Effect of ethephon on protein degradation and the accumulation of pathogensis-related (PR) proteins in tomato leaf discs. [Lycopersicon esculentum]

Journal Article · Mon Jan 01 00:00:00 EST 1990 · Plant Physiology; (USA)

DOI:https://doi.org/10.1104/pp.92.1.227· OSTI ID:6975228

Vera, P; Conejero, V ^[1]

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1. Universidad Politecnica de Valencia (Spain)

The effect of ethephon (2-chloroetylphosphonic acid) on the degradation of proteins and on the induction of Lycopersicon esculentum pathogenesis-related (PR) proteins was studied in tomato leaf discs. The rate of ribulose, -1,5-bisphosphate carboxylase/oxygenase (Rubisco) degradation was maximal in discs after 48 hours of incubation with 1 millimolar ethephon, leading to complete disappearance of Rubisco after 96 hours. This effect was correlated with an increase in PR protein synthesis and the induction of the previously reported alkaline proteolytic enzyme PR-P69. In vivo pulse-chase experiments demonstrated that ethephon not only affected Rubisco content but that of many other {sup 35}S-labeled proteins as well, indicating that ethylene activates a general and nonspecific mechanism of protein degradation. This effect was partially inhibited in vivo by the action of pCMB, a selective inhibitor of cysteine-proteinases such as P69. These data reinforce the hypothesis that P69 and perhaps other PR proteins are involved in the mechanism of accelerated protein degradation activated by ethylene.

• OSTI ID: 6975228
• Journal Information: Plant Physiology; (USA), Vol. 92:1; ISSN 0032-0889
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
PLANT GROWTH REGULATORS
BIOCHEMICAL REACTION KINETICS
TOMATOES
PROTEOLYSIS
BIOLOGICAL STRESS
CARBOXY-LYASES
ENZYME INDUCTION
PATHOGENESIS
SULFUR 35
SULFUR COMPOUNDS
TRACER TECHNIQUES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON-CARBON LYASES
CHEMICAL REACTIONS
DAYS LIVING RADIOISOTOPES
DECOMPOSITION
ENZYMES
EVEN-ODD NUCLEI
FOOD
FRUITS
GENE REGULATION
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIGHT NUCLEI
LYASES
NUCLEI
RADIOISOTOPES
REACTION KINETICS
SULFUR ISOTOPES
551001* - Physiological Systems- Tracer Techniques