Flowers meet Newton: testing the role of gravitational pull in resupination of orchid flowers
Resupination refers to the developmental orientation changes of flowers through ≈180º, leaving them effectively upside-down. It is a widespread trait present in 14 angiosperm families, including the Orchidaceae, where it is a gravitropic phenomenon actively controlled by auxins. Here, we demonstrate...
Gespeichert in:
Veröffentlicht in: | Journal of experimental botany 2024-10 |
---|---|
Hauptverfasser: | , , |
Format: | Artikel |
Sprache: | eng |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | Resupination refers to the developmental orientation changes of flowers through ≈180º, leaving them effectively upside-down. It is a widespread trait present in 14 angiosperm families, including the Orchidaceae, where it is a gravitropic phenomenon actively controlled by auxins. Here, we demonstrate that the passive gravitational pull on flower parts can have an additional influence on resupination. We studied a lady's slipper orchid in which some flowers naturally fail to resupinate. We conducted a manipulative experiment removing floral parts and showed that both the probability of complete resupination and the degree of flower vertical movement (from 0º - 180º) are related to the mass of floral organs. During flower development, the tip of the ovary slightly curves actively (14.75º) due to gravitropism. This promotes a lever arm effect so that the gravitational pull acting on flower mass creates a torque that bends the ovary, orienting the flower into a resupinate position that is accessible to pollinators. The role of the mass of floral organs in resupination provides new insights into flower development and its role in pollination mechanisms. |
---|---|
ISSN: | 0022-0957 1460-2431 1460-2431 |
DOI: | 10.1093/jxb/erae413 |