Plant Cell, Tissue and Organ Culture, cilt.164, sa.1, 2026 (SCI-Expanded, Scopus)
The efficiency of genetic transformation in lettuce is highly genotype-dependent. This study aims to present a comprehensive method that integrates phenotypic and molecular analyses to reliably and reproducibly evaluate transformation efficiency in lettuce. Transformation was performed using a binary vector carrying the RUBY reporter gene. Four lettuce cultivars—Caipira, Emocion, Maritima, and Vaidosa—were compared to assess differences in transformation efficiency. An optimized Rhizobium radiobacter–mediated transformation protocol was successfully developed for all four cultivars. Shoot regeneration on selective media was monitored, and the red coloration conferred by the RUBY gene enabled visual assessment of transformation efficiency. Gene integration was further confirmed by PCR. Transgenic plants were successfully obtained from all cultivars, resulting in 18 PCR-confirmed transformants. Among the tested genotypes, cv. Emocion exhibited the highest rate of RUBY-colored shoots (67.3%), whereas cv. Vaidosa showed the lowest regeneration rate (7%). These findings demonstrate that transformation efficiency in lettuce is strongly genotype-dependent. The protocol developed here provides consistent and effective results across cultivars and offers a valuable reference for future lettuce transformation studies in plant biotechnology.