Transport of UDP-rhamnose by URGT2, URGT4, and URGT6 modulates rhamnogalacturonan-I length

• DOI: 10.1093/plphys/kiaa070
• Publication Date: 2021-01-01T04:12:43Z
• Authors: Susana Saez-Aguayo; Juan Pablo Parra-...; Pablo Sepúlveda-O...; Jonathan Celiz-Ba...; Verónica Arenas-M...; Christine Sallé; Hernán Salinas-Gr...; Asier Largo-Gosens; Helen M North; Marie-Christine R...; Ariel Orellana
• Keywords: Mucilage; Rhamnose

Abstract Rhamnogalacturonan-I biosynthesis occurs in the lumen of Golgi apparatus, a compartment where UDP-Rhamnose and UDP-Galacturonic Acid are main substrates for synthesis backbone polymer pectin. Recent studies showed that UDP-Rha is transported from cytosol into apparatus by family six UDP-rhamnose/UDP-galactose transporters (URGT1-6). In this study, analysis adherent soluble mucilage (SM) Arabidopsis thaliana seeds revealed distinct roles URGT2, URGT4, URGT6 biosynthesis. Characterization SM size shorter chains urgt2 urgt4 urgt6 mutants, suggesting URGT2 URGT4 mainly involved (RG-I) elongation. Meanwhile, mutants exhibited changes only (AM). Surprisingly, estimated number RG-I present was higher than wild-type. Interestingly, increased accompanied an amount xylan. urgt expression other genes some compensation. Studies transcription factors regulating formation indicated likely part gene network controlled these regulators synthesis. These results suggest play different mucilage, lack all three affects production polymers longer xylan domains.