The effects of plant activators on the physiological and biochemical parameters in tomato (Lycopersicon esculentum Mill.) under salt and biotic stresses


Creative Commons License

Tosun N. , Türkan İ. , Demiral T., Çetinel A. H. , Türküsay H., Özfidan Konakçı C., ...More

Second International Symposium on Tomato Diseases, Aydın, Turkey, 8 - 11 October 2007, pp.93

  • Publication Type: Conference Paper / Summary Text
  • City: Aydın
  • Country: Turkey
  • Page Numbers: pp.93

Abstract

The purpose of this project was to find out whether plant activators Stubble-Aid and ISR-2000 furnish any protection for Lycopersicon esculentum Mill. plants against low, medium and high levels of salt stress (35, 70 and 140mM NaCl) in combination with pathogen stress under greenhouse conditions.

Three weeks old tomato (Lycopersicon esculentum Mill) plants were sprayed with Stubble-Aid in three different concentrations (600, 1200 and 1800 µl L-1) or with distilled water until run off. One week after Stubble-Aid treatment, tomato plants were irrigated with 35mM, 70mM and 140mM NaCl concentrations (0 th day of salinity) twice a week. Irrigation with NaCl was continued through 9 weeks together with Stubble-Aid application. 1800µl L-1 Stubble-Aid treatment enhanced root length, root DW, shoot length, shoot FW and shoot DW of tomato plants especially under 70mM NaCl stress. Under 35mM NaCl, generally, 600µl L-1 Stubble-Aid was effective in preventing NaCl-induced reduction in growth. In protecting leaf RWC, Stubble-Aid treatments were all shown to be effective under all salinity levels. Although both Pseudomonas syringae pv tomato and B. cinerea inoculations decreased leaf RWC, 1200 and 1800µl L-1 Stubble-Aid treatments prevented the decrease. Stubble-Aid treatments applied to tomato plants under 70mM NaCl stress in combination with P. syringae pv tomato and B. cinerea inoculations enhanced stomatal conductivity of tomato plants. Superoxide dismutase (SOD; EC 1.15.1.1) activity of tomato plants under 35, 70 and 140mM NaCl stresses were enhanced by, respectively, 600, 1200 and 1800µl L-1 Stubble-Aid applications. 188µl L-1 NFP treatment also induced CAT activity under all salinity levels. Ascorbate peroxidase (AP; EC 1.11.1.11) activity of tomato plants under 35mM NaCl stress was increased by 600 and 1800µl L-1 Stubble-Aid treatments. Under 70mM NaCl, AP activity was enhanced by 600µl L-1 NFP. 1200 and 1800µl L-1 Stubble-Aid applications increased significantly AP activity under 140mM NaCl. Under low and medium salinity levels, glutathione reductase (GR; EC 1.6.4.2) activity was enhanced by both 600 and 1200 µl L-1 Stubble-Aid applications. 600µl L-1 Stubble-Aid application caused a decrease in GR activity under 140mM NaCl stress. POX activity was enhanced by 600µl L-1 Stubble-Aid treatment under 35 and 70mM NaCl stresses. 1200µl L-1 Stubble-Aid treatment of tomato plants inoculated with P. syringae pv tomato increased significantly POX activity. While 600 µl L-1 Stubble-Aid treatment increased POX activity of tomato plants inoculated with P. syringae pv tomato under 70mM NaCl increased POX activity, 1200 and 1800µl L-1 Stubble-Aid treatments decreased it. POX activity of tomato plants inoculated with B. cinerea was increased by 600 and 1200µl L-1 Stubble-Aid treatment. While salinity had no effect on malondialdehyde (MDA) content of tomato plants, Stubble-Aid treatments were found to increase MDA contents of tomato plants under 35, 70 and 140mM NaCl concentrations. Proline accumulation was highest in NaCl applied groups and showed a decreasing trend with Stubble-Aid applications.