Differential effect of water salinity levels on gas exchange, chlorophyll fluorescence and antioxidant compounds in ex vitro date palm plants


  • Besma SGHAIER-HAMMAMI Université de Carthage, Institut National Agronomique de Tunisie, Département Santé Végétale et Environnement, Laboratoire LR14AGR02 43 avenue Charles Nicolle, 1082 Tunis; University of Cordoba, Agroforestry and Plant Biochemistry, Proteomics and Systems Biology, Department of Biochemistry and Molecular Biology, UCO-CeiA3, 14014 Cordoba (TN)
  • Sofiene B.M. HAMMAMI Université de Carthage, Institut National Agronomique de Tunisie, Laboratoire LR13AGR01, 43 avenue Charles Nicolle, 1082 Tunis (TN)
  • Narjes BAAZAOUI King Khalid University, College of Sciences, Biology Department, Abha 61421 (SA)
  • Sami CHAARI Université de Carthage, Institut National Agronomique de Tunisie, Département Santé Végétale et Environnement, Laboratoire LR14AGR02 43 avenue Charles Nicolle, 1082 Tunis (TN)
  • Riadh DRIRA Green Biotechnology Company, Box 125, Sfax (TN)
  • Noureddine DRIRA Green Biotechnology Company, Box 125, Sfax (TN)
  • Malek SMIDA Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj-Cédria, B.P. 901, Hammam-Lif 2050 (TN)
  • Hatem BEN JOUIRA Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj-Cédria, B.P. 901, Hammam-Lif 2050 (TN)
  • Rahma GOUSSI Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj-Cédria, B.P. 901, Hammam-Lif 2050 (TN)
  • Fathia ZRIBI Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj-Cédria, B.P. 901, Hammam-Lif 2050 (TN)
  • Hava F. RAPOPORT Instituto de Agricultura Sostenible - C.S.I.C. Avenida Menéndez Pidal s/n, 14004 Córdoba (ES)
  • Ali SHATTI King Khalid University, College of Sciences, Biology Department, Abha 61421 (SA)
  • Taoufik BETTAIEB Université de Carthage, Institut National Agronomique de Tunisie, Laboratoire LR13AGR01, 43 avenue Charles Nicolle, 1082 Tunis (TN)
  • Jesús V. JORRIN NOVO University of Cordoba, Agroforestry and Plant Biochemistry, Proteomics and Systems Biology, Department of Biochemistry and Molecular Biology, UCO-CeiA3, 14014 Cordoba (ES)




ex vitro plants, high salinity, Phoenix dactylifera, photosynthesis, salt stress adaptation


In this study, the response to salt stress was evaluated in ex vitro acclimated date palm plants, regenerated from in vitro culture multiplication. The plants, eighteen-month-old, were irrigated with 0 (control), 150, 300 or 450 mM NaCl solutions (high to very high-water salinity). Photosynthesis parameters and antioxidant compounds were determined at the end of the experiment in leaves. At 150 mM NaCl, net CO2 assimilation rate and internal CO2 concentration were not impaired; while transpiration and stomatal conductance decreased by 60 and 70%, respectively. By increasing salt concentrations, all gas exchanges parameters were decreased. Measurement of chlorophyll fluorescence and P700 redox state showed that PSII and PSI machineries were significantly enhanced under 150 mM NaCl, conditions. With the 300 mM NaCl, the PSI parameters remained unchanged compared to control, while some of the PSII parameters, such as NPQ and Y (NPQ), were increased. At 450 mM NaCl, photosystems functionality was light intensity (PAR) dependent. Only at low PAR, a significant increase of some PSI and PSII parameters was observed. At the contrary, with high PAR, most of the energy conversion functions were significantly reduced, especially those related to PSI, indicating that PSI was more susceptible for damage by salinity than PSII. To overcome high salinity stress, ex vitro date palm plants mobilized a cascade of physio-biochemical pathways including the antioxidant activity and proline biosynthesis. Overall, the salinity of irrigation water, and up to 150 mM, improves the physiological performance of ex vitro date palm plants, which manage to tolerate very high levels of this stress.


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How to Cite

SGHAIER-HAMMAMI, B., HAMMAMI, S. B., BAAZAOUI, N., CHAARI, S., DRIRA, R., DRIRA, N., SMIDA, M., BEN JOUIRA, H., GOUSSI, R., ZRIBI, F., RAPOPORT, H. F., SHATTI, A., BETTAIEB, T., & JORRIN NOVO, J. V. (2023). Differential effect of water salinity levels on gas exchange, chlorophyll fluorescence and antioxidant compounds in ex vitro date palm plants. Notulae Botanicae Horti Agrobotanici Cluj-Napoca, 51(2), 13057. https://doi.org/10.15835/nbha51213057



Research Articles
DOI: 10.15835/nbha51213057

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