Schematic representation of the pectic polysaccharide rhamnogalacturonan-I (a) and the structure and expression of PAGR (b-d).
a Rhamnogalacturonan-I has a backbone consisting of repeating [−α-d-GalpA-1,2-α-l-Rhap-1,4-] disaccharide units. Approximately half of the rhamnose residues are substituted with sidechains on the 4-position such as type-I and type-II arabinogalactans, α-(1,5)-linked arabinans or single arabinose or galactose residues. b
pagr-1 is a T-DNA insertion in the 11th exon of PAGR; pagr-2 is an insertion in the 7th exon. c
PAGR encodes a type-II membrane protein with an N-terminal disordered domain and a C-terminal O-fucosyltransferase-like DUF246 domain. d Quantitative RT-PCR analysis of PAGR expression in various Arabidopsis tissues. Results show PAGR expression is highest in reproductive tissues and roots. Error bars indicate standard deviation, n = 3