• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.3
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• pp.267-274
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• 1984

This experiment was carried out to investigate the stomatal aperture of wheat variety 'Chokwang' grown in the two different nitrogen level. Stomatal aperture was measured at the maximal tillering, shooting, booting, flowering and grain filling stages. Stomatal aperture in leaf blades gradually increased in accordance with the successive leaf growth. The maximal opening of stomata was observed at flowering stage and around noon in a day, but stomata closed around six o'clock in the afternoon. Stomata opened wider in the high nitrogen application than in the low nitrogen and their effects were the highest at the booting and flowering stage. Diurnal course at stomatal aperture of upper leaves was wider than that of lower leaves regardless of growth stages. Positive correlation (r=0.66$^{**}$) appeared between nitrogen content in leaf blades and stomatal aperture. The leaves of low position and the developing leaves showed smaller stomatal aperture than the full expanded top leaves irrespective of leaf stages. Water content of leaf, root weight and root activity were increased by the nitrogen application and thus considered as factors increase the stomatal aperture.ication and thus considered as factors increase the stomatal aperture.

• Asian Journal of Turfgrass Science
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• v.11 no.1
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• pp.23-31
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• 1997

The K+ and Na+ contents in the guard cells of Agave which had a characteristic of CAM plant were measured by using "Rolling technique". That results were correspond with the change of the stomatal aperture width. That is to say, stomatal movement of Agave is due to the change of K+and Na+ concentration in the guard cells. As Agave which was used in this experiment showed two peaks of which one was at 3 hour and the other was at 24 hour in stomatal aperture width, it was seemed that Agave had both characteristics of CAM and $C_3$pattern.

• Journal of Environmental Science International
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• v.4 no.4
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• pp.15-15
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• 1995

ABA and SA showed different effect on stomatal closing on same condition. The addition of 1 M salicylic acid to fully opened stomata resulted in a significant reductionn of 22 % in stomatal aperture. However, 1 mM ABA reduced 73 % of stomatal aperture. The light absorption spectra of the salicylic acid solution showed that SA was degraded within 1 hour. Therefore, SA solution was resupplied % the detached epidermis every 30 min. during incubation and it was found that even at 10 $mu$M SA induced stomatal closing significantly. Its effect was also greatly pH dependent. The reduction of stomatal aperture caused by 1 mM SA was most effective at lower pH (pH 7.2, 5 %: pH 6.2, 40 %; pH 5.2, 78 %). Therefore, if SA was properly treated to the epidermal strips in the medium, the effects of SA on stomatal closing were similar with those of ABA.

• Journal of Environmental Science International
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• v.4 no.4
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• pp.317-321
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• 1995

ABA and SA showed different effect on stomatal closing on same condition. The addition of 1 M salicylic acid to fully opened stomata resulted in a significant reductionn of 22 % in stomatal aperture. However, 1 mM ABA reduced 73 % of stomatal aperture. The light absorption spectra of the salicylic acid solution showed that SA was degraded within 1 hour. Therefore, SA solution was resupplied % the detached epidermis every 30 min. during incubation and it was found that even at 10 $\mu$M SA induced stomatal closing significantly. Its effect was also greatly pH dependent. The reduction of stomatal aperture caused by 1 mM SA was most effective at lower pH (pH 7.2, 5 %: pH 6.2, 40 %; pH 5.2, 78 %). Therefore, if SA was properly treated to the epidermal strips in the medium, the effects of SA on stomatal closing were similar with those of ABA.

• Korean Journal of Environmental Biology
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• v.20 no.1
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• pp.78-84
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• 2002

The effects of light and darkness on stomatal aperture and guard cell apoplastic pH in the intact leaf and in the isolated epidermal strips of Commelina communis have been investigated. Stomata in the intact leaf opened wide in the light. In contrast, stomata in the isolated epidermal strips did not respond clearly to light. To eucidate the relationship between the stomatal aperture and the guard cell apoplastic pH, apoplastic pH was measured. In the light the guard cell wall of intact leaf was acidified by pH 1.9 units, falling from pH 7.3 to pH 5.4 in the first 10 minutes. On the contrary, apoplastic pH of isolated epidermal strips changed slowly from pH 7.3 to pH 6.9 at 20 min. Stomata in the intact leaf closed rapidly in the dark. On the other hand, stomata in the isolated epidermal strips failed to close in dark. There was a slow increase in apoplastic pH on transfer to the dark after incubation for 1.5 h in the light and the level observed before the experiment was regained after around 40 min. When the isolated epidermal strips were transferred to the dark, apoplastic pH maintained a uniform level of around pH 7.2-7.4. These results indicate that the mechanism of stomatal opening and closing from isolated epidermal strips and intact leaves could be different.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.1
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• pp.33-38
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• 1985

This experiment was carried out to study in stomatal behaviour of wheat (Chokwang) upon the different soil water potentials, lodging and two different nitrogen treatment. Stomatal aperture was measured at flowering stage under diurnal course with two hour intervals, Stomatal apertures were differently changed according to soil water potentials and leaf position on the stem, showing the rapid closure of stomata at low soil water potential and the narrow opening at low leaf position of stem. Wider stomatal opening appeared at the plot of optimal nitrogen application than that of low nitrogen. It was greatly decreased in opening of stomata at plants lodged, appearing that plant investigated of six days after lodging showed less than 50% than that normal plants, which indicated peculiar decrease of low leaf position of stem at afternoon of diurnal course.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.2
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• pp.130-136
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• 1982

Experiments were conducted to establish a measuring method of the stomatal aperture in the leaves of the wheat plant, and to find the diurnal movements of the stomate in leaves of different position and tillers. The measurement methods used were the infiltration and the microrelief impression methods. The aperture of the stomate in the infiltration method was expressed in terms of the solutions pent ration into the leaf and this was refered to as the infiltration score. A score I represents injection with 10% iso-butyl alcohol＋90% ethylene glycol solution and a score 7 represents injection with 70% iso-butyl alcohol +30% ethlene glycol solution. A linear relationship was obtained between the infiltration score and average pore width in a large number. of the stomata observed in the leaves of the adaxial and abaxial epidermis. The aperature of the stomate of flag and the 1st leaf were exhibited diurnal change with the maximum aperture at 10 A.M. but that of 2nd leaf reached maximum aperture 2 hours later than upper two leaves. After reaching the maximum aperture the stomata gradually closed and then completely closed at 6 P.M. The aperture of the stomate in the adaxial epidermis and the base part of the leaf were larger than those in the abaxial and top part of the leaf, and aperture of the stomate in the leaves of the main stem was larger than those on the tillers.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.4
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• pp.307-314
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• 1984

One hundred winter wheat cultivars obtained from the world collections in Korea were planted in 1982. Stomatal frequency of flag leaf of these cultivars were measured, and among these 21 cultivars which showed different stomatal frequency were selected to investigate the relationship of their stomatal frequencies and other characters such as culm length, heading date and characters related to leaf. Stomatal frequency of flag leaf of 100 cultivars different significantly, ranging from 51 to 90 stomata mm$^{-2}$ for the adaxial and 35 to 65 for the abaxial surfaces of leaf. Stomatal frequency was always greater on the adaxial than on the abaxial surface. Mean ratios (adaxial/abaxial) were 1.5 for the flag leaf and 1.3 for the from second to fouth leaves. Among 21 cultivars examined, stomatal size which measured guard cell length varied from 38.5 to 46.6$\mu$ for adaxial surface and from 39.4 to 49.4$\mu$ for abaxial. A negative correlation was obtained between stomatal frequency and its size. Stomatal frequency decreased from flag (L$_1$) to lower leaves, progresively. Stomatal frequency on L$_1$ sheath was compared to those on L$_3$ and L$_4$ abaxial surface of leaf. More stomatal frequency on top and center of adaxial surface showed than that on basal part of a leaf but the abaxial surface resulted in reverse of adaxial one. Cultivars with high stomatal frequency on flag leaf showed higher stomatal frequency on the other leaves and sheaths. Positive correlation between stomatal frequency and other characters such as, culm length, heading date and chlorophyll content showed statistical significance, whearas it revealed the negative correlation of stomatal frequency with leaf weight, leaf area and stomatal aperture. However, no relation appeared between stomatal frequency and leaf vein.

• Journal of Environmental Science International
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• v.23 no.5
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• pp.763-770
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• 2014

The effect of $CO_2$ on the opening of stomata in the intact leaf of Commelina communis has been investigated. Full opening of stomatal apertures(around $18{\mu}m$) was achieved in the intact leaf by addition of $CO_2$($900{\mu}mol\;mol^{-1}$). At 90 minutes, the stomatal apertures of leaves treated with $CO_2$ free air were reduced. In contrast, stomata opened most widely with the treatment of $CO_2$ air at 90 minutes. The effects of light, $CO_2$ air and $CO_2$ free air on the change of membrane potential difference(PD) were measured. Fast hyperpolarization of guard cell membrane PD was recorded reaching up to -12 mV in response to light. If $CO_2$ free air was given firstly, there was no response. When light was given after $CO_2$ free air, the light effect was very clear. At the onset of $CO_2$ air, the PD showed a dramatic hyperpolarization to about -25 mV. Changes in the pH of apoplast in intact leaves in response to $CO_2$ air were observed. $CO_2$ air caused a change of 0.4 pH unit. Therefore, it can be hypothesized that $CO_2$ flowing could stimulate proton efflux which is a necessary precursor of stomatal opening.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.3 no.2
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• pp.121-129
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• 1999

Photosynthesis and transpiration rates were simultaneously measured in attached sunflower leaves(Helianthus annuusL. cv. Russian Mammoth) during exposure to $NO_2$ and $O_3$ to determine the effect of mixed gan on photosynthesis and the stomatal aperture. The application of $O_3$ alone reduced both the net photosynthetic and transpiration rates. An analysis of the $CO_2$ diffusive resistances indicated that the main cause affecting photosynthesis reduction during $O_3$ exposure was not the internal gas phase of the leaf $(rCO_2^{liq})$ but rather the liquid phase or mesophyll diffusive resistance $(rCO_2^{liq})$, suggesting that there is a very concomitant relation between photosynthetic reduction and $rCO_2^{liq}$. The application of NO2 alone caused a marked reduction of the net photosynthesis yet no significant reduction of transpiration, indicating that NO2 affects the $CO_2$ fixation processes with no inluence on the stomatal aperture. A greter reduction in the photosynthesis of sunflower plants was caused by the application of $NO_2$ alone as compared to a combination of $NO_2$ and $O_3$. $NO_2$ alone reduced the photosynthetic rate by 90%, whereas a mixture of NO2 and O3 reduced it by 50%.