Effects of ozone and acidic fog on red spruce needle epicuticular wax ultrastructure

1990 ◽  
Vol 20 (1) ◽  
pp. 117-120 ◽  
Author(s):  
K. E. Percy ◽  
C. R. Krause ◽  
K. F. Jensen
Keyword(s):  
Epicuticular Wax ◽  
Red Spruce ◽  
Ultrastructural Changes ◽  
Acid Fog ◽  
Acidic Fog ◽  
Wax Crystallization ◽  
Wax Deposits ◽  
Spruce Needles

The effect of ozone and acidic fog on the epicuticular wax structure of elongating red spruce (Picearubens Sarg.) was examined. Needle exposure to 70 and 250 ppb ozone for 11 weeks resulted in a coalescence of crystalline tube ends within epistomatal chambers. Exposure to acid fog at pH 3.0 resulted in the formation of amorphous wax deposits over the existing tubes within the epistomatal chambers. New structures consisting of upright, irregular wax plates were observed in nonstomatal areas on needles exposed to pH 3.0 fog. These findings indicate that ozone and acid fog applied at near ambient doses can alter epicuticular wax ultrastructure on elongating red spruce needles. Ultrastructural changes induced by ozone and acid fog resulted from a direct pollutant interaction with wax crystallization and wax biosynthesis, respectively, and were not due to erosion or weathering of needle surfaces.

Quantity, chemistry, and wettability of epicuticular waxes on needles of red spruce along a fog-acidity gradient

1993 ◽  
Vol 23 (7) ◽  
pp. 1472-1479 ◽  
Author(s):  
K.E. Percy ◽  
R. Jagels ◽  
S. Marden ◽  
C.K. McLaughlin ◽  
J. Carlisle
Keyword(s):  
Fatty Acids ◽  
Contact Angles ◽  
Epicuticular Wax ◽  
Red Spruce ◽  
Secondary Alcohols ◽  
Primary Alcohols ◽  
Alkyl Esters ◽  
Needle Age ◽  
Highly Correlated ◽  
Wax Deposits

Needle wettability and epicuticular wax physicochemical characteristics were examined for red spruce (Picearubens Sarg.) trees growing along a gradient of fog quantity and acidity. Trees at four coastal and one inland site were sampled in November 1988 for three needle age-classes. Needle wettability was assessed by measuring needle–water droplet contact angles. Mean angles per site and age-class ranged from 73 to 42° and decreased significantly with increasing needle age. Needle contact angles were highly correlated with fog acidity (R = 0.99), decreasing with increasing acidity. Angles were lower on needles from declining trees than on needles from visually healthy trees. Epicuticular wax amount was highly correlated with quantity of fog collected at the sites (R = 0.99). Needles from trees at the inland site located outside the coastal fog zone had the smallest wax deposits, while needles from trees exposed to the greatest amount of fog had the largest wax deposits. Epicuticular wax was comprised of secondary alcohols (42%), diols (19%), alkyl esters (16%), primary alcohols (6%), hydroxy fatty acids (2%), and fatty acids (1%). Estolides (14%) in the wax were tentatively identified but not confirmed by mass spectrometry. Needles from trees exposed to the most fog had the greatest amounts of secondary alcohols and alkyl esters. Needles from trees not exposed to fog had greater amounts of diols. There was no obvious relationship between fog acidity and wax chemical composition.

Induction of nitrate reductase activity in red spruce needles by NO2 and HNO3 vapor

1989 ◽  
Vol 19 (7) ◽  
pp. 889-896 ◽  
Author(s):  
Richard J. Norby ◽  
Yohan Weerasuriya ◽  
Paul J. Hanson
Keyword(s):  
Nitrate Reductase ◽  
Nitrate Reductase Activity ◽  
Forest Decline ◽  
Reductase Activity ◽  
Control Level ◽  
Red Spruce ◽  
Acid Vapor ◽  
Unexposed Control ◽  
Acid Mist ◽  
Spruce Needles

The induction of the enzyme nitrate reductase in needles may be a prerequisite for the assimilation of foliar-absorbed nitrogen oxide pollutants by red spruce (Picearubens Sarg.) trees. To test for induction of nitrate reductase, 1-year-old red spruce seedlings were exposed to NO2, HNO3 vapor, or acid mist containing nitrate, and the activity of nitrate reductase in needles was measured. One day after exposure to NO2 (75 nL•L−1) began, nitrate reductase activity was three times greater than that of unexposed control plants. One day after exposure ended, the nitrate reductase activity returned to the control level. Older red spruce seedlings that had been excavated from a spruce–fir stand exhibited a similar pattern of response, but the level of nitrate reductase activity was much lower than that of the 1-year-old seedlings. Nitric acid vapor (75 nL•L−1) also induced nitrate reductase in red spruce needles, and the pattern of response was similar to that with NO2, except that the nitrate reductase activity did not return to control levels until 2 days after exposure ended. Exposure of seedlings to acid mist containing nitrate (pH 3.5 and 5.0) did not result in a change in nitrate reductase activity. These results indicate that red spruce is capable of assimilating NO2 and HNO3 vapor and that hypotheses of forest decline based on foliar assimilation of pollutant nitrogen oxides are tenable.

Impact of acid fog and ozone on coastal red spruce

1989 ◽  
Vol 48 (1-2) ◽  
Author(s):  
R. Jagels ◽  
J. Carlisle ◽  
R. Cunningham ◽  
S. Serreze ◽  
P. Tsai
Keyword(s):  
Red Spruce ◽  
Acid Fog

Effects of Filtered Air and Misting Treatments on Cuticles of Red Spruce Needles on Whiteface Mountain, N.Y.

1993 ◽  
Vol 1 (1) ◽  
pp. 25-47 ◽  
Author(s):  
Graeme P. Berlyn ◽  
Ambrose O. Anoruo ◽  
D. R. Vann ◽  
A. H. Johnson ◽  
G. R. Strimbeck ◽  
...  
Keyword(s):  
Red Spruce ◽  
Whiteface Mountain ◽  
Spruce Needles

A study of fungal endophytes of needles of balsam fir (Abies balsamea) and red spruce (Picea rubens) in New Brunswick, Canada, using culture and electron microscope techniques

1989 ◽  
Vol 67 (12) ◽  
pp. 3513-3516 ◽  
Author(s):  
John A. Johnson ◽  
Norman J. Whitney
Keyword(s):  
New Brunswick ◽  
Fungal Endophytes ◽  
Abies Balsamea ◽  
Picea Rubens ◽  
Red Spruce ◽  
Balsam Fir ◽  
Intercellular Spaces ◽  
Parenchyma Cells ◽  
Spruce Needles ◽  
Petiole Segment

Endophytic fungi were isolated from the interiors of surface-sterilized needles of balsam fir (Abies balsamea) and red spruce (Picea rubens) in New Brunswick, Canada. Four different fungi were isolated frequently. One species, designated X-W, was isolated exlusively from the petiole segment of red spruce needles. There was no difference in the variety of species isolated from fir needles from two sites, but a difference in frequency of species did exist. Micrographs of the interior of balsam fir needles showed hyphae occupying intercellular spaces and adhering to the outer walls of parenchyma cells. No penetration of cells by either fungus was observed.

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