Artificial intelligence (AI), utilizing machine learning techniques to 'learn' from data, as humans learn from experiences, has the promise to perform various cognitive tasks, such as learning, thinking, problem-solving, and decision-making, which usually demands human cognition. In recent decades, the remarkable advancements in AI have led to its pervasive integration across various sectors of society, and has facilitated human-machine interactions encompassing language, action, and behaviors. Within the educational sphere, AI has played emerging roles, driving significant changes in teachers' instructional practices and potentially revolutionizing teaching practices in unprecedented ways. To fully harness the innovative potential of AI in teaching, it becomes imperative to unpack the diverse pedagogical roles that AI can assume and examine the emergent relationship between teachers and AI, however, which remain ambiguously defined and have yet to be comprehensively explored. Presented as three journal-ready manuscripts, the dissertation delves into the theoretical and practical exploration of the emerging pedagogical roles of AI and the formation of a novel teacher-AI relationship. The first manuscript (Chapter 2) provides a systematic review to elucidate the pedagogical roles and characteristics of AI in enhancing teachers' instructional practices. Implications for teachers' pedagogy and the teacher-AI relationship are discussed. Given the pedagogical potential of AI in teaching practices, the second manuscript (Chapter 3) proposes an integrated conceptual framework, encompassing a three-dimensional teacher-AI pedagogical partnership model and its impacts on teachers. It has implications for collaborative teaching design and future research foci in this emerging area of research. In the third manuscript (Chapter 4), the qualitative data revealed a mutual interaction between teachers and AI: AI provides substantial support to teachers and teachers actively support work of AI. Two distinct perceived roles of AI were found: a supportive tool and a collaborative partner. Three changes in classroom interactions emerged: individualized instruction, data-driven and targeted approaches, and shifts in teachers' roles. Findings suggest that AI promotes the transformation of technology from being merely a supportive tool to becoming a partner and a novel collaborative relationship. The implications for teachers' changed mindset and professional learning are discussed. Chapter 5 discusses the implications and suggestions for future research. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]