callose


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cal·lose

(kal'ōs),
A linear 1,3-β-d-glucan formed by certain enzymes from UDP-glucose, differing from cellulose (a β-1,4-glucan formed from GDP-glucose) and starch amylose (an α-1,4-glucan formed from ADP-glucose). Found in certain plant cell walls.

callose

a thick CARBOHYDRATE plant material deposited in the pores of sieve plates in response to damage, disease or simply over a period of time, resulting in a blockage of the SIEVE TUBE. Callose is also present in the walls of fungal hyphae.
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References in periodicals archive ?
Exposure to heavy metal stress regulates intercellular signaling via callose deposition and breakdown.
We will investigate how the cell wall glycan callose at the neck of PD is both integrated with the surrounding cell wall molecular architectures involving pectins, xyloglucans and cellulose microfibrils and also how modulations of callose levels (known to impact on PD transport) are orchestrated with the surrounding cell wall glycans to control PD mechanical properties.
Petiole 5-9 mm long, glabrous; leaf blade narrowly ovate, 5-6(-11) x 1.8-2.2(-2.8) cm, 3-4 times as long as wide, thick, glabrous on both surfaces, glaucescent on the lower surface, base obtuse to round, slightly asymmetric, apex acute to acuminate, margin subentire, with 5-12 callose, white (in vivo) intramarginal teeth evenly distributed on each side, main vein prominulous above, impressed beneath, second and higher order veins inconspicuous except by the 5-6 pairs of secondary veins slightly prominulous on the upper surface, submarginal vein lacking.
The presence of galactooligosaccharides, cellulose, lignin, and callose in the cambium is very favorable for growth of bacterial phylum Firmicutes that predominates in summer time.
Previous study was applied on Tetraploid Red Clover (Trifolium pratense L.) pollen which showed present abnormalities pollen tube as bifurcated monosphonic pollen tube, pollen tube with a wavy structure, pollen tube due to cytoplasm deposition and wall swelling, pollen tube with thickened walls, pollen tube with callose formation at its tips and Callose plugs formed in pollen tube cytoplasm, but this research did not mention percentage of each type.
Peterson, "A berberine-aniline blue fluorescent staining procedure for suberin, lignin, and callose in plant tissue," Protoplasma, vol.
Multi-membrane spanning Gts (cellulose and callose synthases) are typically associated with the plasma membrane, while both Gts classes type II and multimembrane spanning have been found in Golgi stacks where they are likely involved in the biosynthesis of complex [beta]-glycan polymers [7-9].
The first barrier against the entering of heavy metals, especially regarding root level, is the immobilization of heavy metals in the cell wall and by extracellular carbohydrates, such as mucilage and callose (FRITZ, 2007; KARTEL et al., 1999), avoiding the presence of free ions in root tissues and, consequently, the translocation of ions to shoots, thereby reducing phytotoxicity.
Jones D, Blancaflor E, Kochian L, Gilroy S (2006) Spatial coordination of aluminium uptake, production of reactive oxygen species, callose production and Wall rigidification in maize roots.
2B), male also with a pair of yellow callose spots close to posterior margin of sternite VIII.