Generative artificial intelligence (AI) is increasingly reshaping how organizations coordinate internal functions to achieve innovation. However, existing research tends to examine human resource management, research and development, and marketing in isolation, overlooking how their joint effects influence product innovation performance under AI enablement. This study investigates the synergistic mechanisms among human resource flexibility, R&D agility, and marketing responsiveness in the context of generative AI adoption. Drawing on resource-based view and dynamic capability theory, we propose that generative AI strengthens the interplay among these three organizational capabilities, thereby enhancing product innovation performance. A conceptual framework is developed to explain how generative AI facilitates information sharing, decision-making speed, and cross-functional alignment. The study contributes to the literature by clarifying the configuration effects of AI-enabled organizational capabilities and offering practical insights for enterprises seeking to leverage generative AI for innovation-driven growth. Future empirical research can validate the proposed relationships using survey or case-based methods. This paper provides a timely theoretical foundation for understanding the value-creation mechanisms of generative AI in product innovation management.