Unlike animals, which breathe through airways lined with pathogen-trapping defenses, plants get air through tiny pores in their leaves that all but invite bacteria to sneak in. How, then, do plants keep them out? They slam their pores, or stomata, shut. Stomata are flanked by guard cells that swell when triggered by bacteria, thus closing the pores. Besides being fascinating in its own right, t...

Stomatal development is tightly regulated through internal and external factors that are integrated by a complex signalling network. Light represents an external factor that strongly promotes stomata formation. Here, we show that auxin-resistant aux/iaa mutants, e.g. axr3-1, exhibit a de-repression of stomata differentiation in dark-grown seedlings. The higher stomatal index in dark-grown axr3-...

Stomata enable gaseous exchange between the interior of the leaf and the atmosphere through the stomatal pore. Control of the pore aperture depends on osmotic solute accumulation by, and its loss from the guard cells surrounding the pore. Stomata in most plants are separated by at least one epidermal cell, and this spacing is thought to enhance stomatal function, although there are several gene...

In order to engage in photosynthesis, plant leaves absorb CO2 via the opening of pores in their surfaces called stomata. Water evaporates through open stomata, however, which is a detriment to plant function. Thus a plant will seek a stomatal aperture that balances its need for CO2 with its aversion to H2O loss. In order to visualize a particular leaf’s stomatal aperture, an experimentalist inj...

Stomata of corn (Zea mays L.) and sorghum (Sorghum bicolor L.) responded to changes in leaf water potential during the vegetative growth phase. During reproductive growth, leaf resistances were minimal and stomata were no longer sensitive to bulk leaf water status even when leaf water potentials approached -27 bars. Stomata of corn, cotton (Gossypium hirsutum L.), and sorghum appear to respond ...

1. GREGORY, F. G., F. L. MILTHROPE, H. L. PEARSE, and H. J. SPENCER. 1950. Experimental studies of the factors controlling transpiration. II. The relation between transpiration and leaf water content. Jour. Exp. Bot. 1: 15-28. 2. HAFEZ, M. G. A. 1958. Effects of rosemary and thyme oil vapors on the stomata of cherry laurel. Plant Physiol. 33: 181-185. 3. HAFEZ, M. G. A. and M. B. YOUNIS. 1960. ...

In leaves of barley (Hordeum vulgare), as previously found with oats (Avena sativa), a group of six antibiotics that interfere in different ways with the sequence DNA --> mRNA --> protein all delay senescence in the dark, acting to conserve chlorophyll (Chl) and protein and also to open the stomata. Among the active compounds is chloramphenicol, which had previously been reported to act only on...

Although changes in stomatal response to elevated doses of cadmium has already been observed several plants, few studies have focused on this phenomenon more detail. The effects different Cd2+ (50 and 100 mg.kg-1 soil) leaf area characteristics (number stomata, number epidermal cells, index size stomata) faba bean (Vicia L. cultivar Aštar) were studied after 15 days heavy metal treatment. No vi...

Stomata consist of two guard cells around a pore and act as turgor-operated valves for gas exchange. Arabidopsis stomata develop from one or more asymmetric divisions followed by the symmetric division of the guard mother cell. Stomatal number is partly a function of the availability of smaller epidermal cells that are competent to divide asymmetrically. Stomata are spaced apart from each other...