Secretory pedicels? Development, morphology, and histochemistry of articulated pedicels in Neotropical Malveae (Malvaceae).

Autor: Freire TL; Programa de Pós‑graduação em Botânica, Escola Nacional de Botânica Tropical, Rua Pacheco Leão 2040, Solar da Imperatriz, Rio de Janeiro, 22460‑036, Brazil. talvanislorenzetti@gmail.com., de Oliveira JF; Programa de Pós‑graduação em Botânica, Escola Nacional de Botânica Tropical, Rua Pacheco Leão 2040, Solar da Imperatriz, Rio de Janeiro, 22460‑036, Brazil., Baumgratz JFA; Programa de Pós‑graduação em Botânica, Escola Nacional de Botânica Tropical, Rua Pacheco Leão 2040, Solar da Imperatriz, Rio de Janeiro, 22460‑036, Brazil.; Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, Rua Pacheco Leão 915, Rio de Janeiro, 22460‑030, Brazil., Bovini MG; Programa de Pós‑graduação em Botânica, Escola Nacional de Botânica Tropical, Rua Pacheco Leão 2040, Solar da Imperatriz, Rio de Janeiro, 22460‑036, Brazil.; Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, Rua Pacheco Leão 915, Rio de Janeiro, 22460‑030, Brazil., De Toni KLG; Programa de Pós‑graduação em Botânica, Escola Nacional de Botânica Tropical, Rua Pacheco Leão 2040, Solar da Imperatriz, Rio de Janeiro, 22460‑036, Brazil.; Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, Rua Pacheco Leão 915, Rio de Janeiro, 22460‑030, Brazil.
Jazyk: angličtina
Zdroj: Journal of plant research [J Plant Res] 2024 Nov 13. Date of Electronic Publication: 2024 Nov 13.
DOI: 10.1007/s10265-024-01592-7
Abstrakt: In the Malveae tribe (Malvaceae), the axis supporting the flower has a joint at the upper third. This axis can be considered as an articulated pedicel, peduncle, peduncle-pedicel, or anthopodium. Such disparity in terminology reveals a duality in interpretation since this structure is classified as part of the inflorescence or part of the flower. In an effort to reach a consensus, this study aims to evaluate axes supporting the flowers of species from the Malveae tribe through ontogenetic, morphological, and histochemical analyses, using light microscopy and scanning electron microscopy. Ontogenetic analyses indicated that the axis supporting the flower is an articulated pedicel, which is divided into proximal and distal parts owing to the presence of the constriction (joint). Simultaneously, the articulated pedicel arises from the floral meristem, along with the establishment of the calyx and androecium. As development progresses, we observed frequent abscissions of the floral bud, along with the distal portion of the pedicel, at the joint. After this, the remaining proximal portion of the pedicel becomes secretory, as an extrafloral nectary, often foraged by ants of the genus Wasmannia. Thus, this ontogenetic analysis of the articulated pedicel helps in understanding its functionality and morphological variability, highlighting the importance of standardized terminology since it would lead to conceptual clarity in different studies. Additionally, this study, for the first time, reveals the presence of extrafloral nectaries on articulated pedicels in Malveae, a previously undocumented feature in Malveae and Malvaceae.
(© 2024. The Author(s) under exclusive licence to The Botanical Society of Japan.)
Databáze: MEDLINE
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