Cytokinesis partitions the cell by a cleavage furrow in animals but by a new cross wall in plants. How this new wall assembles at the molecular level and connects with the mother cell wall remains unclear. A lethal Arabidopsis embryogenesis mutant designated root-, shoot-, hypocotyl-defective (rsh) provides some clues: RSH encodes extensin AtEXT3, a structural glycoprotein located in the nascen...

Membranes from tobacco cell suspension cultures were used as antigens for the preparation of monoclonal antibodies. Use of solid phase and indirect immunofluorescence assays led to the identification of hybridomas producing antibodies directed against cell surface epitopes. One of these monoclonal antibodies (11.D2) was found to recognize a molecular species which on two-dimensional analysis (u...

In dark grown pea (Pisum sativum) seedlings ethylene causes the triple response in which elongation growth is inhibited, radial growth is promoted, and orientation of shoots to gravity is altered. The distribution of extensin and peroxidase activity in pea epicotyls upon ethylene treatment was studied by tissue printing on nitrocellulose paper. It was found that the localization of extensin and...

Grapevine (Vitis vinifera cv. Touriga) callus cell walls contain a high level of the monomeric extensin, GvP1. Hydrogen peroxide stimulus of these cultures causes the rapid loss of monomeric GvP1, concomitant with marked increases in insoluble GvP1 amino acids and wall resistance to digestion by fungal lytic enzymes. JIM11 immunolocalization studies indicated that monomeric and network GvP1 wer...

Extensin, a major hydroxyproline (Hyp)-rich glycoprotein in walls of cultured cells of dicotyledonous plants, is very difficult to solubilize. To learn about the nature of the insolubilization, we have tested the ability of a variety of selective hydrolytic methods, and combinations of them, to liberate extensin or fragments of extensin from suspension-culture cell walls. After the complete deg...

Abbreviations. AGP, arabinogalactan protein; EGFP, enhanced green fluorescent protein; GPI, glycosylphosphatidylinositol; GAGP, gum arabic glycoprotein; GT, glycosyltransferase; HRGP, hydroxyproline rich-glycoprotein; LeAGP1, arabinogalactan protein 1 from tomato; Lys, lysine rich domain; P4H, prolyl-4-hydroxylase; (SP), serine-proline repeat; (VP), valine-proline repeats; (TP), threonine-proli...

The tobacco extensin gene Ext 1.4 is expressed in cells submitted to mechanical constraints and in cells proliferating under hormone control

Plant lodging resistance is an important integrative agronomic trait of grain yield and quality in crops. Although extensin proteins are tightly associated with plant cell growth and cell wall construction, little has yet been reported about their impacts on plant lodging resistance. In this study, we isolated a novel extensin-like (OsEXTL) gene in rice, and selected transgenic rice plants that...

We have searched the Arabidopsis and rice (Oryza sativa) genomes for homologs of LRX1, an Arabidopsis gene encoding a novel type of cell wall protein containing a leucine-rich repeat (LRR) and an extensin domain. Eleven and eight LRX (LRR/EXTENSIN) genes have been identified in these two plant species, respectively. The LRX gene family encodes proteins characterized by a short N-terminal domain...