Premium
Paraquat toxicity in Pisum sativum : Effects on soluble and membrane‐bound proteins
Author(s) -
Peleg Itzhak,
Zer Hagit,
Chevion Mordechal
Publication year - 1992
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1992.tb01321.x
Subject(s) - biochemistry , paraquat , glutathione reductase , malate dehydrogenase , pisum , enzyme , superoxide dismutase , atpase , cellular compartment , biology , peroxidase , chemistry , glutathione peroxidase , cell
The effects of paraquat (PQ) on Pisum sativum L. proteins were investigated in vivo in a new experimental system utilizing 10‐day‐old plant cuts.A marked decrease in the specific activity of membrane‐bound Ca 2+ ‐dependent ATPase was recorded, while that of Mg 2+ ‐dependent ATPase remained unchanged. Concurrently with a drop in the total plant protein, the specific activities of the three cytoplasmic enzymes, malate dehydrogenase, hydroxypyruvate reductase and triose‐phosphate isomerase, were also found to decrease. The effect on various enzymes involved in cellular defense mechanisms was also studied: glutathione reductase and superoxide dismutase activities increased, while ascorbate peroxidase was not affected. These findings shed light on the selectivity of PQ‐induced injurious processes, focusing on protein homeostasis mechanisms in the membrane and cytoplasmic compartments at the cellular level, as well as on the prominent role played by enzymatic defense systems against PQ poisoning.