Morphoanatomic characterization of the stem and the leaf of Tabernaemontana catharinensis A. DC (Apocynaceae) and antimutagenic activity of its leaves / Caracterização morfoanatômica do caule e da folha de Tabernaemontana catharinensis A. DC (Apocynaceae) e atividade antimutagênica de suas folhas

ABSTRACT Tabernaemontana catharinensis A. DC (Apocynaceae) is used as a medicinal plant by the population. In order to contribute to the safe use of the plant as herbal medicine, this study aimed to morphoanatomically characterize the aereal vegetative organs of T. catharinensis and to evaluate the leaves’ mutagenic and antimutagenic activities. Histological blades of leaves and stem of T. catharinensis were performed; the methionine system (methG1) and Aspergillusnidulans conidia germination analysis were employed for mutagenic and antimutagenic evaluation. The morphoanatomic analysis did not show trichomes in the stem, petiole and leaf. Besides, it was observed both the presence of bi-collateral bundles - except in the foliar apex where the bundles were from the collateral type - as well as anamphistomatic leaf with paracyte stomata and sub-epidermal layer in the region of the leaf edges. The mutagenicity/antimutagenicity trial indicated a significant decrease of mutation frequency in comparison with the control group and showed that the T. catharinensis had antimutagenic activity within the type, time and form of treatment. Since the germination test showed that the conidia germination was accelerated from the bud phase, activities at the cell cycle level and polarized growth proved to be possible. The morphoanatomic analysis of the leaf and stem associated with the mutagenic and antimutagenic analyses contributes to the safe use of the plant by humans and also for the quality control of a possible phytotherapeutic drug.

RESUMO Tabernaemontana catharinensis A. DC (Apocynaceae) é utilizada como planta medicinal pela população. A fim de contribuir para o uso seguro da planta como medicinal, este trabalho teve como objetivo caracterizar morfoanatomicamente os órgãos vegetativos aéreos de T. catharinensis e avaliar a atividade mutagênica e antimutagênica de suas folhas. Foram realizados cortes histológicos da folha e do caule de T. catharinensis e, para a avaliação mutagênica e antimutagênica, foi utilizado o sistema metionina (methG1) e análise da germinação de conídios em Aspergillus nidulans. A análise morfoanatômica evidenciou a ausência de tricomas no caule, pecíolo e folha; presença de feixes bicolaterais, com exceção no ápice foliar cujos feixes são do tipo colateral; folha anfiestomática com estômatos paracíticos e camada subepidérmica na região do bordo foliar. O ensaio de mutagenicidade/antimutagenicidade mostrou uma diminuição significativa da frequência de mutação em relação ao controle, indicando que nesse tipo, tempo e forma de tratamento, T. catharinensis apresentou atividade antimutagênica. O ensaio de germinação evidenciou que houve aceleração da germinação dos conídios, a partir da fase de botão, indicando uma possível atuação em nível de ativação de ciclo celular e crescimento polarizado. A análise morfoanatômica da folha e do caule associados à análise mutagênica e antimutagênica, contribuem para o uso seguro da planta pela população e para o controle de qualidade de um possível fitoterápico.

Soybean (Glycine max) root lignification induced by ferulic acid. The possible mode of action.

Ferulic acid, in the form of feruloyl CoA, occupies a central position as an intermediate in the phenylpropanoid pathway. Due to the allelopathic function, its effects were tested on root growth, H(2)O(2) and lignin contents, and activities of cinnamyl alcohol dehydrogenase (CAD, EC 1.1.1.195) and peroxidase (POD, EC 1.11.1.7) from soybean (Glycine max (L.) Merr.) root seedlings. Three-day-old seedlings were cultivated in half-strength Hoagland's solution (pH 6.0), with or without 1.0 mM ferulic acid in a growth chamber (25 degrees C, 12/12 hr light/dark photoperiod, irradiance of 280 micromol m(-2) s(-1)) for 24 or 48 hr. Exogenously supplied ferulic acid induced premature cessation of root growth, with disintegration of the root cap, compression of cells in the quiescent center, increase of the vascular cylinder diameter, and earlier lignification of the metaxylem. Moreover, the allelochemical decreased CAD activity and H(2)O(2) level and increased the anionic isoform PODa5 activity and lignin content. The lignin monomer composition of ferulic acid-exposed roots revealed a significant increase of guaiacyl (G) units. When applied jointly with piperonylic acid (an inhibitor of the cinnamate 4-hydroxylase, C4H), ferulic acid increased lignin content. By contrast, the application of 3,4-(methylenedioxy) cinnamic acid (an inhibitor of the 4-coumarate:CoA ligase, 4CL) with ferulic acid did not. Taken together, these results suggest that ferulic acid may be channeled into the phenylpropanoid pathway (by the 4CL reaction) and, further, may increase the lignin monomer amount solidifying the cell wall and restricting the root growth.

Morphology and anatomy of developing fruits and seeds of Vismia guianensis (Aubl.) Choisy (Clusiaceae)

Morphological, structural and developmental features of fruits and seeds of Vismia guianensis (Aubl.) Choisy. are here presented, with the purpose to elucidate their structure and to contribute to taxonomical and ecological studies of the family. The fruit is a berry and the "rind" is constituted by the exocarp and by the subepidermal layers which constitute the mesocarp. The reddish pulp, rich in starch, is constituted by the parenchymatic mesocarp, with branched secretory ducts and vascular bundles, joined with the endocarp, which arises from a ventral meristem. The bitegmic, anatropous ovules, provided by the endothelium, develop into anatropous, bitegmic and exalbuminous seeds. The reddish uniseriate testa shows phenolic contents. The tegmen becomes crushed resting only the uniseriate exotegmen with undulate, thick walled and lignified cells, which contain a number of calcium oxalate prismatic crystals. The embryo, rich in lipids, is straight and shows foliaceous cotyledons