Phytohormones as Crucial Players in Organ Abscission

Organ abscission in plants is an integral part of their developmental program, ensuring the completion of the entire ontogenetic cycle. This process involves the shedding of unnecessary, non-functioning, or damaged plant organs. However, premature abscission of flowers and fruits, which significantly affects yield in agriculturally important species, can have detrimental effects. The separation of organs is a highly complex process that involves the degradation of the middle lamella in a specific group of cells known as the abscission zone (AZ). Phytohormones, including auxin, ethylene, abscisic acid, cytokinins, brassinosteroids, gibberellins, strigolactones, and jasmonates, play a crucial role in the functioning of the AZ and coordination of the abscission process. These hormones also act as important signaling molecules in response to biotic and abiotic stresses, further influencing the activation of the abscission zone and organ separation.

The aim of this research topic is to advance our understanding of the organ separation processes in plants, particularly focusing on the role of phytohormones. The perception of hormone signals initiates dynamic events that determine the timing of organ abscission. Through this research, we intend to provide a comprehensive overview of the phytohormone-dependent functioning of the abscission zone in different organs and species. Given the economic importance of abscission manipulation in agriculture and horticulture, special emphasis will be placed on economically significant plant species. Additionally, since plant hormones also play a role in stress responses, including the excessive abortion of plant parts resulting from environmental cues, we will explore the involvement of phytohormones in stress-induced abscission. By taking this comprehensive approach, we aim to present a deep understanding of the role of phytohormones in the processes underlying organ abscission.

We encourage researchers to submit articles focusing on, but not limited to, the following areas:

- Modulation of phytohormone biosynthesis and signaling in relation to organ abscission
- Effects of phytohormones and their inhibitors on abscission
- Functioning of the abscission zone under the influence of various plant hormones
- Identification of unknown endogenous molecules involved in phytohormone-dependent abscission
- Metabolic pathways activated in abscised organs as a result of phytohormone action
- Selection of varieties with reduced abortion rates through phytohormone manipulation
- Connections between environmentally triggered organ abscission and plant hormones

This Research Topic welcomes all article types available in Frontiers in Plant Science including Original Research, Reviews and Mini Reviews, Method and Perspective Articles as well as Hypothesis and Theory Articles.