Seasonal differences and within-canopy variations of antioxidants in mature spruce (Picea abies) trees under elevated ozone in a free-air exposure system

Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) seedlings were exposed to low-level ozone (O3) in an open-air exposure system for three or two growing seasons, respectively. Simultaneously, seedlings were supplied with nutrient solution containing either optimum (control) nitrogen (N), 70% of optimum N (low N availability), or 150% of optimum N (high N availability). Carbon-based secondary compounds, e.g., terpenes and resin acids, were analysed from the stemwood. α-Pinene, 3-carene, and limonene + β-phellandrene were the major terpenes in pine wood, whereas α-pinene, β-pinene, and limonene + β-phellandrene dominated in the spruce wood. Palustric + levopimaric and abietic acids were the major resin acids in the wood of both species. Ozone exposure did not cause any remarkable changes in the concentrations and proportional quantities of terpenes and resin acids in the wood of either tree species. Nitrogen availability did not affect the concentrations of carbon-based secondary compounds either, and the effects on proportional quantities were slight and ambiguous with respect to N supply. We conclude that realistically elevated levels of O3 do not have effects on concentrations of carbon-based secondary compounds of conifer wood and N availability might cause only slight changes in them. Therefore, our results do not directly support the carbonnutrient balance hypothesis.

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Mixture Effects of Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX) on Lung Carcinoma Cells via a Hanging Drop Air Exposure System

Chemical Research in Toxicology ◽

10.1021/tx5000552 ◽

2014 ◽

Vol 27 (6) ◽

pp. 952-959 ◽

Cited By ~ 20

Author(s):

Faye F. Liu ◽

Beate I. Escher ◽

Stephen Were ◽

Lesley Duffy ◽

Jack C. Ng

Keyword(s):

Lung Carcinoma ◽

Carcinoma Cells ◽

Hanging Drop ◽

Air Exposure ◽

Exposure System ◽

Mixture Effects ◽

Lung Carcinoma Cells ◽

Benzene Toluene

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Warming and elevated ozone differently modify needle anatomy of Norway spruce (Picea abies) and Scots pine (Pinus sylvestris)

Canadian Journal of Forest Research ◽

10.1139/cjfr-2016-0406 ◽

2017 ◽

Vol 47 (4) ◽

pp. 488-499 ◽

Cited By ~ 7

Author(s):

Minna Kivimäenpää ◽

Sirkka Sutinen ◽

Hanna Valolahti ◽

Elina Häikiö ◽

Johanna Riikonen ◽

...

Keyword(s):

Elevated Temperature ◽

Gas Exchange ◽

Picea Abies ◽

Pinus Sylvestris ◽

Norway Spruce ◽

Scots Pine ◽

Nitrogen Availability ◽

Field Experiments ◽

Needle Anatomy ◽

Elevated Ozone

Acclimation of conifer needle anatomy to climate change is poorly understood. We studied needle anatomy, shoot gas exchange, current-year shoot length, and stem diameter growth in Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) seedlings exposed to elevated ozone (1.35× to 1.5× ambient concentration) and elevated temperature (0.9–1.3 °C + ambient temperature) alone and in combination for two exposure seasons in two separate open-field experiments in central Finland. Pines grew also at two soil nitrogen levels. In spruce, warming increased mesophyll intercellular space and reduced gas exchange and shoot growth and made needles narrower and the epidermis and hypodermis thinner. In pine, warming made needles bigger, increased shoot and stem growth, stomatal row number, and proportions of vascular cylinder, phloem, and xylem and reduced the proportion of mesophyll. These responses indicate that pine benefited and spruce suffered from moderate warming. Ozone caused a thickening of epi- and hypo-dermis and a lower stomatal conductance in both species, reduced stomatal density in spruce, and increased proportions of phloem, xylem, and sclerenchyma and reduced growth in pine. Ozone responses suggest increased oxidative stress defense. Stomatal responses were affected by interactions of elevated temperature and ozone in both species. Nitrogen availability modified ozone and temperature responses, particularly in the vascular tissues in pine.

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Interactive Effects of Elevated Ozone and Temperature on Growth and Yield of Soybean (Glycine max (L.) Merr.) under Field Conditions

Agronomy ◽

10.3390/agronomy10111803 ◽

2020 ◽

Vol 10 (11) ◽

pp. 1803

Author(s):

Kent Burkey ◽

Ripley Tisdale ◽

Richard Zobel ◽

Samuel Ray ◽

Walter Pursley

Keyword(s):

Glycine Max ◽

Seed Yield ◽

Interactive Effects ◽

Growth And Yield ◽

Ozone Treatment ◽

Exposure System ◽

Elevated Ozone ◽

Glycine Max L ◽

The Individual ◽

Yield Responses

Elevated ozone and rising temperature are both factors in climate change, but they are difficult to study in combination due to exposure system requirements. We developed and deployed an air exclusion exposure system to treat soybean (Glycine max (L.) Merr.) cultivar “Jake” with season-long combinations of sub-ambient ozone (18 ppb, 12 h mean), elevated ozone (66 ppb, 12 h mean), and elevated temperature (+3.5 °C daytime, +2.4 °C nighttime) in irrigated field plots. Warming caused a shift in biomass partitioning from reproductive tissues into stems and petioles at mid-season that resulted in a significant 25% reduction in final seed yield and a significant reduction in harvest index. The elevated ozone treatment delayed mid-season biomass production, and final seed yield was reduced by a non-significant 2%. However, there were significant underlying effects of elevated ozone on seed production. The non-significant impact of ozone on seed yield of cultivar “Jake” resulted from significant increases in pod number (+16%) and seed number (+18%) that were offset by a significant reduction in seed size (−16%). No evidence of significant warming–ozone interactions was found in biomass or seed yield responses. In general, significant impacts of the individual warming or ozone treatments were found to be additive.

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