K., Park, S.W., Yang,Y., Kumar, D., Zhou, F., Paddukavidana, T., Gustafsson, C., Pichersky, E. and Klessig, D.F. (2008) Identification of likely orthologs of tobacco salicylic acid-binding protein 2 and their role in systemic acquired resistance in Arabidopsis thaliana. The Plant Journal. vol 56(3):445-56 http://www3.interscience.wiley.com/cgi-bin/fulltext/120747256/PDFSTART
Kumar, D. and Klessig, D.F. (2008) The search for the salicylic acid receptor led to discovery of the SAR signal receptor. Plant Signaling & Behavior vol 3 (9) 689-690 http://www.landesbioscience.com/journals/psb/article/5844
Park, S.W., Kumar, D., Kaimoyo,
E., Vlot, A.C., and Klessig, D.F. (2008)
The roles of salicylic acid-binding protein 2 and methyl salicylate in systemic
acquired resistance in tobacco and Arabidopsis.
In “Biology of Plant Microbe Interactions”, edited by F. Sánchez, C. Quinto I.M.
López-Lara and O. Geiger, IS-MPMI, St Paul, MN. Vol-6.
Park, S.-W., Kaimoyo, E., Kumar, D., Mosher, S., and Klessig, D. F. (2007) Methyl Salicylate is a Critical Mobile Signal for Plant Systemic Acquired Resistance. Science, vol 318 no. 5: 113-116. http://www.sciencemag.org/cgi/content/abstract/318/5847/113
Salicylic acid binding protein (SABP)2 and Systemic Acquired Resistance (2007). In “Biology of Plant Microbe Interactions”, edited by F. Sánchez, C. Quinto I.M. López-Lara and O. Geiger, IS-MPMI, St Paul, MN. 5:176-181.
Kumar D., Gustafsson C. and Klessig, D.F. (2006) Validation of RNAi silencing specificity using synthetic genes: Salicylic acid binding protein 2 is required for innate immunity in plants. The Plant Journal 45: 863-868 http://www.blackwell-synergy.com/doi/pdf/10.1111/j.1365-313X.2005.02645.x
Menke FL, Kang H.G., Chen Z., Park, J.M., Kumar, D. and Klessig, D.F. (2005) Tobacco transcription factor WRKY1 is phosphorylated by the MAP kinase SIPK and mediates HR like cell death in tobacco. Mol. Plant-Microbe Interact. 18: 1027-34. http://www.apsnet.org/mpmi/pdfs/2005/MPMI-18-1027.pdf
Farhad, F., Yang*, Y., Kumar*, D., Chen, Y., Fridman, E., Park, S.W., Chiang, Y., Acton, T.B., Montelione, G.T., Pichersky, E., Klessig D.F. and Tong, L. (2005) Structural and biochemical studies identify tobacco SABP2 as a methyl salicylate esterase and implicate it in plant innate immunity. Proc. Natl. Acad. Sci. USA. 102: 1773-1778 *contributed equally to this work. http://www.pnas.org/cgi/reprint/102/5/1773.pdf
Kumar, D. and Klessig, D.F. (2003) The high-affinity salicylic acid-binding protein 2 is required for plant innate immunity and has salicylic acid-stimulated lipase activity. Proc. Natl. Acad. Sci. USA. 100: 16101-16106. http://www.pnas.org/cgi/reprint/100/26/16101.pdf
SA- and NO-mediated signaling in Plant Disease Resistance (2002) In: Biology of Plant-Microbe Interactions. Ed. S.A. Leong, C. Allen, and E.W. Triplet, IS-MPMI, St Paul, MN. Vol. 3, pp 78-82.
Kumar, D. and Klessig, D.F. (2000) Differential induction of tobacco MAP kinases by the defense signals nitric oxide, salicylic acid, ethylene and jasmonic acid. Mol. Plant-Microbe Interact. 13: 347-351. http://www.apsnet.org/mpmi/pdfs/2000/0112-01N.pdf
Klessig, D.F., Durner, J., Zhou, J.M., Kumar, D., Navarre, R., Zhang, S., Shah, J., Wendehenne, D., Du, H., Trifa, Y., Noad, R., Kachroo, P., Pontier, D., Lam, E. and Silva, H. (2000) NO and salicylic acid signaling in plant defense. Proc. Natl. Acad. Sci. USA. 97: 8849-8855. http://www.pnas.org/cgi/reprint/97/16/8849.pdf
Salicylic acid- and nitric oxide-mediated signal transduction in plant disease resistance (2000) In: Biology of Plant-Microbe Interactions 2: 13-18. Edited by P. de Witt., T. Bisseling and W. Stiekema. Kluwer Academic Publishers, The Netherlands.
Salicylic acid- and nitric oxide-mediated signaling in plant-microorganism interactions (2000) In: 2000 Years of Natural Products Research; Past, Present and Future. Edited by T.J.C. Luijendijk, Phytoconsult, Leiden, The Netherlands, pp. 105-118.
Salicylic acid- and nitric oxide-mediated signal transduction in disease resistance (2000). In: Signal Transduction in Plants: Current Advances. Edited by S.K. Sopory, R. Oelmüller and S.C. Maheshwari. Kluwer Academic/ Plenum Publishers, The Netherlands. pp. 201-207.
Gaikwad, A., Tewari, K.K., Kumar, D., Chen, W. and Mukherjee, S.K. (1999) Isolation and characterization of the cDNA encoding a glycosylated accessory protein of pea chloroplast DNA polymerase. Nuc. Acids Res. 27: 3120-3129. http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=148538&blobtype=pdf
Kumar, D., Verma, H.N., Tuteja, N. and Tewari, K.K. (1997) Cloning and characterization of a gene encoding an antiviral protein from Clerodendrum aculeatum L. Plant. Mol. Biol. 33: 745 751 http://www.springerlink.com/content/h6g550345567h7m3/fulltext.pdf
Verma, H.N, Srivastava, S., Varsha and Kumar, D. (1996) Induction of systemic resistance in plants against viruses by a basic protein from Clerodendrum aculeatum leaves. Phytopathology 86: 485-91 http://www.apsnet.org/phyto/PDFS/1996/Phyto86n05_485.pdf
Patents
Klessig, D.F. and Kumar, D. Novel Salicylic Acid-Binding Protein Encoding Nucleic acid, SABP2, and Methods of Use Thereof. (2007) US Patent No. 7169966.
Klessig, D.F. and Kumar, D. Methods of determining specificity of RNAi silencing. (2009) US Patent No. 7592504.
TEACHING
BIOL 5100 Topics: Cell and Molecular Biology
BIOL 4147/5147 Biochemistry of Macromolecules
BIOL 4157/5157 Biochemistry of Macromolecules-Lab
BIOL 4167/5167 Biochemistry of Metabolism
BIOL 4177/51 Biochemistry of Metabolism- Lab
BIOL 4300-008 Seminar in Biological Sciences
BIOL 1110 Biology for Science Majors-I
BIOL 1020 Biology for Non-Majors-II
Education
Ph.D. (1998) International Center for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
Positions Held
2005-present, Assistant Professor of Biochemistry, Department of Biological Sciences, East Tennessee State University, Johnson City, TN 37614
2000-2005, Research Associate, Boyce Thompson Institute for Plant Research, Ithaca, New York, 14853
1998-2000, Post Doctoral Associate, Waksman Institute, Rutgers, The State University of New Jersey, Piscataway, New Jersey, 08854
Students in Research
Graduate Students (MS):
Diwaker Tripathi is
working in our research group since Fall of 2008. He comes to our lab from India.
Diwaker Tripathi,
won the second place in “Natural Sciences & Mathematics” for Graduate Students
(1-2 yrs) category at the 2009 Appalachian Research Forum. In summer of
2009, he presented his research findings at the 49th Annual meeting for "Phytochemical
Society of North America".
Leonard Fai has come to our
research group in the spring of 2009 from the University of Buea, Cameroon
Joannes Petrus Yuh: has come to our research
group in the fall of 2009 from the University of Buea,Cameroon.
Mir Hossain: has come to our research group in
the fall of 2009 from the University of Dhaka, Bangladesh.
LaTonya F. R. Gillespie: has come to our research
group in the fall of 2009 from the Voorhees College, Denmark, South Carolina.
Undergraduate (BS):
Tazley Hotz : Joined my lab as a freshman. Tazley has recently started working in the lab
and is in the process of identifying a specific project. Tazley was awarded SURF
(Summer Undergraduate Research Fellowship) by American Society for Plant Biologists to conduct research in my lab during
Summer of 2007.
http://www.etsu.edu/etsu/news_text.asp?Action=ListEvent&EventID=6423
and
http://www.etsu.edu/honors/international/newsarticle.asp?newsid=270.
Recently Tazley was invited to present her research findings at the Plant
Biology 2008 meeting held in Merida, Mexico. Abstract of her presentation could
be seen at (http://abstracts.aspb.org/pb2008/public/P48/P48005.html). Tazley is a McNair Fellow.
Arianna Ingram: A sophomore at ETSU.
She is a biology major and wishes to pursue career in biological science
research.
Qian Sun:
A senior at ETSU. She is
pursuing her BS degree at ETSU as an exchange student from China.
Yutika Patel: A chemistry major, has
joined our lab in summer of 2008.
Hira Chaudhary
is an Honors student at ETSU.
Past Students:
Alexander Eddo: Has completed MS in Biology at ETSU and ready to join a Ph.D. program in molecular biology and biochemistry
Kajal Patel: Has graduated in spring of 2009 and joined a Pharmacy college.
Meng Liu: Has graduated and joined MS program in Public and Allied Health at ETSU.
Poonam M. Sheth: Poonam has graduated from ETSU and at present she is a project coordinator at Microbial insights, Rockville, TN 37853 (http://www.microbe.com).
John W. Sayne: Establishment of Suspension Cell culture from tobacco leaves and general support to lab activities. John is expected to graduate shortly. He aspires to become a teacher.
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For students interested in MS in Biology, limited number of Graduate Assistantships for highly deserving candidates are available which covers their tuition fees and stipends. If you are interested in doing some cutting edge science feel free to contact me.
Undergraduate students could also avail the Federal Work Study and Research Discovery positions in my lab. Freshman at ETSU are especially encouraged contact me if interested in molecular biology and bichemistry research projects.
Contact me by telephone 423-439 6928 or email me at (kumard@etsu.edu).
Last updated: 10-01-2009