Research Faculty #22

General Information

Academic History

B.Sc. Biology (1978), Dalhousie Univ.; 
Ph.D. Genetics (1985) Cornell Univ.; 
Postdoctoral Fellow (1985-1987) MSU-DOE Plant Research Laboratory; 
Assistant Professor of Biology (1987-1990), Univ. Saskatchewan; 
Associate Professor of Biology, (1990-1993), Univ. Saskatchewan; 
Associate Professor of Botany, (1993-2000), Univ. of British Columbia;

Contact Information

Email
george.haughn@ubc.ca
Office Phone
Office Location
Room 2239, Biological Sciences Building
Lab Phone
Lab Location
Room 2234, Biological Sciences Building

Research Information

Research Abstract

Plant Developmental Genetics. Molecular genetics of seed coat development in Arabidopsis thaliana.

Research Interests

My laboratory uses molecular genetics and the seed coat epidermal cell of Arabidopsis thaliana as a model to investigate plant cell wall biosynthesis, structure and function.  We also run a TILLING service described below.

Mechanisms underlying cell differentiation. The seed coat is a specialized tissue derived from ovule integuments. In some species, including Arabidopsis thaliana, large quantities of polysaccharide mucilage (pectin) and secondary cell wall are produced by seed coat epidermal cells at specific times during differentiation. Because these modifications are not required for viability, the Arabidopsis seed coat epidermal cells represent a unique dispensable tissue that can be used to identify genes involved in complex polysaccharide biosynthesis and secretion (Haughn and Chaudhury, 2005; Arsovski et al., 2010; Haughn and Western, 2012; Sôla et al., 2019a), important processes that are incompletely understood. As a first step to develop this unique model system we investigated the structure and differentiation of Arabidopsis seed coat secretory cells including the synthesis, secretion and extrusion of mucilage (Western et al., 2000) and isolated a number of mutants defective in the differentiation, synthesis and extrusion of mucilage (Western et al., 2001). Our characterization of these and other mutants and cloning of the mutated genes  has identified a number of proteins playing key roles in cell wall biology including biosynthesis (MUM4; Western et al., 2004) modification (MUM2, BXL1, FLY1, SOS5, HMS, FLY2, RUBY; Dean et al., 2007, Arsovski et al., 2009, Voiniciuc et al., 2013, Griffiths et al., 2014, Levesque-Tremblay et al., 2015, Kunieda et al., 2019; Sôla et al., 2019a) secretion (Young et al., 2008; McFarlane et al., 2013; Shi et al., 2019) and regulation (Western et al., 2004; Huang et al., 2011; Bargava et al., 2013) of mucilage pectins and synthesis of cellulose in mucilage (CESA5; Mendu et al., 2011; Griffiths et al., 2015) and for the secondary cell wall columella (CESA2, CESA5, CESA9; Stork et al., 2009Mendu et al., 2011). We have also developed some useful information and tools for the study of the seed coat including a microarray analysis (Dean et al., 2011); mucilage proteomic analysis (Tsai et al., 2017) and seed coat specific promoters (Esfandiari., 2013; Dean et al., 2017; Tsai et al., 2017; McGee et al., 2019) and used the information to engineer mucilage in situ (McGee et al., 2021).  Finally, we have discovered a metabolic link between the production of mucilage and the synthesis of storage oil in the embryo (Shi et al., 2012).  Due to my upcoming retirement I am no longer initiating new projects.

Team Members

Gillian Dean (Research Associate)
 

Selected Publications

McGee, R., G.H. Dean, D. Wu, Y. Zhang, S.D. Mansfield, G.W. Haughn. 2021. Pectin Modification in Seed Coat Mucilage by In Vivo Expression of Rhamnogalacturonan-I- and Homogalacturonan-Degrading Enzymes Plant Cell Physiol., in press, https://doi.org/10.1093/pcp/pcab077

Šola, K., G.H. Dean and G.W. Haughn. 2019. Arabidopsis seed mucilage: a specialised extracellular matrix that demonstrates the structure–function versatility of cell wall polysaccharides Ann. Plant Rev. 2: 1085-1116, doi: 10.1002/9781119312994.apr0691

Kunieda, T., I. Hara-Nishimura, T. Demura and G.W. Haughn. 2019. Arabidopsis FLYING SAUCER2 functions redundantly with FLY1 to establish normal seed coat mucilage. Plant Cell Physiol. 61: 308-317, https://doi.org/10.1093/pcp/pcz195

Shi, L., G. Dean, H. Zheng, M.J. Meents, T.M. Haslam, G.W. Haughn, L. Kunst. 2019. ECERIFERUM11/C-TERMINAL DOMAIN PHOSPHATASE LIKE 2 affects secretory trafficking. Plant Physiol. 181: 901–915. doi: 10.1104/pp.19.00722

McGee, R., G. Dean, S.D. Mansfield and G.W. Haughn. 2019. Assessing the utility of seed coat-specific promoters to engineer cell wall polysaccharide composition of mucilage. Plant Mol. Biol. 101:373-387 DOI: 10.1007/s11103-019-00909-8

Šola, K, E.J. Gilchrist, D. Ropartz, L.Wang, I. Feussner, S.D. Mansfield, M.-C. Ralet, and G.W. Haughn. 2019.  RUBY, a putative galactose oxidase, influences pectin properties and promotes cell-to-cell adhesion in the seed coat epidermis of Arabidopsis thaliana. Plant Cell: 31:  809-831 (Faculty 1000 Recommended).

Dean, G.H., Z. Jin, L. Shi, E. Esfandiari, R. McGee, K. Nabata, T. Lee, L. Kunst1, T. L. Western and G.W. Haughn. 2017. Identification of a seed coat-specific promoter fragment from the Arabidopsis MUCILAGE-MODIFIED4 gene. Plant Mol. Biol. 95: 33-50.

Tsai, A.Y.-L., T. Kunieda, J. Rogalski, L.J. Foster, B.E. Ellis and G.W. Haughn. 2017. Identification and Characterization of Arabidopsis Seed Coat Mucilage Proteins. Plant Physiol. 173: 1059–1074.

Griffiths J.S., K. Šola, R. Kushwaha, P. Lam, M. Tateno, R. Young, C. Voiniciuc, G. Dean, S.D. Mansfield, S. DeBolt, and G.W. Haughn. 2015.  Unidirectional movement of cellulose synthase complexes in Arabidopsis seed coat epidermal cells deposit cellulose involved in mucilage extrusion, adherence and ray formation. Plant Physiol. 168: 502-520.

Levesque-Tremblay, G., K. Müller, S.D. Mansfield, G.W. Haughn. 2015. HIGHLY METHYL ESTERIFIED SEEDS is a Pectin Methyl Esterase involved in embryo development. Plant Physiol. 167: 725-737.

Griffiths, J.S., A. Y.-L. Tsai, H. Xue, , C. Voiniciuc, K. Šola, G.J. Seifert, S.D. Mansfield and G.W. Haughn. 2014. SOS5 mediates Arabidopsis seed coat mucilage adherence and organization through pectins. Plant Physiol. 165: 991-1004.

Voiniciuc C., G.H. Dean, J.S. Griffiths, K. Kirchsteiger, Y-T. Hwang, A. Gillett, G. Dow, T.L. Western, M. Estelle, and G.W. Haughn. 2013. FLYING SAUCER1 Is a Transmembrane RING E3 Ubiquitin Ligase That Regulates the Degree of Pectin Methylesterification in Arabidopsis Seed Mucilage. Plant Cell 25: 944-959 (cover article).

Esfandiari E., Z. Jin, A. Abdeen, J.S. Griffiths, T.L. Western and G.W. Haughn. 2013. Identification and analysis of an outer-seed-coat-specific promoter from Arabidopsis thaliana. Plant Mol. Biol. 81:93–104.

Haughn G.W. and T.L. Western. 2012. Arabidopsis seed coat mucilage is a specialized cell wall that can be used as a model for genetic analysis of plant cell wall structure and function. Frontiers Plant Sci. 3: 64.

Dean G., Y. Cao, D Xiang, N.J. Provart, L. Ramsay, A. Ahad, R. White, G. Selvaraj, R. Datla and G. Haughn. 2011. Analysis of gene expression patterns during seed coat development in Arabidopsis. Mol. Plant 4: 1074-1091.

Huang J., D. DeBowle2, E. Esfandiari1, G. Dean, N.C. Carpita and G.W. Haughn. 2011. The Arabidopsis Transcription Factor LUH/MUM1 Is Required for Extrusion of Seed Coat Mucilage. Plant Physiol: 156: 491-502.

Arsovski, A.A., G.W. Haughn and T.L. Western. 2010. Seed coat mucilage cells of Arabidopsis thaliana as a model for plant cell wall research. Plant Signaling & Behavior  5: 796 - 801.

Arsovski A.A., T.M. Popma, G.W. Haughn, N.C. Carpita, M.C. McCann and T.L. Western. 2009. AtBXL1 encodes a bifunctional β-D-xylosidase/α-L-arabinofuranosidase required for pectic arabinan modification in Arabidopsis thaliana mucilage secretory cells.  Plant Physiol. 150: 1219-1234.

Young, RE, HE McFarlane, MG Hahn, TL Western, GW Haughn, and AL Samuels. (2008). Analysis of the Golgi Apparatus in Arabidopsis Seed Coat Cells during Polarized Secretion of Pectin-Rich Mucilage. Plant Cell 20: 1623–1638.

Dean G.H., H. Zheng, J. Tewari, J. Huang, D. S. Young, Y.T. Hwang, T. L. Western, N.C. Carpita, M.C. McCann, S.D. Mansfield, and G. W. Haughn. (2007). The Arabidopsis MUM2 Gene Encodes a ß-Galactosidase Required for the Production of Seed Coat Mucilage with Correct Hydration Properties. Plant Cell 19: 4007-4021.

Haughn G. and A. Chaudhury. (2005). All Dressed Up With Nowhere To Go: Genetic Analysis of Seed Coat Development in Arabidopsis. Trends in Plant Science 10: 472-477.

Western T.L., 2, D.S. Young, G.H. Dean, W.L. Tan, A.L. Samuels, and G.W. Haughn (2004) MUCILAGE-MODIFIED4 Encodes a Putative Pectin Biosynthetic Enzyme Developmentally Regulated by APETALA2, TRANSPARENT TESTA GLABRA1, and GLABRA2 in the Arabidopsis Seed Coat. Plant Physiology, 134: 296–306

Western, T.L., J. Burn, W. L. Tan, D. Skinner, L. M. McCaffrey, B. Moffatt and G. W. Haughn. (2001) Isolation and characterization of mutants defective in seed coat mucilage secretory cell development in Arabidopsis . Plant Physiology 127: 998-1011.

Western, TL, DJ Skinner & GW Haughn. (2000). Differentiation of mucilage secretory cells of the Arabidopsis thaliana seed coat. Plant Physiology 122: 345-355.