Mitogen-activated protein kinase (MAPK) cascades are evolutionarily conserved signaling modules with essential regulatory functions in eukaryotes, including yeasts, worms, flies, frogs, mammals, and plants. Numerous studies have shown that plant MAPKs are activated by abiotic stresses, pathogens and pathogen-derived elicitors, and plant hormones. The Arabidopsis genome and EST sequencing projects have revealed large gene families encoding MAPKs and their immediate upstream regulators, MAPKKs and MAPKKKs. However, little is known about the constitution of plant MAPK cascades and the specific roles that particular MAPK cascade genes play in particular plant signal transduction pathways. We are using a comprehensive approach based on genomic information to generate a set of MAPK-, MAPKK-, and MAPKKK-related clones in conjunction with transient expression analysis to determine the function of all Arabidopsis MAPK cascade genes involved in essential plant signaling pathways. Since the functions of MAPK cascades in plant signal transduction pathways are likely conserved, our studies using the Arabidopsis genome resources will have broad implications and applications in other plant species.

Our current studies focus on five MAPK cascades, including those involved in osmotic stress responses, Flg22 peptide-mediated defense responses, the ethylene pathway, and auxin and H₂O₂ signaling. The overall strategy involves the identification and cloning of the complete set of Arabidopsis genes encoding MAPKs, MAPKKs, MAPKKKs, and relevant protein phosphatases. Transient expression of epitope-tagged MAPKs, MAPKKs, and MAPKKKs will be used to determine which MAPK cascades respond to particular abiotic or biotic stress or hormone signals in Arabidopsis and maize protoplasts. Constitutively active and dominant negative forms of these MAPKKKs and MAPKKs will be used to identify specific reporter genes associated with particular signaling pathways. DNA array technology will be used to analyze MAPK-related gene expression patterns, and to reveal new downstream targets and crosstalk between specific MAPK cascades. Identification of Arabidopsis knockout mutants corresponding to key MAPK-related regulatory genes will be initiated. Transgenic Arabidopsis, maize and soybean plants that overexpress particular engineered MAPKKK and MAPKK genes will be generated. The transgenic plants will be tested for the exhibition of agronomically useful traits.

The experimental design is based on Arabidopsis and maize protoplast technology developed in the Sheen and Ausubel laboratories. The transient nature of the protoplast systems allows direct functional analysis of plant genes at an unprecedented rate and at relatively low cost. This approach takes full advantage of the Arabidopsis genome infrastructure that is being created as a part of the NSF Plant Genome Research Program, which includes genome and EST sequencing, DNA microarray gene expression technology, and knockout mutant libraries. The experimental approaches that we are using are especially powerful in unraveling the functions of genes that are difficult to tackle by traditional genetic and biochemical approaches due to redundancy, lethality or low levels of expression. The elucidation and manipulation of MAPK cascades in plants will reveal fundamentally important signaling processes and provide new tools for crop improvement in stress tolerance, disease resistance, and yield enhancement.

Relatedness of Arabidopsis MAPKs

Relatedness of Arabidopsis MAPKKs

Relatedness of Arabidopsis MAPKKKs

Publications

Reviews

Yoo, S-D., Cho, Y. and Sheen, J. 2009. Emerging connections in the ethylene signaling network. Trends in Plant Science 14 in press PDF

Boudsocq, M. and Sheen, J. 2009. Calcium Sensing and Signaling. In: Abiotic Stress Adaptation in Plants: Physiological, Molecular and Genomic Foundation (A.Pareek, S.K. Sopory, H.J. Bohnert, Govindjee, eds). Springer, Dordrecht, The Netherlands: Springer PDF

Sheen, J., He, P., Shan, L., Xiong, Y., Tena, G., Yoo, S., Cho, Y., Boudsocq, M., and Lee, H. 2008. Signaling specificity and complexity of MAPK cascades in plant innate immunity. Biology of Molecular Plant-Microbe Interactions. Chapter 86. PDF

Baena-González, E. and Sheen, J. 2008. Convergent energy and stress signaling. Trends in Plant Science 13:474-482 PDF

Müller, B. and Sheen, J. 2007. Advances in Cytokinin Signaling. Science 318:68-69 PDF

Shan, L., He, P., and Sheen, J. 2007. Intercepting Host MAPK Signaling Cascades by Bacterial Type III Effectors. Cell Host & Microbe 1:167-174 PDF

He, P., Shan, L., and Sheen, J. 2007. Elicitation and Suppression of Microbe-Associated Molecular Pattern-Triggered Immunity in Plant-Microbe Interactions. Cellular Microbiology 9:1385-1396 PDF

Yoo, S.-D., Cho, Y.-H. and Sheen, J. 2007. Arabidopsis Mesophyll Protoplasts: A Versitile Cell System for Transient Gene Expression Analysis. Nature Protocols 2:1565-1572 PDF

Sheen, J. and He, P. 2007. Nuclear Actions in Innate Immune Signaling. Cell 128:821-822 PDF

Shan, L., He, P., and Sheen, J. 2007. Endless Hide-and-Seek: Dynamic Co-evolution in Plant-Bacterium Warfare. J.Integr. Plant Biol. 49(1):105-111 PDF

Hamel, L.-P., Nicole, M.-C., Sritubtim, S., Morency, M.-J., Ellis, M., Ehlting, J., Beaudoin, N., Barbazuk, B., Klessig, D., Lee, J. Martin, G., Mundy, J., Ohashi, Y., Scheel, D., Sheen, J., Xing, T., Zhang, S., Seguin, A. and Ellis, B.E. 2006. Ancient signals: comparative genomics of plant MAPK and MAPKK gene families : Trends in Plant Science 11(4): 192-198 PDF

Sheen, J. and Kay, S. 2004. Exploring new functions and actions of regulatory molecules. Current Opinion in Plant Biology Volume 7: 487-490 PDF

Leon, P. and Sheen, J. 2003. Sugar and hormone connections. Trends in Plant Science 8(3): 110-116 PDF

Ichimura, K., Tena, G., Henry, Y., Zhang, S., Hirt, H., Ellis, B. E., Morris, P. C., Wilson, C., Champion, A., Innes, R. W., Sheen, J., Ecker, J. E., Scheel, D., Klessig, D. F., Machida, Y., Mundy, J., Ohashi, Y., Kreis, M., Heberle-Bors, E., Walker, J. C. and Shinozaki, K. 2002. Mitogen-activated protein kinase cascades in plants: a new nomenclature. Trends in Plant Science 7: 301-308 PDF

Sheen, J. Signal transduction in maize and Arabidopsis mesophyll protoplasts. Plant Physiol. 127:1466-1475 (2001). PDF

Tena, G., Asai, T., Chiu, W.-L., and Sheen, J. Plant mitogen-activated protein kinase signaling cascades. Curr. Opin. Plant Biol. 4:392-400 (2001) PDF

back to top

Articles

Shan, L., He, P., Li, J., Heese, A., Peck, S.C., Nürnberger, T., Martin, G.B. and Sheen, J. 2008. Bacterial Effectors Target the Common Signaling Partner BAK1 to Disrupt Multiple MAMP Receptor Signaling Complexes and Impede Plant Immunity. Cell Host & Microbe 4:17-27 PDF SUPP

Fujii, H., Chinnusamy, V., Rodrigues, A., Rubio, S., Antoni, R., Park, S.-Y., Cutler, S.R., Sheen, J., Rodriguez, P.L. and Zhu, J.-K. 2009. In vitro reconstitution of an abscisic acid signaling pathway. Nature. 462: 660-664. PDF SUPP

Müller, B. and Sheen, J. 2008. Cytokinin and auxin interaction in root stem-cell specification during early embryogenesis. Nature 453:1094-1097 PDF SUPP

Yoo, S-D., Cho Y-H., Tena G., Xiong. Y. and Sheen, J. 2008. Dual control of nuclear EIN3 by bifurcate MAPK cascades in C2H4 signalling. Nature 451:789-795 PDF SUPP

Chen, Z., Agnew, J.L., Cohen, J.D., He, P., Shan, L., Sheen, J. and Kunkel, B.N. 2007. Pseudomonas syringae type III effector AvrRpt2 alters Arabidopsis thaliana auxin physiology. PNAS 104:20131-20136 PDF

Xiao, F., He, P., Abramovitch, R.B., Dawson, J.E., Nicholson, L.K., Sheen, J. and Martin, G.B 2007. The N-terminal region of Pseudomonas type III effector AvrPtoB elicits Pto-dependent immunity and has two distinct virulence determinants. The Plant Journal 52:595-614 PDF

Cho, Y.-H. and Yoo, S.-D. 2007. ETHYLENE RESPONSE 1 Histidine Kinase Activity of Arabidopsis Promotes Plant Growth. Plant Physiology 143: 612-616 PDF

Baena-Gonzalez, E., Rolland, F., Thevelein, J.M. and Sheen, J. 2007. A central integrator of transcription networks in plant stress and energy signalling. Nature 448: 938-943 PDF SUPP

He, P., Shan, L., Lin, N.-C., Martin, G.B., Kemmerling, B., Nurnberger, T., and Sheen, J.> 2006. Specific Bacterial Suppressors of MAMP Signaling Upstream of MAPKKK in Arabidopsis Innate Immunity. Cell 125: 563-575 PDF SUPP

Shou, H., Bordallo, P., Fan, J.-B. Yeakley, J.M., Bibikova, M., Sheen, J., and Wang, K. 2004. Expression of an active tobacco mitogen-activated protein kinase kinase kinase enhances freezing tolerance in transgenic maize. PNAS 101(9): 3298-3303 PDF

Moore, B., Zhou, L.,Rolland, F., Hall, Q., Cheng, W.-H., Liu, Y.-X., Hwang, I., Jones, T., and Sheen, J. 2003. Role of the Arabidopsis Glucose Sensor HXK1 in Nutrient, Light, and Hormonal Signaling. Science 300: 332-336 Abstract Full Text SUPP.

Cheng, W.-H., Endo, A., Zhou, L., Penney, J., Chen, H.-C., Arroyo, A., Leon, P., Nambara, E., Asami, T., Seo, M., Koshiba, T., and Sheen, J. 2002. A Unique Short-Chain Dehydrogenase/Reductase in Arabidopsis Glucose Signaling and Abscisic Acid Biosynthesis and Functions. Plant Cell 14 2723-2743 PDF

Asai, T., Tena, G., Plonikova, J., Willmann, M., Chiu, W.-L., Gomez-Gomez, L., Boller, T., Ausubel, F.M., and Sheen, J. MAP kinase signaling cascade in Arabidopsis innate immunity. Nature 415:977-983 (2002) PDF

Asai, T., Stone, J. M., Head, J.E., Kovtun, Y., Yorgey, P., Sheen, J., and Ausubel, F.M. Fumonisin B1-induced cell death in Arabidopsis protoplasts requires jasmonate-, ethylene-, and salicylate-dependent signaling pathways. Plant Cell 12: 1823-1835 (2000).

Kovtun, Y., Chiu, W.-L. Tena, G., and Sheen, J. Functional analysis of oxidative stress-activated MAPK cascade in plants. PNAS 97:2940-2945 (2000)

Kovtun, Y., Chiu, W.-L. Zeng, W. and Sheen, J. Suppression of auxin signal transduction by a MAPK cascade in higher plants. Nature 395: 716-720 (1998).

Chiu, W.-L. , Niwa, Y, Zeng, W, Hirano, T., Kobayashi, H, and Sheen, J. Engineered GFP as a vital reporter in plants. Current Biol. 6: 325-330 (1996).

Sheen, J., Hwang, S, Niwa, Y., Kobayashi, H., and Galbraith, D.W. Green-fluorescent protein as a new vital marker in plant cells. Plant J. 8: 777-784 (1995).

back to top