Morphology, secretion composition, and ecological aspects of stipular colleters in Rubiaceae species from tropical forest and savanna

Autor(es)

Tresmondi, Fernanda ^[1] ; Nogueira, Anselmo ^[2] ; Guimaraes, Elza ^[3] ; Machado, Silvia Rodrigues ^[3]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, UNESP, Programa Posgrad Ciencias Biol Bot, BR-18618970 Botucatu, SP - Brazil

^[2] Univ Sao Paulo, Inst Biociencias, Dept Bot, BR-05508090 Sao Paulo, SP - Brazil

^[3] Univ Estadual Paulista, UNESP, Inst Biociencias, Dept Bot, BR-18618970 Botucatu, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: NATURWISSENSCHAFTEN; v. 102, n. 11-12 DEC 2015.
• Citações Web of Science: 4

Resumo

Colleters are secretory structures that produce and release mucilage or a mucilage-resin mixture protecting meristems and young structures against desiccation, herbivores, and pathogens. The secretions may vary in colleters of same or different types, indicating that the functionality of colleters may be more specific than previously thought. In this study, we compared 17 Rubiaceae species from savanna and forest environment focusing on colleter secretions and its ecological role. First, we evaluated the morphology, distribution, and histochemistry of stipular colleters using light and scanning electron microscopy. Additionally, we investigated the phenology, microclimate, and the proportion of damaged apices in the savanna and forest species. We recorded standard-type colleters, variable in distribution and size, in 14 of the 17 studied species. The secretion varied from predominantly hydrophilic, mixed to predominantly lipophilic. During the budding period, secretion covered the vegetative apices. Savanna species had a prevalence of lipid secretion in habitats with higher luminosity, which had a lower proportion of damaged apices. In contrast, forest species occurred in habitats with lower luminosity and had a higher proportion of damaged apices, in general with the absence of lipids in the colleters. These results highlight that colleters with similar morphology clearly differed in secretions among species, especially between species from savanna and forest, in which the colleters appear potentially associated with protection against irradiation in savanna, but not in the forest environment. (AU)

• Processo FAPESP: 11/02488-5 - Biologia dos coléteres foliares em Rubiaceae de cerrado e floresta estacional semidecidual do estado de São Paulo
• Beneficiário: Fernanda Tresmondi
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 08/55434-7 - Estruturas secretoras em espécies vegetais de cerrado: abordagens morfológica, química e ecológica
• Beneficiário: Silvia Rodrigues Machado
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOTA - Temático