Induction of 33-kD and 60-kD peroxidases during ethylene-induced senescence of cucumber cotyledons. [Cucumis sativus L]

Journal Article · Fri Jul 01 00:00:00 EDT 1988 · Plant Physiology; (USA)

DOI:https://doi.org/10.1104/pp.87.3.609· OSTI ID:6998906

Abeles, F B; Dunn, L J; Morgens, P; Callahan, A; Dinterman, R E; Schmidt, J ^[1]

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1. Appalachian Fruit Research Station, Kearneysville, WV (USA) Army Medical Research Institute for Infectious Diseases, Frederick, MD (USA)

Ethylene enhanced the senescence of cucumber (Cucumis sativus L. cv Poinsett 76) cotyledons. The effect of 10 microliters per liter ethylene was inhibited by 1 millimolar silver thiosulfate, an inhibitor of ethylene action. An increase in proteins with molecular weights of 33 to 30 kilodaltons and lower molecular weights (25, 23, 20, 16, 12 and 10 kilodaltons) were observed in sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels after ethylene enhanced senescence. The measurement of DNase and RNase activity in gels indicated that these new proteins were not nucleases. Two proteins from ethylene-treated cotyledons were purified on the basis of their association with a red chromaphore and subsequently were identified as peroxidases. The molecular weights and isoelectric points (pI) of two of these peroxidases were 33 kilodaltons (cationic, pI = 8.9) and 60 kilodaltons (anionic, pI = 4.0). The observation that ({sup 35}S)Na{sub 2}SO{sub 4} was incorporated into these proteins during ethylene-enhanced senescence suggests that these peroxidases represent newly synthesized proteins. Antibodies to the 33-kilodalton peroxidase precipitated two in vitro translation products from RNA isolated from ethylene-treated but not from control cucumber seedlings. This indicates that the increase in 33-kilodalton peroxidase activity represents de novo protein synthesis. Both forms of peroxidase degraded chlorophyll in vitro, which is consistent with the hypothesis that peroxidases have catabolic or scavenging functions in senescent tissues.

• OSTI ID: 6998906
• Journal Information: Plant Physiology; (USA), Vol. 87:3; ISSN 0032-0889
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CUCUMBERS
ENZYME ACTIVITY
ETHYLENE
BIOLOGICAL EFFECTS
PEROXIDASES
BIOCHEMICAL REACTION KINETICS
CHLOROPHYLL
PLANTS
SULFUR 35
SULFUR COMPOUNDS
TRACER TECHNIQUES
ALKENES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBOXYLIC ACIDS
DAYS LIVING RADIOISOTOPES
ENZYMES
EVEN-ODD NUCLEI
FOOD
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIGHT NUCLEI
MAGNOLIOPHYTA
MAGNOLIOPSIDA
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDOREDUCTASES
PHYTOCHROMES
PIGMENTS
PORPHYRINS
PROTEINS
RADIOISOTOPES
REACTION KINETICS
SULFUR ISOTOPES
VEGETABLES
551001* - Physiological Systems- Tracer Techniques