SUMMARY
Background: Prosopis, or mesquite (Prosopis juliflora (Sw.) DC.), was introduced in Saudi Arabia several decades
ago and is heavily used in street, roadside, and park plantations. It shows great adaptation to the prevailing
climatic conditions such as high temperature, severe drought, and salinity and spreads naturally in many parts
of the Kingdom. This research was conducted to isolate allergen proteins and biogenic amines from the pollen
grains of P. juliflora genotypes in Saudi Arabia from two regions, namely Al-Qassim and Eastern regions.
Results: The results showed that 18 different allergen proteins were detected in P. juliflora genotypes, with
molecular weight ranging from 14 to 97 kDa. Moreover, P. juliflora genotypes from the two studied regions
contained eight biogenic amines, namely histamine, tyramine, tryptamine, ß-phenylethylamine, butricine,
codapherine, spermidine, and spermine. All genotypes from the Al-Qassim region were found to contain all
eight amines, while in the Eastern region, histamine was absent in three genotypes, spermine was absent in
six genotypes, and spermidine was absent in three genotypes. Genotypes B23, E20, and E21 had the lowest
biogenic amine quantity.
Conclusions: All identified proteins from mesquite trees from both regions (Eastern and Al-Qassim) cause
allergies in patients who are sensitive to pollen grains. Bioamines, except histamine and tyramine, were
recorded at varying concentrations in different genotypes.