Document Type : Original Article
Department of Plant and Environmental Sciences, Copenhagen University, Copenhagen, Denmark
Department of Stem Cell Biology, Graduate School of System Life Sciences, Faculty of Arts and Science, Kyushu University, Fukuoka, Japan
Department of Mathematics and Natural Sciences, BRAC University, Dhaka, Bangladesh
Introduction: Tomato (Solanum lycopersicum L.) is one of the essential vegetables worldwide, for consumption and mitigating malnutrition. Genetic transformation conceivably overcomes its yield challenges due to salinity, a crucial constraint for the economical use of 30% of cultivable lands in the coastal region of Bangladesh. Therefore, a robust and reproducible protocol has been established for in vitro regeneration and transformation to develop transgenic salt-tolerant tomato plants.
Materials and Methods: During micropropagation, cotyledonary leaf explants were excised and cultured on MS media containing different combinations and concentrations of plant growth regulators. In transformation, the pre-cultured explants were inoculated and co-cultivated with Agrobacterium. Then they were transferred to the antibiotics-supplemented media to achieve salt-tolerant putative transformed plants. The transformation was confirmed by β-glucuronidase (GUS) assay and PCR for the antiporter gene.
Results: Maximum regeneration response was achieved from the explants abaxially positioned at a 1.5 cm distance apart. BARI Tomato 14 and BINA Tomato 3 showed the highest shoot regeneration response (%) on MS media supplemented with 2 mg/L BAP and with 0.1 mg/L IAA for BARI Tomato 2 and BARI Tomato 15. Bacterial culture of OD600 0.68 for 30 min and a Co-cultivation period of 48 h resulted in the highest transformation frequency (47%) in Agrobacterium-mediated transformation with pBI121 in BARI Tomato 3. The highest regeneration frequency (20.5%) was obtained in transformation with pH7WG2_OsNHX1_1.6.
Conclusions: The optimized procedure is simple, efficient, and can be used for micro-propagation and the production of tolerant varieties to increase yield in saline areas.