Stomatal opening

Laisk, A., Oja, V. Kull, K. (1980). Statistical distribution of stomatal apertures of Vicia faba and Hordeum vulgare and Spannungsphase of stomatal opening. Journal of Experimental Botany, 31, 49-58. 

The reported (14) mechanisms of action of allelochemlcals Include effects on root ultrastructure and subsequent Inhibition of Ion absorption and water uptake, effects on hormone-induced growth, alteration of membrane permeability, changes In lipid and organic acid metabolism, inhibition of protein synthesis and alteration of enzyme activity, and effects on stomatal opening and on photosynthesis. Reduced leaf water potential Is one result of treatment with ferulic and p-coumaric acids (15). Colton and Einhellig (16) found that aqueous extracts of velvetleaf (Abutllon theophrastl Medic.) Increased diffusive resistance In soybean fGlycine max. (L.) Merr.] leaves, probably as a result of stomatal closure. In addition, there was evidence of water stress and reduced quantities of chlorophyll In Inhibited plants. 

Hwang J-U, Suh SS, Yi H, Kim J, Lee Y. Actin filaments modulate both stomatal opening and inward K+ channel activities in guard cells of Vidafaba. Plant Physiol 1997 115 335-342. 

Stomatal closure was associated with a genetic factor in onion wherein the stomata of sensitive plants did not close. The effect of ozone and PAN on stomatal opening depends on many interacting factors those representing water stress appear to be the most important. Dean related stomatal density to the difference in sensitivity between two tobacco cultivars. Evans and Ting found that maximal sensitivity of bean primary leaves was not associated with changes in stomatal number or leaf resistance. Ozone exposure caused a decrease in relative water content, but no change in resistance. Bean leaf sensitivity seemed more a function of internal activities. 

Todd and Todd and Probst also measured the effects of ozone (at 4 ppm for 40 min) on photosynthesis and found that development of symptoms was associated with inhibition of carbon dioxide fixation. This effect was also confirmed by Macdowall, who reported that the inhibition of photosynthesis was greater than that which could be accounted for by chlorophyll destruction. Hill and Littlefield associated decreased net photosynthesis caused by ozone (at 0.06 ppm for 1 h) with both stomatal opening and rates of transpiration. These studies have generally shown that net photosynthesis can decrease without visible injury. 

There is no reason to believe that stomatal opening is different in leaves of different ages, so the entry of PAN into the intercellular spaces of the leaf is probably the same as the entry of ozone. One can hypothesize that the chemical composition of the leaf is such that resistance is conferred at particular physiologic states. Such a hypothesis would lead to a search for compounds that combat the oxidizing and acylating properties of PAN. 

In some plants, high PEPCase activities have been detected in specialised tissues or cells, other than the mesophyll cells of C4 and CAM plants. For example, PEPCase is found in guard cells where it is involved in stomatal opening and closing (Tarczynski Outlaw, 1990). The authors concluded, however, that - based on the alterations in chemical environment during stomatal activity - the reactions catalysed could be accomplished by a C3-type PEPCase enzyme and that there was no reason to invoke the existence of isoforms. Less well known is the PEPCase activity and protein detected in reproductive tissues. For example, high PEPCase activity has been observed in seed pods of chickpeas (Singh,... 

Adams, D.R. Voillequ6, P.G. (1971) Effect of stomatal opening on the transfer of 131I2 from air to grass. Health Physics, 21, 771-5. 

The lack of understanding of the effect of these substances on whole plant photosynthetic processes (e.g. changes in stomatal opening, membrane permeability, water content, or many other processes that affect the overall photosynthetic process). However, from the available information, an attempt has been... 

At this stage, it is not clear how the growth substances affect the stomatal opening but this research area could be important with respect to water conservation. More work is needed to arrive at any definite conclusions. 

Air-side deposition velocities have been studied extensively for the uptake of inorganic gases in plants. However, the deposition of PCDD/Fs introduces a new dimension to this subject, since these compounds are deposited primarily to the surface of the cuticle,45 not to the stomatal openings as in the case of most inorganic trace gases. Hence the receptor surface is fundamentally different for... 

OPDA was shown to promote tendril coiling response in Bryonia914 This compound was also shown to induce stomatal opening.915 The stomatal opening activity of OPDA is higher than that of other phytohormones that induce stomatal opening. 

Atrial natriuretic peptide (= ANP Atrial natriuretic factor ANF)] (protein) Animals ex stressed heart Activates PM GC (ANPR-A ANPR-B) - via NPR-A NPR-B (guanylyl cyclase-coupled receptors) induces plant stomatal opening inhibited by GC inhibitors LY83583 Methylene blue... 

Eukaryotes quantitated in various plants e.g. Phaseolus vulgaris, Pisum sativum (Fabaceae) fea mays (Poaceae) seedling tissues involvement in plant defence stomatal opening Annona squamosa (Annonaceae), Dicentra eximia, Corydalis ambigua (Fumariaceae), Beilschmiedia podagrica (Lauraceae), Eschscholzia californica, Glauciumflamm (Papaveraceae)... 

Water status, temperature, and PPF all affect stomatal opening (Section 8.1B) and hence the photosynthetic rates of leaves. Sometimes such environmental effects are incorporated into photosynthetic models by their influences on (Eq. 8.5) or Fmax (Eq. 8.27). Indices have also been proposed relating Jcoi to rainfall and the water status of the plants, to the... 

Stomatal opening leading to the C02 uptake that is necessary for photosynthesis results in an inevitable loss of water. A useful parameter relating the two fluxes and showing the total C02 fixed (benefit) per unit water lost... 

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