Physiological, Biochemical, Anatomical, and Agronomic Responses of Sesame to Exogenously Applied Polyamines under Different Irrigation Regimes

Polyamines (PAs) are plant growth regulators that attenuate the destructive impacts of water deficit on sesame plants, particularly in arid regions under abrupt climate change. Limited information is available physiological, biochemical, anatomical, and agronomic responses to exogenous application PAs field conditions. Thus, a two-season trial was carried out assess impact exogenously sprayed spermine (Spm), spermidine (Spd), putrescine (Put) physio-biochemical anatomical parameters their influences performance crop productivity plants. The plants were assessed three irrigation regimes; full (100% ETc), mild drought (75% severe (50% ETc) Drought stress displayed negative all evaluated parameters. However, applied Pas, especially Put, restricted effects deficit. exhibited highly significant enhancement photosynthetic pigments (chlorophyll a, b, carotenoids), gas exchange (net rate, stomatal conductance, rate transpiration), relations (relative content, membrane stability index, excised leaf retention), nutrient content (N, P, K) compared untreated stress. Moreover, PA amelioration osmoprotectants (free proline, soluble sugars, α-Tocopherol, ascorbate, glutathione), antioxidant enzyme activities (catalase, peroxidase, superoxide dismutase, ascorbate glutathione reductase). In addition, foliar nourishing with reduction oxidative markers (malondialdehyde, electrolyte leakage, superoxide, hydrogen peroxide). These positive reflected improvement characteristics (midrib length width, vascular bundle thickness phloem, xylem collenchyma, vessel diameter, number rows midvein bundle), yield-related traits (plant height, area, capsules per plant, 1000-seed weight, seed yield, oil content). Consequently, (in particular, Put) could be exploited enhance yield low availability regions.