Programmed cell death (PCD) is a physiological process in plants that removes unwanted cells, playing a crucial role in development, tissue sculpting, and disease. In animals, PCD is involved in the elimination of cells that are no longer needed, such as those that overproduce or are misplaced. PCD in plants is essential for growth and survival, occurring in various contexts, including the deletion of cells with temporary functions, the elimination of unwanted cells, and the specialization of cells. PCD in plants is characterized by cell condensation, shrinkage, and DNA fragmentation, similar to apoptosis in animals. In plants, PCD is triggered by various signals, including reactive oxygen species (ROS) and phytohormones like gibberellin (GA) and ethylene. For example, in aleurone cells of monocot seeds, GA induces PCD, while ABA blocks it. Root cap cells also undergo PCD during development, and this process is associated with the accumulation of DNA fragments and the condensation of the cytoplasm. In vascular plants, PCD is essential for the differentiation of tracheary elements (TEs), which are dead cells that transport water. The process involves the condensation and fragmentation of the cytoplasm and nucleus, as well as the breakdown of DNA into oligonucleosome-sized fragments. PCD also occurs during plant interactions with the environment, such as in the hypersensitive response (HR) to pathogen attack, where cells die to prevent pathogen spread. In senescence, PCD is involved in the active turnover of cellular material, and DNA fragmentation is observed in senescing leaves. The mechanisms underlying PCD in plants are not fully understood, but they likely involve similar signaling pathways to those in animals, including the role of ROS and calcium ions. While PCD in animals is often regulated by genes like Bcl-2 and the ICE family proteases, the mechanisms in plants may differ, with some studies suggesting that plant PCD may involve different proteins and signaling pathways. The evolution of PCD is conserved across eukaryotes, with similar processes observed in prokaryotes and lower eukaryotes. However, the exact molecular mechanisms remain to be fully elucidated. Overall, PCD is a critical process in plant development and environmental interactions, ensuring proper growth, tissue specialization, and defense against pathogens.Programmed cell death (PCD) is a physiological process in plants that removes unwanted cells, playing a crucial role in development, tissue sculpting, and disease. In animals, PCD is involved in the elimination of cells that are no longer needed, such as those that overproduce or are misplaced. PCD in plants is essential for growth and survival, occurring in various contexts, including the deletion of cells with temporary functions, the elimination of unwanted cells, and the specialization of cells. PCD in plants is characterized by cell condensation, shrinkage, and DNA fragmentation, similar to apoptosis in animals. In plants, PCD is triggered by various signals, including reactive oxygen species (ROS) and phytohormones like gibberellin (GA) and ethylene. For example, in aleurone cells of monocot seeds, GA induces PCD, while ABA blocks it. Root cap cells also undergo PCD during development, and this process is associated with the accumulation of DNA fragments and the condensation of the cytoplasm. In vascular plants, PCD is essential for the differentiation of tracheary elements (TEs), which are dead cells that transport water. The process involves the condensation and fragmentation of the cytoplasm and nucleus, as well as the breakdown of DNA into oligonucleosome-sized fragments. PCD also occurs during plant interactions with the environment, such as in the hypersensitive response (HR) to pathogen attack, where cells die to prevent pathogen spread. In senescence, PCD is involved in the active turnover of cellular material, and DNA fragmentation is observed in senescing leaves. The mechanisms underlying PCD in plants are not fully understood, but they likely involve similar signaling pathways to those in animals, including the role of ROS and calcium ions. While PCD in animals is often regulated by genes like Bcl-2 and the ICE family proteases, the mechanisms in plants may differ, with some studies suggesting that plant PCD may involve different proteins and signaling pathways. The evolution of PCD is conserved across eukaryotes, with similar processes observed in prokaryotes and lower eukaryotes. However, the exact molecular mechanisms remain to be fully elucidated. Overall, PCD is a critical process in plant development and environmental interactions, ensuring proper growth, tissue specialization, and defense against pathogens.