Generative artificial intelligence (GenAI) transforms instructional practice through adaptive content generation, differentiated planning, and interactive learning environments. To effectively navigate these changes, professional development programs are needed to enable teachers to meet the challenges of instruction in GenAI contexts. Few qualitative studies to date have explored how Primary School Teachers (PSTs) develop their technological teaching competencies following GenAI intervention, this study addresses that gap by exploring how PSTs perceived emergence of their I-TPACK competencies after their first encounter with GenAI, and their reflections on how The present study examined the effect of a Gemini-based professional development (GPD) program contributes to shape these competencies on teachers' competencies to work in GenAI contexts. Twenty primary school teachers with no prior GenAI experience participated in the study. They completed a GPD program designed to build competencies in planning, designing, and evaluating instruction through the use of the Gemini GenAI tool. Data were collected through semi-structured interviews and analyzed using deductive–inductive content analysis. Deductive analysis was guided by the I-TPACK model, while inductive analysis revealed an emergent category highlighting the interconnections among I-TPACK components. PSTs perceived that GPD fundamentally reshaped their GenAI teaching competencies. Findings indicated multidimensional growth perceives development in teachers' technological, pedagogical, content, and ethical GenAI competencies following the Gemini-based professional development program. PSTs perceived that Technological competency (I-TK) served as an entry point for developing other domains competencies within I-TPACK, with ethical awareness embedded in instructional decision-making. Despite overall progress, challenges persisted in mastering advanced Gemini features, and assessment-related competencies remained under development. These findings underscore the need for holistic, ethically grounded professional development that fosters digital fluency and sustains competency growthdevelopment. Future programs should differentiate support based on teachers' prior experience and provide structured access to recorded training. Further studies are required to validate these results in middle and high school contexts.
