Recent Advances Using Electron Beam Analysis to Detect Cuticular Changes Induced by Air Pollution

Abstract

Invisible or ''hidden injury'', terms from the earliest air quality literature, expressed the diagnostician's frustration in identifying abiotic disease symptoms Direct visualization was not technically possible until the advent of electron beam analysis (EBA) hardware and software Electron beam analysis, a combination of scanning electron microscopy (SEM) energy dispersive X-ray analysis (EDXA), and computer-controlled image processing (CCIP) is useful for detecting changes in the cuticle and adjacent cells due to common phytotoxicants Artifacts, caused by improper specimen preparation, inherent in the high vacuum of SEM and use of hydrated plant samples, fill the literature Unique methodologies are necessary to interpret the minute changes to plant surfaces caused by a variety of environmental stresses such as sulfur dioxide, ozone, acidic deposition, pesticide residues, NACl, etc EBA was used to show: the progression of surface alterations that occur to stomata of hybrid poplar (Populus spp) following exposure to SO2 and O3; between SO2-sensitive and SO2-tolerant clones of eastern white pine (Pinus strobus L) CCIP was especially useful in determining that acidified rain or mist and O3 do not physically erode existing epicuticular wax of red spruce (Picea rubens Sarg) as previous literature stated EBA was used to correlate field and laboratory data showing similar injury to epistomatal wax of red spruce Improved field emission microscopy and EDXA that offer increased resolution with little sample preparation can provide opportunities to observe cuticular modifications not previously available (orig)