The effect of nitric oxide fumigation at two CO2 concentrations on net photosynthesis and stomatal resistance of tomato (Lycopersicon lycopersicum L. cv. Abunda)

The responses of carbon dioxide exchange and leaf elongation of potted P. maximum var. trichoglume plants to water deficits were investigated in controlled environments and outdoors during drying cycles down to -92 bars leaf water potential, The sensitivities of net photosynthesis and leaf elongation to water deficits were similar. The leaf water potentials at which net photosynthesis and elongation ceased (c. -12 bars), and stomatal resistance increased substantially (- 6 bars), were relatively unaffected by nitrogen supply, environmental conditions during growth, and whether plants had previously experienced stress. However, these factors influenced the rate of net photosynthesis, at high leaf water potentials by affecting stomatal resistance and at moderate water potentials by affecting both stomatal and intracellular resistances. Stomata1 resistance was more sensitive than intracellular resistance to water deficits. Dark respiration rate decreased with leaf water potential, and was higher in plants receiving additional nitrogen. At moderate leaf water potentials (-7 to -9 bars), net photosynthesis of this C4 grass exhibited light saturation and rates similar to C3 plants. We suggest that the difference in behaviour of controlled-environment-grown and field-grown plants to water deficits observed with some species is unlikely to be due to differences in the aerial environment, but may result from differences in the rate at which stress develops. The ecological significance and evolution of the C4 syndrome are discussed briefly.

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Influence of Partial Defoliation on Photosynthesis, Photorespiration and Transpiration by Lucerne Leaves of Different Ages

Functional Plant Biology ◽

10.1071/pp9740561 ◽

1974 ◽

Vol 1 (4) ◽

pp. 561 ◽

Cited By ~ 35

Author(s):

KC Hodgkinson

Keyword(s):

Photosynthetic Rate ◽

Net Photosynthesis ◽

Stomatal Resistance ◽

Long Term Effects ◽

Photosynthetic Rates ◽

Co2 Diffusion ◽

Different Ages ◽

Short And Long Term ◽

Medicago Sativa L

A study was made of the short- and long-term effects of partial defoliation (cutting at 15 cm above the crown) of lucerne plants (Medicago sativa L. cv. Hunter River) on the net photosynthesis, transpiration, photorespiration and CO2 transfer resistances of remaining leaves. The response in gas-exchange properties of leaves of different ages to partial defoliation of the plant was also investigated. Partial defoliation always induced rejuvenation in photosynthetic rate of remaining leaves. Young and middle-aged leaves rejuvenated to rates comparable to those of recently expanded leaves but old leaves only partially rejuvenated. Time after defoliation to attain peak rates increased as leaves aged; values were 5, 9 and 12 days for plants partially defoliated on days 16, 30 and 65 of regrowth respectively. Peak rates were maintained for only 3 or 4 days before declining. Rates of photorespiration and photosynthesis were closely coupled. Transpiration rates varied over time in a similar but more erratic pattern to net photosynthetic rates. Changes in net photosynthetic rates associated with senescence, defoliation treatments and irradiance levels were largely attributable to changes in intracellular resistance to CO2 transfer. Intracellular resistances ranged from 2.6 to 30 s cm-1, constituting 67-95 % of the total resistance to photosynthesis. Stomatal resistance to CO2 diffusion remained low, 0.2 - 1.0 s cm-1, for all but very old leaves. Partial defoliation followed by continual removal of new crown and stubble shoots induced very high net photosynthetic rates, c. 15 days later. Highest net photosynthetic rate was 238 ng CO2 cm-2 s-1. Possible mechanisms responsible for photosynthetic rejuvenation following partial defoliation are discussed, together with ecological implications of this phenomenon.

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Yield, Physiological Performance, and Phytochemistry of Basil (Ocimum basilicum L.) under Temperature Stress and Elevated CO2 Concentrations

Plants ◽

10.3390/plants10061072 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1072

Author(s):

T. Casey Barickman ◽

Omolayo J. Olorunwa ◽

Akanksha Sehgal ◽

C. Hunt Walne ◽

K. Raja Reddy ◽

...

Keyword(s):

Low Temperature ◽

Elevated Co2 ◽

Temperature Stress ◽

Growth Temperature ◽

Intercellular Co2 Concentration ◽

Net Photosynthesis ◽

High Temperature Stress ◽

Low Temperature Stress ◽

Apparent Quantum Yield ◽

Co2 Concentrations

Early season sowing is one of the methods for avoiding yield loss for basil due to high temperatures. However, basil could be exposed to sub-optimal temperatures by planting it earlier in the season. Thus, an experiment was conducted that examines how temperature changes and carbon dioxide (CO2) levels affect basil growth, development, and phytonutrient concentrations in a controlled environment. The experiment simulated temperature stress, low (20/12 °C), and high (38/30 °C), under ambient (420 ppm) and elevated (720 ppm) CO2 concentrations. Low-temperature stress prompted the rapid closure of stomata resulting in a 21% decline in net photosynthesis. Chlorophylls and carotenoids decreased when elevated CO2 interacted with low-temperature stress. Basil exhibited an increase in stomatal conductance, intercellular CO2 concentration, apparent quantum yield, maximum photosystem II efficiency, and maximum net photosynthesis rate when subjected to high-temperature stress. Under elevated CO2, increasing the growth temperature from 30/22 °C to 38/30 °C markedly increased the antioxidants content of basil. Taken together, the evidence from this research recommends that varying the growth temperature of basil plants can significantly affect the growth and development rates compared to increasing the CO2 concentrations, which mitigates the adverse effects of temperature stress.

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CO2 EXCHANGE RATES AND STOMATAL DIFFUSIVE RESISTANCE IN SOYBEAN EXPOSED TO O3 AND SO2

Canadian Journal of Plant Science ◽

10.4141/cjps85-039 ◽

1985 ◽

Vol 65 (2) ◽

pp. 267-274 ◽

Cited By ~ 10

Author(s):

B. I. CHEVONE ◽

Y. S. YANG

Keyword(s):

Exchange Rates ◽

Net Photosynthesis ◽

Stomatal Resistance ◽

Co2 Exchange ◽

Carbon Dioxide Exchange ◽

Simultaneous Application ◽

Diffusive Resistance ◽

Before And After ◽

Glycine Max L ◽

Pollutant Mixtures

Soybean (Glycine max (L.) Merr. ’Essex’) plants, 21–24 days old, were exposed to 400 μg/m3 (0.20 μL/L) ozone (O3) and 1865 μg/m3 (0.70 μL/L) sulfur dioxide (SO2) in various combinations. Fumigation was administered for 2 h either as single pollutants (O3 and SO2), simultaneously (O3 + SO2), or in overlapping pollutant combinations (O3 for 1 h followed by O3 + SO2 or SO2 for 1 h followed by SO2 + O3). Carbon dioxide exchange rates (CER) of trifoliolate leaves were measured during the fumigations, and stomatal resistance to H2O was determined immediately before and after pollutant exposure. At the end of a 2-h exposure, O3 and SO2, administered separately, did not significantly affect CER. Exposure to O3 followed by O3 + SO2, SO2 followed by SO2 + O3, and continuous O3 + SO2 significantly reduced CER to 62, 41 and 33% of preexposure rates, respectively. Stomatal resistance was not significantly altered by pollutant fumigation except in the simultaneous application of O3 + SO2 where an 11% decrease occurred. Reductions in CER in response to fumigation were not attributed to changes in stomatal resistance, but appeared to result from changes in mesophyll resistance. A proposed mechanism for pollutant-induced reduction in CER is discussed.Key words: Air pollution, net photosynthesis, pollutant mixtures

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A COMPARISON OF LEAF AND WHOLE PLANT NET PHOTOSYNTHESIS IN ALSTROEMERIA

HortScience ◽

10.21273/hortsci.27.6.576c ◽

1992 ◽

Vol 27 (6) ◽

pp. 576c-576

Author(s):

E.D. Leonardos ◽

M.J. Tsujita ◽

B. Grodzinski ◽

T.J. Blom

Keyword(s):

Dark Respiration ◽

Net Photosynthesis ◽

Stomatal Resistance ◽

Gas Analysis ◽

Whole Plant ◽

Plant Photosynthesis ◽

Mutual Shading ◽

Photosynthetic Responses ◽

Analysis System ◽

Two Stages

Gas exchange (net photosynthesis Pn, dark respiration, transpiration, and stomatal resistance) of `Jaqueline' Alstroemeria, grown in pots in a greenhouse, were measured. Measurements were made under laboratory conditions using an open-flow infrared gas analysis system for leaf studies, and a semi-closed computer controlled whole plant photosynthesis system for whole plant studies. Apical fully expanded leaves on non-flowering and flowering (at two stages) shoots had similar photosynthetic responses in respect to photosynthetically active radiation (PAR) and to CO2 concentration. Light saturation occurred at 600 umol/m2/s PAR with maximum leaf Pn rates ranging from 9 to 11 umol CO2/m2/s. CO2 saturation was estimated at approximately 1100 to 1200 ppm with maximum leaf Pn rates from 17 to 22 umol CO2/m2/s. Whole plant Pn rates increased with increased PAR. Maximum rates 4 to 5 umol CO2/m2/s (half that of individual leaves) occurred at approximately 1000 to 1100 umol/m2/s PAR. CO2 saturation was estimated at 1100 to 1200 ppm, with maximum whole plant Pn rates ranging from 7 to 8 umol CO2/m2/s. These data will be discussed in relation to respiration and mutual shading at the leaf canopy.

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Is nitric oxide a critical key factor in ABA-induced stomatal closure?

Journal of Experimental Botany ◽

10.1093/jxb/erz437 ◽

2019 ◽

Vol 71 (1) ◽

pp. 399-410 ◽

Cited By ~ 1

Author(s):

Uulke Van Meeteren ◽

Elias Kaiser ◽

Priscila Malcolm Matamoros ◽

Julian C Verdonk ◽

Sasan Aliniaeifard

Keyword(s):

Nitric Oxide ◽

Stomatal Closure ◽

Co2 Concentration ◽

Stomatal Resistance ◽

Stomatal Aperture ◽

No Donor ◽

Leaf Discs ◽

Key Factor ◽

Intact Leaves

Abstract The role of nitric oxide (NO) in abscisic acid (ABA)-induced stomatal closure is a matter of debate. We conducted experiments in Vicia faba leaves using NO gas and sodium nitroprusside (SNP), a NO-donor compound, and compared their effects to those of ABA. In epidermal strips, stomatal closure was induced by ABA but not by NO, casting doubt on the role of NO in ABA-mediated stomatal closure. Leaf discs and intact leaves showed a dual dose response to NO: stomatal aperture widened at low dosage and narrowed at high dosage. Overcoming stomatal resistance by means of high CO2 concentration ([CO2]) restored photosynthesis in ABA-treated leaf discs but not in those exposed to NO. NO inhibited photosynthesis immediately, causing an instantaneous increase in intercellular [CO2] (Ci), followed by stomatal closure. However, lowering Ci by using low ambient [CO2] showed that it was not the main factor in NO-induced stomatal closure. In intact leaves, the rate of stomatal closure in response to NO was about one order of magnitude less than after ABA application. Because of the different kinetics of photosynthesis and stomatal closure that were observed, we conclude that NO is not likely to be the key factor in ABA-induced rapid stomatal closure, but that it fine-tunes stomatal aperture via different pathways.

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Photosynthesis and Carbon Dioxide Transfer Resistance of Lodgepole Pine Seedlings in Relation to Irradiance, Temperature, and Water Potential

Canadian Journal of Forest Research ◽

10.1139/x74-030 ◽

1974 ◽

Vol 4 (2) ◽

pp. 201-206 ◽

Cited By ~ 22

Author(s):

Gary F. Dykstra

Keyword(s):

Carbon Dioxide ◽

Water Potential ◽

Environmental Conditions ◽

Net Photosynthesis ◽

Stomatal Resistance ◽

Transfer Resistance ◽

Pine Seedlings ◽

Rate Limiting ◽

Potential Maximum ◽

Mesophyll Resistance

Photosynthesis and stomatal and total equivalent mesophyll resistances to CO2 transfer were measured in relation to irradiance, needle temperature, and tree water potential. Maximum rates of net photosynthesis were attained at 380 W m−2 irradiance, 20 °C needle temperature, and the highest tree water potential obtained, ca. −2.5 bars. Stomatal and total mesophyll resistances have a significant rate-limiting role when environmental conditions are less than optimum. Mesophyll resistance was larger than stomatal resistance under all environmental conditions.

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