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The climatic changes crossing the world menace the green life through limitation of water availability. The goal of this study was to determine whether Moringa oleifera Lam. trees cultivated under Tunisian arid climate, retain their tolerance ability to tolerate accentuated environmental stress factors such as drought and salinity. For this reason, the seeds of M. oleifera tree planted in Bouhedma Park (Tunisian arid area), were collected, germinated, and grown in the research area at the National Institute of Research in Rural Engineering, Waters and Forests (INRGREF) of Tunis (Tunisia). The three years aged trees were exposed to four water-holding capacities (25, 50, 75, and 100%) for 60 days to realise this work. Growth change was traduced by the reduction of several biometric parameters and fluorescence (Fv/Fm) under severe water restriction (25 and 50%). Whereas roots presented miraculous development in length face to the decrease of water availability (25 and 50%) in their rhizospheres. The sensitivity to drought-induced membrane damage (Malondialdehyde (MDA) content) and reactive oxygen species (ROS) liberation (hydrogen peroxide (H2O2) content) was highly correlated with ROS antiradical scavenging (ferric reducing antioxidant power (FRAP) and (2, 2’-diphenyl-1-picrylhydrazyle (DPPH)), phenolic components and osmolytes accumulation. The drought stress tolerance of M. oleifera trees was associated with a dramatic stimulation of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), ascorbate peroxidase (APX), and glutathione peroxidase (GPX) activities. Based on the several strategies adopted, integrated M. oleifera can grow under drought stress as accentuated adverse environmental condition imposed by climate change.

This work investigates the combined effects of N form and Cd treatment on photosynthesis of tomato (Solanum lycopersicum Mill. cv Ibiza F1). Our study shows that, compared to plants fed with NO₃“, dry weight, fresh weight and leaf area decrease when plants received NH₄ ⁺ as N form. Regardless the N form used, Cd inhibits this parameters. In this report we show that, when grown in NH₄ ⁺, Cd—stressed seedlings accumulate higher levels of chlorophyll. Under Cd stress, water content, transpiration rate (E), stomatal conductance (Gs) and photosynthetic activity (Amax) decreased in plants fed with NO₃ ⁻ and increased in NH₄ ^+- grown-plants. The F_v/F_m ratio of dark adapted leaves was lower in NH₄+- grown tomato compared to in NO₃“-grown seedlings. Upon exposure to metal, the F_v/F_m ratio and the fraction of open PSII reaction centers (qp) were depressed by Cd in NO₃“⁻grown plants and enhanced in NH₄ ^+-grown ones. NPQ stimulated by Cd in NO₃ ⁻-grown plants was inhibits in NH₄ ⁺-grown ones.