BACKGROUND AND AIMS The pattern of callose deposition was followed in developing stomata of the fern Asplenium nidus to investigate the role of this polysaccharide in guard cell (GC) wall differentiation and stomatal pore formation. METHODS Callose was localized by aniline blue staining and immunolabelling using an antibody against (1 --> 3)-beta-d-glucan. The study was carried out in stomata...

Seaton, D. (1974). Thorax, 29, 595-598. Primary diaphragmatic haemangiopericytoma. Haemangiopericytomas are tumours consisting of vascular spaces surrounded by proliferating pericytes. Since this neoplasm was first described (Stout and Murray, 1942) over 300 cases have been reported. All tumours of the diaphragm are rare, and a primary diaphragmatic haemangiopericytoma has not been previously r...

The barley leaf rust fungus forms appressoria over host leaf stomata and penetrates via the stomatal pore. High levels of avoidance to leaf rust fungi have been described in some wild accessions of Hordeum species where a prominent wax layer on the stomata inhibits triggering of fungal appressorium differentiation. Leaf rust avoidance has not yet been found in H. vulgare. Since cuticular leaf w...

In vivo oxygen evolution above single stomata in Brassica juncea has been used to investigate, for the first time, the effect of Cd-induced stress as imaged by scanning electrochemical microscopy (SECM). SECM images showed a clear stomatal structure-a pore, whose aperture is modulated by two guard cells, serving as the conduit for the oxygen produced. Lower stomatal density and larger stoma siz...

In plant post-embryonic epidermis mitogen-activated protein kinase (MAPK) signaling promotes differentiation of pavement cells and inhibits initiation of stomata. Stomata are cells specialized to modulate gas exchange and water loss. Arabidopsis MAPKs MPK3 and MPK6 are at the core of the signaling cascade; however, it is not well understood how the activity of these pleiotropic MAPKs is constra...

Using quantitative histochemical techniques, the carbohydrate levels of guard cells from open and closed stomatal apparatus of Vicia faba L. were compared. To minimize experimental error, all comparisons were between leaflets of the same pair. Stomata on one leaflet were caused to open by light and reduced CO(2). The other leaflet, which was in darkness, had closed stomata. In one experiment, d...

Endoparasitism by gall-forming insects dramatically alters the plant phenotype by altering growth patterns and modifying plant organs in ways that appear to directly benefit the gall former. Because these morphological and physiological changes are linked to the presence of the insect, the induced phenotype is said to function as an extension of the parasite, albeit by unknown mechanisms. Here ...

Green light reversal of blue light-stimulated stomatal opening was discovered in isolated stomata. The present study shows that the response also occurs in stomata from intact leaves. Arabidopsis thaliana plants were grown in a growth chamber under blue, red and green light. Removal of the green light opened the stomata and restoration of green light closed them to baseline values under experim...

Flooding the intercellular air spaces of leaves with water was shown to cause rapid closure of stomata in Tradescantia pallida, Lactuca serriola, Helianthus annuus, and Oenothera caespitosa. The response occurred when water was injected into the intercellular spaces, vacuum infiltrated into the intercellular spaces, or forced into the intercellular spaces by pressurizing the xylem. Injecting 50...