From Purdue Genomics Database Facility

Contents 1 Authors 2 Introduction 3 Major findings 4 Polysaccharide composition analysis of Selaginella moellendorffii cell walls 5 Cell wall related glycosyltransferases 5.1 GT8 (Retaining) 5.2 GT31 (Inverting) 5.3 GT34 (Retaining) 5.4 GT37 (Inverting) 5.5 GT43 (Inverting) 5.6 GT47 (Inverting) 5.7 GT48 (Inverting) 5.8 GT64 (Retaining) 5.9 GT77 (Retaining) 6 References 7 Summary 7.1 Number of genes identified in Selaginella compared to number of sequences in Physcomitrella, Arabidopsis and rice 7.2 Protein names and ID's for the Selaginella moellendorffii entries annotated

Authors

Jesper Harholt	Department of Plant Biology	University of Copenhagen	Denmark
Peter Ulvskov,	Biotechnology Group, GBI	University of Aarhus	Denmark
Iben Sørensen	Department of Biology	University of Copenhagen	Denmark
William Willats	Department of Biology	University of Copenhagen	Denmark
Bent Larsen Petersen	Biotechnology Group, GBI	University of Aarhus	Denmark
Henrik V. Scheller*	Joint BioEnergy Institute	Lawrence Berkeley National Laboratory	CA, USA
*) hscheller@lbl.gov

Introduction

Plant cells, with very few exceptions, are surrounded by a polysaccharide-based cell wall, which has been modified during the course of plant evolution. Some cell wall features are shared by all plants, for example cellulose (CESA Superfamily), the main load-bearing structure in the wall and callose, probably the first polymer to be laid down in the phragmoplast during cell division. However, variations in the structures and compositions of matrix polysaccharides such as xyloglucan fucosylation, rhamnogalacturonan-I side chain structure, and the occurrence of rhamnogalacturonan-II appear to be taxonomically significant. A subset of the 91 families of glycosyltransferases (GTs) in the CAZy-database (CAZy) is analyzed in the following comparative study of Selaginella moellendorffii, Physcomitrella patens, Oryza sativa and Arabidopsis thaliana. Family selection was based both on a polysaccharide analysis of Selaginella compared to Arabidopsis (see below) and on our current understanding of polysaccharide biosynthesis in flowering plants (for example, see the review by Scheller et al., 2007 for a discussion of CAZy-families involved in cell wall biosynthesis. The CESA Superfamily of cellulose synthase and cellulose synthase like proteins was not included in the analysis)

Major findings

• S. moellendorffii cell walls contain many of the polysaccharides commonly found in less basal plant groups such as angiosperms, including mannan, xyloglucan (including fucosylated xyloglucan) and pectic polymers.
• Mannans appear to be generally more abundant in the cell walls of more basal plants including S. moellendorffii and P. patens.
• CoMPP analysis indicated that the extractability of pectic polysaccharides in Selaginella moellendorffii differs from most higher plants. Also, whilst xylan was strongly labeled in stem sections, only very low signals for xylan were obtained by CoMPP analysis. This suggests that, unlike for most higher plants, NaOH was not effective in solubilising xylan from S. moellendorffii cell walls. Taken together these data indicate that although several major polysaccharides are common to S. moellendorffii and higher plants they may be arranged in somewhat different cell wall architectures.
• Mannan is an abundant cell wall polymer in S. moellendorffii.
• The GT-families of relevance to cell wall biosynthesis are not of similar age. Some families eg. GT8 and GT31 appear to have evolved substantially after the divergence of the angiosperms whereas old families like GT47, GT48 and GT77 have stable clades that date from before the emergence of vascular plants.

Polysaccharide composition analysis of Selaginella moellendorffii cell walls

Cell wall polysaccharides were analysed using the microarray/antibody based Comprehensive Microarray Polymer Profiling or ‘CoMPP’ technique (Fig 1a, Moller et al., 2007). CoMPP indicated that compared to A. thaliana, S. moellendorffii cell walls contain significant amounts of xyloglucan (XG) and mannan, and this is consistent with the presence of the ‘A’ and ‘C’ classes of cellulose-synthase-like genes in S. moellendorffii (CESA Superfamily). The fucosylated XG epitope recognized by antibody CCRC-M1 was also present and at a similar level to in A. thaliana. CoMPP and monosaccharide linkage analysis has previously indicated that this epitope is essentially absent from the bryophyte Physcomitrella patens (Moller et al., 2007). In all plant species studied to date using CoMPP, pectic and particularly homogalacturonan (HG) epitopes are generally more abundant in CDTA extracted material, so it is of particular note that in S. moellendorffii HG was more abundant in the NaOH rather than CTDA extracts. Thus, the extractability of HG in S. moellendorffii appears to differ from in A. thaliana, and this may indicate a different association between the pectic matrix and other cell wall components.

Heatmap showing the relative abundance of cell wall components in Physcomitrella patens, S. moellendorffii and Arabidopsis thaliana, as extracted using 1,2-diaminocyclohexanetetraacetic acid (CDTA) and sodium hydroxide (NaOH). The same amount of cell wall material (alcohol insoluble residue) was used for each species. Analysis and quantification was performed using the microarray/antibody based CoMPP technique (Moller et al., 2007). XG, xyloglucan. AGP, arabinogalactan protein.

The spatial distribution of selected cell wall polymers as analyzed by immunofluorescence microscopy of S. moellendorffii stems is shown below.

(A), schematic representation of a section through a S. moellendorffii stem showing the location of the cortex (C), sclerenchyma (S), xylem (X), phloem and leaf traces (L). An unusual feature of S. moellendorfii stem anatomy is that the stele is separated from the cortex by an air space which is spanned intermittently by specialized endodermal cells known as trabeculae (T). Indirect immunofluorescence microscopy reveals the location of three cell wall polysaccharides – homogalacturonan (HG) (B), (1→4)-β-galactan (C) and (1→4)-β-xylan (D) recognized by the antibodies JIM5, LM5 and LM10 respectively (http://www.bmb.leeds.ac.uk/staff/jpk/antibodies.htm). Strong JIM5 labeling indicted that HG is abundant in xylem, phloem and leaf trace cells (not shown) but is present at low levels in other stem tissues. Certain phloem cell were intensely labelled by LM5, but this galactan epitope occurred at low levels in other tissues. In contrast, the xylan epitope recognized by LM10 was strongly labelled in cortical and xylem tissues, but very weakly labelled in phloem tissue.

Analysis of the monosaccharide cell wall composition of S. moellendorffii complemented the CoMMP analysis. Compared to Arabidopsis and Rice high levels of mannose were detected (Harholt et al. 2006, Carpita 1996). This is in good agreement with the abundance of the mannan epitope in S. moellendorffii compared to Arabidopsis. Relative low amounts of the pectic sugars Galacturonic acid and Rhamnose were deteted compared to P. patens and Arabidopsis (Harholt et al., 2006, Moller et al., 2007). This difference may reflect a difference in the way in which pectin is deposited and utilized and this is supported by CoMMP analysis that revealed that S. moellendorffii pectins have unusual extractability characteristics.

Monosaccharide cell wall composition of Selaginella. Cell walls were prepared and hydrolyzed as described in Harholt et al. 2006. Analysis of monosaccharide composition was performed by HPAEC-PAD. The amount of mannose detected is much higher than normally found in higher plants. This is consistent with the difference in mannan content as both P. patens (Moller et al., 2007) and Selaginella (see CoMMP analysis below) have relativly larger proportions of mannan epitopes in their cell wall. The relative amount of pectin in the cell wall of S. moellendorffii is low compared both Physcomitrella and Arabidopsis possibly reflecting the difference in which pectin is deposited and utilized (see CoMMP analysis below)(Moller et al., 2007, Harholt et al., 2006).

Cell wall related glycosyltransferases

GT8 (Retaining)

In GT8 both cell wall and non cell wall related plant sequences are present, but all appears to be of retaining activity. The non cell wall related sequences are involved in starch accumulation and galactinol synthesis (Chattejee et al., 2005, Panikulangara et al., 2004). The cell wall related activities include homogalacturonan synthase (GAUT) and a still unknown activity involved in xylan biosynthesis (GATL) (Sterling et al., 2006, Bouton et al., 2002, Orfila et al., 2005 , Lee et al., 2007b).

The arabidopsis GAUTs are generally assumed all to be galacturonosyltransferases involved in pectin biosynthesis. Only one arabidopsis sequence, QUA1, has a clear Selaginella ortholog while none have Physcomitrella orthologs. This is taken to mean that GT8 is a young family where much of the evolution in the family has taken place after the split of the major plant groups.

The GATL groups of GTs have no clades with both angiosperm and lower plant members. The only characterized gene, At1g19300, appears from analysis of the mutant Parvus to be involved in secondary wall formation in vascular tissues. The complete family GT8 tree positions Physcomitrella very marginally in the GATL group (not shown). At1g19300 encodes an as yet unknown activity, but suggested to be involved in the synthesis of the oligosaccharide primer for xylan elongation.

GT31 (Inverting)

The GT31 glycosyltransferases appear to transfer hexosyl monosaccharides in β-1,3. This generalization is based on the well-characterized mammalian members (see Narimatsu 2006 for a review). The chondroitin sulphate transferases that posses β-1,4-transferase activity belong in the family because they are dual function and also have β-1,3-transferase activity. A large group of mammalian members are the fringe GTs, which are N-acetyl-glucosaminyltransferases. The fringe-related GTs in GT31 form Group A, which is distinct from the non-fringe related GTs in Groups B to F. It is generally assumed that the plant members of family GT31 comprise activities involved in adding galactosyl units in β-1,3 to N-glycans, to O-glycans of AGPs and to pectic type-II arabinogalactans. However, only a single plant member of GT31, At1g26810, has been functionally characterized and shown to be a galactosyltransferase involved in the synthesis of the Fucα1-4(Galβ1-3) GlcNAc-R structure of N-glycans (Strasser et al 2007).

The mammalian fringe GT’s are involved in synthesis of the Lewis structures and specifically in Notch signaling, a process that involves trans endocytosis, i.e. endocytosis of a cell surface protein by the neighboring cell, a process that is unlikely to have a counterpart in plants. Some of the members may nonetheless encode N-acetyl-glucosaminyltransferases. It is noteworthy that there is one clade with a member from each species. This clade is probably where the tree shall be rooted while the other clades are later diversifications.

The clade stucture of the non-fringe GT31s reflects splits after establishments of major plant groups. Clades are often organized with the younger angiosperm sequences at the tips and the closer to ancestral Physcometrella and Selaginella sequences at the base of the clade. The B clade containing At1g26810 (GalT1) is one example. One clade has Physcomitrella members, but lacks a Selaginella member.

GT34 (Retaining)

This family comprises the α-1,6-xylosyltransferases that add the innermost residue of the short side chains of xyloglucan (Faik et al 2002). The family also contains the α-1,6-galactosyltransferase involved in galactomannan biosynthesis,which was originally cloned from fenugreek (Edwards et al 1999).

Both Physcomitrella and Selaginella have the core xyloglucan structure including the isoprimverose motif ,α-1,6-xylosyl-glucose, that requires the GT34 enzymes for their synthesis. Selaginella has two A-clade members, which most likely encode xylosyltransferases. Physcomitrella appears to have none. Two Physcomitrella sequences are already annotated in CAZy family GT34 as α-1,6-xylosyltransferases under the accession numbers CAJ57380 and CAJ57381, marked in the tree with asterixes. They are slightly more similar to At5g07720 and At1g74380, which are annotated as galactosyltransferases,, than to At3g62720 which encodes AtXT1. The reason for the ambiguity is that the GT34-sequences are rather similar and assignment of function cannot be resolved without additional biochemical evidence.

GT37 (Inverting)

The family comprises the α-1,2-fucosyltransferases that fucosylates xyloglucan (Vanzin et al 2002). Fucosylated xyloglucan occurs widely in angiosperms but is known to be absent from Solanaceae and from many, but not all genera in Poaceae. Selaginella also has fucosylated xyloglucan, see the CoMPP analysis above. Physcomitrella yielded a clear signal for unfucosylated xyloglucan in the CoMMP analysis by Moller et al (2007) while the signal for fucosylated xyloglucan was below the detection limit.

None of the clade structure in this family dates back to early vascular plant evolution. Rice and Arabidopsis form species specific clades while the Selaginella and Physcomitrella sequences can hardly be said to form clades. The tree thus does not suggest which Selaginella sequences encode xyloglucan specific fucosyltransferases.The fact that rice and arabidopsis do not share any clades is consistent with the fact that rice is one of those grasses that do not have fucosylated xyloglucan, see discussion by Yokoyama and Nishitani (2004).

GT43 (Inverting)

This family holds just four Arabidopsis sequences, at least one of which appears to be involved in synthesis of the xylan backbone (Lee et al 2007b). β-1,3-glucuronosyltransferase activity has been shown for animal members of the family.

At1g27600 of unknown activity is member of a clade comprising all four species whereas the clade holding At2g37090, the putative UDP-Xyl: xylan β-1,4-xylosyltransferase, has no Selaginella or Physcomitrella sequences. Nevertheless, Selaginella GT43A1 is a likely candidate to be a UDP-Xyl: xylan β-1,4-xylosyltransferase.

GT47 (Inverting)

GT47 is dominated by plant sequences with a more than 10 fold larger number of members from plant species than from animal species. Although most of the GT47 members in plants still have an unknown function it seems likely that most if not all the proteins are involved in cell wall biosynthesis. The plant members of GT47 are highly diverse with respect to the substrates they use and the linkages they form. GT47 members are involved in biosynthesis of pectin and hemicellulose, they can form several different linkages, and they use both neutral and acidic substrates as shown by analysis of MUR3 (Madson et al 2003), GT18 (Li et al., 2004), Gut1 (ortholog of the NpGUT, Iwai et al 2002), Fra8 (Zhong et al 2005), XGD1 (Jensen et al., 2008) and ARAD1 (Harholt et al., 2006).

GT47 is an old family of the plant lineage as all clades comprise all four species with the exception of At1g21480, which may a pseudogene in arabidopsis and completely lost in rice and Selaginella. The family has Chlamydomonas members; one orthologous to At3g57630, and probably members from other primitive algae like family GT77 (data not shown). The occurrence of Chlamydomonas sequences suggests that GT47 also holds genes involved in cell wall glycoprotein synthesis. The family is large and divergent so although quite a few genes have been functionally characterized from the family, the general patterns, if any, are still not discernible.

GT48 (Inverting)

The GT48 glucan synthases are 200kDa integral plasma membrane proteins from plants and fungi that synthesize linear (1,3)-β-D-glucan or callose (Østergaard et al 2002). Callose is not a general component of plant cell walls. Callose is deposited transiently in the phragmoplast; it is component of pollen mother cell walls and pollen tubes in flowering plants; and of the cell wall during endosperm cellularisation in developing grain (Wilson et al., 2006).

Some fundamental GT48 processes like phragmoplast synthesis during cell division are conserved while other GT48 members are involved in pollen growth, unique to the higher plants. All sub-clades of the phylogenetic tree of GT48 contain all four species, which shows that the clade structure in GT48 does not reflect physiological function and that the pollen GT48s could be recruited for their role without significant changes to the amino acid sequence.

GT64 (Retaining)

The α-N-acetylhexosaminyltransferase domain of the mammalian bi-functional heparan synthases defines this family. The family comprises just three members from arabidopsis and three from rice, none of which have two GT-domains. The function is unknown, but mutant studies indicate an essential role in cell wall biosynthesis. The most striking phenotype of the mutants is the compromised cell adhesion, which inspired the gene naming, EPC1 for “ectopically parting cells” (Singh et al 2005).

In GT64 there are three distinct sub-clades. Selaginella sequences are present in all of these three sub-clades along with Physcomitrella sequences. One sub-clade has no apparent Rice orthologs.

GT77 (Retaining)

This is the last added GT-family with plant entries in CAZy. It was identified by searching for plant specific glycosyltransferases not yet classified in CAZy at the time (Egelund et al 2004). The only known activities are the Dictyostelium α-1,3-galactosyltransferase AgtA (Ercan et al 2006), which is the only non-plant member of the family; and the founding α-1,3-xylosyltransferases RGXT1 & 2 involved in rhamogalacturonan-II biosynthesis in Arabidopsis (Egelund et al 2006). The family comprises a number of enzymes from primitive algae and generally appears to be an old family of the plant lineage.

The GT77 phylogenetic tree is shown in figure 9 with clade designations according to Egelund et al (2007). These authors also discussed whether the genes of the A-clade which has Chlamydomonas members, could be involved in extensin biosynthesis. Extensins are conserved very far back in evolution so it is to be expected that all four species have members of the A-clade. It should be borne in mind, however, that biochemical evidence for the function of the A-clade gene products is still missing. In contrast, the B-clade has been demonstrated to encode xylosyltransferases with a role in RG-II biosynthesis. RG-II is conserved among vascular plants including lycophytes like Selaginella, but it is an open question whether bryophytes also have RG-II in their walls (Popper and Fry 2004). They do contain the monosaccharide methyl xylose, a signature sugar of RG-II, albeit in much lower concentration than that found in higher plant. Our observation that Physcomitrella has a B-clade member strongly suggests that bryophytes share some of the RG-II biosynthetic machinery with vascular plants. We thus propose that the Me-Xyl-containing component in Physcomitrella is either RG-II like in vascular plants or a precursor oligosaccharide homologous to RG-II.

References

Bouton S, Leboeuf E, Mouille G, Leydecker MT, Talbotec J, Granier F, Lahaye M, Höfte H, Truong HN. (2002) QUASIMODO1 encodes a putative membrane-bound glycosyltransferase required for normal pectin synthesis and cell adhesion in Arabidopsis. Plant Cell 14: 2577-90

Chatterjee M, Berbezy P, Vyas D, Coates S, Barsby T (2005) Reduced expression of a protein homologous to glycogenin leads to reduction of starch content in Arabidopsis leaves. Plant Science 168:2 501-509
Carpita N (1996) Structure and biogenesis of the cell walls of grasses. Ann Rev Plant Physiol Plant Mol Biol 47: 445-476

Edwards ME, Dickson CA, Chengappa S, Sidebottom C, Gidley MJ, Reid JS (1999) Molecular characterisation of a membrane-bound galactosyltransferase of plant cell wall matrix biosynthesis. Plant J. 19:691-697

Egelund J, Petersen BL, Motawia MS, Faik A, Olsen CE, Ishii T, Clausen H, Damager, I, Ulvskov P, Geshi N (2006) Arabidopsis thaliana RGXT1 and RGXT2 Encode Golgi-Localized (1,3)-a-D-Xylosyltransferases Involved in the Synthesis of Pectic Rhamnogalacturonan-II The Plant Cell 18: 2593–2607

Egelund J, Obel N, Ulvskov P, Geshi N, Pauly M, Bacic A, Petersen BL (2007) Molecular characterization of two Arabidopsis thaliana glycosyltransferase mutants, rra1 and rra2, which have a reduced residual arabinose content in a polymer tightly associated with the cellulosic wall residue. Plant Mol Biol 64: 439-451

Egelund J, Skjødt M, Geshi N, Ulvskov P, Petersen BL (2004) A complementary bioinformatics approach to identify potential plant cell wall glycosytransferase encoding genes. Plant Physiol 136:2609-2620

Ercan A, Panico M, Sutton-Smith M, Dell A, Morris HR, Matta KL, Gay DF. West CM. (2006) Molecular characterization of a novel UDP-Gal:fucoside alpha 3-galactosyltransferase that modifies Skp1 in the cytoplasm of dictyostelium. J. Biol. Chem. 281: 12713-12721

Faik A, Price NJ, Raikhel NV, Keegstra K (2002) An Arabidopsis gene encoding an alpha-xylosyltransferase involved in xyloglucan biosynthesis. Proc Natl Acad Sci USA 99: 7797-7802

Harholt J, Jensen JK, Sørensen SO, Orfila C, Pauly M, Scheller HV (2006) ARABINAN DEFICIENT 1 is a putative arabinosyltransferase involved in biosynthesis of pectic arabinan in Arabidopsis. Plant Physiol 140: 49-58.

Jensen JK, Sørensen SO, Harholt J, Geshi N, Sakuragi Y, Møller I, Zandleven J, Bernal AJ, Jensen NB, Sørensen C, Pauly M, Beldman G, Willats WG, Scheller HV (2008) Identification of a Xylogalacturonan Xylosyltransferase Involved in Pectin Biosynthesis in Arabidopsis. Plant Cell. 2008 May 6. Epub ahead of print 0.1105/tpc.107.050906

Iwai H, Masaoka N, Ishii T, Satoh S (2002) A pectin glucuronyltransferase gene is essential for intercellular attachment in the plant meristem. Proc Natl Acad Sci USA 99: 16319–16324

Lee CH , O'Neill MA , Tsumuraya Y , Darvill AG , Ye ZH (2007a) The irregular xylem9 mutant is deficient in xylan xylosyltransferase activity. Plant Cell Physiol 48: 1624-1634

Lee CH , Zhong RQ , Richardson EA , Himmelsbach DS , McPhail BT , Ye ZH (2007b) The PARVUS gene is expressed in cells undergoing secondary wall thickening and is essential for glucuronoxylan biosynthesis. Plant Cell Physiol 48: 659-1672

Li X, Cordero I, Caplan J, Mølhøj M, Reiter WD (2004) Molecular analysis of 10 coding regions from Arabidopsis that are homologous to the MUR3 xyloglucan galactosyltransferase. Plant Physiol 134: 940-50

Madson M, Dunand C, Li X, Verma R, Vanzin G.F, Caplan J, Shoue DA Carpita NC, Reiter WD (2003) The MUR3 Gene of Arabidopsis Encodes a Xyloglucan Galactosyltransferase That Is Evolutionarily Related to Animal Exostosins Plant Cell 15: 1662-1670.

Moller I, Sørensen I, Bernal AJ, Blaukopf C, Lee K, Øbro J, Pettolino F, Roberts A, Mikkelsen J, Knox JP, Bacic T, Willats WGT (2007) High-throughput mapping of cell wall polymers within and between plants using novel microarrays. Plant J 50: 1118-28.

Narimatsu H. (2006) Human glycogene cloning: focus on β3-glycosyltransferase and β4-glycosyltransferase families. Curr Opinion Struct Biol 16:567–575.

Orfila C, Sørensen SO, Harholt J, Geshi N, Crombie H, Truong HN, Reid JS, Knox JP, Scheller HV (2005) QUASIMODO1 is expressed in vascular tissue of Arabidopsis thaliana inflorescence stems, and affects homogalacturonan and xylan biosynthesis. Planta. 222: 613-22.

Panikulangara TJ, Eggers-Schumacher G, Wunderlich M, Stransky H, Schöffl F. (2004) Galactinol synthase1. A novel heat shock factor target gene responsible for heat-induced synthesis of raffinose family oligosaccharides in Arabidopsis. Plant Physiol 136: 3148-58.

Popper ZA, Fry SC (2004) Primary cell wall composition of pteridophytes and spermatophytes. New Phytologist 164: 165–174.

Scheller HV , Jensen JK , Sørensen SO , Harholt J , Geshi N (2007) Biosynthesis of Pectin. Physiol Plant 29: 283-295.

Singh, S.K., Eland, C., Harholt, J., Scheller, H.V. & Marchant, A. (2005) Cell adhesion in Arabidopsis thaliana is mediated by ECTOPICALLY PARTING CELLS 1 - a glycosyltransferase (GT64) related to the animal exostosins. Plant J 43: 384-397.

Sterling JD, Atmodjo MA, Inwood SE, Kolli VSK, Quigley HF, Hahn MG, Mohnen D (2006) Functional identification of an Arabidopsis pectin biosynthetic homogalacturonan galacturonosyltransferase. Proc Natl Acad Sci USA 103: 5236-5241.

Strasser R, Singh Bondili J, Vavra U, Schoberer J, Svoboda B, Glössl J, Léonard R, Stadlmann J, Altmann F, Steinkellner H, Macha L. (2007) A Unique β1,3-Galactosyltransferase Is Indispensable for the Biosynthesis of N-Glycans Containing Lewis a Structures in Arabidopsis thaliana. Plant Cell 19: 2278–2292.

Vanzin GF, Madson M, Carpita NC, Raikhel NV, Keegstra K, Reiter WD (2002) The mur2 mutant of Arabidopsis thaliana lacks fucosylated xyloglucan because of a lesion in fucosyltransferase AtFUT1. Proc Natl Acad Sci USA 99(5): 3340-3345.

Wilson SM, Burton RA, Doblin MS, Stone BA, Newbigin EJ, Fincher GB, Bacic A. (2006) Temporal and spatial appearance of wall polysaccharides during cellularization of barley (Hordeum vulgare) endosperm. Planta 224: 655–667.

Yokoyama R, Nishitani K (2004) Genomic Basis for Cell-Wall Diversity in Plants. A Comparative Approach to Gene Families in Rice and Arabidopsis. Plant Cell Physiol. 45: 1111–1121

Zhong RQ, Pena MJ, Zhou GK, Nairn CJ, Wood-Jones A, Richardson EA, Morrison WH, Darvill AG, York WS, Ye ZH (2005) Plant Cell 17: 3390-3408.

Østergaard L, Petersen M, Mattsson O, Mundy J (2002) An Arabidopsis callose synthase. Plant Mol Biol 49: 559–566.

Summary

Number of genes identified in Selaginella compared to number of sequences in Physcomitrella, Arabidopsis and rice

Glycosyltransferase family	Selaginella	Physcomitrella	Arabidopsis	Oryza
GT8	8	14	25	30
GT31	15	13	33	39
GT34	7	19	7	5
GT37	5	12	10	16
GT43	2	5	4	10
GT47	27	46	39	35
GT48	7	12	12	10
GT64	4	5	3	3
GT77	4	5	18	16

In GT8 only cell wall related sequences are included. Numbers for Rice and Arabidopsis are from the CAZy database and could vary from the of sequences presented in the phylogenetic trees, which resulted from a more comprehensive analysis.

Protein names and ID's for the Selaginella moellendorffii entries annotated

GT Family	Gene Name	Protein ID
GT8 (only wall related proteins included, i.e. homologs of GAUT and GATL sub-families of Arabidopsis)	GAUT1-1	405514
	GAUT1-2	440136
	GAUT2-1	451073
	GAUT2-2	112387
	GAUT3	170799
	GAUT4-1	451048
	GAUT4-2	183138
	GAUT5	440751
	GAUT6-1	268781
	GAUT6-2	269662
	GATL1-1	122431
	GATL1-2	125336
GT31 – Fringe related proteins	GT31A1-1	451109
	GT31A1-2	154762
	GT31A2-1	414010
	GT31A2-2	415787
	GT31A3-1	403190
	GT31A3-2	420424
	GT31A4-1	82794
	GT31A4-2	124093
	GT31A5	406513
	GT31A6-1	410318
	GT31A6-2	411436
	GT31A7-1	98767
	GT31A7-2	137339
GT31 – non-fringe related proteins	GATL1-1	451089
	GATL1-2	451090
	GATL2-1	451083
	GATL2-2	451084
	GATL3-1	451085
	GATL3-2	451086
	GT31C1-1	407750
	GT31C1-2	417997
	GT31D1-1	451091
	GT31D1-2	451092
	GT31E1-1	232457
	GT31E1-2	106746
	GT31E2-1	267164
	GT31E2-2	231618
	GT31E3	427432
	GT31E4	233250
GT34	GT34A1-1	414690
	GT34A1-2	132407
	GT34A2-1	88477
	GT34A2-2	268491
	GT34A3-1	97077
	GT34A3-2	135562
	GT34A4-1	112156
	GT34A4-2	126121
	GT34A5-1	112143
	GT34A5-2	126161
	GT34A6-1	407925
	GT34A6-2	417834
	GT34A7-1	428682
	GT34A7-2	430688
GT37	GT37A1-1	416793
	GT37A1-2	451093
	GT37A2	451094
	GT37A3-1	451095
	GT37A3-2	451096
	GT37A4-1	451097
	GT37A4-2	451098
	GT37A5-1	451099
	GT37A5-2	451100
	GT37A6-1	441628
	GT37A6-2	451101
GT43	GT43A1-1	404697
	GT43A1-2	419863
	GT43B1-1	451106
	GT43B1-2	451107
GT47	GT47A1-1	426341
	GT47A1-2	451115
	GT47A2-1	451116
	GT47A2-2	451117
	GT47A3-1	451118
	GT47A3-2	431791
	GT47A4	79836
	GT47A5-1	126654
	GT47A5-2	131571
	GT47A6-1	451119
	GT47A6-2	451120
	GT47A7-1	118133
	GT47A7-2	126624
	GT47A8-1	407784
	GT47A8-2	451121
	GT47A9-1	451122
	GT47A9-2	451123
	GT47A10-1	441713
	GT47A10-2	417256
	ARAD1-1	107675
	ARAD1-2	110998
	GT47B2-1	98362
	GT47B2-2	127314
	GT47B3-1	85747
	GT47B3-2	115810
	GT47B4-1	99588
	GT47B4-2	174998
	GT47B5-1	171414
	GT47B5-2	108808
	GT47C1-1	230410
	GT47C1-2	235809
	GT47D1-1	73496
	GT47D1-2	86803
	GT47D2-1	92752
	GT47D2-2	114272
	GT47D3-1	106537
	GT47D3-2	134783
	GT47D4-1	136816
	GT47D4-2	137613
	GT47D5-1	416846
	GT47D6-1	172637
	GT47D6-2	119956
	GT47E1-1	442111
	GT47E1-2	431651
	GT47E2	442723
	GT47E3	5415
	GT47F1-1	449327
	GT47F1-2	431709
GT48	Gsl1	439692
	Gsl2	177798
	Gsl3-1	163802
	Gsl3-2	87485
	Gsl4-1	267830
	Gsl4-2	451068
	Gsl5	429757
	Gsl6	431892
	Gsl7-1	133452
	Gsl7-2	187626
GT64	GT64A1-1	81258
	GT64A1-2	88187
	GT64A2	403218
	GT64A3	420395
	GT64B1	451050
	GT64C1-1	133103
	GT64C1-2	133161
GT77	RRA1-1	103279
	RRA1-2	136459
	RGXT1-1	87970
	RGXT1-2	115185
	GT77C1-1	127789
	GT77C1-2	133541
	GT77D1-1	76256
	GT77D1-2	113492