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Titre du document / Document title

Dynamics of thermogenesis and structure of epidermal tissues in inflorescences of Arum maculatum

Auteur(s) / Author(s)

BERMANDINGER-STRABENTHEINER E. (1) ; STABENTHEINER A. ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

(1) Karl-Franzens-Univ. Graz, Inst. Pflanzenphysiologie, 8010 Graz, AUTRICHE

Résumé / Abstract

The temporal dynamics and spatial distribution of heat production by inflorescences of Arum maculatum L. were investigated by infra-red thermography. Two centres of heat production, the appendix and the male flowers, and three thermogenic phases, two of the male flowers and one of the appendix, could be observed. On the first day of flowering, when the spathe was still firmly closed, the male flowers became thermogenic ( = first thermogenic phase of the inflorescence) and reached surface temperatures of 4.1-8.0 °C above ambient temperature. Afterwards the spathe unfolded and the appendix started heating to temperatures of 5.0-14.0 °C above ambient temperature (second thermogenic phase of the inflorescence). On the second day of flowering the male flowers revealed a second temperature maximum of 0.5-6.1 °C above ambient temperature (third thermogenic phase of the inflorescence) which was followed by the release of the pollen grains. When the male flowers started heating, a fruit-like and pleasant scent became evident and continued until the heat production in the male flowers stopped. Only during the heating phase of the appendix was this fruit-like scent overlaid by the dung-like odour typical of many aroid species. The surface of the spadix and the inner surface of the basal bulb (floral chamber) as investigated by scanning electron microscopy were characterized by smooth epidermal cells of papillate shape. These cells were turgid before the onset of flowering and heat production and collapsed afterwards. Distinct intercellular spaces creating a lacunose epidermis (Lückenepidermis) were observed between the papillate epidermal cells of the inner surface of the basal bulb (floral chamber). This coincided with a high density of stomata on its outer surface. It is suggested that, beside other pathways, these structures contribute to the maintenance of sufficient oxygen support of the captured insects and the thermogenic tissues inside the floral chamber.

Revue / Journal Title

New phytologist    ISSN  0028-646X   CODEN NEPHAV 

Source / Source

1995, vol. 131, no1, pp. 41-50 (22 ref.)

Langue / Language

Anglais

Editeur / Publisher

Blackwell, Oxford, ROYAUME-UNI  (1902) (Revue)

Mots-clés anglais / English Keywords

Inflorescence

;

Thermogenesis

;

Epidermis

;

Scanning electron microscopy

;

Flowering

;

Arum maculatum

;

Araceae

;

Monocotyledones

;

Angiospermae

;

Spermatophyta

;

Wild plant

;

Mots-clés français / French Keywords

Inflorescence

;

Thermogenèse

;

Epiderme

;

Microscopie électronique balayage

;

Floraison

;

Arum maculatum

;

Araceae

;

Monocotyledones

;

Angiospermae

;

Spermatophyta

;

Plante sauvage

;

Mots-clés espagnols / Spanish Keywords

Inflorescencia

;

Termogénesis

;

Epidermis

;

Microscopía electrónica barrido

;

Floración

;

Arum maculatum

;

Araceae

;

Monocotyledones

;

Angiospermae

;

Spermatophyta

;

Planta salvaje

;

Localisation / Location

INIST-CNRS, Cote INIST : 3019, 35400005469391.0030

Nº notice refdoc (ud4) : 3695623



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