ABSTRACT
The level of active oxygen species (AOS)--superoxide anion radical (O2*-) and hydrogen peroxide (H2O2)--in pea (Pisum sativum L.) cultivar Marat seedlings was studied upon their inoculation with symbiotic (Rhizobium leguminosarum bv. viceae strain CIAM 1026) and pathogenic (Pseudomonas syringae pv. pisi Sackett) microorganisms. Different patterns of the changes in AOS in pea seedlings during the interactions with the symbiont and the phytopathogen were recorded. It is assumed that O2*- and H2O2 are involved in the defense and regulatory mechanisms of the host plant.
Subject(s)
Hydrogen Peroxide/metabolism , Pisum sativum/metabolism , Plant Diseases , Pseudomonas syringae , Rhizobium , Seedlings/metabolism , Superoxides/metabolism , Pisum sativum/microbiology , Plant Diseases/microbiology , Seedlings/microbiologySubject(s)
Peroxidases/metabolism , Pisum sativum/enzymology , Pisum sativum/microbiology , Rhizobium/physiology , Hydrogen Peroxide/pharmacology , Pisum sativum/drug effects , Plant Diseases/microbiology , Plant Roots/enzymology , Plant Roots/microbiology , Rhizobium/pathogenicity , Species SpecificityABSTRACT
Cold shock (-4° C, 1 h) induces qualitative and quantitative changes in the composition of free fatty acids in mitochondria of winter-hardy cereals (Secale cereale L.,Triticum aestivum L.). The amount of these compounds and the degree of their unsaturation increases. Simultaneously, a marked change occurs in the oxidative and phophorylative activities of the mitochondria: respiratory control decreases, respiration in state 4 and antimycin A-resistant respiration increase. The changes in mitochondrial activity are presumed to be caused by endogenous free fatty acids, the amount of which is increased because of phospholipase activity.
