This study presents a programmable communication system between bacteria and plants, enabling bacteria to convey environmental signals to plants. The system uses a synthetic communication channel based on the small molecule p-coumaroyl-homoserine lactone (pC-HSL). Bacteria, such as Pseudomonas putida and Klebsiella pneumoniae, produce pC-HSL in response to environmental stimuli, which then activates gene expression in plants like Arabidopsis thaliana and potato (Solanum tuberosum). The system includes a "sender device" in bacteria that produces pC-HSL when a sensor or circuit is activated, and a "receiver device" in plants that responds to pC-HSL by activating gene expression. The system was validated in hydroponic and soil environments, demonstrating its modularity by swapping bacteria that process different stimuli, including IPTG, aTc, and arsenic. The communication channels allow plants to respond to different environmental signals by changing the bacteria, rather than genetically modifying the plant. This approach enables microbial sentinels to transmit information to crops and provides the building blocks for designing artificial consortia. The study also demonstrates the ability of bacteria to detect and communicate signals to plants, including the detection of arsenic and the implementation of logic gates for signal processing. The results show that the system is effective in both hydroponic and soil environments, with the plant responding to pC-HSL with increased gene expression. The study highlights the potential of synthetic biology in developing communication systems between bacteria and plants for agricultural applications.This study presents a programmable communication system between bacteria and plants, enabling bacteria to convey environmental signals to plants. The system uses a synthetic communication channel based on the small molecule p-coumaroyl-homoserine lactone (pC-HSL). Bacteria, such as Pseudomonas putida and Klebsiella pneumoniae, produce pC-HSL in response to environmental stimuli, which then activates gene expression in plants like Arabidopsis thaliana and potato (Solanum tuberosum). The system includes a "sender device" in bacteria that produces pC-HSL when a sensor or circuit is activated, and a "receiver device" in plants that responds to pC-HSL by activating gene expression. The system was validated in hydroponic and soil environments, demonstrating its modularity by swapping bacteria that process different stimuli, including IPTG, aTc, and arsenic. The communication channels allow plants to respond to different environmental signals by changing the bacteria, rather than genetically modifying the plant. This approach enables microbial sentinels to transmit information to crops and provides the building blocks for designing artificial consortia. The study also demonstrates the ability of bacteria to detect and communicate signals to plants, including the detection of arsenic and the implementation of logic gates for signal processing. The results show that the system is effective in both hydroponic and soil environments, with the plant responding to pC-HSL with increased gene expression. The study highlights the potential of synthetic biology in developing communication systems between bacteria and plants for agricultural applications.