In situ localization of the sites of paraquat action

Vaughn, K.C. and Duke, S.O. (1983) In situ localization of the sites of paraquat action. Plant, Cell and Environment, 6 (1). pp. 13-20.

PDF Restricted to ICRISAT researchers only

Abstract

Effects of paraquat were monitored by electron microscopic, cytochemical and in vivo spectrophotometric procedures. Electron microscopy of paraquat-treated pea leaf discs indicated that the chloroplasts were affected primarily with both thylakoid dilation and apparent lamellar fusions, resulting in a honeycomb of lamellae. No ultrastructrual effects were noted when leaf discs were incubated in both DCMU [diuron] and paraquat. Paraquat-induced peroxide was located cytochemically along the stroma lamellae, on the ends of the grana stack and in the dilated thylakoids. Less destruction was noted in those samples where peroxide was precipitated by cerium chloride, indicating that peroxide or one of its products is one of the major causes of paraquat toxicity. In C4 plants including Sorghum bicolor mesophyll plastids exhibited much more peroxide deposition than was detected in bundle sheath plastids. In situ cytochrome f oxidation-reduction was followed during paraquat treatments and resulted in a hastening of the dark re-reduction of cytochrome f after only 1 h of treatment. This effect was prevented by DCMU or CeCl3. Electron transport, as measured by cytochrome f oxidation-reduction, was completely obliterated by a 24 h paraquat treatment

Item Type:	Article
Author Affiliation:	Southern Weed Science Laboratory, USDA-ARS, Stoneville, MS 38776, USA
Subjects:	Plant Protection > Pesticides Plant Protection > Pests Plant Physiology and Biochemistry > Plant Physiology Plant Physiology and Biochemistry > Biochemistry
Divisions:	Sorghum
Depositing User:	Ms K Syamalamba
Date Deposited:	22 Nov 2012 06:12
Last Modified:	22 Nov 2012 06:12
URI:	http://eprints.icrisat.ac.in/id/eprint/8869

Actions (login required)

View Item