Author/Authors :
CHOJAK، Joanna نويسنده Department of Plant Physiology and Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland , , KU?NIAK، El?bieta نويسنده Department of Plant Physiology and Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland , , SEKULSKA-NALEWAJKO، Joanna نويسنده Computer Engineering Department, Technical University of Lodz, Stefanowskiego 18/22, 90-924 Lodz, Poland , , GOC?AWSKI، Jaros?aw نويسنده Computer Engineering Department, Technical University of Lodz, Stefanowskiego 18/22, 90-924 Lodz, Poland ,
Abstract :
We studied the effects of sequentially applied salt stress and Pseudomonas
syringae pv lachrymans (Psl) infection in cucumber (Cucumis sativus L.). Infection
development, shoot and root growth potential, the concentrations of
chlorophyll and proline as well as electrolyte leakage, lipid peroxidation and
H2O2 production were determined. Cucumber plants were first exposed to salt
stress and irrigated for seven days with 50 or 100 mM NaCl and thereafter inoculated
by Psl. Abiotic stress compromised the defence response to pathogen and
disease severity was the highest in 100 mM NaCl-treated plants. The reduced
performance of salinized plants under biotic stress could be related to salt stressinduced
plant growth inhibition with leaf expansion being the most sensitive to
salinity, decreased chlorophyll content, increased electrolyte leakage and prolonged
H2O2 accumulation in leaves implying perturbations in redox homeostasis.
The response of NaCl-treated and control plants to bacterial infection differed
in terms of H2O2 generation and lipid peroxidation. This study confirmed
that proline is an important component of local and systemic responses to salt
stress and infection. The results contribute to our knowledge of the nature of
plant response to a combination of abiotic and biotic stresses.
