Variability in the chloroplast area lining the intercellular airspace and cell walls drives mesophyll conductance in gymnosperms

2020 ◽  
Vol 71 (16) ◽  
pp. 4958-4971 ◽  
Author(s):  
Linda-Liisa Veromann-Jürgenson ◽  
Timothy J Brodribb ◽  
Ülo Niinemets ◽  
Tiina Tosens
Keyword(s):  
Cell Walls ◽  
Mesophyll Cell ◽  
Dry Mass ◽  
Detailed Knowledge ◽  
Mesophyll Conductance ◽  
Phylogenetic Groups ◽  
Leaf Dry Mass ◽  
Component Traits ◽  
Structural Traits ◽  
Distinguishing Features

Abstract The photosynthetic efficiency of plants in different environments is controlled by stomata, hydraulics, biochemistry, and mesophyll conductance (gm). Recently, gm was demonstrated to be the key limitation of photosynthesis in gymnosperms. Values of gm across gymnosperms varied over 20-fold, but this variation was poorly explained by robust structure-bound integrated traits such as leaf dry mass per area. Understanding how the component structural traits control gm is central for identifying the determinants of variability in gm across plant functional and phylogenetic groups. Here, we investigated the structural traits responsible for gm in 65 diverse gymnosperms. Although the integrated morphological traits, shape, and anatomical characteristics varied widely across species, the distinguishing features of all gymnosperms were thick mesophyll cell walls and low chloroplast area exposed to intercellular airspace (Sc/S) compared with angiosperms. Sc/S and cell wall thickness were the fundamental traits driving variations in gm across gymnosperm species. Chloroplast thickness was the strongest limitation of gm among liquid-phase components. The variation in leaf dry mass per area was not correlated with the key ultrastructural traits determining gm. Thus, given the absence of correlating integrated easy-to-measure traits, detailed knowledge of underlying component traits controlling gm across plant taxa is necessary to understand the photosynthetic limitations across ecosystems.

scholarly journals CO 2 diffusion in tobacco: a link between mesophyll conductance and leaf anatomy

2021 ◽  
Vol 11 (2) ◽  
pp. 20200040
Author(s):  
Victoria C. Clarke ◽  
Florence R. Danila ◽  
Susanne von Caemmerer
Keyword(s):  
Cell Walls ◽  
Leaf Age ◽  
Mesophyll Cell ◽  
Tunable Diode Laser ◽  
Mesophyll Conductance ◽  
Anatomical Changes ◽  
Unit Leaf ◽  
Diode Laser Spectroscopy ◽  
Isotope Measurements

The partial pressure of CO 2 at the sites of carboxylation within chloroplasts depends on the conductance to CO 2 diffusion from intercellular airspace to the sites of carboxylation, termed mesophyll conductance ( g m ). We investigated how g m varies with leaf age and through a tobacco ( Nicotiana tabacum ) canopy by combining gas exchange and carbon isotope measurements using tunable diode laser spectroscopy. We combined these measurements with the anatomical characterization of leaves. CO 2 assimilation rate, A , and g m decreased as leaves aged and moved lower in the canopy and were linearly correlated. This was accompanied by large anatomical changes including an increase in leaf thickness. Chloroplast surface area exposed to the intercellular airspace per unit leaf area ( S c ) also decreased lower in the canopy. Older leaves had thicker mesophyll cell walls and g m was inversely proportional to cell wall thickness. We conclude that reduced g m of older leaves lower in the canopy was associated with a reduction in S c and a thickening of mesophyll cell walls.

scholarly journals Influence of leaf dry mass per area, CO2, and irradiance on mesophyll conductance in sclerophylls

2009 ◽  
Vol 60 (8) ◽  
pp. 2303-2314 ◽  
Author(s):  
Foteini Hassiotou ◽  
Martha Ludwig ◽  
Michael Renton ◽  
Erik J. Veneklaas ◽  
John R. Evans
Keyword(s):  
Dry Mass ◽  
Mesophyll Conductance ◽  
Leaf Dry Mass

scholarly journals Physiological responses of two tropical weeds to shade: I. Growth and biomass allocation

1999 ◽  
Vol 34 (6) ◽  
pp. 944-952 ◽  
Author(s):  
Moacyr Bernardino Dias-Filho
Keyword(s):  
Leaf Area ◽  
Weed Management ◽  
Dry Mass ◽  
High Light ◽  
Low Light ◽  
Light Regimes ◽  
Leaf Dry Mass ◽  
Lower Ability ◽  
Total Plant ◽  
Plant Dry Mass

Ipomoea asarifolia (Desr.) Roem. & Schultz (Convolvulaceae) and Stachytarpheta cayennensis (Rich) Vahl. (Verbenaceae), two weeds found in pastures and crop areas in Brazilian Amazonia, were grown in controlled environment cabinets under high (800-1000 µmol m-² s-¹) and low (200-350 µmol m-² s-¹) light regimes during a 40-day period. For both species leaf dry mass and leaf area per total plant dry mass, and leaf area per leaf dry mass were higher for low-light plants, whereas root mass per total plant dry mass was higher for high-light plants. High-light S. cayennensis allocated significantly more biomass to reproductive tissue than low-light plants, suggesting a probably lower ability of this species to maintain itself under shaded conditions. Relative growth rate (RGR) in I. asarifolia was initially higher for high-light grown plants and after 20 days started decreasing, becoming similar to low-light plants at the last two harvests (at 30 and 40 days). In S. cayennensis, RGR was also higher for high-light plants; however, this trend was not significant at the first and last harvest dates (10 and 40 days). These results are discussed in relation to their ecological and weed management implications.

scholarly journals Sensitivity of Shoots and Roots of Young Watermelon Plants to End-of-day Red and Far-red Light

1997 ◽  
Vol 122 (4) ◽  
pp. 481-484
Author(s):  
Heather A. Hatt Graham ◽  
Dennis R. Decoteau
Keyword(s):  
Citrullus Lanatus ◽  
Red Light ◽  
Dry Mass ◽  
Stem Length ◽  
Hoagland Solution ◽  
Full Strength ◽  
Leaf Dry Mass ◽  
Half Strength

The sensitivity of shoots and roots to end-of-day (EOD) red (R) or far-red (FR) light on growth of `Sugar Baby' watermelon [Citrullus lanatus (Thunb.) Matsum & Nakai] was investigated. Plants were grown in full-strength Hoagland solution and treated for 14 days to 15 minutes EOD light in trial 1 and in half-strength Hoagland solution and treated for 10 days to EOD light in trial 2. Exposing shoots to EOD FR resulted in elongated petioles of leaves 1 to 3 (as counted from the cotyledons), internodes 1 to 3, and total stem length in both trials. Exposure to EOD FR resulted in increased stem and petiole dry mass in trial 1, whereas EOD FR resulted in increased root and leaf dry mass in trial 2. EOD FR exposure of roots increased the length of petiole 4 in trial 1. In general, shoots were more responsive than roots to the growth-regulating effects of EOD FR.

scholarly journals FLAME RETARDANTS EFFECTS ON THE INITIAL GROWTH OF Schizolobium amazonicum HUBER EX DUCKE

2021 ◽  
Vol 45 ◽  
Author(s):  
Elen Silma Oliveira Cruz Ximenes ◽  
Andréa Carvalho da Silva ◽  
Adilson Pacheco de Souza ◽  
Josiane Fernandes Keffer ◽  
Alison Martins dos Anjos ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Leaf Area ◽  
Flame Retardants ◽  
Biomass Accumulation ◽  
Dry Mass ◽  
Initial Growth ◽  
Environmental Implications ◽  
Leaf Dry Mass ◽  
Height Increase ◽  
Positive Effect

ABSTRACT Flame retardants are efficient in fighting wildfire; however, their environmental implications, especially regarding the vegetation, need to be clarified. This work aimed at assessing the effects of flame retardant on the initial growth of Schizolobium amazonicum. Treatments consisted in applying different flame retardant concentrations via substrate and leaf: Phos-Chek WD-881® (0, 3.00, 6.00, 8.00 and 10.00 mL L-1), Hold Fire® (0, 7.00, 9.00, 12.00 and 15.00 mL L-1) and water-retaining polymer Nutrigel® used as alternative retardant (0, 0.25, 0.50, 0.75 and 1.00 g L-1). Growth analyses were carried out to assess the effects of these substances (10 repetitions per treatment). The aliquot of 10.00 mL L-1 of Phos-Chek WD881 applied on the leaves led to an increase of 70% in leaf area and 15% in seedling height. The same Phos-Chek concentration favored height increase (32%) and total dry mass accumulation (33%) throughout time. The concentration of 15 mL L-1 of Hold Fire® applied on leaves, compromised 45% the accumulation of dry biomass in the seedling. Initially, 1.00 g L-1 of Nutrigel® applied via substrate led to an increase of 70% in leaf area, 29% in plant height, and 89% in leaf dry mass. Therefore, Phos-Chek applied on leaves favored shoot growth in S. amazonicum. Hold Fire® applied on leaves impaired biomass accumulation in seedlings. Nutrigel® applied on substrate does not cause long-lasting damage to the initial growth of S. amazonicum. The aliquot of 0.50 g L-1 administered via polymer leave had positive effect on seedling shoot.

The behaviour of plants in various gas mixtures

1971 ◽  
Vol 179 (1056) ◽  
pp. 177-188
Keyword(s):  
Carbon Dioxide ◽  
Gas Exchange ◽  
Partial Pressure ◽  
Higher Plants ◽  
Dry Mass ◽  
Carbon Dioxide Partial Pressure ◽  
Ambient Oxygen ◽  
Leaf Dry Mass ◽  
Rate Of Photosynthesis ◽  
Effect Of Oxygen

The effects of the composition and pressure of the ambient gas mixture on the diffusive gas exchange of leaves, and the effects of carbon dioxide and oxygen on respiration and photosynthesis are described. When photosynthesis is limited by the rate at which carbon dioxide reaches the chloroplasts, the net rate of photosynthesis of many (but not all) plant species depends on the ambient oxygen partial pressure. The effect of oxygen may be principally to stimulate a respiratory process rather than to inhibit carboxylation. However, when photosynthesis is not limited by the carbon dioxide supply, this respiratory process seems to be suppressed. The gas exchange of plant communities responds to the aerial environment in the way expected from measurements on single leaves, but the growth response to a given difference in gas composition is smaller than expected because of adaptation, notably in the ratio of leaf dry mass to leaf area. It is concluded that the growth rate of higher plants in given illumination will be independent of the partial pressure of oxygen and of other gases likely to be used to dilute it, provided that the carbon dioxide partial pressure is so adjusted (probably to not more than 2 mbar (200 Pa)) that the rate of photosynthesis is not limited by the rate of diffusion to the chloroplasts.

scholarly journals Environmental Impact On Morphological and Anatomical Structure of Ricinus communis L. Leaves Growing in Kathmandu, Nepal

2019 ◽  
Vol 7 (2) ◽  
pp. 274-278
Author(s):  
Belai Meeta Singh Suwal ◽  
Ratna Silwal Gautam ◽  
Dikshya Manandhar
Keyword(s):  
Climatic Factors ◽  
Ricinus Communis ◽  
Dry Mass ◽  
Anatomical Features ◽  
Ricinus Communis L ◽  
Leaf Dry Mass ◽  
Polluted Sites ◽  
Study Sites ◽  
The Comparative Study ◽  
The Impact

The current study was done to examine the impact of environmental pollution on morphology and anatomy of leaf of Ricinus communis L. of Kathmandu. The comparative study was done between the plants of high polluted sites i.e Ringroad sides and less polluted sites i.e Raniban forest of Kathmandu. The plants from both sites showed visible morphological and anatomical changes in leaves. These both study sites were found with similar soil factors and climatic factors. Reductions in some morphological and anatomical features were observed in leaves growing in highly polluted site. Reduction in leaf area, petiole length, thickness of palisade layer and thickness of spongy parenchyma was noticed in the leaves from highly polluted sites of Kathmandu. Other morphological and anatomical features such as leaf dry mass content, stomata frequency, thickness of cuticle and size of epidermal cells were noticed to be increased in leaves from highly polluted sites. Int. J. Appl. Sci. Biotechnol. Vol 7(2): 274-278  

Ozone-induced cytochemical and ultrastructural changes in leaf mesophyll cell walls

1997 ◽  
Vol 27 (4) ◽  
pp. 453-463 ◽  
Author(s):  
M S Günthardt-Georg ◽  
C J McQuattie ◽  
C Scheidegger ◽  
C Rhiner ◽  
R Matyssek
Keyword(s):  
Cell Walls ◽  
Mesophyll Cell ◽  
Ultrastructural Changes ◽  
Leaf Mesophyll ◽  
Leaf Mesophyll Cell

Selection of alfalfa for a lower initial rate of digestion and corresponding changes in epidermal and mesophyll cell wall thickness

1993 ◽  
Vol 73 (1) ◽  
pp. 111-122 ◽  
Author(s):  
B. P. Goplen ◽  
R. E. Howarth ◽  
G. L. Lees
Keyword(s):  
Cell Wall ◽  
Wall Thickness ◽  
Cell Walls ◽  
Dry Matter ◽  
Initial Rate ◽  
Environmental Influence ◽  
Mesophyll Cell ◽  
Cell Wall Thickness ◽  
Advanced Stage ◽  
Selection Of

A modified nylon bag technique, described in detail in this paper, appears to be an effective method of selecting for a lower initial rate of digestion (IRD) in alfalfa. Breeding for reduced IRD in alfalfa resulted in a 15% reduction in 4-h dry matter disappearance (DMD) after three cycles of selection (ultimate goal of 25–30 % reduction for a bloat-safe alfalfa). No further reduction in IRD occurred with a 4th cycle of selection. The IRD characteristic appears to be expressed at early stages of vegetative growth (pre-bud to early bud) and not at a more advanced stage of maturity (mid-bud to early bloom). The IRD characteristic also appears to be subject to environmental influence. Alfalfa plants selected for reduced IRD have consistently thicker cell walls compared to the unselected alfalfa check cv. Beaver. The advanced cycle 4 LIRD synthetic is being increased for subsequent pasture trials and assessment of bloat reduction. Key words: Nylon bag technique, cell rupture, pasture bloat, initial rate of digestion, cell wall thickness

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