Anatomia foliar de leguminosas arboreas de cerrado com enfase nas estruturas secretoras / Leaf anatomy of cerrado Leguminosae trees with emphasis on secretory sctructures

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

Foliar anatomy (leaflet lamina, petiolule and rachis) and secretory structures of four papilionoid tree species occurring in the cerrado were studied. The presence of anatomical characters common to these and other species occurring in the same formation was also investigated. Secretory epidermis and mesophyll idioblasts were found in Acosmium dasycarpum, A. subelegans, Bowdichia virgilioides and Dalbergia miscolobium; secretory hypodermis, tanniferous cell ring in the petiolule and idioblasts in the rachis were restricted to the first three species. Mucilage is produced by the upper leaflet epidermis in both Acosmium species and B. virgilioides. The whole leaf epidermis produce lipophilic phenolic compounds in D. miscolobium; the same chemical compound class was also present in the cortical cells from the petiolule and rachis. A heterogeneous secretion containing fatty acids and phenolic compounds was found in the hypodermal and idioblastic cells from A. dasycarpum, A subelegans and B. virgilioides. The information about the secretory structures is new for these four species. The mucilage may serve for water retention, cuticular transpiration reduction and light refraction; the phenolic compounds may filter the UV radiation and reduce pathogen attack and feeding by herbivores in these species. Supporting tissues, thick cuticle and phenolic compounds are present in the four species studied and other cerrado species. Gelatinous fibers are recorded for the first time associated with the leaf phloem and/or perivascular fibers in both Acosmium species and in B. virgilioides.

ASSUNTO(S)

plantas - histoquimica papilionoideae plant histochemistry papilionoideae leguminosae cerrado flora plant anatomy flora dos cerrados anatomia vegetal leguminosa

ACESSO AO ARTIGO

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