The Golgi apparatus of plant cells is the site of assembly of glycoproteins, proteoglycans, and complex polysaccharides, but little is known about how the different assembly pathways are organized within the Golgi stacks. To study these questions we have employed immunocytochemical techniques and antibodies raised against the hydroxyproline-rich cell wall glycoprotein, extensin, and two types o...

The pathway of hydroxyproline-containing proteins to the cell wall, and to the growth medium in suspension-cultured Acer pseudoplatanus cells is traced by following the kinetics of the transfer of protein-bound (14)C-hydroxyproline into various fractions, and by comparing the hydroxyproline-arabinoside profiles of these fractions after alkaline hydrolysis.Hydroxyproline-rich protein passes dire...

The green algae represent a large group of morphologically diverse photosynthetic eukaryotes that occupy virtually every photic habitat on the planet. The extracellular coverings of green algae including cell walls are also diverse. A recent surge of research in green algal cell walls fueled by new emerging technologies has revealed new and critical insight concerning these coverings. For examp...

Abundant microtubules (MTs) were present both in protoplasts isolated from tobacco BY-2 cells and on membrane ghosts prepared from such protoplasts. However, only a few MTs or none at all were observed on membrane ghosts prepared from protoplasts pretreated with protease, trypsin or chymotrypsin, although abundant MTs were present in protease-pretreated protoplasts. These observations suggest t...

ABSTRACT A light sphagnum peat mix inoculated with Trichoderma hamatum 382 consistently provided a significant (P = 0.05) degree of protection against bacterial spot of tomato and its pathogen Xanthomonas euvesicatoria 110c compared with the control peat mix, even though this biocontrol agent did not colonize aboveground plant parts. To gain insight into the mechanism by which T. hamatum 382 in...

Graminaceous monocots generally contain low levels of hydroxyproline-rich Glycoproteins (HRGPs). As HRGPs are often at the cell surface, we used the intact cell elution technique (100 millimolar AlCl(3)) to isolate soluble surface proteins from Zea mays cell suspension cultures. Further fractionation of the trichloroacetic acid-soluble eluate on the cation exchangers phospho-cellulose and BioRe...

The biological conversion of cellulosic biomass to biofuel is hindered by cell wall recalcitrance, which can limit the ability of cellulases to access and break down cellulose. The purpose of this study was to investigate whether hydroxyproline-rich cell wall proteins (extensins) are present in poplar stem biomass, and whether these proteins may contribute to recalcitrance. Three classical exte...