Biologic Markers of Air-Pollution Stress and Damage in Forests (1989) / Chapter Skim
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Alteration of Chlorophyll in Plants Upon Air Pollutant Exposure
Alteration of Chlorophyll in Plants Upon Air Pollutant Exposure
Pages 347-356
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From page 347... ...
has been long used to assess injury induced by varied air pollutants, and is believed to signal a decline in photosynthetic capacity and plant productivity. Unfortunately, chlorosis is not specific for air pollutant stress; other stresses and, even, normal development can alter pigment content.
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From page 348... ...
, used for general lipid extraction, perform the best in fully extracting the pigments and their products [4,21,261. Some chemical alterations of chlorophylls can be observed by spectral analysis (however, one should use a relatively sophisticated spectrophotometer)
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From page 349... ...
The Modification of Chlorophyll Pigments upon Exposure to Air During Thin Layer Chromography Separation. Pigments from spinach were isolated by standard lipid extractions using chloroform:methanol (1:1, v/v)
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From page 350... ...
suggested sulfur dioxide fumigation of lichen caused the formation of pheophytin (presumably by acidification and monitored by both bleaching and a spectral shift) but stated that chlorophyll loss was too slow to cause the measured decline in photosynthesis.
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From page 351... ...
Many of their experiments involved the combined action of cold and air pollutants in conifers. Frost inhibited photosynthesis and the secondary pollutant stress induced a photooxidation of the structure of the chloroplast.
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From page 352... ...
These changes are thought to be due to only primary photochemistry of Photosystem II of the electron transport pathways [16,25,28] and can only be measured with rapidly responding equipment (certainly not pen recorders)
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From page 353... ...
A lowering of Fo is only observed when gross injury to the system has occurred and most probably great chlorophyll loss is likewise occurring [11,25~. The immense body of literature on chlorophyll fluorescence and its interpretation (for some reviews, see [8, 1 0, 11 , 1 3, 1 4, 1 6,20,24,281)
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From page 354... ...
CONCLUSION While visible injury still dominates the literature as a marker of pollutant injury, the technology is available to measure chlorophyll loss in viva and to monitor some alterations of the primary events of the chloroplasts through chlorophyll fluorescence kinetics. However, it is too soon to be able to interpret these changes biochemically and these alterations may not be specific to only air pollutant injury.
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From page 355... ...
In: How are the Effects of Air Pollutants on Agricultural Crops Influenced by the Interaction with Other Limiting Factors?
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From page 356... ...
1985. Evaluation of a Technique for the Measurement of Chlorophyll Fluorescence from Leaves Exposed to Continuous White Light.
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