Effect of salicylic acid and salinity on the photochemical functioning of strawberry using JIP test

This study was carried out to evaluate the effects of salicylic acid (SA) and salinity on the photochemical functioning of strawberry. The experimental layout was a complete randomized block design (RBD) with 3 independent replications. After SA treatment at 0.1 mM, photosystem performance index (PIabs) showed an increase as compared to the control ones. Plants treated for 6 days with 50 mM NaCl exhibited a decline in PSII function, as estimated by a large reduction of PIabs. This down-regulation of PSII function was associated with decreases in electron transport (ET0/CS) per excited crosssection of leaf, as well as in the efficiency of the watersplitting complex on the donor side of PSII (as inferred from Fv/Fo) for plants treated with salinity. This downregulation of photochemical functioning observed in plants subjected to salinity conditions was greatly mitigated after pretreatment with both 0.1 and 0.5 mM SA, as evidenced by higher PIabs levels, compared with NaCl-alone treated plants. This positive effect of SA was attributed to the improvement of PSII functioning, resulted in enhanced tolerance to salt stress

Keywords:

Electron transport , NaCl stress , PSII function , Estrawberry , Salicylic acid , Water-splitting complex