In the grass species Brachypodium distachyon, the production of mixed-linkage (1,3;1,4)-β-glucan (MLG) occurs in the Golgi apparatus
- Michigan State Univ., East Lansing, MI (United States). Great Lakes Bioenergy Research Center
- Michigan State Univ., East Lansing, MI (United States). Great Lakes Bioenergy Research Center; Michigan State Univ., East Lansing, MI (United States). Dept. of Plant Biology
- Michigan State Univ., East Lansing, MI (United States). Great Lakes Bioenergy Research Center; Michigan State Univ., East Lansing, MI (United States). Dept. of Biochemistry & Molecular Biology; Michigan State Univ., East Lansing, MI (United States). Dept. of Plant Biology
- Michigan State Univ., East Lansing, MI (United States). Great Lakes Bioenergy Research Center; Michigan State Univ., East Lansing, MI (United States). MSU-DOE Plant Research Lab.; Michigan State Univ., East Lansing, MI (United States). Dept. of Biochemistry & Molecular Biology
- Michigan State Univ., East Lansing, MI (United States). Great Lakes Bioenergy Research Center; Michigan State Univ., East Lansing, MI (United States). MSU-DOE Plant Research Lab.; Michigan State Univ., East Lansing, MI (United States). Dept. of Plant Biology
Summary Mixed‐linkage (1,3;1,4)‐β‐glucan ( MLG ) is a glucose polymer with beneficial effects on human health and high potential for the agricultural industry. MLG is present predominantly in the cell wall of grasses and is synthesized by cellulose synthase‐like F or H families of proteins, with CSLF 6 being the best‐characterized MLG synthase. Although the function of this enzyme in MLG production has been established, the site of MLG synthesis in the cell is debated. It has been proposed that MLG is synthesized at the plasma membrane, as occurs for cellulose and callose; in contrast, it has also been proposed that MLG is synthesized in the Golgi apparatus, as occurs for other matrix polysaccharides of the cell wall. Testing these conflicting possibilities is fundamentally important in the general understanding of the biosynthesis of the plant cell wall. Using immuno‐localization analyses with MLG ‐specific antibody in Brachypodium and in barley, we found MLG present in the Golgi, in post‐Golgi structures and in the cell wall. Accordingly, analyses of a functional fluorescent protein fusion of CSLF 6 stably expressed in Brachypodium demonstrated that the enzyme is localized in the Golgi. We also established that overproduction of MLG causes developmental and growth defects in Brachypodium as also occur in barley. Our results indicated that MLG production occurs in the Golgi similarly to other cell wall matrix polysaccharides, and supports the broadly applicable model in grasses that tight mechanisms control optimal MLG accumulation in the cell wall during development and growth. This work addresses the fundamental question of where mixed linkage (1,3;1,4)‐β‐glucan (MLG) is synthesized in plant cells. By analyzing the subcellular localization of MLG and MLG synthase in an endogenous system, we demonstrated that MLG synthesis occurs at the Golgi in Brachypodium and barley. A growth inhibition due to overproduced MLG in Brachypodium supports the general applicability of the model that a tight control of the cell wall polysaccharides accumulation is needed to maintain growth homeostasis during development.
- Research Organization:
- Michigan State Univ., East Lansing, MI (United States). Great Lakes Bioenergy Research Center
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- SC0018409; FC02-07ER64494; FG02-91ER20021; DE‐FG02‐91ER20021
- OSTI ID:
- 1459435
- Alternate ID(s):
- OSTI ID: 1424806
- Journal Information:
- The Plant Journal, Vol. 93, Issue 6; ISSN 0960-7412
- Publisher:
- Society for Experimental BiologyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Post-Golgi Trafficking and Transport of Cell Wall Components
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journal | December 2018 |
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