COLD-ACCLIMATION AND ALTERATIONS IN DEHYDRIN-LIKE AND BARK STORAGE PROTEINS IN THE LEAVES OF SIBLING DECIDUOUS AND EVERGREEN PEACH

Seasonal changes in cold tolerance and proteins were studied in the le aves of sibling deciduous and evergreen peach [Prunus persica (L.) Bat sch]. Freezing tolerance [defined as the subzero temperature at which 50% injury occurred (LT(50))] was assessed using electrolyte leakage. Proteins were separated by sodium dodecyl sulfate polyacrylamide-gel e lectrophoresis. Electroblots were probed with anti-dehydrin and anti-1 9-kD peach bark storage protein (BSP) antibodies, Leaf LT(50) decrease d successively from 5.8 degrees C on 18 Aug. to -10.3 degrees C in the evergreen genotype and from -7.0 degrees C to -15.0 degrees C in the deciduous genotype by 14 Oct. Protein profiles and immunoblots indicat ed the accumulation of a 60- and 30-kD protein during cold acclimation in the leaves of deciduous trees; however, levels of these proteins d id not change significantly in the evergreen trees. Immunoblots indica te that the 60-kD protein is a dehydrin-like protein. Gel-electrophore sis and immunoblots also indicated that the 19-kD BSP progressively di sappeared from summer through fall in leaves of deciduous peach but ac cumulated to a high level in bark tissues. A similar inverse relations hip was not evident in evergreen peach.