The effects of exogenous sodium nitroprusside (SNP), as nitric oxide donor, and spermidine (Spd) on growth and photosynthetic characteristics of Bakraii seedlings (Citrus reticulata x Citrus limetta) were studied under NaCl stress. In citrus plants, SNP- and Spd-induced growth improvement was found to be associated with reduced electrolyte leakage, malondialdehyde, hydrogen peroxide content, and leaf Na+ and Cl- concentration. However, we found increased leaf Ca2+, Mg2+, and K+ concentrations, relative water content, chlorophyll fluorescence parameters, antioxidant enzyme activities, such as ascorbate peroxidase, catalase, superoxide dismutase and peroxidase, as well as higher photosynthetic rate, intercellular CO2 concentration, stomatal conductance, and transpiration rate under saline regime. Foliar application of SNP and Spd alone mitigated the adverse effect of salinity, while the combined application proved to be even more effective., D. Khoshbakht, M. R. Asghari, M. Haghighi., and Obsahuje bibliografii
The effects of polyamines (PAs) on salt stress in Bakraii (Citrus reticulata × Citrus limetta) seedlings were studied. Foliar treatments by putrescine (Put), spermidine (Spd), and spermine (Spm) (0, 0.5, and 1 mM) were applied during the salinity period
(0 and 75 mM of NaCl). PA-treated seedlings showed a lower content of Na+ and Cl- in leaves. Application of PAs increased net photosynthetic rate in salt-stressed plants and it contributed to the enhanced growth parameters. PAs application considerably induced growth improvement in Bakraii seedlings which was found to be associated with reduced electrolyte leakage, increased relative water content, chlorophyll fluorescence parameters, activities of key antioxidant enzymes, as well as increased photosynthetic pigment concentration under saline regime. These results showed the promising use of PAs, especially of Spd and Spm, for reducing the negative effects of salinity stress and improving the growth of citrus seedlings., D. Khoshbakht, M. R. Asghari, M. Haghighi., and Obsahuje bibliografii