Mechanical stimulation of the stigmas triggers switch from female to male phase in the protogynous trap flower of Aristolochia rotunda (Aristolochiaceae)

Floral longevity is a selected trait that shows plasticity, allowing plants to balance resource allocation and reproduction. In dichogamous flowers—in which female and male functions are decoupled in time—the duration of the female phase is expected to vary according to pollination status. We used...

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Main Authors: Rumsaïs Blatrix, Aroonrat Kidyoo, Inès Matrougui, Paradorn Samsungnoen, Doyle McKey, Magali Proffit
Format: Article
Language:English
Published: Universidad Complutense de Madrid 2023-10-01
Series:Mediterranean Botany
Subjects:
Online Access:https://revistas.ucm.es/index.php/MBOT/article/view/85906
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author Rumsaïs Blatrix
Aroonrat Kidyoo
Inès Matrougui
Paradorn Samsungnoen
Doyle McKey
Magali Proffit
author_facet Rumsaïs Blatrix
Aroonrat Kidyoo
Inès Matrougui
Paradorn Samsungnoen
Doyle McKey
Magali Proffit
author_sort Rumsaïs Blatrix
collection DOAJ
description Floral longevity is a selected trait that shows plasticity, allowing plants to balance resource allocation and reproduction. In dichogamous flowers—in which female and male functions are decoupled in time—the duration of the female phase is expected to vary according to pollination status. We used Aristolochia rotunda as a model to test the hypothesis that the female phase should be shortened following pollen deposition on the stigma, and to identify the signal for phase switching. Aristolochia flowers are protogynous (female phase first) and trap pollinators for several days (trap flowers). The four experimental treatments we applied to flowers, i.e. hand pollination, presence of pollinators with or without pollen load in the flower, and deposition of a nylon thread on the stigma, shortened the female phase to a similar extent, demonstrating that the duration of the female phase depended on the presence of pollinators, independently of whether or not they carried pollen, and that mechanical stimulation of the stigmas was the signal for phase switching. Temperature was also shown to shorten the female stage. This mechanism of post-anthesis floral changes is original because usually such changes are triggered by chemical interactions between pollen and stigmas. We interpret the mechanical signal used in A. rotunda for phase switching to be adaptive when pollinators are limiting, because switching to the male phase even if the trapped pollinator does not bring pollen would ensure fulfilling the flower’s male function.
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spelling doaj.art-f4a9fee4163e45e7a329fae1eb83ee8b2023-10-20T22:10:43ZengUniversidad Complutense de MadridMediterranean Botany2603-91092023-10-01Online first10.5209/mbot.85906Mechanical stimulation of the stigmas triggers switch from female to male phase in the protogynous trap flower of Aristolochia rotunda (Aristolochiaceae)Rumsaïs Blatrix0Aroonrat Kidyoo1Inès Matrougui2Paradorn Samsungnoen3Doyle McKey4Magali Proffit5CEFE, University of Montpellier, CNRS, EPHE, IRD, Montpellier, Francea:1:{s:5:"en_US";s:44:"Faculty of Science, Chulalongkorn University";}CEFE, University of Montpellier, CNRS, EPHE, IRD, Montpellier, FranceFaculty of Science, Chulalongkorn UniversityCEFE, University of Montpellier, CNRS, EPHE, IRD, Montpellier, FranceCEFE, University of Montpellier, CNRS, EPHE, IRD, Montpellier, France Floral longevity is a selected trait that shows plasticity, allowing plants to balance resource allocation and reproduction. In dichogamous flowers—in which female and male functions are decoupled in time—the duration of the female phase is expected to vary according to pollination status. We used Aristolochia rotunda as a model to test the hypothesis that the female phase should be shortened following pollen deposition on the stigma, and to identify the signal for phase switching. Aristolochia flowers are protogynous (female phase first) and trap pollinators for several days (trap flowers). The four experimental treatments we applied to flowers, i.e. hand pollination, presence of pollinators with or without pollen load in the flower, and deposition of a nylon thread on the stigma, shortened the female phase to a similar extent, demonstrating that the duration of the female phase depended on the presence of pollinators, independently of whether or not they carried pollen, and that mechanical stimulation of the stigmas was the signal for phase switching. Temperature was also shown to shorten the female stage. This mechanism of post-anthesis floral changes is original because usually such changes are triggered by chemical interactions between pollen and stigmas. We interpret the mechanical signal used in A. rotunda for phase switching to be adaptive when pollinators are limiting, because switching to the male phase even if the trapped pollinator does not bring pollen would ensure fulfilling the flower’s male function. https://revistas.ucm.es/index.php/MBOT/article/view/85906pollinationfloral longevitydichogamypollinator limitationMediterranean region
spellingShingle Rumsaïs Blatrix
Aroonrat Kidyoo
Inès Matrougui
Paradorn Samsungnoen
Doyle McKey
Magali Proffit
Mechanical stimulation of the stigmas triggers switch from female to male phase in the protogynous trap flower of Aristolochia rotunda (Aristolochiaceae)
Mediterranean Botany
pollination
floral longevity
dichogamy
pollinator limitation
Mediterranean region
title Mechanical stimulation of the stigmas triggers switch from female to male phase in the protogynous trap flower of Aristolochia rotunda (Aristolochiaceae)
title_full Mechanical stimulation of the stigmas triggers switch from female to male phase in the protogynous trap flower of Aristolochia rotunda (Aristolochiaceae)
title_fullStr Mechanical stimulation of the stigmas triggers switch from female to male phase in the protogynous trap flower of Aristolochia rotunda (Aristolochiaceae)
title_full_unstemmed Mechanical stimulation of the stigmas triggers switch from female to male phase in the protogynous trap flower of Aristolochia rotunda (Aristolochiaceae)
title_short Mechanical stimulation of the stigmas triggers switch from female to male phase in the protogynous trap flower of Aristolochia rotunda (Aristolochiaceae)
title_sort mechanical stimulation of the stigmas triggers switch from female to male phase in the protogynous trap flower of aristolochia rotunda aristolochiaceae
topic pollination
floral longevity
dichogamy
pollinator limitation
Mediterranean region
url https://revistas.ucm.es/index.php/MBOT/article/view/85906
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