Search

Additional file 3. Germination medium and standard growth solution used in the study for hydroponic growth of Arabidopsis to obtain root material.

Additional file 2. Bar graphs and heat maps showing the differences in extractability of individual lipid classes from flowers, roots, siliques, stems, seedlings and seeds of Arabidopsis.

Additional file 3. Germination medium and standard growth solution used in the study for hydroponic growth of Arabidopsis to obtain root material.

Pectin is a major component of primary cell walls and performs a plethora of functions crucial for plant growth, development and plant-defense responses. Despite the importance of pectic polysaccharides their biosynthesis is poorly understood. Several genes have been implicated in pectin biosynthesis by mutant analysis, but biochemical activity has been shown for very few. We used reverse genetics and biochemical analysis to study members of Glycosyltransferase Family 92 (GT92) in Arabidopsis thaliana. Biochemical analysis gave detailed insight into the properties of GALS1 (Galactan synthase 1) and showed galactan synthase activity of GALS2 and GALS3. All proteins are responsible for adding galactose onto existing galactose residues attached to the rhamnogalacturonan-I (RG-I) backbone. Significant GALS activity was observed with galactopentaose as acceptor but longer acceptors are favored. Overexpression of the GALS proteins in Arabidopsis resulted in accumulation of unbranched β-1, 4-galactan. Plants in which all three genes were inactivated had no detectable β-1, 4-galactan, and surprisingly these plants exhibited no obvious developmental phenotypes under standard growth conditions. RG-I in the triple mutants retained branching indicating that the initial Gal substitutions on the RG-I backbone are added by enzymes different from GALS.

Additional file 2. Monosaccharide composition of stem cell walls of engineered lines. Alcohol-insoluble residue (AIR) of stem cell walls of W- (A) and X- (B) engineered lines, hydrolyzed with trifluoroacetic acid, and analyzed by HPAEC-PAD. Bars: SD, n = 3.

Additional file 1. Phenotypes of W5 and X5 engineered lines.

Additional file 4. Summary of jStack constructs.

Root phenotypes of NbPAGR-silenced and TRV-infected unsilenced control plants. (A) Roots of NbPAGR-silenced plants are shorter than those of control plants and were discolored. (B) Roots of NbPAGR-silenced and control plants were measured and were found to be significantly shorter in s * p

The approximate mass (kDa) of each monosaccharide residue in RG-I purified from 35S::PAGR-YFP and wild type (Col-0) plants. (DOCX 44 kb)

Additional images of in vitro pollen germination assays showing reduced germination rates in pollen from pagr-1 and pagr-2 heterozygous plants compared to the wild type. Scale bars are 100Â Îźm. (PPTX 1073 kb)

Tissue specific microarray data heat map depicting the relative expression level of PAGR in various tissues throughout growth and development. Publicly available data was retrieved and displayed using the Arabidopsis eFP browser ( http://bar.utoronto.ca/efp/cgi-bin/efpWeb.cgi ) [23]. (PPTX 235 kb)

Sequential extraction of cell wall material from NbPAGR-silenced Nicotiana benthamiana plants. Cell wall material from NbPAGR-silenced and control plants was sequentially extracted with CDTA, sodium carbonate, 1 M KOH and 4 M KOH. The monosaccharide composition of the extracted and residual materials was then analyzed. Cell wall polysaccharides with reduced galactan and increased glucuronic acid content in PAGR-silenced plants were extracted with the CDTA and sodium carbonate fractions. *: p

Additional images of in vitro pollen germination assays showing reduced germination rates in pollen from pagr-1 and pagr-2 heterozygous plants compared to the wild type. Scale bars are 100Â Îźm. (PPTX 1073 kb)

Sequential extraction of cell walls from 35S:PAGR-YFP expressing Arabidopsis seedlings. Cell wall material from was sequentially extracted with CDTA, sodium carbonate, and 4 M KOH. The monosaccharide composition of the extracted and residual materials was then analyzed. Cell wall polysaccharides with increased arabinan content were extracted in the CDTA fraction. *: p

The approximate mass (kDa) of each monosaccharide residue in RG-I from NbPAGR-silenced and control N. benthamiana plants. (DOCX 39 kb)

Root phenotypes of NbPAGR-silenced and TRV-infected unsilenced control plants. (A) Roots of NbPAGR-silenced plants are shorter than those of control plants and were discolored. (B) Roots of NbPAGR-silenced and control plants were measured and were found to be significantly shorter in s * p

Sequential extraction of cell walls from 35S:PAGR-YFP expressing Arabidopsis seedlings. Cell wall material from was sequentially extracted with CDTA, sodium carbonate, and 4 M KOH. The monosaccharide composition of the extracted and residual materials was then analyzed. Cell wall polysaccharides with increased arabinan content were extracted in the CDTA fraction. *: p

Multiple amino acid sequence alignment of the Arabidopsis thaliana, Nicotiana benthamiana, Selaginella moellendorfii and Physcomitrella patens orthologs of PAGR. * identical amino acids, : conserved substitutions, . semi-conserved substitutions. (PPTX 36 kb)