Salt stress induced sex-related spatial heterogeneity of gas exchange rates over the leaf surface in Populus cathayana Rehd.

ABSTRACT Salinity is one of the factors that most limit agricultural yield in the Brazilian semi-arid region. In this context, the present study aimed to evaluate the leaf gas exchange and biometric characteristics of accessions of the Saccharum complex subjected to salt stress. The experiment was carried out in a greenhouse, installed at Embrapa Semiárido, in Petrolina, PE, Brazil. The experimental design was in randomized blocks, with the treatments represented by 19 accessions belonging to different genera/species, being 10 accessions of Saccharum officinarum (BGCN 6, BGCN 91, BGCN 104, BGCN 127, BCGN 90, BGCN 101, BGCN 102, BGCN 118, BGCN 125 and BGCN 122), two accessions of Saccharum spp. (BGCN 87 and BGCN 89), one accession of Saccharum hybridum (BGCN 88), one accession of Saccharum robustum (BGCN 94), four accessions of Erianthus arundinaceus (BGCN 117, BGCN 119, BGCN 120 and BGCN 123) and one accession of Miscanthus spp., with three repetitions. Biometric characteristics, chlorophyll index and leaf gas exchange of the accessions were evaluated when they were subjected to irrigation with salinized water (6.0 dS m-1). E. arundinaceus accessions (BGCN 120 and BGCN 123) showed the highest photosynthetic rate, transpiration rate, plant height and leaf length, indicating greater adaptability to salt stress and could be promising in breeding programs.

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Variations in leaf gas exchange, chlorophyll fluorescence and membrane potential of Medicago sativa root cortex cells exposed to increased salinity: The role of the antioxidant potential in salt tolerance

Archives of Biological Sciences ◽

10.2298/abs171019001f ◽

2018 ◽

Vol 70 (3) ◽

pp. 413-423 ◽

Cited By ~ 2

Author(s):

Mohamed Farissi ◽

Mohammed Mouradi ◽

Omar Farssi ◽

Abdelaziz Bouizgaren ◽

Cherki Ghoulam

Keyword(s):

Antioxidant Enzymes ◽

Salt Stress ◽

Chlorophyll Fluorescence ◽

Membrane Potential ◽

Salt Tolerance ◽

Gas Exchange ◽

Medicago Sativa ◽

Leaf Gas Exchange ◽

Root Cortex ◽

Root Cortex Cells

Salinity is one of the most serious agricultural problems that adversely affects growth and productivity of pasture crops such as alfalfa. In this study, the effects of salinity on some ecophysiological and biochemical criteria associated with salt tolerance were assessed in two Moroccan alfalfa (Medicago sativa L.) populations, Taf 1 and Tata. The experiment was conducted in a hydro-aeroponic system containing nutrient solutions, with the addition of NaCl at concentrations of 100 and 200 mM. The salt stress was applied for a month. Several traits in relation to salt tolerance, such as plant dry biomass, relative water content, leaf gas exchange, chlorophyll fluorescence, nutrient uptake, lipid peroxidation and antioxidant enzymes, were analyzed at the end of the experiment. The membrane potential was measured in root cortex cells of plants grown with or without NaCl treatment during a week. The results indicated that under salt stress, plant growth and all of the studied physiological and biochemical traits were significantly decreased, except for malondialdehyde and H2O2 contents, which were found to be increased under salt stress. Depolarization of membrane root cortex cells with the increase in external NaCl concentration was noted, irrespective of the growth conditions. The Tata population was more tolerant to high salinity (200 mM NaCl) and its tolerance was associated with the ability of plants to maintain adequate levels of the studied parameters and their ability to overcome oxidative stress by the induction of antioxidant enzymes, such as guaiacol peroxidase, catalase and superoxide dismutase.

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Gas-Exchange Rates in a Small Lake as Determined by the Radon Method

Journal of the Fisheries Research Board of Canada ◽

10.1139/f73-237 ◽

1973 ◽

Vol 30 (10) ◽

pp. 1475-1484 ◽

Cited By ~ 36

Author(s):

Steve Emerson ◽

Wallace Broecker ◽

D. W. Schindler

Keyword(s):

Exchange Rate ◽

Gas Exchange ◽

Exchange Rates ◽

Partial Pressure ◽

Lake Water ◽

Radon Concentration ◽

Natural Waters ◽

Carbon Dioxide Partial Pressure ◽

Nitrogen And Phosphorus ◽

Gas Exchange Rate

The radon method, used previously in ocean-atmosphere systems, is used here to determine the gas-exchange rate between the atmosphere and lake 227 of the Experimental Lakes Area. Fertilization of the lake with nitrogen and phosphorus caused the carbon dioxide partial pressure in the lake water to drop well below atmospheric levels; hence, in order to better understand the carbon budget of the lake, an estimate of the CO2 gas-exchange rate was necessary.To determine gas-exchange rates by measuring radon evasion to the atmosphere the source of radon in the lake water must be dissolved radium. Since the radon concentration in lakes derives not only from the decay of dissolved radium but also from the inflow of radon-rich groundwaters, radium was added to the lake to increase the radon concentration well above this fluctuating background level. Although this procedure was complicated by algal uptake of the radium in the lake (Emerson and Hesslein 1973), we were able to place limits on the gas-exchange rate.Our results indicate that the "stagnant boundary layer" thickness is approximately 300 μ. This value is among the largest observed in natural waters. Using this value and the partial pressure of CO2 in the lake water we have calculated an invasion rate of 17 ± 8 mmoles CO2/m2 day.

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Biochar amendment improves shoot biomass of tomato seedlings and sustains water relations and leaf gas exchange rates under different irrigation and nitrogen regimes

Agricultural Water Management ◽

10.1016/j.agwat.2020.106580 ◽

2021 ◽

Vol 245 ◽

pp. 106580

Author(s):

Lili Guo ◽

Marie Louise Bornø ◽

Wenquan Niu ◽

Fulai Liu

Keyword(s):

Gas Exchange ◽

Exchange Rates ◽

Water Relations ◽

Leaf Gas Exchange ◽

Shoot Biomass ◽

Tomato Seedlings ◽

Biochar Amendment

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Robust Quantification of Gas Exchange Rates Using Hyperpolarized Xenon-129

10.1164/ajrccm-conference.2020.201.1_meetingabstracts.a7903 ◽

2020 ◽

Author(s):

F. Amzajerdian ◽

S. Kadlecek ◽

H. Hamedani ◽

Y. Xin ◽

R. Baron ◽

...

Keyword(s):

Gas Exchange ◽

Exchange Rates ◽

Hyperpolarized Xenon

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xpression of aquaporin subtypes (GhPIP1;1, GhTIP2;1, and GhSIP1;3) in cotton (Gossypium hirsutum L.) submitted to salt stress

AoB Plants ◽

10.1093/aobpla/plz072 ◽

2019 ◽

Author(s):

Luana C C Braz ◽

Pedro D Fernandes ◽

Daniela D Barbosa ◽

Wellison F Dutra ◽

Carliane R C Silva ◽

...

Keyword(s):

Salt Stress ◽

Gas Exchange ◽

Gossypium Hirsutum ◽

Water Content ◽

Relative Water Content ◽

Dry Matter ◽

Rna Extraction ◽

Gossypium Hirsutum L ◽

Relative Water ◽

Agricultural Regions

Abstract Salinization leads to several worldwide damages in agricultural regions, mainly in semiarid regions where leaching of salt is poor due to limited and erratic rainfall. Cotton (Gossypium hirsutum L.) is a Malvaceae with wide genetic variability to salt stress. The identification of salinity tolerant genotypes is a dynamic target in a breeding program, and the selection is often based on plant phenotypes. Molecular markers are reliable tools to aid in these selection procedures. Aquaporin (AQPs) are channel proteins that play fundamental role in water relations and tolerance to environmental stresses. Plants have fine regulation of water transport through AQPs activities. In order to evaluate the AQP expressions of different cotton cultivars submitted to salt stress, we use molecular and physiological tools, based on RT-qPCR and gas exchange assays. Seven cultivars were submitted to 95 mM NaCl, started at V3 stage (21 days after emergence), during 72 h. At the end of stress treatment, root tissues were used to total RNA extraction, followed by cDNA synthesis and RT-qPCR analyzes. Three sets of specific primers were used, drawn from AQP accessions deposited in NCBI. Additionally, full expanded leaves were used to gas exchange assays and to estimate the relative water content. The dry matter of the shoots was also evaluated. Based on pattern of AQPs transcripts, we found that all semiarid tolerant cultivars (BRS Seridó, 7MH, CNPA MT 2009 152 and BRS 416) showed downregulation of AQP subtypes, mainly GhPIP1;1 and GhTIP2;1 whose action is characterized as tolerant to salinity. The results of gas exchanges, relative water content and dry matter were consistent with the molecular findings in these cultivars, confirming that GhPIP1;1 and GhTIP2;1, located at plasma membrane and vacuoles, respectively, could be adopted as AQP markers for identification of cotton tolerant to salt stress.

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