The effect of 1-methylcyclopropene on the components of pro- and antioxidant systems of wheat and the development of defense reactions in fungal pathogenesis

Abstract

The effect of 1 methylcyclopropene (1 MCP), which inhibits the reception of ethylene, on the following has been studied: hydrogen peroxide generation, oxalate oxidase activity, peroxidase activity, cata lase activity, and lignin accumulation in infected leaves of soft spring wheat (Triticum aestivum L.) cultivars that differ in their resistance to the leaf blotch disease, caused by the hemibiotrophic fungus Septoria nodorum Berk. A decrease in the development of leaf blotch in wheat leaves under the influence of 1 MCP was, on one hand, followed by an inhibition of catalase activity; on the other hand, it was accompanied by an increase in oxalate oxidase and peroxidase activity, as well as an accumulation of H 2 O 2 in tissues and lignin in the infected zone. The role of the ethylene reception system in the defense response of plants to infection with a hemi biotrophic pathogen, that causes leaf blotch disease, is discussed.

Ethylene-Cytokinin Interaction Determines Early Defense Response of Wheat against Stagonospora nodorum Berk.

“…All experiments were carried out on intact six-day-old seedlings, with the exception of experiments evaluating the resistance of genotypes, which were performed on the separated first leaves by the lawns method [ 27 ]. In some cases, parts of 6-days-old seedlings placed in separate vessels were sprayed with 2 mM solution of 1-methylcyclopropene (1-MCP) to study the role of ethylene.…”

“…In all cases, vessels were closed with caps and transferred into the darkness. During the experiments by the lawns method, the first leaves of the 6-day-old seedlings were separated and placed in Petri dishes on wet cotton wool containing 0.004% benzamidazole (10–12 leaves/dish) [ 27 ]. Then, leaves were sprayed with 1-MCP, ET, or trans -zeatin, and the Petri dishes were covered and placed in the darkness.…”

“…Concentration of H 2 O 2 in the supernatant was determined using xylenol orange in the presence of Fe 2+ at 560 nm by the method of [ 36 ]. POD activity was determined by a micromethod in 96-well plates (Corning-Costar, Glendale, AZ, USA) by the oxidation of (o-) phenylenediamine in the presence of H 2 O 2 at 490 nm on a Benchmark Microplate Reader spectrophotometer (Bio-Rad Laboratories, Hercules, CA, USA) [ 27 ]. The enzyme activity was expressed in optical density/mg protein per minute.…”

“…The enzyme activity was expressed in optical density/mg protein per minute. CAT activity was determined by a micromethod based on the ability of H 2 O 2 to form a stable colored complex with molybdate salts [ 27 ]. Optical density was measured at 405 nm on a Benchmark Microplate Reader spectrophotometer.…”

“…We have previously shown that ethylene provided favorable conditions for the penetration and growth of S. nodorum in the tissues of wheat plants at the initial stage of infection due to the regulation of redox metabolism and a decrease in the generation of H 2 O 2 [ 27 ], and development of the wheat plants resistance against S. nodorum was accompanied by an increase in the zeatin content in the leaves [ 28 ]. Here, we address the early signaling events in wheat responding to the S. nodorum and analyze the role of NE SnTox3 in the suppression of the PTI reaction such as ROS production.…”