Ph.D., Yale University, 1981
M.S., Yale University, 1977
B.A., College of Wooster, 1974
Plants change as they develop. Some of these changes occur gradually over a long period of time, whereas others occur quickly, often resulting in major changes in shoot morphology. This latter phenomenon is termed phase change, and is the primary focus of our research. We are particularly interested in the juvenile-to-adult transition, also known as vegetative phase change. This transition precedes flowering, and is characterized by changes in shoot architecture and patterns of cellular differentiation, and by changes in a variety of physiological processes such as photosynthesis. Vegetative phase change is promoted by a group of plant-specific transcription factors (SBP/SPL proteins), whose expression is repressed during the juvenile phase by the miRNAs, miR156 and miR157. Vegetative phase change occurs when the levels of miR156/miR157 decline, leading to an increase in the abundance of SBP/SPL proteins. We are studying how the temporal expression pattern of miR156/miR157 is regulated and how these miRNAs operate to regulate the expression of SBP/SPL genes in natural accessions of Arabidopsis. We are also interested in the relationship between vegetative phase change and reproductive competence.
In addition to our work on Arabidopsis, we have conducted studies on the adaptive significance and evolution of vegetative phase change in Acacias and related tree species. Some species of Acacia (now Vachellia) in both Central America and Africa have developed close a mutualistic relationship with ants, and we are interested in how the timing of vegetative phase change in these species has evolved to facilitate this relationship. We are also studying the molecular basis for the evolution of species of Acacia in Australia that remain permanently in the juvenile phase.
A final area of interest is the development of genetic tools for Arabidopsis thaliana. We have produced a set of transgenic lines (Traffic Lines) that significantly increase the speed and decrease the cost of many common tasks in genetic analysis. We are currently developing Traffic lines that will allow investigators to monitor the segregation of 1 mB segments across the entire genome, and identify recombination events within these regions.
Biology 17: The Biology of Food
Biology 540: Genetic Analysis
Zhao, J. Doody, E. and R. S. Poethig (2023). Reproductive competence is regulated independently of vegetative phase change in Arabidopsis thaliana. Curr. Biol. 33: 487-497. https://doi.org/10.1016/j.cub.2022.12.029
Poethig, R. S., Cullina, W.L, Doody, E.,Floyd, T., Fouracre, J.P., Hu,T., Xu, M., Zhao, J. (2022). Short-interval Traffic Lines: versatile tools for genetic analysis in Arabidopsis thaliana. G3 12: jkac202. https://doi.org/10.1093/g3journal/jkac202
Doody, E., Zha, Y., He, J. and R. S. Poethig (2022). The genetic basis of natural variation in the timing of vegetative phase change in Arabidopsis thaliana. Development 149:dev200321. doi:10.1242/dev.200321
Lawrence, E. H., Springer, C. J., Helliker, B. R. (2022). The carbon economics of vegetative phase change. Plant Cell Environ. 45:1286-1297. doi:10.1111/pce.14281
Xu, M, T. Hu, and R. S. Poethig (2021). Low light intensity delays vegetative phase change. Plant Physiol. 187:1177-1188. https//doi.org/10.1093/plphys/kiab243
Fouracre, J. P., He, J., Chen V. J., Sidoli, S. and R. S. Poethig (2021). VAL genes regulate vegetative phase change via miR156-dependent and miR156-independent mechanisms. PLoS Genetics 17: e1009626.
Lawrence E. H., Springer, C. J., Helliker, B. R. and R. S. Poethig (2021). miR156-mediated changes in leaf composition lead to altered photosynthetic traits during vegetative phase change. New Phytol. 231:1008-1022 doi:10.1111/nph.17007
Lawrence, E. H., Leichty, A. R., Ma, C., Strauss, S. H. and R. S. Poethig. (2021). Vegetative phase change in Populus tremula x alba. New Phytol. 231: 351-364 doi:10.1111/nph.17316
Fouracre, J. P. and R. S. Poethig (2020). Lonely at the top? Regulation of shoot apical meristem activity by intrinsic and extrinsic factors. Curr. Op. Plant Biol. 58:17-24.
Fouracre, J. P., Chen, V. J., and R. S. Poethig (2020) ALTERED MERISTEM PROGRAM1 regulates leaf identity independently of miR156-mediated translational repression. Development 147: dev186874. doi:10.1242/dev.186874
Leichty, A. R. and R. S. Poethig (2019). Development and evolution of age-dependent defenses in ant-acacias. Proc. Natl. Acad. Sci. 116: 15596-15601
Fouracre, J. P. and R. S. Poethig (2019). A role for the shoot apical meristem in the specification of juvenile leaf identity in Arabidopsis. Proc. Natl. Acad. Sci 116:10168-10177
He, J, Xu, M., Willmann, M. R., McCormick, K., Hu, T., Yang, L., Starker, C. G., Voytas, D. F., Meyers, B. C., and R. S. Poethig (2018). Threshold-dependent repression of SPL gene expression by miR156/miR157 controls vegetative phase change in Arabidopsis thaliana. PLoS Genetics 14(4): e1007337
Xu, M., Hu, T., and R. S. Poethig (2018). ACTIN-RELATED PROTEIN6 promotes the transcription of MIR156A and MIR156C by facilitating the deposition of H3K4me3. Development 145: dev152868. doi:10.1242/dev.152868
Guo, C., Xu Y., Shi, M., Lai,Y.,Wu, X.,Wang, H., Zhu, Z.,Poethig, R. S.,and G. Wu (2017) Repression of miR156 by miR159 regulates the timing of the juvenile-to-adult transition in Arabidopsis. Plant Cell 29:1293-1304.
Xu, M., Hu, T., Zhao, J., Park, M-Y, Earley, K.W., Wu, G., Yang, L., R. S. Poethig (2016). Developmental functions of miR156-regulated SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) genes in Arabidopsis thaliana. PLoS Genetics 12(8): e1006263
Xu, M., Hu, T., Smith, M. R. and R. S. Poethig (2016). Epigenetic regulation of vegetative phase change in Arabidopsis. Plant Cell 28: 28-41.
Wu, G., Rossidivito, G., Hu, T., Berlyand, Y., and R. S. Poethig (2015). Traffic lines: new tools for genetic analysis in Arabidopsis thaliana. Genetics 200: 35-45