Immunolocalization of LeAGP-1, a modular arabinogalactan-protein, reveals its developmentally regulated expression in tomato.
Arabinogalactan-proteins (AGPs) are highly glycosylated cell surface proteins that are thought to function in plant growth and development. The developmentally regulated expression of LeAGP-1, a novel and major AGP in tomato, was examined in different organs and tissues of tomato (Lycopersicon esculentum Mill. cv. UC82B) plants with an anti-peptide antibody (i.e. the PAP antibody) directed specifically against the lysine-rich subdomain of the LeAGP-1 core protein. During cell differentiation in tomato plants, LeAGP-1 was associated with cell wall thickening and lignification of particular cell types. Specifically, LeAGP-1 was detected in secondary wall thickenings of maturing metaxylem and secondary xylem tracheary elements in roots and stems, and in thickened cell walls of phloem sieve elements. However, LeAGP-1 was also present in thin-walled, cortical parenchyma cells of seedling roots as well as thick-walled collenchyma cells in young stems, both of which are not lignified. Based on these observed patterns, possible roles for LeAGP-1 in plant growth and development are discussed.
Gao
M
M
Department of Environmental and Plant Biology, Ohio University, Athens 45701-2979, USA.
Showalter
A M
AM
D015153:Blotting, Western; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D007150:Immunohistochemistry; D018551:Solanum lycopersicum / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D008854:Microscopy, Electron; D009088:Mucoproteins / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D010940:Plant Proteins / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D018514:Plant Structures / Q000378:metabolism / Q000648:ultrastructure
D009088:Mucoproteins; D010940:Plant Proteins; C006619:arabinogalactan proteins