A new study from the John Innes Centre has discovered how a molecular feedback loop triggers the shedding of petals in flowers, an important process that allows seeds to disperse and the flower to make way for new growth. The findings, published in the journal Nature Plants, could have implications for improving the post-harvest life of cut flowers and even help increase crop yields.

The study focused on the model plant Arabidopsis thaliana. When Arabidopsis flowers are pollinated, the petals will eventually wilt and fall off, a process known as petal abscission. This process is essential for the plant's reproductive success, as it allows the seeds to be dispersed and the flower to make way for new growth.

The researchers found that the molecular trigger for petal abscission is a hormone called auxin. Auxin is produced in the ovary of the flower, and it travels to the petals where it binds to a receptor protein called AUXIN BINDING PROTEIN1 (ABP1). This binding triggers a cascade of events that leads to the production of ethylene, another hormone that promotes petal abscission.

Interestingly, the researchers also found that the ethylene produced in the petals can travel back to the ovary, where it inhibits the production of auxin. This negative feedback loop helps to ensure that petal abscission occurs at the right time, after the petals have served their purpose.

"Our study has revealed a new molecular mechanism that controls petal abscission in Arabidopsis," says Dr. Silvia Rojas-Pierce, lead author of the study. "This mechanism could be conserved in other plants, and understanding it could have implications for improving the post-harvest life of cut flowers and even increasing crop yields."

Cut flowers are a major economic crop, but they have a relatively short vase life. By understanding the molecular mechanisms that control petal abscission, it may be possible to develop new ways to extend the life of cut flowers. This would benefit florists and consumers alike.

Additionally, the findings of this study could have implications for increasing crop yields. By manipulating the auxin-ethylene feedback loop, it may be possible to increase the number of seeds that are produced by each flower. This could lead to higher yields and increased food production, which could help to feed a growing global population.

The study was funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and the European Union's Horizon 2020 research and innovation program.