Differential Foliar Sensitivity of Soybean Cultivars to Ozone Associated with Differential Enzyme Activities

Abstract

Soybean [Glycine max (L.) Merr.] cultivars Dare and Hood were exposed to ozone (980 μg/m3) for 2 h to determine if differences in cultivar sensitivity were associated with differential activation of selected enzymes. The first trifoliate leaves of the cultivars were in similar stages of development (14 days from sowing) when exposed. The ozone treatment increased the activities of glucose 6‐phosphate dehydrogenase, phenylalanine ammonia lyase, polyphenol oxidase and peroxidase above the control in both cultivars within 30 h after exposure. However, the activity of all these enzymes increased several hours sooner in Dare (sensitive) than in Hood (tolerant). Our data suggest that the differential sensitivity of these two cultivars to ozone could be based on the differential ozone induced activation of the enzymes involved in the lesion formation process.

Phenolic Compounds as a Tool of Bioindication for Novel Forest Decline at Numerous Spruce Tree Sites in Germany

“…Reprint requests to Prof. and th eir absolute am ounts were quantitatively com parable betw een different sites (R ichter and W ild, 1992, 1994). These observations agree with earlier findings of increased biosynthesis of p h e nolic com pounds in response to various kinds of stress (H ow ell, 1974;Tingey et al, 1976;R ubin et al, 1983;Kicinski et al, 1988).…”

Responses to ozone of varieties of common bean (Phaseolus vulgar is L.)

“…The present study did not find a relationship between chlorophyll loss and measures of polyphenol oxidase activity. This was unexpected, because Tingey et al (1976) observed more rapid ozoneinduced activation of enzymes active in lesion formation, including PPO, to be associated with greater foliar damage in an ozone-sensitive soybean variety compared to a resistant variety. The biochemical changes induced by wounding, by biotic pathogens and by ozone, include increases in lignification activity, mediated through PPO activity and peroxidases.…”

Radish (Raphanus sativus L.) Cultivar‐Specific Response to O3: Patterns of Biochemical and Plant Growth Characteristics

“…A tolerant tobacco ( Nicotiana tabacum L.) cultivar Bel‐B exhibited a higher leaf resistance to gas exchange Bel‐W3, an O 3 ‐sensitive cultivar . However, a differential foliar sensitivity of soybean ( Glycine max L.) plants to O 3 was associated with differential enzyme activity . Moreover, the variations in response of different cultivars of white bean ( Phaseolus vulgaris L.) were attributed to an internal physiological mechanism that prevents irreversible membrane damage, rather than stomatal mechanisms .…”