Table 1.
The occurrence of selected nucleotide sugar biosynthetic genes and pectic polysaccharides in green plants.
| Plant | UDP-Api | UDP-Rha | UDP-GalA | UDP-Xyl | UDP-Araf | CMP-Kdo | GDP-Gal | Pectic polysaccharide | ||
|---|---|---|---|---|---|---|---|---|---|---|
| Nucleotide sugar biosynthetic genes1 | RG-I | RG-II | HG | |||||||
| VASCULAR | ||||||||||
| Arabidopsis thaliana | G+/E+ | G+/E+ | G+/E+ | G+/E+ | G+/E+ | G+/E+ | G+/E+ | + | + | + |
| Oryza sativa | G+/E+ | G+/E+ | G+/E+ | G+/E+ | G+/E+ | G+/E+ | G+/E+ | + | + | + |
| Selaginella moellendorffii | G+/E+ | G+/E+ | G+/E+ | G+/E+ | G+/E+ | G+ | G+/E+ | + | + | + |
| AVASCULAR | ||||||||||
| Physcomitrella patens | G+/E− | G+/E+ | G+/E+ | G+/E+ | G+/E+ | G+/E+ | G+/E+ | + | ? | + |
| ALGAE STREPTOPHYTE | ||||||||||
| Mesostigma viride | Nd | Nd | Nd | E− | E− | E + | E− | ? | ? | ? |
| CHLOROPHYTES | ||||||||||
| Chlamydomonas reinhardtii | Nd | G+/E+ | G+/E+ | G+/E+ | G+/E+ | Nd | G+/E+ | ? | ? | ? |
| Volvox carteri | Nd | G+/E+ | G+/E + | G+/E− | G+/E+ | G−/E− | G+/E + | ? | ? | ? |
| Scherffelia dubia | Nd | Nd | Nd | Nd | Nd | E+2 | Nd | ? | ? | ? |
| Chlorella sp. | Nd | G+/E− | Nd | G+/E− | G+/E− | G+/E− | Nd | ? | ? | ? |
| Micromonas sp. | Nd | G+/E+ | G+/E− | G+E− | Nd | G+/E− | G+/E− | ? | ? | ? |
| Ostreococcus tauri/lucima | Nd | G+/E+ | G+/E+ | G+/E+ | Nd | G+/E− | G+/E+ | ? | ? | ? |
1Genes used for database queries were the functionally characterized Arabidopsis genes: UDP-apiose synthase (UAXS, AXS, At2g27860); UDP-Rha synthase (URS, Rhm, At1g78570); UDP-GalA 4-epimerase (UGlcAE, GAE, At2g45310, for UDP-GalA); UDP-xylose synthase (UXS, AT3g62830); UDP-arabinose mutase (UAM, RGP, At3g02230); CMP-Kdo synthase (CKS, AT1G53000); GDP-Man 3,5-epimerase (GME, AT5g28840, for GDP-l-Gal). G, presence (+) or absence (−) of a sequence homolog in publically available genomic data base (NCBI, January 2012). E, presence (+) or absence (−) of sequence homolog in expressed sequence tag (EST) data (NCBI, January 2012).?, indicates not detected or no data available. Nd, gene, or EST not detected in database. 2The scaly walls of Scherffelia dubia contain a sulfated KDO polymer. No KDO synthase sequences were identified, although an EST was reported by Becker et al. (2001). No GalA-kinase detected in Physcomitrella and the green algae. The possibility cannot be excluded that a transcript of the gene is expressed during a specific stage in the life of the plant.