Mechanisms of date palm Phoenix dactylifera salt tolerance, effect of water salinity on some cell wall enzymes activity during development of Sayer date palm fruit

The activities of polygalacturonase (PG), pectinesterase (PE), cellulase (Cx) and polyphenol oxidize were investigated in Sayer date palm fruit cultivar were arrogation by two different water salinity (16 dsm and 4 dsm) during fruit development. The date palm Phoenix dactylifera fruit has single sigmoid growth curve with three stages (the first stage was 5 weeks and the second stage was 12 weeks whereas the third stage was 4 weeks). The pectin content was high during early stage of fruit development, but declined gradually with fruit development and reached their lowest value when the fruit entered the ripening phase. The PG, PE and Cx were low level during early stages of fruit development, but there were rapid increase in these enzymes activity as the date palm entered variation stage and maturity phase, the water salinity was a significant effect in all ripening enzymes.