Plants use volatile organic compounds (VOCs) for communication between organs and with microbes. A study reveals that a KAI2-mediated signaling pathway is crucial for this process. In petunia flowers, volatile terpenoids are produced in flower tubes and released before anthesis, influencing reproductive organ development. The petunia KAI2 receptor, PhKAI2ia, specifically recognizes the enantiomer (-)-germacrene D, triggering a signaling cascade that affects plant fitness. This pathway is essential for normal pistil development and seed production. The study shows that PhKAI2ia is stereo-specifically involved in sensing (-)-germacrene D, and its activity is regulated by MAX2 proteins, which mediate the degradation of the transcriptional repressor SMAX1. The findings highlight the role of KAI2-mediated signaling in plant communication and provide insights into the molecular mechanisms underlying volatile perception and response in plants.Plants use volatile organic compounds (VOCs) for communication between organs and with microbes. A study reveals that a KAI2-mediated signaling pathway is crucial for this process. In petunia flowers, volatile terpenoids are produced in flower tubes and released before anthesis, influencing reproductive organ development. The petunia KAI2 receptor, PhKAI2ia, specifically recognizes the enantiomer (-)-germacrene D, triggering a signaling cascade that affects plant fitness. This pathway is essential for normal pistil development and seed production. The study shows that PhKAI2ia is stereo-specifically involved in sensing (-)-germacrene D, and its activity is regulated by MAX2 proteins, which mediate the degradation of the transcriptional repressor SMAX1. The findings highlight the role of KAI2-mediated signaling in plant communication and provide insights into the molecular mechanisms underlying volatile perception and response in plants.