Document Detail

Effects of ethephon on aging and photosynthetic activity in isolated chloroplasts.
MedLine Citation:
PMID:  16664618     Owner:  NLM     Status:  PubMed-not-MEDLINE    
Chloroplasts, isolated from the primary leaves of 7-day-old seedlings, were incubated in vitro at 25 degrees C with 2-chloroethylphosphonic acid (ethephon) under light (0.16 milliwatts per square centimeter) and dark conditions. Ethephon at 1 micromolar (0.1445 ppm), 0.1 and 1 millimolar, or 5 microliters ethylene promoted the deterioration of chloroplasts, increased proteolysis, and reduced the chlorophyll content and PSI and PSII during 72 hours under both light and dark conditions. The decline in PSI and PSII occurred prior to a measurable loss of chlorophyll. The loss of photosynthetic activity affected by ethephon was initiated prior to 12 hours of incubation. After 24 hours in light, 0.1 millimolar (1.445 ppm) epthephon significantly reduced PSI and PSII and promoted the total free amino acid liberation in isolated chloroplasts. In darkness the rate of loss of PSI activity was about 50% of that in light. After 24 hours, in light at 1 millimolar epthephon, PSII activity was 55% of the control, yet nearly 90% of the chlorophyll remained, which indicates that the loss of thylakoid integrity was promoted by ethephon. Ethylene injected in the chloroplast medium at 5 microliters (0.22 micromolar per milliliter) reduced PSI by nearly 50% of the initial in 12 hours. In leaf sections floated in 5 microliters per milliliter suspension medium, a 36% loss of chlorophyll of the control in 36 hours was observed. Cycloheximide at 0.5 millimolar masked the effect of 1 millimolar ethephon and maintained the initial chlorophyll content during the 72 hour period.
H T Choe; M Whang
Related Documents :
21979048 - Resonances arising from hydrodynamic memory in brownian motion.
21910988 - A comparative study on the viscoelastic properties of human and animal lenses.
22002818 - The size of the lumenal proton pool in leaves during induction and steady-state photosy...
7272468 - Evolution of the control of pigment and plastid development in photosynthetic organisms.
23429068 - Chronobiology of micturition: putative role of the circadian clock.
20517498 - An analysis of visual masking, with a defense of 'stopped processing'.
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Plant physiology     Volume:  80     ISSN:  0032-0889     ISO Abbreviation:  Plant Physiol.     Publication Date:  1986 Feb 
Date Detail:
Created Date:  2010-06-29     Completed Date:  2010-06-29     Revised Date:  2010-09-15    
Medline Journal Info:
Nlm Unique ID:  0401224     Medline TA:  Plant Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  305-9     Citation Subset:  -    
Department of Biological Sciences, Mankato State University, Mankato, Minnesota 56001.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Distinction between Cytosol and Chloroplast Fructose-Bisphosphate Aldolases from Pea, Wheat, and Cor...
Next Document:  Development of (1-->3,1-->4)-beta-d-Glucan Endohydrolase Isoenzymes in Isolated Scutella and A...