Rosani do Carmo de Oliveira Arruda

Glandular trichomes of Rosmarinus officinalis L.: Anatomical and phytochemical analyses of leaf volatiles

Abstract Rosmarinus officinalis is known for the production of volatile compounds used in medicinal and food preparations. Leaves of R. officinalis are densely covered with capitate and peltate glandular trichomes where biosynthesis of volatiles mainly occurs. This study aims to conduct a morphological assessment to identify anatomical characteristics of both leaves and trichomes, as well as a chemical analysis of leaf volatile compounds, using histochemistry and stem distillation extraction. Specifically, anatomical and chemical constituents of the secretory structures of R. officinalis leaves were investigated using light and scanning electron microscopy, in addition to gas chromatography. One peltate and three types of capitate glandular trichomes were observed on the leaves of R. officinalis. Histochemical tests showed positive reactions to lipophilic compounds for both capitate and peltate trichomes, with only a slight detection of terpenoids with carbonyl group in peltate glands. Gas chromatography revealed camphor (23.2%) as the main volatile compound, mostly accumulating in peltate glandular trichomes. This phytochemical study of volatile compounds, together with anatomical and histochemical analyses of R. officinalis leaves, demonstrated the importance of leaves as a center of volatile production in peltate and capitate trichomes, as well as the nature of volatile composition, which is involved in species survival.

Anatomia foliar de Trilepis lhotzkiana Nees e Trilepis ciliatifolia T. Koyama (Cyperaceae) Juss.

The present study deals with the leaf anatomy of two species of Cyperaceae: Trilepis lhotzkiana and Trilepis ciliatifolia. Both species grow on granitic outcrop from Rio de Janeiro State, Brazil. The results reveal that they present commom features as: single-layered epidermis, with conical silica bodies, paracitic stomata, unicellular hairs and collateral vascular bundles. The sclerenchyma is well developed and is associated with the vascular tissues forming lignified bundles sheath extensions. Chlorenchyma is restricted to sectors between vascular bundles. The arrangement and particularities of epidermal cells and the presence of a continuous lignified hypodermis are particularly important for taxonomic use. The leaf structure of both species have shown xeromorphic characters that can be related environmental conditions.

Leaf anatomy and micromorphology of six Posoqueria Aublet species (Rubiaceae)

longiflora Aublet, P. macropus Mart., P. palustris (Rudge) Roem. and Posoqueria sp., collected in fragments of Atlantic rain forest, Rio de Janeiro, Brazil. The epicuticular wax may occur in the form of filaments, granules or crusts. The leaves are covered by a thick cuticular layer that may be smooth or striated. Paracytic stomata, and non-glandular trichomes are limited to the abaxial surface; the latter are numerous in P. palustris, and rare in P. longiflora and P. latifolia. Leaves have a dorsiventral structure, with only one layer of palisade parenchyma and varied amounts of spongy parenchyma. Idioblasts containing crystalliferous sand were observed, and were more abundant in P. latifolia. The leaf blade vascular system is formed by collateral bundles with a parenchymatous sheath, associated with fibers. The vascular system of the petiole and the leaf blade forms an arch. Some of the anatomical features observed can be used to distinguish the species studied. Anatomical leaf characters could be used in the recognition of six species of Posoqueria studied, such as anticlinal wall of epidermal cells, wax deposition, trichomes and shape of the leaf margin.

STRUCTURAL LEAF CHANGES IN TREES AROUND A SUBWAY AIR DUCT

Varios artigos vem mostrando que os sistemas de metro causam impactos na qualidade do ar, atraves da emissao de material particulado. No entanto, nao ha informacoes disponiveis sobre o efeito desse impacto na vegetacao. Folhas de arvores de tres especies diferentes localizadas do lado da saida de dutos de um metro no Rio de Janeiro, Brasil, se mostraram mais assimetricas do que as de arvores localizadas do lado da entrada. Essas folhas tambem apresentaram alteracoes na camada de cera epicuticular e no conteudo de clorofila.

Erratum to: Meristematic activity of the endodermis and the pericycle in the primary thickening in monocotyledons. Considerations on the "PTM" [An Acad Bras Cienc 77(2005): 259-274]

of trace metal toxicity using molecular, physiological and behavioural Instituto de Biociencias