Ramanjulu Sunkar

	Title	Assistant Professor
	Office	359 NRC
	Phone	405-744-8496
	Email	ramanjulu.sunkar@okstate.edu
	Degree	Ph.D. Botany. 1996. Sri Krishnadevaraya University, Anantapur, India
	Website

Research Area (top)

MicroRNA-guided post-transcriptional gene regulation

Recent discovery of microRNAs with regulatory roles has uncovered an active role for RNA in regulating gene expression besides its passive intermediary role between genes and proteins. MicroRNAs are 22-nt non-coding regulatory RNA molecules processed from the longer transcripts adopting hairpin-like structures. They can suppress the target gene expression at the post-transcriptional level by causing the degradation of the mRNA or inhibiting the protein production. MicroRNAs play critical roles in plant growth and development, stress responses and in nutrient homeostasis. We focus on identification of miRNAs and characterization of their roles in plants. The findings from such studies will contribute to our basic knowledge of plant biology involving post-transcriptional regulation of gene expression and have potential for biotechnological applications.

Selected Publications (top)

Shukla, L., Chinnusamy, V. and Sunkar, R. (2008) The Role of MicroRNAs and other Endogenous Small RNAs in Plant Stress Responses. Biochem. Biophys. Acta; Gene Regulatory Mechanisms, oi:10.1016/j.bbagrm.2008.04.004

Sunkar, R. and Jagadeeswaran, G. (2008)  In silico identification of conserved miRNAs in large number of diverse plant species. BMC Plant Biology, 8:37.

Subramanian, S., Fu, Y., Sunkar, R., Barbazuk, B. W., Zhu, J-K. and Yu, O. (2008) Novel and nodulation-regulated microRNAs in soybean roots. BMC Genomics, 9:160.

Sunkar, R, Zhou, X., Zheng, Y., Zhang, W. and Zhu, J-K. (2008) Identification of novel and candidate miRNAs in rice by high throughput sequencing. BMC Plant Biology, 8:25.

Sunkar, R. Chinnusamy, V., Zhu, J. and Zhu, J.K. (2007) Small RNAs as big players in plant abiotic stress responses and nutrient deprivation. Trends in Plant Sciences, 12: 301-309.

Yao, Y., Guo, G., Ni. Z., Sunkar, R., Du, J., Zhu, J.K. Sun, Q.  (2007) Cloning and characterization of microRNAs from Wheat, (Triticum aestivum L.). Genome Biology, 8: R96.

Sunkar, R., Kapoor, A. and Zhu, J.K. (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, 18, 2051-2065.

Borsani, O. Zhu, J.H., Verslues, P.E., Sunkar, R. and Zhu, J.K. (2005) A novel biogenesis pathway and physiological function for endogenous siRNAs from natural cis-antisense transcripts in Arabidopsis. Cell, 123, 1279-1291.

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

Sunkar, R., Girke, T., Jain, P.K. and Zhu, J-K. (2005) Cloning and characterization of microRNAs from rice. Plant Cell, 17, 1397-1411. (one of the highlighted papers in the same issue of Plant Cell).

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

Sunkar, R. and Zhu, J-K. (2004) Novel and stress-regulated microRNAs and other small RNAs from Arabidopsis. Plant Cell, 16, 2001-2019. (Highlighted in Plant Cell 16, 1951-1954, 2004).

Sunkar, R., Bartels, D and Kirch, H-H. (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, I.N., Maathius, F.J.M., Sanders, D., Bouchez, D. and 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.

Lab Members (top)