Assimilation and release of internal carbon dioxide by woody plant shoots

1970 ◽  
Vol 48 (7) ◽  
pp. 1351-1354 ◽  
Author(s):  
W. żelawski ◽  
F. P. Riech ◽  
R. G. Stanley
Keyword(s):  
Gas Exchange ◽  
Woody Plants ◽  
Woody Plant ◽  
Leaf Gas Exchange ◽  
Soluble Sugars ◽  
Pinus Elliottii ◽  
Short Term ◽  
Transpiration Stream ◽  
Pine Seedlings ◽  
Plant Shoots

This study was undertaken to determine whether tree stems can reassimilate internal CO2 produced by respiration or whether this CO2 is evolved and could possibly interfere with measurements of leaf gas exchange. Radioactive CO2 was added to the stem transpiration stream of slash pine seedlings (Pinus elliottii Engelm.) and the distribution of 14C studied in shoots and needles exposed to dark and light conditions.Photosynthesis decreases the amount of internal CO2 evolved. Large amounts of 14CO2 from the transpiration stream are incorporated into organic compounds of needles and stems, primarily into ethanol-soluble sugars and organic acids, and in time, small amounts of 14C occur in the ethanol-insoluble materials.These results indicate that respiratory CO2 transported in the transpiration stream of woody plants can be reused in photosynthesis or possibly other metabolic processes. Internal CO2 is also evolved to the atmosphere in large amounts, but related research indicates it diffuses primarily out of the stem tissue not the needles. The evolved CO2 supplied from stems does not significantly affect short term measurements of needle gas exchange in pine seedlings.

scholarly journals Beyond the extreme: recovery of carbon and water relations in woody plants following heat and drought stress

2019 ◽  
Vol 39 (8) ◽  
pp. 1285-1299 ◽  
Author(s):  
Nadine K Ruehr ◽  
Rüdiger Grote ◽  
Stefan Mayr ◽  
Almut Arneth
Keyword(s):  
Heat Stress ◽  
Gas Exchange ◽  
Water Relations ◽  
Woody Plants ◽  
Leaf Gas Exchange ◽  
Experimental Studies ◽  
Drought Severity ◽  
Stress Recovery ◽  
Mild Stress ◽  
Post Stress

Abstract Plant responses to drought and heat stress have been extensively studied, whereas post-stress recovery, which is fundamental to understanding stress resilience, has received much less attention. Here, we present a conceptual stress-recovery framework with respect to hydraulic and metabolic functioning in woody plants. We further synthesize results from controlled experimental studies following heat or drought events and highlight underlying mechanisms that drive post-stress recovery. We find that the pace of recovery differs among physiological processes. Leaf water potential and abscisic acid concentration typically recover within few days upon rewetting, while leaf gas exchange-related variables lag behind. Under increased drought severity as indicated by a loss in xylem hydraulic conductance, the time for stomatal conductance recovery increases markedly. Following heat stress release, a similar delay in leaf gas exchange recovery has been observed, but the reasons are most likely a slow reversal of photosynthetic impairment and other temperature-related leaf damages, which typically manifest at temperatures above 40 °C. Based thereon, we suggest that recovery of gas exchange is fast following mild stress, while recovery is slow and reliant on the efficiency of repair and regrowth when stress results in functional impairment and damage to critical plant processes. We further propose that increasing stress severity, particular after critical stress levels have been reached, increases the carbon cost involved in reestablishing functionality. This concept can guide future experimental research and provides a base for modeling post-stress recovery of carbon and water relations in trees.

Dynamics of leaf gas exchange, chlorophyll fluorescence and stem diameter changes during freezing and thawing of Scots pine seedlings

2015 ◽  
Vol 35 (12) ◽  
pp. 1314-1324 ◽  
Author(s):  
Lauri Lindfors ◽  
Teemu Hölttä ◽  
Anna Lintunen ◽  
Albert Porcar-Castell ◽  
Eero Nikinmaa ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Scots Pine ◽  
Leaf Gas Exchange ◽  
Stem Diameter ◽  
Freezing And Thawing ◽  
Pine Seedlings

scholarly journals Determining the Effects of Abscisic Acid Drenches on Evapotranspiration and Leaf Gas Exchange of Tomato

HortScience ◽  
2011 ◽  
Vol 46 (11) ◽  
pp. 1512-1517 ◽  
Author(s):  
Manuel G. Astacio ◽  
Marc W. van Iersel
Keyword(s):  
Abscisic Acid ◽  
Gas Exchange ◽  
Shelf Life ◽  
Water Use ◽  
Water Loss ◽  
Leaf Gas Exchange ◽  
Short Term ◽  
Leaf Physiology ◽  
Rate Dependent ◽  
Short Period

It is common for plants in the retail market to receive inadequate water and lose aesthetic value within a short period of time. The plant hormone abscisic acid (ABA) is naturally produced in response to drought conditions and reduces transpiration (E) by closing the stomata. Thus, ABA may lengthen shelf life of retail plants by reducing water loss. Two studies were conducted to look at effects of ABA on plant water use and shelf life over a 13-day period and short-term effects of ABA on leaf physiology. The objective of the short-term study was to determine how quickly 100-mL drenches of 250 mg·L−1 ABA solution affect leaf gas exchange of tomatoes (Solanum lycopersicum ‘Supersweet 100’). ABA drenches reduced stomatal conductance (gS), E, and photosynthetic rate (Pn) within 60 min. After 2 h, E, gs, and Pn were reduced by 66%, 72%, and 55% respectively, compared with the control plants. In the13-day study, ABA was applied to tomatoes as a 100-mL drench at concentrations ranging from 0 to 1000 mg·L−1 and ABA effects on water use and time to wilting were quantified. Half of the plants were not watered after ABA application, whereas the other plants were watered as needed. In general, higher ABA concentrations resulted in less water use by both well-watered and unwatered plants. ABA delayed wilting of unwatered plants by 2 to 8 days (dependent on the dose) as compared with control plants. In well-watered plants, ABA reduced daily evapotranspiration (ET) for 5 days, after which there were no further ABA effects. Negative side effects of the ABA application were rate-dependent chlorosis of the lower leaves followed by leaf abscission. These studies demonstrate that ABA drenches rapidly close stomata, limit transpirational water loss, and can extend the shelf life of retail plants by up to 8 days, which exemplifies its potential as a commercially applied plant growth regulator.

Seasonal trends in reduced leaf gas exchange and ozone-induced foliar injury in three ozone sensitive woody plant species

2005 ◽  
Vol 136 (1) ◽  
pp. 33-45 ◽  
Author(s):  
K. Novak ◽  
M. Schaub ◽  
J. Fuhrer ◽  
J.M. Skelly ◽  
C. Hug ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Plant Species ◽  
Woody Plant ◽  
Leaf Gas Exchange ◽  
Foliar Injury ◽  
Seasonal Trends ◽  
Woody Plant Species

A dynamic leaf gas-exchange strategy is conserved in woody plants under changing ambient CO2 : evidence from carbon isotope discrimination in paleo and CO2 enrichment studies

2016 ◽  
Vol 22 (2) ◽  
pp. 889-902 ◽  
Author(s):  
Steven L. Voelker ◽  
J. Renée Brooks ◽  
Frederick C. Meinzer ◽  
Rebecca Anderson ◽  
Martin K.-F. Bader ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Carbon Isotope ◽  
Woody Plants ◽  
Carbon Isotope Discrimination ◽  
Leaf Gas Exchange ◽  
Co2 Enrichment ◽  
Isotope Discrimination ◽  
Ambient Co2

scholarly journals Gas exchange and organic solutes in forage sorghum genotypes grown under different salinity levels

2018 ◽  
Vol 22 (4) ◽  
pp. 231-236 ◽  
Author(s):  
Daniela S. Coelho ◽  
Welson L. Simões ◽  
Alessandra M. Salviano ◽  
Alessandro C. Mesquita ◽  
Keila da C. Alberto
Keyword(s):  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Block Design ◽  
Soluble Sugars ◽  
Forage Sorghum ◽  
Randomized Block Design ◽  
Salinity Levels ◽  
Sorghum Genotypes ◽  
Amino Acid Contents ◽  
Saline Solutions

ABSTRACT Adaptation of plants to saline environments depends on the activation of mechanisms that minimize the effects of excess ions on vital processes, such as photosynthesis. The objective of this study was to evaluate the leaf gas exchange, chlorophyll, and organic solute in ten genotypes of forage sorghum irrigated with solutions of different salinity levels. The experiment was conducted in a randomized block design, in a 10 x 6 factorial arrangement, with three replications, using ten genotypes - F305, BRS-655, BRS-610, Volumax, 1.015.045, 1.016.005, 1.016.009, 1.016.013, 1.016.015 and 1.016.031 - and six saline solutions, with electrical conductivity (ECw) of 0, 2.5, 5.0, 7.5, 10 and 12.5 dS m-1. The photosynthetic activity in forage sorghum plants reduces with increasing salinity, and this response was found in the ten genotypes evaluated. The chlorophyll and protein contents were not affected by salinity, whereas carbohydrates and amino acid contents increased with increasing ECw. Soluble sugars are essential for osmoregulation of forage sorghum due to its high content in leaves.

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