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Contact Information

P: 864-656-6237
E: kgthoma@clemson.edu

Campus Location

D153 Poole Agricultural Center

Hours

Monday - Friday:
8 a.m. - 4:30 p.m.

Profile


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Rajan Sekhon

Genetics and Biochemistry

Associate Professor

AG Biotech/Biosystems Research Complex / BRC 314 [Office]
AG Biotech/Biosystems Research Complex / BRC 319A [Research Laboratory Service]
AG Biotech/Biosystems Research Complex / BRC 319C [Office]
AG Biotech/Biosystems Research Complex / BRC 321 [Research Laboratory Service]
AG Biotech/Biosystems Research Complex / BRC 342 [Research Laboratory Service]

sekhon@clemson.edu

Educational Background

Ph.D., Plant Biology, Pennsylvania State University, University Park, Pennsylvania, 2007
M.S., Plant Breeding, Punjab Agricultural University, Ludhiana, India, 1994
B.S., Agriculture, Punjab Agricultural University, Ludhiana, India, 1992

Research Interests

My research program is focused on understanding the genetic architecture of complex agronomic traits relevant to boosting climate resilience in maize and sorghum. Most of these traits are controlled by many small effect genes that are often missed by the traditional genetic and genomic approaches. Furthermore, these traits are dynamically shaped by internal and external signals to produce a continuum of temporal and spatial phenotypes that are not fully captured by traditional phenotyping approaches. We develop and refine phenotyping strategies to capture these dynamic phenotypes, and use systems-scale integration of multi-omics data to identify underlying genes. My research expertise spans molecular genetics, genomics, tissue- and cell-specific transcriptomics, metabolomics, epigenetics, and statistical genomics.

One focus of my lab is to elucidate the role of source-sink interactions in the regulation of senescence in maize. Leaf senescence is an inevitable developmental switch in the plant lifecycle that begins with the death of leaves and culminates in the death of annual plants. Delayed leaf senescence, a trait referred to as staygreen (or stay-green), is a fountain of youth that offers higher net carbon yield, resilience to drought and heat stress, and enhanced adaptive potential to unpredictable climatic events. Our comprehensive systems genetics analysis has revealed a complex regulatory network of diverse genes underlying senescence.

The second focus of the lab is to understand the biological, chemical, and biomechanical determinants of stalk (plant stem) strength in maize and identify the underlying genes. Stalk lodging (breakage of the stem) causes as much as 25% loss in maize yield worldwide. This problem will worsen rapidly due to a continuous increase in planting density, higher application of nitrogen fertilizer, and ever-worsening climate resulting in untimely rainfall and flooding events. In a highly collaborative effort involving biomechanics, mathematics, material chemistry, and systems genetics, we are developing a comprehensive genome-to-phenome map for stalk lodging resistance in maize.

Courses Taught

1) Epigenetics (GEN4600, undergraduate, 3 credits). In this course the students acquire detailed understating of various epigenetic mechanisms operating in tandem to impose epigenetic gene regulation in eukaryotes, learn the molecular basis of key epigenetic phenomena observed in animals and plants, learn the role of epigenetic mechanisms in human and animal disease, and gain valuable presentation and discussion skills.
2) Molecular and General Genetics (GEN3020, undergraduate,3 credits) - This is the flagship course for the students majoring in genetics and biochemistry in the department.
3) Senior Seminar (GEN4930, 2 credits) - In this course meant for the senior undergrads, the students learn to read and critically evaluate scientific literature, prepare and present a scientific presentation, engage in scientific discussion and critique, and learn scientific writing.

Selected Publications

Kunduru B., Kumar R., Brar M.S., Stubbs C.J., Tabaracci K., Bokros N., Bridges W.C., Cook D.D., DeBolt S., McMahan C.S., Robertson D.J., Sekhon R.S. (2023) Evaluation of intermediate phenotypes underlying stalk lodging resistance in maize. Field Crop Research. https://doi.org/10.1016/j.fcr.2023.109168

Singh, V., Krause, M., Sandhu, D., Sekhon, R.S., Kaundal, A. (2023) Salinity stress tolerance prediction for biomass-related traits in maize (Zea mays L.) using genome-wide markers. The Plant Genome. https://doi.org/10.1002/tpg2.20385

Kumar R., Brar M.S., Kunduru B., Ackerman, A.J., Yang, Y., Luo, F., Saski, C.A., Bridges W.C., de Leon, N., McMahan C.S., Kaeppler, S.M., Sekhon R.S. (2023) Genetic architecture of source-sink regulated senescence in maize. Plant Physiology. https://doi.org/10.1093/plphys/kiad460

Stubbs, C.J., Kunduru, B., Bokros, N., Verges, V., Porter, J., Cook, D.D., DeBolt, S., McMahan, C., Sekhon, R.S., Robertson, D.J. (2023) Moving toward short stature maize: The effect of plant height on maize stalk lodging resistance. Field Crop Research. https://doi.org/10.1016/j.fcr.2023.109008

Stubbs, C.J., McMahan, C.S., Tabaracci, K., Kunduru, B., Sekhon, R.S., Robertson, D.J. (2022) Cross-sectional geometry predicts failure location in maize stalks. Plant Methods. https://doi.org/10.1186/s13007-022-00887-x

Kumar, R., Gyawali, A., Morrison, G.D., Saski, C.A., Robertson, D.J., Cook, D.D., Tharayil, N., Schaefer, R.J., Beissinger, T.M., Sekhon, R.S. (2021) Genetic architecture of maize rind strength revealed by the analysis of divergently selected populations. Plant & Cell Physiology. https://doi.org/10.1093/pcp/pcab059

Stubbs, C.J., Seegmiller, K., McMahan, C.S., Sekhon, R.S., Robertson, D.J. (2020) Diverse maize hybrids are structurally inefficient at resisting wind induced bending forces that cause stalk lodging. Plant Methods. https://doi.org/10.1186/s13007-020-00608-2

Sekhon, R.S., Joyner, C.S., Ackerman, A.J., McMahan, C.S., Cook, D.D., Robertson, D.J. (2020) Stalk bending strength is strongly associated with maize stalk lodging incidence across multiple environments. Field Crop Research. https://doi.org/10.1016/j.fcr.2020.107737

Sandhu, D., Pudussery, M.V., Kumar, R., Pallete, A., Markley, P., Bridges, W.C., Sekhon, R.S. (2019) Characterization of natural genetic variation identifies multiple genes involved in salt tolerance in maize. Functional & Integrative Genomics. https://doi.org/10.1007/s10142-019-00707-x.

Bishop, E.H., Kumar, R., Luo, F., Saski, C., Sekhon, R.S. (2019) Genome-wide identification, expression profiling, and network analysis of AT-hook gene family in maize. Genomics. https://doi.org/10.1016/j.ygeno.2019.07.009.

Sekhon, R.S.*, Saski, C., Kumar, R., Flinn, B., Luo, F., Beissinger, T.M., Ackerman, A.J., Breitzman, M.W., Bridges, W.C., de Leon, N., Kaeppler, S.M. (2019) Integrated genome-scale analysis identifies novel genes and networks underlying senescence in maize. The Plant Cell. https://doi.org/10.1105/tpc.18.00930. (selected as the issue highlight and accompanied a commentary by the Plant Cell editorial staff; * - corresponding author)

Kumar, R., Bishop, E., Bridges, W.C., Tharayil, N., Sekhon, R.S. (2019) Sugar partitioning and source-sink interaction are key determinants of leaf senescence in maize. Plant, Cell & Environment. https://doi.org/10.1111/pce.13599.

Memberships

Crop Science Society of America
American Society of Plant Biologists
American Association for the Advancement of Science

Outreach

• Associate editor of Crop Science
• Served on four USDA-NIFA grant review panels
• Served on NSF-GRPF panels and several NSF ad-hoc review assignments
• Reviewed over 60 manuscripts mostly for society journals including ASPB (Plant Cell, Plant Physiology), CSSA (Crop Science, Plant Genome), and GSA (Genetics, G3)
• Trained over 60 undergrad students to nurture their interest in STEM fields
• Member of the departmental executive committee for three years
• Research adviser to VPR, Clemson University

Links

Google Scholar
LinkedIn

Contact Information

P: 864-656-6237
E: kgthoma@clemson.edu

Campus Location

D153 Poole Agricultural Center

Hours

Monday - Friday:
8 a.m. - 4:30 p.m.