biostudies-literatureBegum RACommonwealth Scholarship CommissionBiotechnology and Biological Sciences Research Council703-715https://www.ebi.ac.uk/biostudies/studies/S-EPMC9670748biostudies-literatureUnknown130(5)<h4>Background and aims</h4>Rhamnogalacturonan-II (RG-II) is a domain of primary cell-wall pectin. Pairs of RG-II domains are covalently cross-linked via borate diester bridges, necessary for normal cell growth. Interpreting the precise mechanism and roles of boron bridging is difficult because there are conflicting hypotheses as to whether bridging occurs mainly within the Golgi system, concurrently with secretion or within the cell wall. We therefore explored the kinetics of RG-II bridging.<h4>Methods</h4>Cell-suspension cultures of Rosa and arabidopsis were pulse-radiolabelled with [14C]glucose, then the boron bridging status of newly synthesized [14C]RG-II domains was tracked by polyacrylamide gel electrophoresis of endo-polygalacturonase digests.<h4>Key results</h4>Optimal culture ageAnnals of botanyBoron bridging of rhamnogalacturonan-II in Rosa and arabidopsis cell cultures occurs mainly in the endo-membrane system and continues at a reduced rate after secretion.PMC9670748BB/H000690/1BDCS-2016-64Fry SCBegum RAfalseBoron bridging of rhamnogalacturonan-II in Rosa and arabidopsis cell cultures occurs mainly in the endo-membrane system and continues at a reduced rate after secretion.<h4>Background and aims</h4>Rhamnogalacturonan-II (RG-II) is a domain of primary cell-wall pectin. Pairs of RG-II domains are covalently cross-linked via borate diester bridges, necessary for normal cell growth. Interpreting the precise mechanism and roles of boron bridging is difficult because there are conflicting hypotheses as to whether bridging occurs mainly within the Golgi system, concurrently with secretion or within the cell wall. We therefore explored the kinetics of RG-II bridging.<h4>Methods</h4>Cell-suspension cultures of Rosa and arabidopsis were pulse-radiolabelled with [14C]glucose, then the boron bridging status of newly synthesized [14C]RG-II domains was tracked by polyacrylamide gel electrophoresis of endo-polygalacturonase digests.<h4>Key results</h4>Optimal culture age2022-01-01T00:00:00Z2022 Nov2025-04-04T00:36:39.843Z2024-11-20T21:59:33.135ZS-EPMC96707483611202110.1093/aob/mcac119