Tag Archives: resistance

Influence of salicylic and succinic acids on formation of active oxygen forms in wheat coleoptiles

Yu. Ye. Kolupaev, T. O. Yastreb, M. V. Shvidenko, Yu. V. Karpets

V. V. Dokuchaev Kharkiv National Agrarian University, Ukraine;
e-mail: plant_biology@mail.ru

The comparative study of influence of exogenous salicylic (SaA) and succinic (SuA) acids on the production of reactive oxygen species by isolated wheat coleoptiles has been provided. Under the action of both acids the increase of generation of superoxide anion-radical (O2•–) was observed. This increase was partially suppressed by treatment of coleoptiles with inhibitors of peroxidase (salicylhydroxamic acid) and NADP·H-oxidase (imidazole and α-naphthol). The increase of hydrogen peroxide content, activity of peroxidase and superoxide dismutase (SOD) was registered under the influence of SaA and SuA; catalase activity did not change essentially. The treatment of coleoptiles with the indicated acids resulted in the increase of their resistance to abiotic stress (damaging heating, 43±0.1 °С, 10 min). The conclusion is made, that the increase of O2•– generation in wheat coleoptiles under the action of SaA and SuA is related, probably, to the increase of apoplast peroxidase and NADP·H-oxidase activity, and the rise of H2O2 content is related to the growth of SOD activity. These enzymatic systems are involved in the induction of plant cells protective reactions to the hyperthermia.

Phenylalanine ammonia-lyase activity and anthocyanin content in different varieties of lettuce under the cadmium influence

O. I. Kosyk, I. M. Khomenko, L. M. Batsmanova, N. Yu. Taran

Educational and Scientific Centre “Institute of Biology and Medicine”,
Taras Shevchenko National University of Kyiv;
e-mail: i.m.homenko@gmail.com

Cadmium ions influence on the content of anthocyanins as non-plastid pigments and the activity of phenylalanine ammonia-lyase (EC 4.3.1.24) as primary enzyme of their biosynthesis in two lettuce varieties (Lactuca sativa L.) with different anthocyanin content was investigated. The increases in anthocyanin content and enzymatic activity of phenylalanine ammonia-lyase of both lettuce plant varieties during the 14-day exposure in solution of cadmium nitrate (0.1 mmol) were established. The difference in levels of adaptive capacity in two lettuce varieties with different content of anthocyanins under the effect of cadmium ions was revealed. The indexes of tolerance have shown faster adaptive response and higher resistance in red variety plants, compared with plants of the green lettuce variety. These data are consistent with the corresponding changes in anthocyanins content and indicate their active participation in neutralizing the negative impact of cadmium stress.