engleski

Stress response of Brassica rapa plants to salt treatment

High salt concentration in soil causes unfriendly, stress enviroment for habitating plants by distrupting their growth and develoment and causing lost in crop productivity. The aim of this study was to investigate Chinese cabagge (Brassica rapa L. ssp. pekinensis) response to salt stress induced by NaCl (50, 100 and 200 mM). Plants were grown in hydroponic system for three weeks before applying salt treatments in duration of 24 hours. To detect physiological state of plants and their ability to interface given stress conditions, a set of biochemical markers (glutathione level, antioxidant enzymes activity, carbonyl content), plant hormones auxin and abscisic acid, as well as photosynthetic efficiency were determined. Levels of reduced glutathione and the activity of guaiacol peroxidase measured in leaves and roots increased in comparison to control in a dose dependent manner. Carbony content in leaves increased upon 100 mM and 200 mM NaCl treatments. Preliminary analysis of plant hormones indole-3-acetic acid (IAA) and abscisic acid (ABA) were analyzed in leaves by GC-MS. Results showed tendency in forming conjugated form of auxin as stress occurs. Furthermore, content of ABA has been elevated approximately 6.5 times upon treatment with 200 mM NaCl compared to the control, indicating a serious stress. Photosynthetic parameters measured by OJIP test didn't showed that photosynthetic apparatus response to salt stress by changing photosynthetic efficiency.

Brassica rapa L.; salt stress; glutathione; plant hormones; photosynthesis

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