ORIGINAL ARTICLE

Differential Responses of Growth, Metals Accumulation, Oxidative Stress and Osmo-compatible Solutes in the Halophyte Tamarix gallica under Arsenic and Aluminum Stress Alone or Combined with Salt

Several studies have been investigated to determine the ability of plants to reduce heavy metals in polluted soils. Conducted within the strong halophyte Tamarix gallica, known for thriving under harsh environmental conditions, the major objective was to study the tolerance and accumulation capabilities of Tamarix gallica under Arsenic, Aluminium, and salt stress. Plants were exposed to different concentrations of Al and As alone (200, 500 and 800 µM), or added to NaCl (200 mM). The results evinced that both metals impaired the mature and expanation of T. gallica. Furthermore, the accumulation of the metals was dependent on the concentrations of the metals in the medium. Interestingly, when salt diminished As uptake, a rise in Al accumulation was noted. Besides, T. gallica demonstrated that APX was the predominant enzyme to scavenge excess ROS. Nonetheless, SOD and GPOX were responsive to the metal, demonstrating different behaviour in metal stress alone or when added with salt. Proline accumulated in a dose-dependent manner under Al and As stress, instead of lower or unchanged levels of glycine betaine. The application of NaCl led to a decrease in proline content but an increase in glycine betaine levels. Under combined stress, there was an augmentation in proline levels, while glycine betaine levels remained unchanged. This underscores T. gallica's capacity to thrive under elevated concentrations of As/Al.