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Ramanjulu Sunkar
Oklahoma State University
Assistant Professor, Department of Biochemistry and Molecular Biology
Address: 246 Noble Research Center, OSU, Stillwater, OK 74078
Phone: 405-744-8496 Fax: 405-744-7799
Email: rsunkar@biochem.okstate.edu
URL: http://biochem4.okstate.edu/
Ph.D., Sri Krsihnadevaraya University, Anantapur, India, 1996
  
Postdoctoral: University of California-Riverside, 2004-2006; University of Arizona-Tucson, 2003; University of Bonn, 2000-2003; Weizmann Institute of Science, 1997-2000
Research Emphasis:
Related Activities:
 
Research Description:

MicroRNAs (miRNAs) and small-interfering RNAs (siRNAs) have recently emerged as key regulators of gene expression in eukaryotes. miRNAs are small, ~21-nucleotides, and are processed from longer non-coding single-stranded RNAs with characteristic fold-back structures by double-strand specific RNases Dicer-like 1 (DCL-1) whereas siRNAs are processed from longer double-stranded RNAs by other members of the Dicer family of enzymes. Upon processing, they are incorporated into RISC (RNA induced silencing complex) or RITS (RNA induced transcriptional silencing complex). These small RNAs serve as the specificity components of RISC or RITS, as they guide these complexes to target mRNAs for post-transcriptional gene silencing or to homologous DNA sequences for transcriptional gene silencing. Small RNAs, particularly miRNAs have been found to play a central role in plant development. Recently small RNAs have also been found to play important roles in stress responses. Research in my laboratory is directed to identify and understand the roles of endogenous small RNAs (microRNAs and small-interfering RNAs) in plant abiotic stress responses. Identification of small RNA-guided gene regulation in plant stress responses will provide new tools for improving plant stress tolerance. lowed by a functional genomics and metabolomic analysis of their effects on plant development.
 
Recent Publications:

Sunkar R, Kapoor A, Zhu JK (2006) Posttranscriptional induction of two Cu/Zn superoxide dismutase genes in Arabidopsis is mediated by down-regulation of miR398 and important for oxidative stress tolerance. Plant Cell 20: 2051-2065.

Borsani O, Zhu JH, Verslues PE, Sunkar R, Zhu JK (2005) Endogenous siRNAs derived from a pair of natural cis-antisense transcripts regulate salt tolerance in Arabidopsis. Cell 123: 1279-1291.

Sunkar R, Girke T, Zhu JK (2005) Identification and characterization of endogenous small-interfering RNAs from rice. Nucleic Acids Research, 33: 4443-4454.

Sunkar R, Girke T, Jain PK, Zhu JK (2005) Cloning and characterization of microRNAs from rice. Plant Cell 17: 1397-1411.

Bartels D, Sunkar R (2005) Drought and salt tolerance in plants. Critical Reviews in Plant Sciences 24: 23-58.
 
Selected Additional Publications:

 Sunkar R, Zhu JK (2004) Novel and stress-regulated microRNAs and other small RNAs from Arabidopsis. Plant Cell 16: 2001-2019, 2004.

Sunkar R, Bartels D, Kirch HH (2003) Improved abiotic stress tolerance of transgenic Arabidopsis plants overexpressing a stress-inducible aldehyde dehydrogenase. Plant Journal 35: 452-464.

Sunkar R, Kaplan B, Nicolas B, Arazi T, Dolev D, Talke IN, Maathius FJM, Sanders D, Bouchez D, Fromm H (2000) Expression of a truncated tobacco NtCBP4 channel in transgenic plants and disruption of the homologous Arabidopsis CNGC1 gene confer Pb2+ tolerance. Plant Journal 24:533-542.

Arazi T, Sunkar R*, Kaplan B, Fromm H (1999) A tobacco plasma membrane calmodulin-binding transporter confers Ni2+ tolerance and Pb2+ hypersensitivity in transgenic plants. Plant Journal 20: 171-182 (* equal contribution).
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