Stomata in Flacourtiaceae

Figs. 1-3. Camera lucida drawings of leaf epidermal features of Berberidopsis and Vertical scale line for hairs. Horizontal scale line for epidermis in transverse section (above) and in surface view (below). — 1: Berberidopsis beckleri B. corallina (F.v.M.) Veldkamp. — 2: Hook.f. — 3: Streptothamnus moorei F.v.M.

Berberidopsis corallina – Coral Plant – https://www.dobbies.com/media/4742506/Berberidopsis-corallina.jpg

Vegetative anatomy and taxonomy of Berberidopsis and Streptothamnus (Flacourtiaceae)

by Baas P. (1984)

Pieter Baas,

Rijksherbarium Leiden, The Netherlands

in Blumea 30: 39–44 –

Google Scholar –

 http://arno.uva.nl/cgi/arno/show.cgi?fid=566208

Summary

The leaf and twig anatomy of Berberidopsis and Streptothamnus are described in detail. The two genera are very similar in most aspects of their vegetative anatomy and together take a very isolated position in the Flacourtiaceae on account of their xylem anatomy and stomatal type.

Differences in indumentum, crystal complement and epidermal cell morphology (whether or not papillate) support the distinction of Streptothamnus moorei from Berberidopsis sensu Veldkamp, i.e., including Berberidopsis corallina and B. beckleri (formerly Streptothamnus beckleri).

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DISCUSSION

From the descriptions it becomes evident that all three species have many leafand twig anatomical features in common. This can be taken as an indication of close mutual affinity, especially if the shared characters of Berberidopsis and Streptothamnus are contrasted with anatomical tendencies in the Flacourtiaceae.

Cyclocytic and bicyclic stomata (two closely related stomatal types) have not been recorded for the Flacourtiaceae. Paracytic or anisocytic stomata or their intermediate types are most common in the family, a minority (Camptostylus and Scotellia according to Solereder, 1908, and Azara dentata according to original observation) has anomocytic stomata.

The latter type can intergrade with cyclocytic stomata in other families (cf. Baas et al., 1982) and may be considered related to the cyclocytic type.

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The superficial resemblance between Berberidopsis and Erythrospermum commented on by earlier authors can be contrasted by differences in wood and leaf anatomy: Erythrospermum has laterocytic stomata (original observation, this type is termed intermediate between paracytic and anisocytic by Metcalfe & Chalk, 1950), crystalliferous epidermal cells, septate fibres and fairly common vessel multiples.

The differential characters in vegetative anatomy of Berberidopsis and Streptothamnus are summarised in table 1. Many of them, especially the crystal complement and lignification of the medullary ground tissue (pith) of the petiole are of very limited taxonomic value, and should be tested on their diagnostic worth in more samples. Character differences like cyclocytic versus predominantly bicyclic stomata and papillae present or absent can also be found within closely knit taxa (cf. Baas, 1970, 1975).

Effects of salt stress on stomatal behaviour

 

 

Effects of salt stress on the growth, ion content, stomatal behaviour and photosynthetic capacity of a salt sensitive species, Phaseolus vulgaris L

by Seemann J. R., Critchley C. (1985)

Department of Environmental Biology, Australian National University, Canberra, Australia

Department of Botany, Australian National University, Canberra, Australia

• Jeffrey R. Seemann,
• Christa Critchley,

in Planta 164: 151-162 –

https://link.springer.com/article/10.1007/BF00396077

Abstract

Phaseolus vulgaris (cv. Hawkesbury Wonder) was grown over a range of NaCl concentrations (0–150 mM), and the effects on growth, ion relations and photosynthetic performance were examined.

Dry and fresh weight decreased with increasing external NaCl concentration while the root/shoot ratio increased. The Cl^– concentration of leaf tissue increased linearly with increasing external NaCl concentration, as did K⁺ concentration, although to a lesser degree. Increases in leaf Na⁺ concentration occurred only at the higher external NaCl concentrations (≧100 mM).

Increases in leaf Cl^– were primarily balanced by increases in K⁺ and Na⁺. X-ray microanalysis of leaf cells from salinized plants showed that Cl^– concentration was high in both the cell vacuole and chloroplast-cytoplasm (250–300 mM in both compartments for the most stressed plants), indicating a lack of effective intracellular ion compartmentation in this species.

Salinity had little effect on the total nitrogen and ribulose-1,5-bisphosphate (RuBP) carboxylase (EC 4.1.1.39) content per unit leaf area. Chlorophyll per unit leaf area was reduced considerably by salt stress, however.

Stomatal conductance declined substantially with salt stress such that the intercellular CO₂ concentration (C_i) was reduced by up to 30%. Salinization of plants was found to alter the δ¹³C value of leaves of Phaseolus by up to 5‰ and this change agreed quantitatively with that predicted by the theory relating carbon-isotope fractionation to the corresponding measured intercellular CO₂ concentration.

Salt stress also brought about a reduction in photosynthetic CO₂fixation independent of altered diffusional limitations. The initial slope of the photosynthesis versus C_i response declined with salinity stress, indicating that the apparent in-vivo activity of RuBP carboxylase was decreased by up to 40% at high leaf Cl^– concentrations. The quantum yield for net CO₂ uptake was also reduced by salt stress.

 

Extracellular Ca2+ alleviates NaCl-induced stomatal opening

 

 

Extracellular Ca²⁺ alleviates NaCl-induced stomatal opening through a pathway involving H₂O₂-blocked Na⁺ influx in Vicia guard cells

by Zhao X., Wang Y.-J., Wang Y.-L., Wang X.-L., Zhang X. (2011)

Xiang Zhao, Ya-Jing Wang, Yan-Liang Wang, Xi-Li Wang, Xiao Zhang

in Journal of Plant Physiology 168(9): 903-910 – https://doi.org/10.1016/j.jplph.2010.11.024

http://www.sciencedirect.com/science/article/pii/S0176161711000630

Abstact

To gain further insights into the function of extracellular Ca²⁺ in alleviating salt stress, Vicia faba guard cell protoplasts (GCPs) were patch-clamped in a whole-cell configuration.

The results showed that 100 mM NaCl clearly induced Na⁺ influx across the plasma membrane in GCPs and promoted stomatal opening. Extracellular Ca²⁺ at 10 mM efficiently blocked Na⁺ influx and inhibited stomatal opening, which was partially abolished by La³⁺ (an inhibitor of plasma membrane Ca²⁺ channel) or catalase (CAT, a H₂O₂ scavenger), respectively.

These results suggest that the plasma membrane Ca²⁺channels and H₂O₂ possibly mediate extracellular Ca²⁺-blocked Na⁺influx in GCPs. Furthermore, extracellular Ca²⁺ activated the plasma membrane Ca²⁺ channels under NaCl stress, which was partially abolished by CAT.

These results, taken together, indicate that hydrogen peroxide (H₂O₂) likely regulates Na⁺ uptake by activating plasma membrane Ca²⁺ channels in GCPs. In accordance with this hypothesis, H₂O₂ could mimic extracellular Ca²⁺ to activate Ca²⁺channels and block Na⁺ influx in guard cells.

A single-cell analysis of cytosolic free Ca²⁺ ([Ca²⁺]_cyt) using Fluo 3-AM revealed that extracellular Ca²⁺ induced the accumulation of cytosolic Ca²⁺ under NaCl stress, but had few effects on the accumulation of cytosolic Ca²⁺under non-NaCl conditions.

All of these results, together with our previous studies showing that extracellular Ca²⁺ induced the generation of H₂O₂ in GCPs during NaCl stress, indicate that extracellular Ca²⁺ alleviates salt stress, likely by activating the H₂O₂-dependent plasma membrane Ca²⁺ channels, and the increase in cytosolic Ca²⁺ appears to block Na⁺ influx across the plasma membrane in Vicia guard cells, leading to stomatal closure and reduction of water loss.

Stomatal responses to Ca2+ and Na+ in relation to salinity tolerance

 

 

Responses of the stomata of Aster tripolium to calcium and sodium ions in relation to salinity tolerance

by Perera L. K. R. R., Robinson M. F., Mansfield T. A., (1995)

in Journal of Experimental Botany, 46(6) 623–629 – https://doi.org/10.1093/jxb/46.6.623 –

https://academic.oup.com/jxb/article-abstract/46/6/623/511165

Abstract

In previous work, the stomata of the maritime halophyte Aster tripolium L. were shown to close when NaCl concentrations rise in the vicinity of the guard cells. Further studies have now revealed important effects of calcium on the ionic responses of the stomata.When the guard cells were presented with KCl, Ca²⁺ suppressed opening in a manner similar to that which has become familiar in other species such as Commelina communis L. However, in the presence of NaCl, Ca²⁺ had the opposite effect, reducing the closing response to NaCl. This pattern of behaviour is discussed in relation to known salt effects on membranes, but the underlying physiological basis remains obscure.

A previous study led to the hypothesis that the closing response of the stomata to Na⁺ ions may make an important contribution to the salinity tolerance of this species.

Here we report that increasing supplies of Ca²⁺ ions reduce the effect of salinity on stomatal conductance in the whole plant as well as in the isolated epidermis. This finding is consistent with the well established role of calcium in increasing resistance to salinity: in the presence of high calcium the plant can tolerate a greater salt intake, and hence there is a reduced need for transpiration to be restricted by partial stomatal closure.

Chloride reduces malate production in epidermis during stomatal opening

 

 

Presence of Chloride Reduces Malate Production in Epidermis during Stomatal Opening

by Van Kirk C. A., Raschke K. (1978)

Carol A. Van Kirk, Klaus Raschke,

Michigan State University/Energy Research and Development Administration Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824

in Plant Physiol. 61: 361-364 –

http://www.plantphysiol.org/content/plantphysiol/61/3/361.full.pdf

ABSTRACT

When stomata of isolated epidermis of Vicia faba are allowed to open in the presence of K+ and iminodiacetate (an impermeant zwitterion), malate is formed in the epidermis; the increases in malate content follow a nearly linear relationship with stomatal aperture.

Stomata of leaf sections of V. faba floated on water during opening also exhibit this relationship. When isolated epidermis is offered KC, this relationship is not observed and less malate is detected at comparable stomatal apertures.

The data indicate that Cl-, if present at concentrations ; 10-5 eq liter-‘, can partially satisfy the anion requirement of guard cels of V. faba during stomatal opening. Discrepancies between earler reports on the relative roles Cl- and malate play as counterions for K+ in guard cells of V. faba could now be explained as resulting from variations in the availability of Cl- to guard cells.

Stomatal Patchiness

 

 

by Beyschlag W., Eckstein J. (1998)

Lehrstuhl für Experimentelle Ökologie und Ökosystem-Biologie, Universität Bielefeld, Germany

• Wolfram Beyschlag, Jürgen Eckstein,

In: Behnke HD., Esser K., Kadereit J.W., Lüttge U., Runge M. (eds) Progress in Botany. Progress in Botany, vol 59.:283-298, Springer, Berlin, Heidelberg –

https://link.springer.com/chapter/10.1007/978-3-642-80446-5_10#citeas

Abstract

“Stomatal patchiness”, the phenomenon where the heterogeneous distribution of stomatal apertures results in a patchy carbon assimilation and transpiration, has increasingly drawn the attention of plant eco-physiologists, particularly of those who employ gas-exchange methodology.

Since stomatal homogeneity is an assumption in the standard method of calculating net photosynthesis (A), transpiration rate (E), stomatal conductance (G_s) and leaf internal CO₂ partial pressure (c_i) from gas-exchange measurements (von Caemmerer and Farquhar 1981), stomatal patchiness may lead to erroneous estimations.

Although several investigations reported inhomogeneous distributions of stomatal aperture on a leaf surface (e.g. Molisch 1912; Cruiziat et al. 1979; Laisk et al. 1980; Spence 1987; van Gardingen et al. 1989), the consequences on calculated gas-exchange parameters were not assessed.

Justification for ignoring inhomogeneous stomatal aperture was suggested by Sharkey et al. (1982), who found (in unstressed leaves) that direct measurements of internal CO₂ partial pressures were quite similar to values calculated from gas-exchange measurements assuming stomatal homogeneity.

Effects of flooding on stomatal resistance of Bruguiera (mangrove)

Photo credit: Google

Bruguiera gymnorrhiza 6 Copenhagen Bot Garden 120919 – Photo: Jan Thomas Johansson (© 2014 Jan Thomas Johansson).

 

Orange mangrove (Bruguiera gymnorrhiza) – https://farm6.staticflickr.com/5307/5579397742_9973245d6a_b.jpg

 

Effects of flooding on leaf water potential and stomatal resistance in Bruguiera gymnorrhiza (L.) Lam.

by Naidoo G. (1983)

in New Phytologist 93: 369-376 – doi:10.1111/j.1469-8137.1983.tb03437.x –

http://onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.1983.tb03437.x/full

SUMMARY

The effects of 10, 20, 40 and 80 days of flooding on stomatal responses in the halophyte, Bruguiera gymnorrhiza (L.) Lam were investigated. Measurements were made of leaf water potential and stomatal resistance (r_g) during the period of flooding, and continuing for 12 to 14 days after its termination.

Generally, plants flooded for prolonged periods had lower leaf water potentials than the controls both during and after flooding. Prolonged flooding also resulted in higher r_g during flooding and continuing for 8 to 10 days afterwards. Leaf water potentials decreased with increase in the duration of flooding. Decrease in leaf water potential was also associated with an increase in r_g.

Prolonged flooding also resulted in ultrastructural modifications. The chloroplasts had smaller grana and the lamellae were considerably swollen. There also appeared to be some degradation of thylakoid membrane structure.

Strong, nonuniform stomatal closure.

Photo credit: Google

Plantago maritima

Photosynthetic and stomatal responses of the halophyte,Plantago maritima L. to fluctuations in salinity

by Flanagan L. B., Jefferies R. L. (1989)

Department of Biology. University of Utah, Salt Lake City, Utah, 84112, USA.

in Plant, Cell & Environment 12(5): 559–568 – DOI: 10.1111/j.1365-3040.1989.tb02129.x – 

http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3040.1989.tb02129.x/full

Abstract

Measurements of photosynthesis as a function of intercellular CO₂ (A-C₁ curve) were made on single. attached leaves of Plantago maritima L. while plants were exposed to changes in salinity.

Salinity was increased in steps from 50 to 500 mol m^-3 NaCl and then returned to 50 mol m^-3 NaCl at two rates, 75 mol m^-3 (NaCl) day^-1 (experiment 1) and 150 mol m^-3 (NaCl) day^-1(experiment 2). In experiment one, the CO₂ assimilation rate declined at high CO₂concentrations, but the initial slope of the A-C₁ curve was unaffected in young leaves after salinity was increased to 500 mol m^-3 NaCl.

The insensitivity of photosynthesis to increases in CO₂ concentration above air levels was not associated with insensitivity to a reduction in oxygen concentration. In experiment two increasing the rate at which salinity was changed resulted in larger declines in photosynthesis and leaf conductance than were observed in experiment one.

Both the initial slope and the CO₂ saturated region of the A-C₁ curve were substantially reduced at high salinity suggesting that mesophyll biochemical capacity had been inhibited. However, concurrent measurements of photosynthesis as oxygen evolution under 5% CO₂ indicated no effect of increased salinity on photosynthetic capacity.

This suggests that the apparent non-stomatal limitations indicated by A-C₁ measurements were artifacts caused by strong, nonuniform stomatal closure.

Stomatal limitation of photosynthesis at high salinity

Photo credit: Google

Plantago maritima

Stomatal limitation of photosynthesis and reduced growth of the halophyte, Plantago maritima L., at high salinity

by Flanagan L. B., Jefferies R. L. (1988)

in Plant, Cell & Environment 11(4): 239–245 – DOI: 10.1111/j.1365-3040.1988.tb01142.x – 

http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3040.1988.tb01142.x/full

Abstract.

Plantago maritima L. was grown at three levels of salinity, 50, 200, 350 mol m⁻³ NaCl, and the effects on growth, ion content and photosynthetic capacity were studied.

Shoot and root dry weight, leaf production and leaf length were all substantially reduced in plants grown at high salinity. Total leaf area of plants grown at 350 mol m⁻³ NaCl was only 20% of that in plants at low salinity. Both the Na⁺ and K⁺ content of leaves and roots increased with external salinity.

There was no change in the Na⁺/K⁺ ratio of leaves or roots at different salinity levels. Despite the large reductions in growth and high accumulation of Na⁺ ions, leaf photosynthetic rate was only slightly reduced by salinity stress. The reduction in photosynthesis was not caused by reduced biochemical capacity as judged by photosynthetic response to intercellular CO₂ and by ribulose-1,5-bisphosphate carboxylase activity, but was due to reduced leaf conductance and low intercellular CO₂ concentration. The increased stomatal limitation of photosynthesis resulted in higher water-use efficiency of plants grown at high salinity.

Avoidance of sodium accumulation by the stomatal guard cells

Photo credit: Google

Sea Aster (Aster tripolium)

 

Avoidance of sodium accumulation by the stomatal guard cells of the halophyte Aster tripolium

by Perera L. K. R. R., De Silva D. L. R. , Mansfield T. A. (1997)

in Journal of Experimental Botany  48(3): 707–711 –

https://academic.oup.com/jxb/article/48/3/707/447764/Avoidance-of-sodium-accumulation-by-the-stomatalhttps://doi.org/10.1093/jxb/48.3.707

Abstract

X-ray microanalysis has revealed that the sodium content of the stomatal guard cells of Aster tripolium remains much lower than that of other leaf cells when the plants are grown at high salinity.

Large amounts of sodium did, in contrast, accumulate in epidermal and subsidiary cells, and particularly in the mesophyll tissue, suggesting that a mechanism exists to limit the extent of its entry into guard cells. Even in plants grown at high salinity, the content of potassium was much higher than that of sodium in the guard cells, consistent with the view that this is a major ion involved in determining stomatal movements in this halophyte.

Determinations were also made for the nonhalophyte Commelina communis, and it was found that the guard cells accumulated large amounts of sodium when it was presented to them as an alternative to potassium.

It is suggested that the acquisition by the guard cells of some ability to restrict the intake of sodium ions may be an important component of sodium-driven regulation of transpiration, and hence of salinity tolerance, in A. tripolium.