Plant Senescence: How Plants Choose, How and When to Die

Abstract

The word "senescence in plants" refers to the natural ageing process that takes place in plant tissues, organs, and cells and ultimately causes plant death. It is an intricate, tightly controlled process that is affected by both external and internal variables. The internal biological clock of the plant, which is controlled by many external conditions like temperature, light, and nutrition availability, is one of the primary causes of senescence. The internal clock alerts the plant to begin senescing when it reaches a specific age or developmental stage. Several biochemical and physiological changes that the plant experiences during senescence cause the disintegration of cellular elements such as nucleic acids, proteins, chlorophyll and other macromolecules. The plant may continue to grow and develop because these breakdown products are recycled and utilised to create new tissues and organs.
 In addition, the plant generates and stores a variety of signalling chemicals, including reactive oxygen species (ROS) and hormones, that control the senescence process. The different physiological and biochemical changes that take place during senescence are coordinated by these signalling molecules, which serve as messengers. Senescence is an ordinary and necessary component of the life cycle of plants, but it can also be brought on early by many environmental challenges, including disease, nutrient inadequacy, and drought. The relevance of comprehending the processes that regulate the senescence procedure is emphasized by the fact that premature senescence can have a major influence on plant growth and productivity.
 The genetically controlled degenerative process of leaf/plant senescence includes nutrient remobilization before the death of leaf/plant tissues. Together with other senescence-causing elements, age plays a significant developmental role in the process. Senescence is regulated at the cellular level by a variety of signalling molecules, hormones, and transcription factors. The complexity of the senescence process, as well as the perception and transmission of senescence signals, as well as subsequent regulatory events, are briefly reviewed in this overview, which also covers current advancements in this area. It will be explored where this field is headed in the future and how related techniques might be used to improve crops.