Baer et al. (2021) 685 SABRAO Journal of Breeding and Genetics 53 (4) 685-696, 2021 http://doi.org/10.54910/sabrao2021.53.4.11 http://sabraojournal.org/ pISSN 1029-7073; eISSN 2224-8978 EXPRESSION OF SOME SALT TOLERANCE GENES ISOLATED FROM EGYPTIAN GRAY MANGROVE (AVICENNIA MARINA) A.A. EL-ATAWY, M.S. RIZK, E.S. EL-DEMERDASH * and M.Z.S. AHMED 3 Genetic Resources Department, Desert Research Center (DRC), Mathaf Al-Mataria, Cairo, Egypt *Corresponding author email: saadelshaimaa1@yahoo.com Email addresses of co-authors: dralaaalden@yahoo.com, drmokhtarsaid@yahoo.com, zoelfakar99@yahoo.com SUMMARY Mangroves are well-adapted halophytes that thrive in coastal saline environments. They live under difficult environmental conditions, such as high light intensity and external salt concentrations, as well as low-oxygen environments, such as water-logged muck, that are typically inappropriate for the survival of other plants. Salinity is a major abiotic factor that affects plant growth, productivity, and dispersal in tropical and semitropical intertidal areas. Furthermore, it affects approximately 20% of all cultivable land and 50% of all irrigated land on the planet. Mangroves have developed a sophisticated salt filtration mechanism and a complicated root structure to withstand salty water exposure and tidal movement. The expression patterns of five salt tolerance genes (amFer1, amDhna, amSod1, amCat1, and amUbc2) in the Egyptian gray mangrove (Avicennia marina Forssk.) grown under different environmental conditions in South Sinai protectorates (Nabq, Ras Mohamed, Safaga, and Wadi El-Gemal), Egypt, were investigated in this study. This study aimed to assess and examine the genetic behavior of mangroves in response to salinity by using quantitative real-time PCR. Findings revealed differences in the expression patterns of the investigated genes under various conditions, showing that salinity influences plant genetic response. Ferritin gene expression was high in all locations, indicating that ferritin represents an essential component of the mangrove response mechanisms. Keywords: Mangrove (Avicennia marina), (amFer1, amDhna, amSod1, amCat1, and amUbc2), salt tolerance genes, quantitative real-time PCR Key findings: The variations in the expression levels of five selected genes (amFer1, amDhna, amSod1, amCat1, and amUbc2) in the Egyptian gray mangrove were examined. Plant samples were collected from four sites in South Sinai (Nabq, Ras Mohamed, Safaga, and Wadi El-Gemal). The ferritin gene showed the highest expression level in A. marina Forssk regardless of collection site, reflecting its vital role in the response (adaptation) mechanism of A. marina to abiotic stresses. Manuscript received: September 9, 2021; Accepted: November 8, 2021. © Society for the Advancement of Breeding Research in Asia and Oceania (SABRAO) 2021 Communicating Editor: Dr. Kamile Ulukapi RESEARCH ARTICLE