A recent study published in the journal Plant Biology by researchers from Macquarie University and international collaborators has revealed that plants have the ability to reuse resources from wilting flowers to support future reproduction. The lead author of the study, Honorary Professor Graham Pyke, explains that this finding sheds light on a common but poorly understood plant process. The resources that plants are able to salvage from wilting flowers include energy and the chemical makeup of the petals, such as carbohydrates and nutrients like nitrogen and phosphorus.
The three-year study focused on Blandfordia grandiflora, also known as Christmas Bells, a perennial plant species native to eastern Australia that flowers mostly in December. The researchers conducted their study on a plantation containing several hectares of native wet heath where Christmas bells flower quite profusely, as well as in a commercial shadehouse. Through a series of experiments controlling pollination and flower wilting, the team found that plants do not use the resources from wilted flowers to improve short-term reproduction, but instead, they store these resources underground in corms and roots to aid in producing new flowering stems in the following season.
Professor Pyke emphasizes that plant economics involve trade-offs and decisions about where to allocate limited resources. He explains that plants must make strategic decisions about resource allocation, which ultimately led to the investigation of flower wilting as a potential strategy for resource management. The researchers were surprised to find that the plants were not using their reclaimed resources immediately but were saving them for the next flowering season. This highlights the complexity of plant strategies for managing flowers after they have served their primary reproductive function.
The study tested resource reuse in various ways, including comparing seed production in plants with wilting flowers versus those with petals removed to prevent wilting, as well as monitoring seed production in flowers where wilting was allowed in comparison to those where it was prevented. The results indicated that plants with wilting flowers were more likely to reflower in the following season than those where wilting was prevented. Other factors such as flowering stem height, number of flowers per stem, and flower position were also considered in relation to seed production.
Professor Pyke suggests that this study opens up opportunities for further research into how different plant species recover and reuse resources from wilting flowers. Future studies could explore the composition of salvaged resources, how plants transport and transform these resources, and whether the benefits of saving resources outweigh the costs of producing flowers in the first place. Understanding the mechanisms behind resource reuse in plants could provide valuable insights into plant reproductive strategies and resource management in diverse plant species.
