Sodium could meet the requirement of potassium for stomatal opening

Replacibility of potassium by sodium for stomatal opening in epidermal strips of Commelina benghalensis

Raghavendra A. S., Rao I. M., Das V. S. R. (1976)

Department of Botany, Sri Venkateswara University, Tirupati — 517502, Andhra Pradesh, India

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Z. Pflanzenphysiol. 80: 36-42 – https://doi.org/10.1016/S0044-328X(76)80048-7 –

https://www.sciencedirect.com/science/article/abs/pii/S0044328X76800487

Summary

Sodium enhanced stomatal opening in epidermal strips of Commelina benghalensis, both in light and darkness. Potassium was not needed for stomatal opening when enough sodium ions were already present in the medium. The optimal concentration of sodium required for stomatal opening was nearly double that of potassium. The stimulatory effect of sodium was essentially similar to potassium in all respects. Sodium-stimulated stomatal opening in light was sensitive to the functioning of cyclic photophosphorylation, inhibited by abscisic acid and enhanced by fusicoccin. The results suggested that sodium could meet the requirement of potassium for stomatal opening.

Shrinkage of stomatal guard cell chloroplasts in relation to stomatal opening

Shrinkage of guard cell chloroplasts in relation to stomatal opening in Commelina benghalensis

Raghavendra A. S., Rao I. M., Das V. S. R. (1976)

Ann. Bot. 40: 899-901 – https://doi.org/10.1093/oxfordjournals.aob.a085207 –

https://academic.oup.com/aob/article-abstract/40/4/899/129615

Stomatal characteristics of several C4 and C3 dicotyledonous plants

Stomatal characteristics of some dicotyledonous plants in relation to the C3 and C4 pathway of photosynthesis

Das V. S. R., Santakumari M. (1977)

Plant and Cell Physiology 18: 935-938 – https://doi.org/10.1093/oxfordjournals.pcp.a075510 –

https://academic.oup.com/pcp/article-abstract/18/4/935/1861106

Abstract

A comparative study of some stomatal characteristics and transpirational rates of several C₄ and C₃ dicotyledonous plants was made. Among the plants studied, C₄ species had higher stomatal frequency in upper leaf surfaces (relative to their lower leaf surfaces) than the C₃ ones. The maximal stomatal opening was at 12 noon in C₄ plants but at 10 AM in C₃ plants. C₄ plants had lower stomatal conductance and and higher water-use efficiency than C₃ plants.

Herbicide-induced desiccation is the consequence of inhibition of stomatal scotoactive behavior and increased water loss

The Reversal of Scotoactive Stomatal Behavior in some Woody Weeds by Paraquat and 2,4,5-T

Rao I. M., Swamy P. M., Das V. S. R. (1977)

Weed Science 25(6): 469-472 –https://doi.org/10.1017/S0043174500033920 –

https://www.cambridge.org/core/journals/weed-science/article/abs/reversal-of-scotoactive-stomatal-behavior-in-some-woody-weeds-by-paraquat-and-245t/490E1C364EB179E65712DFA7C3998691

Abstract

A typical scotoactive stomatal behavior was noticed in Carissa spinarum L.; Gymnosporia emarginata Laws; Maba buxifolia Cl.; Flacourtia sepiaria Roxb.; Dodonaea viscosa L. and Randia malabarica Lamk. This stomatal behavior was reversed artificially by foliar application of paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) at 100 ppmw or 2,4,5-T [(2,4,5-trichlorophenoxy)acetic acid] at 2000 ppmw. The size of the stomatal aperture, stomatal conductance and the rates of transpiration were enhanced significantly by the herbicide treatment. The physiological basis for the induction of desiccation and death of plant organs is thought to be the excessive stimulation of stomatal aperture, stomatal conductance and consequently high rates of transpiration observed here. The data suggest that herbicide-induced desiccation is the consequence of inhibition of scotoactive behavior and increased water loss with attendant desiccation and death of leaves.

Stomatal movement

Mechanism of stomatal movement

Das V. S. R., Rao I. M., Raghavendra A. S., (1977)

Nature 266: 282 –  https://doi.org/10.1038/266282a0 –

https://www.nature.com/articles/266282a0#citeas

Stomatal behaviour towards four classes of herbicides

Stomatal behaviour towards four classes of herbicides as a basis of selectivity to certain weeds and crop plants

by Das V. S. R., Santakumari M. (1975)

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In Proceedings of the Indian Academy of Sciences – Section B 82(3)108–116 – https://doi.org/10.1007/BF03050523 –

https://link.springer.com/article/10.1007/BF03050523#citeas

Abstract

Changes in the stomatal aperture and the rate of transpiration under foliar application with triazine (atrazine) urea (diuron), amide (alachlor, butachlor) and thiocarbamate (EPTC and Molinate) type of herbicides onAmaranthus viridis L.;Digera arvensis Forsk;Boerhaavia diffusa L.;B. repanda Willd.;Commelina benghalensis L.;Cyperus rotundus L.;Pisum sativum L.; andPennisetum typhoides Stapf and Hubb; were studied. It was observed that the triazine and urea herbicides have caused an appreciable stimulation of stomatal opening within two hours of chemical contact, while the amides possessed a contrasting behaviour in as much as they have brought a rapid closure of the open stomata. Thiocarbamates on the other hand have exhibited a differential response characteristically relating to the C₃ or C₄ type plants. The general trend observed with the thiocarbamates was that they were stimulatory for the C₃ and inhibitory for the C₄ plants in respect of stomatal opening.

A definite correlation of the rate of the transpiration with the stomatal response to the herbicide was found. The present study suggests that the resistance or susceptibility of the plants is determined by the selective stomatal behaviour towards different herbicides.

Reversal of ABA induced stomatal closure by benzyl adenine

Reversal of abscisic acid induced stomatal closure by benzyl adenine

by Das V. S. R., Rao I. M., Raghavendra A. S. (1976)

Department of Botany, Sri Venkateswara University, Tirupati 51702, India

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In New Phytol 76: 449–452 – https://doi.org/10.1111/j.1469-8137.1976.tb01480.x –

http://repository.ias.ac.in/40192/1/17-PUB.pdf

Abstract

Benzyl adenine enhanced stomatal opening in isolated epidermal strips of Commelina benghalensis and Tridax procumbens.

The stimulation was maximum at a concentration of 5 x io”^ M BA. But kinetin had no remarkable effect on stomatal opening. The activity of benzyl adenine was observed over a narrow range of concentrations, from io~ M to io”* M.

The increase in stomatal aperture was more pronounced in Commelina than in Tridax. Presence of benzyl adenine in the medium prevented the stomatal closure expected from abscisic acid and could reverse considerably the stomatal closure induced earlier by abscisic acid.

It is felt that the balance between abscisic acid and cytokinins can possibly control the stomatal aperture effectively.

ABA inhibition of stomatal opening in isolated epidermal strips.

 

Characterization of abscisic acid inhibition of stomatal opening in isolated epidermal strips.

by Raghavendra A. S., Rao I. M., Das V. S. R. (1976)

Department of Botany, Sri Venkateswara University, Tirupati 517502, A.P., India

in Plant Sci. Lett. 6, 111–115. – doi: 10.1016/0304-4211(76)90144-9 –

CrossRef Full Text | Google Scholar – 

http://www.sciencedirect.com/science/article/pii/0304421176901449?via%3Dihub

Abstract

Abscisic acid (ABA) inhibited the light-induced opening of stomata in isolated epidermal strips of Commelina benghalensis. It did not alter stomatal closure in the dark.

The ABA-induced inhibition in light was released under conditions conducive for cyclic photophosphorylation and remarkably reversed by ATP in the presence of pyruvate.

Cyclic photophosphorylation rates of isolated guard cell chloroplasts were significantly reduced by ABA.

It is proposed that the direct effect of ABA on stomatal opening was mediated in two ways:

(1) by inhibition of cyclic photophosphorylation activities of guard cell chloroplasts and

(2) by blocking organic acid formation in guard cells.

Bicarbonate, fusicoccin and stomatal opening

 

Stimulation and inhibition by bicarbonate of stomatal opening in epidermal strips of Commelina benghalensis. 

by Mrinalini T., Latha Y. K., Raghavendra A. S., Das V. S. R. (1982)

in New Phytology 91, 413–418. – doi:10.1111/j.1469-8137.1982.tb03320.x –

Wiley Online Library | CrossRefWeb of ScienceGoogle Scholar – 

http://onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.1982.tb03320.x/full

SUMMARY

The effect of 0 to 100μM bicarbonate on stomatal opening in epidermal strips of Commelina benghalensis was examined in the presence or absence of fusicoccin in light or darkness.

Low concentrations of bicarbonate (up to 10 μM in the absence and 25 μM in presence of fusicoccin) stimulated stomatal opening while higher concentrations inhibited.

The enhancement of opening by low concentrations of bicarbonate and phosphoenol pyruvate (PEP), and prevention of bicarbonate stimulation by malate or oxaloacetate suggested PEP carboxylase as a CO₂ sensor in the guard cells. However, the inhibition of PEP carboxylase did not completely suppress the opening caused by fusicoccin. The action of fusicoccin therefore appears to involve a site other than CO₂ fixation, presumably through the stimulation of proton excretion.