Leaf injury to bean plants grown in carbon dioxide enriched atmospheres

1985 ◽  
Vol 63 (11) ◽  
pp. 2015-2020 ◽  
Author(s):  
David L. Ehret ◽  
Peter A. Jolliffe
Keyword(s):  
Water Status ◽  
Photosynthetic Photon Flux Density ◽  
High Light Intensity ◽  
Starch Accumulation ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Cool Temperature ◽  
Leaf Water Status ◽  
Leaf Injury ◽  
Diffusive Resistance

Bush bean (Phaseolus vulgaris L.) plants grown in atmospheres enriched with CO2 (1400 μL L−1) showed marked reductions in photosynthetic capacity and accelerated chlorosis of primary leaves. Leaf injury was observed only in CO2-enriched plants, but the degree of injury was regulated by secondary factors, light and temperature. Conditions of relatively high light intensity (340–370 μmol m−2 s−1 photosynthetic photon flux density) or cool temperature (20 °C) promoted leaf injury of CO2-enriched plants. Leaf starch accumulation was highest under conditions that caused injury. The enhanced chlorosis and corresponding decline in photosynthetic activity, however, were not related to changes in stomatal diffusive resistance or leaf water status. Contaminant gases, such as ethylene, were not detectable in the CO2-enrichment chambers.

Studies on the physiology and propagation of the ostrich fern, Matteuccia struthiopteris

1985 ◽  
Vol 86 ◽  
pp. 153-159
Author(s):  
Robert K. Prange
Keyword(s):  
Flux Density ◽  
Water Availability ◽  
Water Status ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Base Temperature ◽  
Photosynthetic Photon Flux ◽  
Fertile Frond ◽  
Rate Of Emergence

SynopsisThe effect of photosynthetic photon flux density (PPFD), water, temperature and nutrition on frond emergence, vegetative frond production, fertile frond production, vegetative propagation and dormancy is examined. Ostrich fern plants will not break winter dormancy until they have received a minimum amount of cold exposure below a base temperature which is above 5.8°C and may be as high as 20°C. After the plants have received their chilling requirement, vegetative frond emergence does not occur until temperatures at or above ca. 9.3°C are reached. Percent germination and rate of emergence increases up to ca. 24°C. Photosynthetic photon flux density, water availability and mineral nutrition can affect both vegetative and fertile frond production but water availability appears to be the most critical. A mild water stress of −0.15MPa can have significant effects on water status and gas exchange in fronds. Sporophyte plants for field production have been produced vegetatively from detached meristems occurring naturally on the rhizomes, and through fertilization of axenic gametophytes.

Gas Exchange Properties of Jointed Goatgrass (Aegilops cylindrica)

Weed Science ◽  
1987 ◽  
Vol 35 (4) ◽  
pp. 482-489 ◽  
Author(s):  
David R. Gealy
Keyword(s):  
Dark Respiration ◽  
Stomatal Density ◽  
Photosynthetic Photon Flux Density ◽  
Compensation Point ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Aegilops Cylindrica ◽  
Jointed Goatgrass ◽  
Diffusive Resistance ◽  
Leaf Surfaces

Net (apparent) photosynthesis rate (Pn) of jointed goatgrass (Aegilops cylindricaHost # AEGCY) leaves in the greenhouse became light saturated at a photosynthetic photon flux density (PPFD) of about 1000 μE·m–1-2·s–1with a maximum Pn of 27 mg CO2·dm–2·h–1. Diffusive resistance to water vapor (rl) of adaxial leaf surfaces was 43% that of abaxial surfaces, in part, because stomatal density was 50% greater on adaxial leaf surfaces than on abaxial surfaces. Dark respiration rate (Rd) was 1.6 mg CO2·dm−2·h−1. Light compensation point (CPl) was 21 μE·m−2·s−1and CO2compensation point (CPc) was 32 ppmv. In the field, where light intensity and temperature were greater than in the greenhouse, leaves became light saturated for Pn at a higher intensity, and Rd and CPl were three times greater than in the greenhouse. Pn and Rd of spikes at anthesis were at least 30% less and 200% greater, respectively, than the values for leaves.

scholarly journals NaCl salinity-induced changes in water status, ion contents and photosynthetic properties of Shepherdia argentea (Pursh) Nutt. seedlings

2010 ◽  
Vol 56 (No. 7) ◽  
pp. 325-332 ◽  
Author(s):  
J. Qin ◽  
W.Y. Dong ◽  
K.N. He ◽  
Y. Yu ◽  
G.D. Tan ◽  
...  
Keyword(s):  
Water Status ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Nacl Salinity ◽  
Chl A ◽  
Chlorophyll Contents ◽  
Cellular Dehydration ◽  
Ionic Imbalance ◽  
Stomatal Limitations

Two-year old seedlings of Silver buffaloberry (Shepherdia argentea (Pursh) Nutt.) were exposed to NaCl salinity (0, 200, 400 and 600 mmol/l) for 30 days. Leaf water potential (&Psi;<sub>w</sub>), chlorophyll contents (Chl a, b, and a + b) and K<sup>+</sup> content decreased with an increase in salinity. Relative water content (RWC) declined significantly with<br />400 and 600 mmol/l NaCl. However, salinity induced an excessive accumulation of Na<sup>+</sup> in the leaves of plants. Light responses of photosynthesis showed that net photosynthetic rate (P<sub>N</sub>) values were continuously raised with the increase of photosynthetic photon flux density (PPFD) at all salinity levels and plants treated with 600 mmol/l salinity suffered from photoinhibition with the lowest P<sub>N</sub> values. The reduction of P<sub>N</sub> and stomatal conductance (g<sub>s</sub>) associated with a sharp increase of intercellular CO<sub>2</sub> concentration (C<sub>i</sub>) in the leaves at 600 mmol/l salt-treated plants showed that non-stomatal limitations might have prevailed over stomatal limitations under severe saline conditions, due to severe cellular dehydration, inhibited synthesis of chlorophyll and ionic imbalance and toxicity. It is concluded that S. argentea possesses high salt tolerance capacity and can be widely cultivated in salt-affected areas.

scholarly journals LED Illumination Spectrum Manipulation for Increasing the Yield of Sweet Basil (Ocimum basilicum L.)

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 344
Author(s):  
Md Momtazur Rahman ◽  
Mikhail Vasiliev ◽  
Kamal Alameh
Keyword(s):  
Growth Rate ◽  
Fold Increase ◽  
Photosynthetic Photon Flux Density ◽  
Ocimum Basilicum ◽  
Photon Flux ◽  
Photon Flux Density ◽  
White Led ◽  
Experimental Conditions ◽  
Sweet Basil ◽  
Optimal Illumination

Manipulation of the LED illumination spectrum can enhance plant growth rate and development in grow tents. We report on the identification of the illumination spectrum required to significantly enhance the growth rate of sweet basil (Ocimum basilicum L.) plants in grow tent environments by controlling the LED wavebands illuminating the plants. Since the optimal illumination spectrum depends on the plant type, this work focuses on identifying the illumination spectrum that achieves significant basil biomass improvement compared to improvements reported in prior studies. To be able to optimize the illumination spectrum, several steps must be achieved, namely, understanding plant biology, conducting several trial-and-error experiments, iteratively refining experimental conditions, and undertaking accurate statistical analyses. In this study, basil plants are grown in three grow tents with three LED illumination treatments, namely, only white LED illumination (denoted W*), the combination of red (R) and blue (B) LED illumination (denoted BR*) (relative red (R) and blue (B) intensities are 84% and 16%, respectively) and a combination of red (R), blue (B) and far-red (F) LED illumination (denoted BRF*) (relative red (R), blue (B) and far-red (F) intensities are 79%, 11%, and 10%, respectively). The photosynthetic photon flux density (PPFD) was set at 155 µmol m−2 s−1 for all illumination treatments, and the photoperiod was 20 h per day. Experimental results show that a combination of blue (B), red (R), and far-red (F) LED illumination leads to a one-fold increase in the yield of a sweet basil plant in comparison with only white LED illumination (W*). On the other hand, the use of blue (B) and red (R) LED illumination results in a half-fold increase in plant yield. Understanding the effects of LED illumination spectrum on the growth of plant sweet basil plants through basic horticulture research enables farmers to significantly improve their production yield, thus food security and profitability.

scholarly journals Plant buffering against the high-light stress-induced accumulation of CsGA2ox8 transcripts via alternative splicing to finely tune gibberellin levels and maintain hypocotyl elongation

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Bin Liu ◽  
Shuo Zhao ◽  
Pengli Li ◽  
Yilu Yin ◽  
Qingliang Niu ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Light Intensity ◽  
Intron Retention ◽  
Light Stress ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Rna Seq ◽  
Multiple Transcripts ◽  
Novel Transcript

AbstractIn plants, alternative splicing (AS) is markedly induced in response to environmental stresses, but it is unclear why plants generate multiple transcripts under stress conditions. In this study, RNA-seq was performed to identify AS events in cucumber seedlings grown under different light intensities. We identified a novel transcript of the gibberellin (GA)-deactivating enzyme Gibberellin 2-beta-dioxygenase 8 (CsGA2ox8). Compared with canonical CsGA2ox8.1, the CsGA2ox8.2 isoform presented intron retention between the second and third exons. Functional analysis proved that the transcript of CsGA2ox8.1 but not CsGA2ox8.2 played a role in the deactivation of bioactive GAs. Moreover, expression analysis demonstrated that both transcripts were upregulated by increased light intensity, but the expression level of CsGA2ox8.1 increased slowly when the light intensity was >400 µmol·m−2·s−1 PPFD (photosynthetic photon flux density), while the CsGA2ox8.2 transcript levels increased rapidly when the light intensity was >200 µmol·m−2·s−1 PPFD. Our findings provide evidence that plants might finely tune their GA levels by buffering against the normal transcripts of CsGA2ox8 through AS.

scholarly journals Effects of Light Quality on the Chlorophyll Degradation Pathway in Rice Seedling Leaves

2016 ◽  
Vol 44 (2) ◽  
pp. 393-398
Author(s):  
Chang-Chang CHEN ◽  
Kuan-Hung LIN ◽  
Meng-Yuan HUANG ◽  
Wen-Dar HUANG ◽  
Chi-Ming YANG
Keyword(s):  
Light Quality ◽  
Protoporphyrin Ix ◽  
Degradation Pathway ◽  
Photosynthetic Photon Flux Density ◽  
Rice Seedling ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Rice Seedlings ◽  
Rice Varieties ◽  
Enriched Environments

The objective of this study was to investigate the dynamics of chlorophyll (Chl), biosynthetic intermediates (protoporphyrin IX, magnesium protoporphyrin IX, and protochlorophyllide), degradation intermediates [chlorophyllide (Chlide), pheophytin (Phe), and pheophorbide (Pho)], and carotenoids (Car) in leaves of rice seedlings. Two rice varieties, 'Taichung Shen 10' ('TCS10') and 'IR1552', were grown under different light quality conditions controlled by light emitting diodes (LED). Lighting treatments for rice seedlings were included by red (R), blue (B), green (G), and red + blue (RB), with fluorescent lighting (FL) as the control and photosynthetic photon flux density being set at 105 µmol m-2 s-1. The results show that lower levels of Chl and Car in leaves were detected under G lighting, and light quality did not mediate porphyrins in biosynthetic pathways. Rice seedling leaves took Chl→Phe→Pho and Chl→Chlide→Pho as the major and minor degradation routes, respectively. Furthermore, higher Phe/Chlide ratios were observed under G and FL lighting conditions, indicating that green-enriched environments can up-regulate the minor degradation route in leaves.

scholarly journals Analyzing the major drivers of NEE in a Mediterranean alpine shrubland

2010 ◽  
Vol 7 (9) ◽  
pp. 2601-2611 ◽  
Author(s):  
B. R. Reverter ◽  
E. P. Sánchez-Cañete ◽  
V. Resco ◽  
P. Serrano-Ortiz ◽  
C. Oyonarte ◽  
...  
Keyword(s):  
Net Ecosystem Exchange ◽  
High Elevation ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Precipitation Pattern ◽  
Key Factors ◽  
Cold Temperatures ◽  
Carbon Sequestration Potential ◽  
Sequestration Potential

Abstract. Two years of continuous measurements of net ecosystem exchange (NEE) using the eddy covariance technique were made over a Mediterranean alpine shrubland. This ecosystem was found to be a net source of CO2 (+ 52 ± 7 g C m−2 and + 48 ± 7 g C m−2 for 2007 and 2008) during the two-year study period. To understand the reasons underlying this net release of CO2 into the atmosphere, we analysed the drivers of seasonal variability in NEE over these two years. We observed that the soil water availability – driven by the precipitation pattern – and the photosynthetic photon flux density (PPFD) are the key factors for understanding both the carbon sequestration potential and the duration of the photosynthetic period during the growing season. Finally, the effects of the self-heating correction to CO2 and H2O fluxes measured with the open-path infrared gas analyser were evaluated. Applying the correction turned the annual CO2 budget in 2007 from a sink (− 135 ± 7 g C m−2) to a source (+ 52 ± 7 g C m−2). The magnitude of this change is larger than reported previously and is shown to be due to the low air density and cold temperatures at this high elevation study site.

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