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Daniel J. Cosgrove

Daniel J. Cosgrove

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Professor and Holder of the Eberly Chair in Biology

350 N Frear Lab
(send mail to 208 Mueller Lab)

University Park, PA 16802
Phone: (814)863-3892
Lab Address: 350 N Frear Lab
Lab Phone: (814) 865-3752


  1. Ph.D, Stanford University, 1980
  2. B.S, University of Massachusetts, 1974

Research Interests

Mechanisms of Plant Cell Growth

Cell expansion plays a crucial role in shaping the form and size of plants. My research focuses on the cellular and molecular mechanisms of cell expansion. By use of biophysical, biochemical, and molecular techniques, in combination with whole-plant measurements, we are trying to determine: (a) which processes limit growth under normal and stressed conditions and (b) how plants regulate their growth rates. Current projects include the following:


Wall Loosening Proteins


We have identified a conserved family of proteins—which we named named expansins—that catalyze wall extension. For this work, we devised a novel reconstitution assay to measure the ability of extracted proteins to induce extension of isolated walls, and then purified the active fractions using HPLC, electrophoresis, and related techniques. We have found that expansins do not act by the conventional theory of wall loosening by polysaccharide hydrolysis; rather, they disrupt hydrogen bonding between wall polysaccharide in a unique way that might have commercial applications. Our current work is focused on the molecular genetics and biochemistry of expansins to gain a deeper understanding of the function and evolution of these proteins. By use of transgenic plants with alterations in the expression of expansins, we plan to decipher the role of these proteins in cell enlargement, plant morphogenesis, and wall structure. Identification of genetic mutants in which T-DNA or transposon insertions interrupt expansin genes is also underway. In our studies to date, we have found that expansins are phylogenetically widespread and may serve a common function in regulating wall yielding and cell expansion in vascular plants. Recent studies have focused on expansin structure and the molecular biophysics underlying its action to loosen cell walls.


Grass Pollen Allergens as Beta-Expansins


Group I allergens are the major allergens of grass pollen and cause seasonal asthma and related immune responses in many people. We showed these group-I allergens to be structurally related to expansins. Extracts of maize pollen possess potent expansin-like activity, as measured in wall extension and wall stress relaxation assays. This activity is selective for grass cell walls and is, at least partly, due to the action of maize group I allergens. It is likely that group I allergens facilitate invasion of the pollen tube into the maternal tissues by loosening the cell walls of the grass stigma and style. Additionally, the presence of related mRNAs in vegetative tissues of rice, Arabidopsis, and soybean implies that allergen homologs may function to loosen walls in growing vegetative tissues as well. Future work will examine the development roles and biochemical functions of this subfamily of expansins.


Growth Adaptations to Water Stress


Growing maize roots respond to mild water deficits by increasing the extensibility of cell walls in the apical growth zone, thereby permitting the roots to continue to grow. We are exploring the molecular basis of this change in wall properties. Part of this adaptive response appears to be mediated by a build up of expansins in the cell walls. Other possible changes in wall structure are also being explored.


Structure and Assembly of Plant Cell Walls


To understand how plant cells grow (enlarge), we need to know how the cell wall expands irreversibly and incorporates new structural materials into the cell wall to maintain its structural and mechanical integrity in the face of sustained expansion and thinning of the older wall layers. Our approach is to characterize the extensibility of cell walls by use of specific enzymes to modify cell wall cross-linking polymers and by the use of genetic mutants with defects in specific cell wall polymers.


Selected Publications

Zhang T, Vavylonis D, Durachko DM, Cosgrove DJ (2017) Nanoscale Movements of Cellulose Microfibrils in Primary Cell Walls. Nature Plants 3, 17056 DOI: 10.1038/nplants.2017.56

Wang T, Chen Y, Tabuchi A, Cosgrove DJ, Hong M. 2016. The Target of beta-Expansin EXPB1 in Maize Cell Walls from Binding and Solid-State NMR Studies. Plant Physiol 172: 2107-19

Zhang T, Zheng Y, Cosgrove DJ (2016) Spatial organization of cellulose microfibrils and matrix polysaccharides in primary plant cell walls as imaged by multi-channel atomic force microscopy. Plant J 85: 179-192 (highlighted article & featured on journal cover)

Cosgrove DJ (2016) Catalysts of plant cell wall loosening. F1000 Reviews 5: 119-ff  doi 10.12688/f1000research.7180.1

Cosgrove DJ (2016) Plant cell wall extensibility: Connecting plant cell growth with cell wall structure, mechanics and the action of wall-modifying enzymes. J Exp Bot 67: 463-76

Cosgrove DJ (2015) Plant expansins: diversity and interactions with plant cell walls. Curr. Opin. Plant Biol., 25, 162-172.

Wang T, Park YB, Cosgrove D, J., Hong M (2015) Cellulose-pectin spatial contacts are inherent to never-dried Arabidopsis thaliana primary cell walls: Evidence from solid-state NMR. Plant Physiology 168: 871-884

Georgelis N, Nikolaidis N, Cosgrove DJ (2015) Bacterial expansins and related proteins from the world of microbes. Applied Microbiology and Biotechnology 99: 3807-3823

Park YB, Cosgrove DJ (2015) Xyloglucan and its interactions with other components of the growing cell wall. Plant Cell Physiol 56(2):180-94 doi:10.1093/pcp/pcu204

Sampedro J., Guttman M., Li L.C., Cosgrove D.J. 2015 Evolutionary divergence of beta-expansin structure and function in grasses parallels emergence of distinctive primary cell wall traits. Plant J 81(1):108-20 doi:10.1111/tpj.12715

Cosgrove D.J. 2014 Re-constructing our models of cellulose and primary cell wall assembly. Curr Opin Plant Biol 22C:122-131 doi:10.1016/j.pbi.2014.11.001

Nikolaidis N., Doran N., & Cosgrove D.J. 2014. Plant expansins in bacteria and fungi: evolution by horizontal gene transfer and independent domain fusion. Mol Biol Evol 31: 376-386.

Georgelis, N., Nikolaidis, N., & Cosgrove, D. J. 2014. Biochemical analysis of expansin-like proteins from microbes. Carbohydrate Polymers, 100: 17-23

Zhao, Z., Crespi, V. H., Kubicki, J. D., Cosgrove, D. J., Zhong, L. 2014. Molecular dynamics simulation study of xyloglucan adsorption on cellulose surfaces: effects of surface hydrophobicity and side-chain variation. Cellulose. 21: 1025-1039

Wang T., Park Y.B., Caporini M.A., Rosay M., Zhong L., Cosgrove D.J., Hong, M. 2013. Sensitivity-enhanced solid-state NMR detection of expansin’s target in plant cell walls. Proc. Nat. Acad. Sci. USA 110: 16444-16449

Cosgrove D.J. & Jarvis M.C. 2012. Comparative structure and biomechanics of plant primary and secondary cell walls. Frontiers in Plant Science 3, article 204, doi: 10.3389/fpls.2012.00204

Carey, R.E. Hepler N.K. & Cosgrove D.J. 2013. Selaginella moellendorffii has a reduced and highly conserved expansin superfamily with genes more closely related to angiosperms than to bryophytes. BMC Plant Biology 13:4 doi:10.1186/1471-2229-13-4

 Barnette, A.; C.Lee; L.Bradley; E.Schreiner; Y.B. Park; H.Shin; D.J.Cosgrove; S. Park; S.H Kim. 2012. Quantification of crystalline cellulose in lignocellulosic biomass using sum frequency generation (SFG) vibration spectroscopy and comparison with other analytical methods. Carbohydrate Polymers 89: 802-809

 Georgelis N., Yennawar N., and Cosgrove D.J. 2012. Structural basis for entropy-driven cellulose binding by a type-A cellulose-binding module (CBM) and bacterial expansin Proc. Nat. Acad. Sci. USA 109:14830-14835

 Park Y.B. and Cosgrove D.J. 2012. Changes in cell wall biomechanical properties in the xyloglucan-deficient xxt1/xxt2 mutant of Arabidopsis. Plant Physiology 158: 465–475

 Park Y.B. and Cosgrove D.J. 2012. A revised architecture of primary cell walls based on biomechanical changes induced by substrate-specific endoglucanases. Plant Physiology 158: 1933-1943

 Tabuchi, A., L.-C. Li, and D. J. Cosgrove. 2011. Matrix solubilization and cell wall weakening by β-expansin (group-1 allergen) from maize pollen. Plant Journal 68: 546-559

 Georgelis, N., A. Tabuchi, N. Nikolaidis, and D. J. Cosgrove. 2011. Structure-function analysis of the bacterial expansin EXLX1. Journal of Biological Chemistry 286: 16814-16823.

 Cosgrove, D. J. 2011. Measuring in-vitro extensibility of growth plant cell walls. Methods in Molecular Biology 715: 291-303.

 Sella Kapu, N. U. and D. J. Cosgrove. 2010. Changes in growth and cell wall extensibility of maize silks following pollination. Journal of Experimental Botany 61: 4097-4107.

 Valdivia, E. R., A. G. Stephenson, D. M. Durachko, and D. J. Cosgrove. 2009. Class B β-expansins are needed for pollen separation and stigma penetration. Sexual Plant Reproduction 22: 141-152.

 Szymanski, D. B. and D. J. Cosgrove. 2009. Dynamic coordination of cytoskeletal and cell wall systems during plant cell morphogenesis. Current Biology 19: R800-R811.

 Durachko, D. M. and D. J. Cosgrove. 2009. Measuring plant cell wall extension (creep) induced by acidic pH and by alpha-expansin. Journal of Visual Experimentation 25 doi: 10.3791/1263.

 Kerff, F., A. Amoroso, R. Herman, E. Sauvage, S. Petrella, P. Filée, P. Charlier, B. Joris, A. Tabuchi, N. Nikolaidis, and D. J. Cosgrove. 2008. Crystal structure and activity of Bacillus subtilis YoaJ (EXLX1), a bacterial expansin that promotes root colonization. Proceedings of the National Academy of Sciences USA 105(44): 16876-81.

 Valdivia, E. R., J. Sampedro, C. Lamb, S. Chopra, and D. J. Cosgrove. 2007. Recent Proliferation and Translocation of Pollen Group 1 Allergen Genes in the Maize Genome. Plant Physiology 143: 1269-81.

 Valdivia, E.R., Y. Wu, L.-C. Li, D. J. Cosgrove, and A. G. Stephenson. 2007. A group-1 grass pollen allergen influences the outcome of pollen competition in maize. PloS ONE 2(1): e154. doi:10.1371/journal.pone.0000154.