Journal
PLANT PHYSIOLOGY
Volume 178, Issue 3, Pages 1045-1064Publisher
OXFORD UNIV PRESS INC
DOI: 10.1104/pp.18.00584
Keywords
-
Categories
Funding
- Natural Sciences and Engineering Research Council of Canada (NSERC PGS-D3)
- Deutsche Forschungsgemeinschaft [US98/13-1]
- Ministry of Innovation, Science, and Research of North-Rhine Westphalia [313/323-400-00213]
- BioEnergy Science Center Grant [DE-PS02-06ER64304]
- Center for Bioenergy Innovation
- Office of Biological and Environmental Research in the Department of Energy's Office of Science
- Department of Energy Center Grant [DE-SC0015662]
- U.S. National Institutes of Health [P41GM103390, P01GM107012]
- NSF Plant Genome Program [DBI-0421683]
- NATIONAL INSTITUTE OF GENERAL MEDICAL SCIENCES [P01GM107012, P41GM103390] Funding Source: NIH RePORTER
Ask authors/readers for more resources
Pectin is a vital component of the plant cell wall and provides the molecular glue that maintains cell-cell adhesion, among other functions. As the most complex wall polysaccharide, pectin is composed of several covalently linked domains, such as homogalacturonan (HG) and rhamnogalacturonan I (RG I). Pectin has widespread uses in the food industry and has emerging biomedical applications, but its synthesis remains poorly understood. For instance, the enzymes that catalyze RG I elongation remain unknown. Recently, a coexpression- and sequence-based MUCILAGE-RELATED (MUCI) reverse genetic screen uncovered hemicellulose biosynthetic enzymes in the Arabidopsis (Arabidopsis thanana) seed coat. Here, we use an extension of this strategy to identify MUCI70 as the founding member of a glycosyltransferase family essential for the accumulation of seed mucilage, a gelatinous wall rich in unbranched RG I. Detailed biochemical and histological characterization of two muci70 mutants and two galacturonosyltransferase11 (gaut11) mutants identified MUCI70 and GAUT11 as required for two distinct RG I domains in seed mucilage. We demonstrate that, unlike MUCI70, GAUT11 catalyzes HG elongation in vitro and, thus, likely is required for the synthesis of an HG region important for RG I elongation. Analysis of a muci70 gaut11 double mutant confirmed that MUC170 and GAUT11 are indispensable for the production and release of the bulk of mucilage RG I and for shaping the surface morphology of seeds. In addition, we uncover relationships between pectin and hemicelluloses and show that xylan is essential for the elongation of at least one RG I domain.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available