Leaf glands act as nectaries in Diplopterys pubipetala (Malpighiaceae)

Autor(es)

Possobom, C. C. F. ^[1] ; Guimaraes, E. ^[1] ; Machado, S. R. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, UNESP, Dept Bot, Inst Biociencias, Botucatu, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Plant Biology; v. 12, n. 6, p. 863-870, NOV 2010.
• Citações Web of Science: 14

Resumo

Leaf glands of Diplopterys pubipetala were studied with light and electron microscopy. Aspects of their secretion, visitors and phenology were also recorded. Glands occur along the margin, at the apex and at the base of the leaf blade. All the glands begin secretion when the leaf is still very young, and secretion continues during leaf expansion. The highest proportion of young leaves coincides with the beginning of flowering. The glucose-rich secretion is collected by Camponotus ants, which patrol the newly formed vegetative and reproductive branches. All the glands are sessile, partially set into the mesophyll, and present uniseriate epidermis subtended by nonvascularised parenchyma. The glands at the apex and base are larger and also consist of vascularised subjacent parenchyma. The cytoplasm of epidermal and parenchyma cells has abundant mitochondria, polymorphic plastids filled with oil droplets and a few starch grains. Golgi bodies and endoplasmic reticulum are more abundant in the epidermal cells. The parenchyma cells of the subjacent region contain chloroplasts and large vacuoles. Plasmodesmata connect all the nectary cells. The zinc iodide-osmium tetroxide (ZIO) method revealed differences in the population of organelles between epidermal cells, as well as between epidermal cells and parenchyma cells. Ultrastructural results indicate that leaf glands of D. pubipetala can be classified as mixed secretory glands. However, the secretion released by these glands is basically hydrophilic and composed primarily of sugars, hence these glands function as nectaries. (AU)

• Processo FAPESP: 06/54268-0 - Estrutura e função das glândulas florais e extraflorais em banisterriopsis pubipetala (ADR. jussieu) cuatrecasas (Malpighiaceae)
• Beneficiário: Clívia Carolina Fiorilo Possobom
• Modalidade de apoio: Bolsas no Brasil - Mestrado