Eastern white pine phenotypes with differential sensitivity to oxidative stress-soluble proteins and gas exchange properties

• Published in: Plant Physiology; (United States) Vol. 102:1
• Main Authors: Hess, J.L., Cheyone, B.I.
• Format: Conference Proceeding
• Language: English
• Published: United States 01.05.1993
• Subjects: BIOLOGICAL EFFECTS; CHEMICAL REACTIONS; CONIFERS; LEAVES; ORGANIC COMPOUNDS; OXIDIZERS; OZONE; PHENOTYPE; PHOTOCHEMICAL REACTIONS; PHOTOSYNTHESIS; PINES; PINOPHYTA; PLANTS; PROTEINS; RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT; SENSITIVITY; SYNTHESIS; TREES 560300 > Chemicals Metabolism & Toxicology
• ISSN: 0032-0889; 1532-2548

We are interested in characterizing molecular markers of oxidative stress in higher plants. Phenotypes of 10- to 12-year-old eastern white pine with differential sensitivity to oxidative stress were selected on the basis of foliar symptomology. During hot, dry, high-ozone summers, only sensitive phenotypes displayed a moderate to severe tip burn on needles. Net photosynthesis (P[sub n]) and needle conductance (g[sub n]) increased during the summer to a maximum in early September and then declined to near zero during mid-winter. In a high-oxidant year, both P[sub n] and g[sub n] were 50[plus minus]10% greater throughout the summer in the tolerant compared to the sensitive phenotype. Gluthathione reductase (GR) activity occurred at low activity in [open quotes]summer[close quotes] needles and increased 10-fold or more in [open quotes]winter[close quotes] tissue. Activity of GR in the summer was only moderately higher in tolerant compared to sensitive needles. Two-dimensional gel electrophoresis (pH 4-8) revealed a significant increase in the number of soluble proteins as tissue shifted from active photosynthesis in summer to winter-hardened dormancy. These protein populations differed between the phenotypes, and may provide specific information about oxidant sensitivity.