Phytochelatin synthesis in tomato cells
Tomato cells that are exposed to cadmium and other heavy metals synthesize phytochelatins (PCs), a family of peptides that bind heavy metals and are structurally related to glutathione (GSH). PCs have the structure (..gamma..-glutamyl-cysteinyl) glycine; for PCs, n=2-10; GSH, n=1. GSH levels decline rapidly in tomato cells exposed to Cd/sup 2 +/. Buthionine sulfoximine (BSO), an inhibitor of GSH synthesis, prevents sustained synthesis of PC. However the addition of GSH to the medium of BSO-treated cells restores PC production. In vivo labeling studies indicate that /sup 35/(S)-cysteine is incorporated into PC via GSH, rather than being added directly to GSH or pre-formed PC. Initial synthesis of PCs is not inhibited by cycloheximide. Tomato cell cultures that are tolerant of high levels of Cd/sup 2 +/ contain large amounts of PCs. However, when sensitive and tolerant cells that have been grown in the absence of Cd/sup 2 +/ are exposed to relatively low concentrations of Cd/sup 2 +/, they synthesize PCs at similar rates. These and other results suggest that, although PCs are necessary, increased PC synthesis is not sufficient for expression of the Cd/sup 2 +/ tolerant phenotype.
- Research Organization:
- Purdue Univ., West Lafayette, IN
- OSTI ID:
- 6060200
- Report Number(s):
- CONF-8707108-; TRN: 87-037634
- Journal Information:
- Plant Physiol., Suppl.; (United States), Vol. 83:4; Conference: Annual meeting of the American Society of Plant Physiologists, St. Louis, MO, USA, 19 Jul 1987
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
CADMIUM
TOLERANCE
CHELATING AGENTS
BIOSYNTHESIS
CYCLOHEXIMIDE
CYSTEINE
GLUTATHIONE
INHIBITION
LABELLED COMPOUNDS
PEPTIDES
PHENOTYPE
PLANT CELLS
SULFUR 35
TOMATOES
TRACER TECHNIQUES
AMINO ACIDS
ANTI-INFECTIVE AGENTS
ANTIBIOTICS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBOXYLIC ACIDS
DAYS LIVING RADIOISOTOPES
DRUGS
ELEMENTS
EVEN-ODD NUCLEI
FOOD
FRUITS
FUNGICIDES
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
METALS
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PESTICIDES
POLYPEPTIDES
PROTEINS
RADIOISOTOPES
RADIOPROTECTIVE SUBSTANCES
SULFUR ISOTOPES
SYNTHESIS
THIOLS
560300* - Chemicals Metabolism & Toxicology
550201 - Biochemistry- Tracer Techniques