Stomata in selected species of Lythraceae

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Figure 1. A- Ammannia Baccifera subsp. baccifera (A1.abaxial surface with polygonal or irregular epidermal cells and wavy to sinuate anticlinal cell wall & A2. adaxial surface with polygonal epidermal cells and straight to curved anticlinal cell wall); B- Ammannia baccifera subsp. aegyptiaca (B1. abaxial surface with polygonal epidermal cells and wavy to sinuate anti clinal cell wall & B.2. adaxial surface with polygonal epidermal cells and straight to curved anticlinal cell wall); C- Ammannia multiflora (C1. abaxial & C2. adaxial surfaces- both surfaces with irregular epidermal cells and sinuate anticlinal cell wall)

 

Cuticular features of selected species of Ammannia, Rotala and Nesaea (Lythraceae) in South India

by Lemiya K. M., Pradeep A. K. (2017)

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in International Journal of Current Research 9(07): 54432-54440 –

https://www.journalcra.com/sites/default/files/24536.pdf

Abstract

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Stomatal ontogeny in some Lythraceae

 

 

Stomatal ontogeny in some Lythraceae

by Thanki Y. I., Shah K., Garasia K. K., (2000)

Department of Biosciences, South Gujarat University, Udhna Magdalla Road, Surat – 395 007, India.

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in Journ. Phytological Research 13(2): 187-189 –

https://www.cabdirect.org/cabdirect/abstract/20023036143

Abstract :

The stomatal structure and development in Ammannia bacciferaLagerstroemia indicaLagerstroemia parvifloraLagerstroemia speciosaLawsonia inermisPunica granatumRotala serpyllifolia, Sonneratia apetala and Woodfordia fruticosa were studied.

The leaves of A. baccifera, R. serpylifolia and S. apetala were amphistomatic while the rest of the species were hypostomatic. The stomata identified were either anemocytic (all species), haplocytic (all species), paracytic (S. apetala), tetracytic (S. apetala), contiguous (A. baccifera, Lagerstroemia indica, Lagerstroemia speciosa and W. fruticosa) or that which consisted of a single guard cell (all species except W. fruticosa).

The development of meristemoid, which is a heavily stained cell with a prominent nucleus and is smaller than the surrounding epidermal cells, in relation to the formation of the various stomatal types is briefly discussed.

Stomata in Rotala (Lythraceae)

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Foliar epidermal features and their taxonomic significance in Rotala L. (Lythraceae)

by Kshirsagar A. A., Vaikos N. P. (2013)

Anil A. Kshirsagar1 and N. P. Vaikos2

1 UG & PG Department of Botany, Shivaji Arts, Comm. & Science College, Kannad, Aurangabad (MS)

2 Department of Botany, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad (MS), Presently at Sonchafa, Mahavir Nagar, Osmanpura, Aurangabad

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in Asian Journal of Plant Science and Research 3(3): 117-120 –

http://www.imedpub.com/articles/foliar-epidermal-features-and-their-taxonomic-significancein-rotala-l-lythraceae.pdf

ABSTRACT

The present study deals with the epidermal diversity in nine species of Rotala L. belonging to the family Lythraceae.

The leaves are small, variable in shape, size and amphistomatic. The upper epidermal cells are generally larger than the lower epidermal cells; the anticlinal cell walls are wavy or sinuous.

The stomata are anisocytic and anomocytic. A peculiar wall thickening at polar end of the stomata is noted in Rotala serpyllifolia. The 2-celled glandular trichomes occur in R. malampuzhensis and the scales in R. floribunda.


 

The number of stomata is more on the lower surface whereas few stomata occur on the upper surface. A peculiar wall thickening at polar end of guard cells is observed in the leaves of Rotala serpyllifolia [Figs. QR]. The stomata are anomocytic in Rotala densiflora, R. floribunda, R. indica, R. occultiflora, R. serpyllifolia [Figs. AB, EF, GH, KL, QR] whereas anisocytic in R. fimbriata, R. malampuzhensis, R. rotundifolia, and R. rosea [Figs. CD, IJ, MN, OP].Trichomes are 2-celled and glandular in the leaves of R. malampuzhensis [Fig. S ] and in the form of scales in R. floribunda. [Fig. S].

The maximum number of stomatal index occurs in abaxial surface of leaf as in Rotala serpyllifolia, while minimum in R.occultiflora , whereas in adaxial surface the maximum number of stomatal index is noted in R.serpyllifolia and the minimum in R. floribunda [Table: 1]. The stomatal index of other plants are given in Table No. 1. The maximum number of stomatal frequency occurs in abaxial surface [lower epidermis] of leaf as in Rotala occultiflora.[38.1/mm2 ] while minimum number in Rotala fimbriata [23.6/mm2 ] whereas in adaxial surface [upper epidermis] the maximum number of stomatal frequency is noted in R.floribunda[27.7/mm2 ] and the minimum in R.rosea [19.4/ mm2 ] [Table: 2]. The stomatal frequency of other plants are given in Table No.2.

Effect of auxins on the modulation of stomatal opening, mediated through the activity of the plasma-membrane H+-ATPase.

 

 

Characterization of the plasma-membrane H+-ATPase from Vicia faba guard cells. Modulation by extracellular factors and seasonal changes.

by Lohse G., Hedrich R. (1992)

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in Planta 166: 206–214 –

Google Scholar – 

https://www.jstor.org/stable/23381682?seq=1#page_scan_tab_contents

Abstract

Stomatal movement is controlled by external and internal signals such as light, phytohormones or cytoplasmic Ca2+.
Using Vicia faba L., we have studied the dose-dependent effect of auxins on the modulation of stomatal opening, mediated through the activity of the plasma-membrane H+-ATPase. The patch-clamp technique was used to elucidate the electrical properties of the H+-ATPase as effected by growth regulators and seasonal changes. The solute composition of cytoplasmic and extracellular media was selected to record pump currents directly with high resolution. Proton currents through the ATPase were characterized by a voltage-dependent increase in amplitude, positive to the resting potential, reaching a plateau at more depolarized values.
Upon changes in extracellular pH, the resting potential of the cell shifted with a non-Nernst potential response (±21 mV), indicating the contribution of a depolarizing ionic conductance other than protons to the permeability of the plasma membrane. The use of selective inhibitors enabled us to identify the currents superimposing the H+-pump as carried by Ca2+.
Auxin-stimulation of this electroenzyme resulted in a rise in the outwardly directed H+ current and membrane hyperpolarization, indicating that modulation of the ATPase by the hormone may precede salt accumulation as well as volume and turgor increase.
Annual cycles in pump activity (1.5—3.8 μA·cm-2) were expressed by a minimum in pump current during January and February. Resting potentials of up to -260mV and plasma-membrane surface area, on the other hand, did not exhibit seasonal changes. The pump activity per unit surface area was approximately 2- to 3-fold higher in guard cells than in mesophyll cells and thus correlates with their physiological demands.

 

Modeling stomatal responses to environment

 

 

Modeling stomatal responses to environment in Macadamia integrifolia 

by Lloyd J. (1991)

Jonathan_Lloyd8
Jonathan Lloyd, Imperial College London, UK

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in Australian Journal of Plant Physiology 18: 649660 – DOI – 10.1071/PP9910649 –

CrossRef

http://www.publish.csiro.au/fp/PP9910649

Abstract

Gas exchange measurements were made of photosynthetic and stomatal responses of Macadamia integrifolia under controlled conditions. Test leaves were subjected to a range of temperatures, humidities and photon irradiances. When stomatal responses to humidity were plotted as a function of vapour mol fraction difference (D) a similar curvilinear response was observed at all temperatures and at photon irradiances of 200 and 1500 μmol quanta m-2 s-1. By contrast, when expressed as a function of relative humidity, different slopes in the humidity response were observed, and at high photon irradiances, stomatal conductances (gs) appeared to have an optimum temperature below 15ºC. Simple equations to quantify responses to leaf temperature (TI) and D were developed, the best of which was

gs = [1-k1(1-[Tl/Topt)]/k2√D,

where Topt is the leaf temperature at which maximal stomatal opening is observed and k1 and k2 are constants fitted by non-linear least squares regression analysis.

Calculation of the gain ratio of CO2 assimilation (A) to transpiration (E) (δA/δE) was complicated by effects of D on the relationship between A and leaf intercellular mol fraction of CO2 (CI). Calculation of δA/δE using A/CIrelationships derived by varying external CO2 mol fraction at constant D showed the gain ratio to be virtually constant (1.5 mmol mol-1) across a range of leaf temperatures and vapour mol fraction differences but, when calculated directly from the relationship between A and gs, a decrease in δA/δE with D was observed. Macadamia leaves have heavily sclerified bundle sheath extensions and it is considered that this dependence was an artefact due to non-uniform stomatal closure in response to increasing D. It is shown that, at any given temperature, a stomatal response of the form gsD-1/2 gives rise to an approximately constant δA/δE.

Leaf water and stomatal movement, visual observation of stomata in situ

 

 

Leaf water and stomatal movement in Gossypium and a method of direct visual observation of stomata in situ

by Lloyd F. E. (1913)

Francis E. Lloyd

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in Bull. Torrey Bot. Club 40: 1-2 –

https://archive.org/stream/jstor-2479849/2479849_djvu.txt

Francis E. Lloyd 

In a previous paper* it is shown that the rates of transpiration 
in cut shoots of the ocotillo, Fouquieria splendens, recorded by 
simultaneous volumetric readings and weighings, are not paraliel, 
but that the loss of water from the plant during the day is in 
excess of that taken up by the cut end of the shoot from the 
porometer. This result is in general harmony with the findings 
of Eberdtf with rooted plants of Helianthus annuus. It was not, 
however, found to be true in my study of the ocotillo that the loss 
of water takes place at a constant ratio during the hours of day- 
light, since the whole relation between the income and outgo may 
be reversed within a short space of time even during daylight by 
an apparently slight modification of the environmental condi- 
tions. This ready susceptibility of the plant lent color to the 
idea that the differences indicated by volumetric and gravimetric 
readings are measures of differences in the leaf moisture content, 
to be more briefly referred to as leaf water in the present paper.

RAP2.6L overexpression delays waterlogging induced premature senescence by increasing stomatal closure

 

 

RAP2.6L overexpression delays waterlogging induced premature senescence by increasing stomatal closure more than antioxidant enzyme activity

by Liu P., Sun F., Gao R., Dong H. (2012)

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in Plant Mol. Biol. 79: 609–622 – doi: 10.1007/s11103-012-9936-8 –

https://www.ncbi.nlm.nih.gov/pubmed/22661072

Abstract

Waterlogging usually results from overuse or poor management of irrigation water and is a serious constraint due to its damaging effects. RAP2.6L (At5g13330) overexpression enhances plant resistance to jasmonic acid, salicylic acid, abscisic acid (ABA) and ethylene in Arabidopsis thaliana. However, it is not known whether RAP2.6L overexpression in vivo improves plant tolerance to waterlogging stress.

In this study, the RAP2.6L transcript was induced by waterlogging or an ABA treatment, which was reduced after pretreatment with an ABA biosynthesis inhibitor tungstate. Water loss and membrane leakage were reduced in RAP2.6L overexpression plants under waterlogging stress. Time course analyses of ABA content and production of hydrogen peroxide (H(2)O(2)) showed that increased ABA precedes the increase of H(2)O(2).

It is also followed by a marked increase in the antioxidant enzyme activities. Increased ABA promoted stomatal closure and made leaves exhibit a delayed waterlogging induced premature senescence.

Furthermore, RAP2.6L overexpression caused significant increases in the transcripts of antioxidant enzyme genes APX1 (ascorbate peroxidase 1) and FSD1 (Fe-superoxide dismutase 1), the ABA biosynthesis gene ABA1 (ABA deficient 1) and signaling gene ABH1 (ABA-hypersensitive 1) and the waterlogging responsive gene ADH1 (alcohol dehydrogenase 1), while the transcript of ABI1 (ABA insensitive 1) was decreased.

ABA inhibits seed germination and seedling growth and phenotype analysis showed that the integration of abi1-1 mutation into the RAP2.6L overexpression lines reduces ABA sensitivity.

These suggest that RAP2.6L overexpression delays waterlogging induced premature senescence and might function through ABI1-mediated ABA signaling pathway.