Effect of Different Antibiotics and Polyamines on In Vitro Organogenesis of Tomato

Successful plant transformation depends on efficient and reproducible in vitro regeneration protocols, particularly in economically important crops such as tomato (Solanum lycopersicum). This study investigated the effects of polyamines and antibiotics on organogenesis in tomato explants to optimize tissue culture conditions for potential transformation applications. In the first experiment, the impact of two polyamines—putrescine and spermidine—was assessed in combination with 1–2 mg/L benzylaminopurine (BAP) and 1 mg/L indole-3-acetic acid (IAA) using cotyledon explants. Results indicated that all media induced shoot formation, with the highest shoot number and explant regeneration observed in media containing 50 mg/L putrescine, 1 mg/L IAA, and 1–2 mg/L BAP. In the second experiment, the phytotoxic effects of two antibiotics commonly used in Agrobacterium-mediated transformation—Tavanex¹ and ceftriaxone—were evaluated. Although both antibiotics inhibited bacterial growth at low concentrations, they caused complete necrosis in all explants, even at minimal dosages. These results highlight the synergistic role of polyamines with growth regulators in enhancing tomato organogenesis and the detrimental effects of commonly used antibiotics on tissue viability. The study provides practical recommendations for refining regeneration protocols in tomato and contributes to improving genetic transformation strategies. [1] Tavanex is a commercial name for the antibiotic levofloxacin, a fluoroquinolone compound. Levofloxacin is a broad-spectrum antibiotic of the fluoroquinolone class, effective against a wide range of bacterial infections (North et al. 1998).