Heat shock protein synthesis is induced by diethyl phthalate but not by di(2-ethylhexyl) phthalate in radish ( Raphanus sativus)

• Published in: Journal of plant physiology Vol. 160; no. 9; pp. 1001 - 1010
• Main Authors: Saarma, Kaari, Tarkka, Mika T., Itävaara, Merja, Fagerstedt, Kurt V.
• Format: Journal Article
• Language: English
• Published: Germany Elsevier GmbH 01-09-2003; Elsevier Science Ltd
• Subjects: di(2-ethylhexyl) phthalate; Diethyl phthalate; Diethylhexyl Phthalate - toxicity; Electrophoresis, Gel, Two-Dimensional; esters; heat shock proteins; heat stress; Heat-Shock Proteins - biosynthesis; Heat-Shock Proteins - isolation & purification; nutrient solutions; phthalic acid; Phthalic Acids - toxicity; plant proteins; Plant Proteins - biosynthesis; Plant Proteins - isolation & purification; plant response; plant stress; Plasticizers - toxicity; protein synthesis; radishes; Raphanus - drug effects; Raphanus - growth & development; Raphanus - metabolism; Raphanus sativus; seedling growth; seedlings; Seedlings - drug effects; Seedlings - growth & development; soil pollution; stress proteins; toxic substances; two demensional polyacrylamide gel electrophoresis; vegetable crops; stress proteins; di(2-ethylhexyl) phthalate; heat shock proteins; Raphanus sativus; Diethyl phthalate
• ISSN: 0176-1617; 1618-1328
• DOI: 10.1078/0176-1617-00525

The toxicity and effects on protein synthesis of the phthalate esters diethyl phthalate (DEP) and di(2-ethylhexyl) phthalate (DEHP) was studied in radish seedlings (
Raphanus sativus cv. Kööpenhaminan tori). Phthalate esters are a class of commercially important compounds used mainly as plasticizers in high molecular-weight polymers such as many plastics. They can enter soil through various routes and can affect plant growth and development. First the effect of DEP and DEHP on the growth of radish seedlings was determined in an aqueous medium. It was found that DEP, but not DEHP, caused retardation of growth in radish. A further investigation on protein synthesis during DEP-stress was executed by
in vivo protein labeling combined with two-dimensional gel electrophoresis (2D-PAGE). For comparisons with known stress-induced proteins a similar experiment was done with heat shock, and the induced heat shock proteins (HSPs) were compared with those of DEP-stress. The results showed that certain HSPs can be used as an indicator of DEP-stress, although the synthesis of most HSPs was not affected by DEP. DEP also elicited the synthesis of numerous proteins found only in DEP-treated roots. The toxic effect of phthalate esters and the roles of the induced proteins are discussed.