- Sunkar Lab
- Department of Biochemistry and Molecular Biology
- Oklahoma State University
- 359 Noble Research Center
- Stillwater, OK 74078
- Phone: 405-744-8496
- Fax: (479) 575-7465
- Email: ramanjulu.sunkar@okstate.edu
- Webpages:
- https://experts.okstate.edu/ramanjulu.sunkar
- http://dasnr54.dasnr.okstate.edu:8080/biochemistry2018/people/faculty/dr_ramanjulu_sunkar
- Research Interests:
- > Complex molecular networks that underlie plant stress tolerance mechanisms
- > microRNA-guided gene regulation for post-transcriptional gene regulation
- > Epigenetic modifications for gene regulation
Dr. Ramanjulu Sunkar is a Professor in the Department of Biochemistry and Molecular Biology at the Oklahoma State University. He has a well-funded research program (NSF, USDA, OCAST etc) and his main research area is plant molecular biology involving transcriptional and post-transcriptional gene regulation.
The microRNAs regulate when, where and how much of a protein needs to be made by degrading certain number of the mRNA molecules of specific genes while leaving the rest for protein production. In other words, microRNAs serve as controllers of how much of a specific microRNA target protein needs to be produced. We are particularly interested in identifying the importance of microRNA-controlled gene regulation in plants under abiotic stresses.
Towards addressing this, we use high-throughput sequencing of small RNA libraries to identify microRNAs that are altered in response to abiotic stresses. To identify microRNA targets, we use computational prediction of targets as well as the experimental approach, i.e., degradome analysis. Overall, identification of microRNA-guided gene regulation during stress responses will broaden our understanding of post-transcriptional gene regulation important for stress tolerance in plants.
- Research Participants:
- Dr. Yongfang Li (Postdoctoral Fellow)
- David Payne (Graduate student)
- Pei Jia Ng (Graduate student)
- Andre Abit (Undegraduate student)
Role in the project
OSU’s role in this EPSCoR project is to undertake the small RNA analysis by analyzing the small RNA profiles to identify microRNAs that are differentially regulated in HNT-tolerant rice genotypes compared to sensitive genotypes. The tissues selected for this analysis include developing caryopsis (R6 stage) and the flag leaves. The project is also focused on determining the impact of heat-regulated miRNAs on their mRNA targets.
Our participation began during the year 2 of the project. As part of the overall goal of identifying microRNAs that could play important roles in HDT or HNT in rice, microRNA profiles were analyzed in the same samples of rice genotypes in which transcriptome and metabolome are being analyzed.
During year 2019-20, a total of 60 small RNA libraries (three replicate libraries) have been generated and sequenced from the milky caryopsis of Nipponbare, Bengal, Kaybonnet, LaGrue, and Cypress that were exposed to HDT or HNT stress conditions along with their corresponding control samples. Interestingly, majority of these regulations appeared to be genotype-specific (figure above). The analysis also identified several novel miRNAs in caryopsis tissue. Using computational tools, approximately 500 genes have been predicted as putative targets for the miRNAs that have been detected in caryopsis.
In continuation of this task, during year 2020-21, a total of 84 small RNA libraries from developing R6-staged caryopsis and flag leaves of the 7 genotypes (four are new genotypes – Wells, Roy J, Starbonnet and 311258 and 3 are the same as last year – Cypress, LaGrue, Kaybonnet) have been sequenced and analyzed. The bioinformatics analysis of these 84 small RNA libraries is currently in progress.