The effects of environmental conditions on the inhibition of leaf gas exchange by NO2

1975 ◽  
Vol 53 (5) ◽  
pp. 475-482 ◽  
Author(s):  
H. S. Srivastava ◽  
P. A. Jolliffe ◽  
V. C. Runeckles
Keyword(s):  
Gas Exchange ◽  
Dark Respiration ◽  
Leaf Gas Exchange ◽  
Absolute Magnitude ◽  
High Irradiance ◽  
Diffusion Resistance ◽  
Inhibitory Effects ◽  
Natural Ecosystems ◽  
Photosynthetic Inhibition ◽  
Free Air

An open flow system was used to examine the uptake and effects of NO2 on gas exchange by primary leaves of bean (Phaseolus vulgaris L.) under a variety of conditions of irradiance, temperature, humidity, and atmospheric CO2 and O2 concentrations. At 3.0 ppm, NO2 inhibited apparent photosynthesis and dark respiration in all the conditions tested. Both 3.0 ppm and 7.0 ppm NO2 inhibited the evolution of CO2 into CO2-free air. The absolute magnitude of photosynthetic inhibition by NO2 was greatest at high irradiance, at the optimum temperature for apparent photosynthesis, and at high humidities. Changes in CO2 concentration from 100 to 600 ppm and in O2 concentration from 0 to 21% did not affect the percentage inhibition of apparent photosynthesis by NO2. High temperatures increased the inhibitory effects of NO2 on dark respiration.The effects of NO2 on apparent photosynthesis, dark respiration, and CO2 evolution into CO2-free air were based on inhibitory effects exerted within the leaves and not on CO2 diffusion into the leaf. Transpiration rate and stomatal diffusion resistance were only slightly affected by NO2. The uptake of NO2 was enhanced by high temperature, low CO2 concentration, and high humidity. The results of these studies support the view that NO2 uptake is subject to internal limitations ("mesophyll resistance") under many environmental conditions.The range and prevalence of NO2 effects suggest that NO2 may cause general detrimental changes in the physiology of leaf cells. Furthermore, the circumstances under which NO2 effects were found to occur indicate that such effects may be significant in natural ecosystems.

scholarly journals Salinity Influences Photosynthetic Characteristics, Water Relations, and Foliar Mineral Composition of Annona squamosa L.

1996 ◽  
Vol 121 (2) ◽  
pp. 243-248 ◽  
Author(s):  
Thomas E. Marler ◽  
Yasmina Zozor
Keyword(s):  
Gas Exchange ◽  
Water Relations ◽  
Salinity Stress ◽  
Root Zone ◽  
Dark Respiration ◽  
Leaf Gas Exchange ◽  
Chloride Concentration ◽  
Sand Culture ◽  
Mineral Nutrient ◽  
Annona Squamosa

Leaf gas exchange, chlorophyll fluorescence, water relations, and mineral nutrient relations responses of Annona squamosa seedlings to mild salinity were studied in sand culture in five experiments during 1990, 1991, and 1993. Trees were irrigated with a complete nutrient solution (control) or with this solution amended to 3 or 6 dS·m-1 with sea salt. Inhibition of net CO2 assimilation, stomatal conductance of CO2, and transpiration was apparent within 2 weeks of initiating salinity treatments, and gas exchange continued to decline until day 30 to 35. The diurnal pattern of leaf gas exchange was not altered by increased salinity. Salinity reduced CO2, light energy, and water-use efficiencies. Salinity sometimes reduced the ratio of variable to maximum fluorescence below that of the control, and this response was highly dependent on the ambient light conditions that preceded the measurements. Dark respiration was unaffected by salinity stress. Root zone salinity of 3 dS·m-1 administered for 52 days did not influence foliar sodium concentration or the ratio of sodium to potassium, but increased chloride concentration and decreased nitrogen concentration. The sodium response indicated that some form of exclusion or compartmentation occurred. Salinity reduced osmotic potential of root tissue but did not influence foliar osmotic or predawn xylem potential. These results indicate that A. squamosa is sensitive to salinity stress, and that the responses to salinity are consistent with other salt-sensitive woody perennial species.

Elevated CO2 increases the leaf temperature of two glasshouse-grown C4 grasses

2002 ◽  
Vol 29 (12) ◽  
pp. 1377 ◽  
Author(s):  
Katharina Siebke ◽  
Oula Ghannoum ◽  
Jann P. Conroy ◽  
Susanne von Caemmerer
Keyword(s):  
Gas Exchange ◽  
Elevated Co2 ◽  
Leaf Gas Exchange ◽  
Stomatal Closure ◽  
Co2 Assimilation ◽  
High Irradiance ◽  
Leaf Temperature ◽  
C4 Grasses ◽  
Co2 Partial Pressure ◽  
The Difference

This study investigates the effect of elevated CO2 partial pressure (pCO2)-induced stomatal closure on leaf temperature and gas exchange of C4 grasses. Two native Australian C4 grasses, Astrebla lappacea (Lindl.) Domin and Bothriochloa bladhii Kuntze, were grown at three different pCO2 (35, 70 and 120 Pa) in three matched, temperature-controlled glasshouse compartments. The difference between leaf and air temperature (ΔT) was monitored diurnally with thermocouples. ΔT increased with both step-increases of ambient pCO2. Average noon leaf temperature increased by 0.4 and 0.3°C for A. lappacea with the 35–70 and 70–120 Pa steps of pCO2 elevation, respectively. For B. bladhii, the increases were 0.5°C for both pCO2 steps. ΔT was strongly dependent on irradiance, pCO2 and air humidity. Leaf gas exchange was measured at constant temperature and high irradiance at the three growth pCO2. Under these conditions, CO2 assimilation saturated at 70 Pa, while stomatal conductance decreased by the same extent (0.58-fold) with both step-increases in pCO2, suggesting that whole-plant water use efficiency of C4 grasses would increase beyond a doubling of ambient pCO2. The ratio of intercellular to ambient pCO2 was not affected by short- or long-term doubling or near-tripling of pCO2, in either C4 species when measured under standard conditions.

Inhibition of gas exchange in bean leaves by NO2

1975 ◽  
Vol 53 (5) ◽  
pp. 466-474 ◽  
Author(s):  
H. S. Srivastava ◽  
P. A. Jolliffe ◽  
V. C. Runeckles
Keyword(s):  
Gas Exchange ◽  
Exposure Time ◽  
Gas Flow ◽  
Dark Respiration ◽  
Leaf Gas Exchange ◽  
Leaf Growth ◽  
Stomatal Resistance ◽  
Air Pollutant ◽  
Phaseolus Vulgaris L ◽  
Rate Of Absorption

An open gas-flow system was used to examine the effects of the air pollutant NO2 on gas exchange by primary leaves of bean (Phaseolus vulgaris L.). Apparent photosynthesis and dark respiration were both inhibited by NO2 concentrations between 1.0 and 7.0 ppm. The degree of inhibition was increased by increasing NO2 concentration and increasing exposure time. Leaf susceptibility to NO2 varied during leaf growth. NO2 was most inhibitory at the ages when maximum rates of apparent photosynthesis or respiration were observed in the NO2-free controls (11 or 12, or 8 days after sowing, respectively). The rate of absorption of NO2 by leaves increased in direct proportion with the NO2 concentration and declined with increasing exposure time. The NO2 uptake rate in the dark was about half of its rate during illumination because of greater stomatal resistance to NO2 absorption in the dark. Transpiration rate was less affected by NO2 than was photosynthesis or respiration. Accordingly, it is suggested that the principal effects of NO2 on leaf gas exchange are exerted in the leaf mesophyll and are not on the stomata.

scholarly journals SHORT-AND LONG-TERM EFFECTS OF SOURCE MANIPULATION IN SOUR CHERRY (Prunus cerasus L.)

HortScience ◽  
1991 ◽  
Vol 26 (6) ◽  
pp. 748C-748
Author(s):  
Desmond R. Layne ◽  
J.A. Flore
Keyword(s):  
Dark Respiration ◽  
Leaf Gas Exchange ◽  
Sour Cherry ◽  
Complete Recovery ◽  
Co2 Assimilation ◽  
Continuous Illumination ◽  
Long Term Effects ◽  
Source Reduction ◽  
Photosynthetic Inhibition ◽  
One Year

A series of experiments were conducted with one-year-old potted sour cherry trees to evaluate the effects of source reduction (removal of 70% of the expanded leaves = Defol.) or source enhancement (continuous illumination = C.L.) on source leaf gas exchange. There was a significant increase in net CO2 assimilation (A) and stomatal conductance (gs) of Defol. within one day in contrast to the non-defoliated control (Cont.). Defol. had lower daily dark respiration rates (Rd) and higher A values throughout the 14 h diurnal photoperiod than Cont. Defol. had daily assimilation rates 50% higher than Cont. in as early as 3 days. One month later, specific leaf weight, leaf chlorophyll and A was higher in Defol. Non-defoliated plants were also placed under either a 14 h photoperiod (Cont.) or a 24 h photoperiod (24h). A of 24h was reduced from Cont. by 50% after one day. The diurnal response of A in Cont. was removed when plants were put in C.L. Following 7 days in C.L., 70% defoliation of 24h plants resulted in a complete recovery from photosynthetic inhibition within 48 hours. The short-term effects of source manipulation on photochemical and carboxylation efficiencies, photorespiration and stomatal limitations will also be addressed.

Growth and Photosynthetic Response to Light and Nutrients of Flindersia brayleyana F. Muell., A Rainforest Tree With Broad Tolerance to Sun and Shade

1988 ◽  
Vol 15 (2) ◽  
pp. 299 ◽  
Author(s):  
WA Thompson ◽  
GC Stocker ◽  
PE Kriedemann
Keyword(s):  
Chlorophyll Content ◽  
Dark Respiration ◽  
Leaf Gas Exchange ◽  
Co2 Assimilation ◽  
High Irradiance ◽  
Leaf Expansion ◽  
Tree Seedlings ◽  
Apparent Quantum Yield ◽  
Leaf Chlorophyll ◽  
Flindersia Brayleyana

Seed from four species of rainforest trees with widely contrasting sunlight requirements for growth and development were sown within disturbance gaps amidst mature forest on the Herberton Range in North Queensland. Observations on seedling persistence plus comparative growth of young trees of Acacia aulacocarpa, Toona australis, Flindersia brayleyana and Darlingia darlingiana (species ranked according to adaptation from full sun to deep shade) confirmed a broad tolerance of Flindersia to sunlight under all conditions, from wide to narrow gaps (minimum 0.6% full sun equivalent). Photosynthetic attributes which underlie such broad tolerance were subsequently inferred from single leaf gas exchange, plus foliar analyses of nitrogen, phosphorus and chlorophyll on tree seedlings held for 180 days under two nutrient × three irradiance levels adjusted to represent natural irradiance incident upon the forest floor (low), mid-canopy (medium) and emergent crowns (high irradiance treatment). Medium irradiance plus high nutrients proved optimal for leaf expansion, chlorophyll content and photosynthesis in air. Growth under low irradiance was characterised by thinner leaf palisade tissue, lower rates of dark respiration, increased leaf chlorophyll per unit nitrogen and lower light compensation point for photosynthesis. Such leaves retained a relatively high photosynthetic capacity despite these other shade-leaf attributes. High irradiance plus low nutrients proved supraoptimal for leaf expansion and expression of photosynthetic activity. Chronic photoinhibition appeared to prevail because apparent quantum yield was reduced, while photosynthetic processes on a nitrogen basis were substantially impaired. Nitrogen use efficiency, as inferred from leaf chlorophyll content, light saturated CO2 assimilation rate, electron transport rate and carboxylation rate on a nitrogen basis declined with increasing growth irradiance. Some ecological implications for the establishment and growth of these rainforest tree species in disturbance gaps are discussed.

scholarly journals Physiological responses of two tropical weeds to shade: II. Leaf gas exchange and nitrogen content

1999 ◽  
Vol 34 (6) ◽  
pp. 952-961 ◽  
Author(s):  
Moacyr Bernardino Dias-Filho
Keyword(s):  
Nitrogen Content ◽  
Weed Management ◽  
Dark Respiration ◽  
Leaf Gas Exchange ◽  
Co2 Assimilation ◽  
Leaf Nitrogen ◽  
High Irradiance ◽  
Leaf Nitrogen Content ◽  
Light Regimes ◽  
Stachytarpheta Cayennensis

Ipomoea asarifolia (Desr.) Roem. & Schultz (Convolvulaceae) and Stachytarpheta cayennensis (Rich) Vahl. (Verbenaceae), two weeds found in pastures and crop areas in the Brazilian Amazonia, Brazil, 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. The objective was to determine the effect of shade on photosynthetic features and leaf nitrogen content of I. asarifolia and S. cayennensis. High-irradiance grown I. asarifolia leaves had significantly higher dark respiration and light saturated rates of photosynthesis than low-irradiance leaves. No significant differences for these traits, between treatments, were observed in S. cayennensis. Low-irradiance leaves of both species displayed higher CO2 assimilation rates under low irradiance. High-irradiance grown leaves of both species had less nitrogen per unit of weight. Low-irradiance S. cayennensis had more nitrogen per unit of leaf area than high-irradiance plants; however, I. asarifolia showed no consistent pattern for this variable through time. For S. cayennensis, leaf nitrogen content and CO2 assimilation were inversely correlated to the amount of biomass allocated to developing reproductive structures. These results are discussed in relation to their ecological and weed management implications.

scholarly journals Leaf Gas Exchange Performance of Ten Quinoa Genotypes under a Simulated Heat Wave

Plants ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 81 ◽  
Author(s):  
Ashley Eustis ◽  
Kevin M. Murphy ◽  
Felipe H. Barrios-Masias
Keyword(s):  
Heat Treatment ◽  
Heat Stress ◽  
Gas Exchange ◽  
High Temperatures ◽  
Heat Waves ◽  
Dark Respiration ◽  
Leaf Gas Exchange ◽  
Reproductive Capacity ◽  
Plant Water ◽  
Assimilation Capacity

Quinoa (Chenopodium quinoa Willd.) is a highly nutritious crop that is resilient to a wide range of abiotic stresses; however, sensitivity to high temperatures is regarded as an impediment to adoption in regions prone to heat waves. Heat stress is usually associated with a decrease in crop reproductive capacity (e.g., pollen viability), yet little is known about how leaf physiological performance of quinoa is affected by high temperatures. Several trials were conducted to understand the effect of high temperatures, without confounding stressors such as drought, on ten selected quinoa genotypes considered to encompass heat sensitive and heat tolerant plant material. Plants were grown under favorable temperatures and exposed to two temperature treatments over four consecutive days. The heat treatment simulated heat waves with maximum and minimum temperatures higher during the day and night, while the control treatment was maintained under favorable temperatures (maximum and minimum temperatures for ‘Heat’: 45/30 °C and ‘Control’: 20/14 °C). Leaf gas exchange (day), chlorophyll fluorescence (predawn and day) and dark respiration (night) were measured. Results show that most quinoa genotypes under the heat treatment increased their photosynthetic rates and stomatal conductance, resulting in a lower intrinsic water use efficiency. This was partly corroborated by an increase in the maximum quantum yield of photosystem II (Fv/Fm). Dark respiration decreased under the heat treatment in most genotypes, and temperature treatment did not affect aboveground biomass by harvest (shoot and seeds). These results suggest that heat stress alone favors increases in leaf carbon assimilation capacity although the tradeoff is higher plant water demand, which may lead to plant water stress and lower yields under non-irrigated field conditions.

scholarly journals Leaf Gas-exchange Characteristics of Sixteen Cycad Species

1997 ◽  
Vol 122 (1) ◽  
pp. 38-42 ◽  
Author(s):  
Thomas E. Marler ◽  
Leah E. Willis
Keyword(s):  
Gas Exchange ◽  
Water Use Efficiency ◽  
Water Use ◽  
Growth Form ◽  
Dark Respiration ◽  
Leaf Gas Exchange ◽  
African Species ◽  
Use Efficiency ◽  
Gas Exchange Characteristics ◽  
The Difference

Leaf gas exchange characteristics for 16 species of cycad were determined under field conditions in Miami, Fla. Net CO2 assimilation (ACO2) ranged from 4.9 μmol·m-2·s-1 for Lepidozamia peroffskyana Regel to 10.1 μmol·m-2·s-1 for Zamia furfuracea L. fil. in Aiton. Stomatal conductance to H2O (gs) was more variable, ranging from 85 mmol·m-2·s-1 for Cycas seemannii A. Br. to 335 mmol·m-2·s-1 for Encephalartos hildebrandtii A. Br. & Bouche. Transpiration (E) ranged from 1.7 mmol·m-2·s-1 for Cycas chamberlainii W.H. Brown & Keinholz to 4.8 mmol·m-2·s-1 for Encephalartos hildebrandtii. Highly variable E was more controlling of water-use efficiency than the less-variable ACO2. The difference between air and pinnae temperature ranged from 0.3 to 1.6 °C and was inversely related to mean gs among the species. The values within geographic regions representative of the native habitats of the species were highly variable. For example, two of the African species exhibited the highest and lowest values of water-use efficiency in the survey. Leaf gas exchange for the four largest species with arborescent growth form was less than that for the three small species with subterranean or short bulbous growth form. The diurnal variation in leaf gas exchange for Zamia furfuracea exhibited a two-peaked pattern with a distinct midday depression in ACO2 and gs. The ratio of dark respiration to maximum ACO2 for Zamia furfuracea was 0.04. As a group, the values for ACO2 and gs for these cycads ranked at the lower end of the range for all plants species.

scholarly journals 476 Reducing Midday Irradiance Increases Net CO2 Assimilation in Citrus Leaves

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 476B-476
Author(s):  
John L. Jifon ◽  
Jim Syvertsen
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Vapor Pressure ◽  
Beneficial Effect ◽  
Leaf Gas Exchange ◽  
Co2 Assimilation ◽  
High Irradiance ◽  
Air Temperatures ◽  
Net Co2 Assimilation ◽  
Citrus Leaves

Maximum CO2 assimilation rates (ACO2) in citrus are not realized in environments with high irradiance, high temperatures, and high leaf-to-air vapor pressure differences (D). We hypothesized that moderate shading would reduce leaf temperature and D, thereby increasing stomatal conductance (gs) and ACO2. A 61% reduction in irradiance under aluminum net shade screens reduced midday leaf temperatures by 8 °C and D by 62%. This effect was prominent on clear days when average midday air temperature and vapor pressure deficits exceeded 30 °C and 3 kPa. ACO2 and gs increased 42% and 104%, respectively, in response to shading. Although shaded leaves had higher gs, their transpiration rates were only 7% higher and not significantly different from sunlit leaves. Leaf water use efficiency (WUE) was significantly improved in shaded leaves (39%) compared to sunlit leaves due to the increase in ACO2. Early in the morning and late afternoon when irradiance and air temperatures were low, shading had no beneficial effect on ACO2 or other gas exchange characteristics. On cloudy days or when the maximum daytime temperature and atmospheric vapor pressure deficits were less than 30 °C and 2 kPa, respectively, shading had little effect on leaf gas exchange properties. The results are consistent with the hypothesis that the beneficial effect of radiation load reduction on ACO2 is related to improved stomatal conductance in response to lowered D.

scholarly journals 558 PB 377 SALINITY AND LEAF GAS-EXCHANGE OF ANNONA SOUAMOSA

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 511e-511
Author(s):  
Thomas E. Marler ◽  
Yasmina Zozor
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Gas Phase ◽  
Water Use ◽  
Dark Respiration ◽  
Leaf Gas Exchange ◽  
Sea Salt ◽  
Sand Culture ◽  
Diurnal Pattern ◽  
Complete Nutrient Solution

Leaf gas-exchange responses of A. souamosa seedlings to salinity were studied in sand culture in a series of glasshouse experiments. Trees were irrigated with a complete nutrient solution as the control, or with this solution amended to 3 or 6 dS/m with sea salt. Inhibition of net CO2 assimilation, stomatal conductance of CO2, and transpiration was apparent 14 days after treatments were imposed, and continued to decline until day 30 to 35. The diurnal pattern of leaf gas exchange was not altered by salinity. Salinity reduced CO2, light energy, and water use efficiencies. Dark respiration and internal partial pressure of CO2 were unaffected by salinity stress. Results indicated that substrate salinity inhibited photosynthesis of A. souamosa via limitations on mesophyll capacity for CO2 assimilation and had little effect on gas phase limitations.

Sign in / Sign up

Export Citation Format

Share Document