Karen Schumaker

Professor - School of Plant Sciences
621-9635 / 621-8910 (Lab)

Educational Background

  • B.S., Plant Sciences, University of California, Davis
  • M.S., Plant Breeding and Genetics, Oregon State University
  • Ph.D., Botany, University of Maryland
  • Post-doctoral Fellow, Cellular and Molecular Physiology, Yale University School of Medicine

Research Interests

  • More than 25 percent of the world’s agriculture is grown in areas of severe water stress. This figure doubles when irrigated cropland, which produces 40 percent of the global food supply, is included. It has been estimated that the demand for water will increase 50 percent by 2030, and that water supply will not grow in parallel. Agriculture will be responsible for nearly half of the additional demand, because global food production must increase almost 70 percent to feed 9.6 billion people by 2050. To meet future food demand, farmers must increase crop yields -- essential to achieving this goal will be the identification and development of crops with improved ability to grow during drought (osmotic) stress. Seed germination is a critical part of the plant’s life cycle, insuring survival of all plant species. Because of its role in stand establishment, seed germination remains key to agricultural productivity. Therefore, a fundamental understanding of germination is essential for crop production. While much is known about the mechanisms that underlie seed germination under well-watered conditions, little is known about the extent of genetic variability for germination during osmotic stress. Comparative studies of seed germination in the salt-sensitive plant Arabidopsis thaliana (Arabidopsis) and its salt-tolerant relative Eutrema salsugineum (Eutrema) identified genetic variability for seed germination during osmotic stress. Seed germination is similar for the two species in the absence of osmotic stress (without salt) -- seeds from both species germinate and seedling growth takes place. However, when seeds are germinated in the presence of salt, very different responses are observed in the two species. At low concentrations of salt, Arabidopsis seeds germinate and seedlings quickly die, while at high concentrations of salt, seeds do not germinate even when they are subsequently transferred to media without salt. Eutrema has a consistent pattern at both levels of salt -- it does not germinate on media with salt; however, when seeds are transferred to media without salt, germination and seedling growth take place. These studies indicate that Eutrema has a unique ability to sense its osmotic environment and delay germination until conditions are favorable for growth. We are characterizing the sensor at the physiological level and working to uncover its molecular identity. Results from these studies will contribute to understanding of the regulation of seed germination, link environmental sensing to plant adaptation to abiotic stress, and identify a molecular determinant for our toolkit for crop improvement during drought stress.

Selected Publications

Monihan SM, Magness CA, Ryu C-H, McMahon MM, Beilstein MA, Schumaker KS. 2020. Duplication and functional divergence of a calcium sensor in the Brassicaceae. J. Exp. Bot. 71, 2782-2795
Monihan SM, Ryu C-H, Magness CA, Schumaker KS. 2019. Linking duplication of a calcium sensor to salt tolerance in Eutrema salsugineum. Plant Physiol. 179, 1176-1192
Zhang S, Wang D, Zhang H, Skaggs MI, Lloyd A, Ran D, An L, Schumaker KS, Drews GN, Yadegari R. 2018. FERTILIZATION-INDEPENDENT SEED-Polycomb Repressive Complex 2 plays a dual role in regulating type I MADS-box genes in early endosperm development. Plant Physiol. 177, 285-299
Monihan SM, Magness CA, Smith SE, Yadegari R, Schumaker KS. 2016. Arabidopsis CALCINEURIN B-LIKE10 functions independently of the SOS pathway during reproductive development in saline conditions. Plant Physiol. 171, 369-379
Zhou X, Hao H, Zhang Y, Bai Y, Zhu W, Qin Y, Yuan F, Zhao F, Wang M, Hu J, Xu H, Guo A, Zhao H, Zhao Y, Cao C, Yang Y, Schumaker KS, Guo Y, Xie CG. 2015. SOS2-LIKE PROTEIN KINASE5, an SNF1-RELATED PROTEIN KINASE3-TYPE protein kinase, is important for abscisic acid responses in Arabidopsis through phosphorylation of ABSCISIC ACID-INSENSITIVE5. Plant Physiol. 168, 659-676
Li J, Liu J, Wang G, Cha J-Y, Li G, Chen S, Li Z, Guo J, Zhang C, Yang Y, Kim W-Y, Yun D-J, Schumaker KS, Chen Z, Guo Y. 2015. A chaperone function of NO CATALASE ACTIVITY1 is required to maintain catalase activity and for multiple stress responses in Arabidopsis. Plant Cell 27, 908-925
Jarvis DE, Ryu C-H, Beilstein MA, Schumaker KS. 2014. Distinct roles for SOS1 in the convergent evolution of salt tolerance in Eutrema salsugineum and Schrenkiella parvula. Mol. Biol. Evol. (doi:10.1093/molbev/msu152)
Lin H, Du W, Yang Y, Schumaker KS, Guo Y. 2014. A calcium-independent activation of the Arabidopsis SOS2-Like Protein Kinase24 by its interacting SOS3-Like Calcium Binding Protein1. Plant Physiol. 164, 2197-2206
Zhou H, Lin H, Chen S, Becker K, Yang Y, Zhao J, Kudla J, Schumaker KS, Guo Y. 2014. Inhibition of the Arabidopsis Salt Overly Sensitive Pathway by 14-3-3 Proteins. Plant Cell 26, 1166-1182
Zhao Y, Pan Z, Zhang Y, Qu X, Zhang Y, Yang Y, Jiang X, Huang S, Yuan M, Schumaker KS, Guo Y. 2013. The Actin-Related Protein2/3 Complex Regulates Mitochondrial-Associated Calcium Signaling during Salt Stress in Arabidopsis. Plant Cell 25, 4544-4559
Yang R, Jarvis DE, Chen H, Beilstein MA, Grimwood J, Jenkins J, Shu SQ, Prochnik S, Xin M, Ma C, Schmutz J, Wing RA, Mitchell-Olds T, Schumaker KS, Wang X. 2013. The reference genome of the halophytic plant Eutrema salsugineum. Frontiers in Plant Science (doi: 10.3389/fpls.2013.00046)
Haudry A, Platts AE, Vello E, Hoen D, Leclercq M, Williamson R, Forczek E, Joly-Lopez Z, Steffen JG, Hazzouri KM, Dewar K, Stinchcombe JR, Schoen DJ, Wang X, Schmutz J, Town CD, Edger PP, Pires JC, Schumaker KS, Jarvis DE, Mandáková T, Lysak MA, van den Bergh E, Schranz ME, Harrison PM, Moses AM, Bureau TE, Wright SI, Blanchette M. 2013. An atlas of over 90,000 conserved noncoding sequences provides insight into crucifer regulatory regions. Nature Genetics 45, 891–898
Zheng Y, Schumaker KS, Guo Y. 2012. Sumoylation of transcription factor MYB30 by the small ubiquitin-like modifier E3 ligase SIZ1 mediates abscisic acid response in Arabidopsis thaliana. Proc. Natl. Acad. Sci. USA 109, 12822–12827
Zhou H, Zhao J, Yang Y, Chen C, Liu Y, Jin X, Chen L, Li X, Deng X-W, Schumaker KS, Guo Y. 2012. UBIQUITIN-SPECIFIC PROTEASE 16 modulates salt tolerance in Arabidopsis by regulating Na+/H+ antiport activity and serine hydroxymethyltransferase stability. Plant Cell 24, 5106-5122
Drews GN, Wang D, Steffen JG, Schumaker KS, Yadegari R. 2011. Identification of genes expressed in the angiosperm female gametophyte. J. Exp. Bot. 62, 1593-1599
Yang Y, Qin Y, Xie C, Zhao F, Zhao J, Liu D, Chen S, Fuglsang AT, Palmgren MG, Schumaker KS, Deng XW, Guo Y. 2010. The Arabidopsis chaperone J3 regulates the plasma membrane H+-ATPase through interaction with the PKS5 kinase. Plant Cell 22, 1313-1332
Zhang C, Guo H, Zhang J, Guo G, Schumaker KS, Guo Y. 2010. Arabidopsis CSAat1A and CSAat1B proteins form a complex with CULLIN4 and DDB1A and regulate the response to UV radiation. Plant Cell 22, 2352-2369
Wang D, Zhang C, Hearn DJ, Kang I-H, Punwani JA, Skaggs MI, Drews GN, Schumaker KS, Yadegari R. 2010. Identification of transcription-factor genes expressed in the Arabidopsis female gametophyte. BMC Plant Biology 10:110
Lin H, Yang Y, Quan R, Mendoza I, Wu Y, Du W, Zhao S, Schumaker KS, Pardo JM, Guo Y. 2009. SOS2 phosphorylation of SCaBP8 stabilizes the SCaBP8-SOS2 complex and enhances salt tolerance in Arabidopsis. Plant Cell 21, 1607-1619
Nah G, Pagliarulo CL, Mohr PG, Luo M, Sisneros N, Yu Y, Collura K, Currie J, Goicoechea JL, Wing RA, Schumaker KS. 2009. Comparative Sequence Analysis of the SALT OVERLY SENSITIVE1 Orthologous Region in Thellungiella halophila and Arabidopsis thaliana. Genomics 94, 196-203
Batelli G, Versules PE, Agius F, Qiu Q-S, Songqin FH, Schumaker KS, Grillo S, Zhu J-K. 2007. SOS2 promotes salt tolerance in part by interacting with the vacuolar H+-ATPase and upregulating its transport activity. Mol. Cell. Biol. 27, 7781-7790
Fulsang AT, Guo Y, Cuin TA, Qiu Q-S, Song C, Kristiansen KA, Bych K, Schulz A, Shabala S, Schumaker KS, Palmgren MG, Zhu J-K. 2007. Arabidopsis protein kinase PKS5 inhibits the plasma membrane H+-ATPase by preventing interaction with 14-3-3 protein. Plant Cell 19, 1617-1634

Teaching Responsibilities

  • PLS/MCB/EEB 440/540, Mechanisms of Plant Development
  • PLS/MCB/EEB 560, Current Topics in Plant Biology

Research Areas

  • Biochemistry and Physiology
  • Biodiversity and Evolutionary Biology
  • Cell and Developmental Biology
  • Environmental and Stress Biology
  • Genomics, Bioinformatics, and Systems Biology