Aeluropus littoralis as a genetic source for salinity resistance is one of the promising species for genetic improvement and performance of crop plants. We studied the cell wall bound peroxidase enzyme and some wall phenolics to find the possible role of them in wall extensibility and further effect on leaf growth. The effect of different salt concentrations on cell wall-bound peroxidase (CWPRX) activity, CWPRX gene expression and the related cell wall phenolic acid content were investigated along different ages of Aeluropus littoralis leaves. Growth Parameters and enzyme activity were measured in nine replications. For Study of Gene expression levels and Phenolic content changes, We used Real Time PCR and high performance liquid chromatography Systems, respectively. Salt treatment progressively inhibited elongation and expansion of the leaves. The activities of ionically and covalently bound peroxidases increased in leaves due to salt treatment. Analysis of variance of covalently bound enzyme activity measurements revealed significant differences between leaves in all treatments, whereas cell wall peroxidase gene expression increased only in leaf 4 at 200 that possibly caused induction in ferulate network production at 200 mM. Ferulic acid, p-coumaric acid and sinapic acid contents increased significantly in leaves 7 and 10 by 200 and 400 mM. These results suggested a correlation between cell wall-bound peroxidase activity and CWPRX gene expression with leaf developmental stages and salt treatment. It is concluded that cell wall bound enzyme activity and cell wall phenolic acid profile may contribute to the stiffening of cell wall during salt stress and at different leaf developmental stages.
