How can the analysis of reserve dynamics after fire support the phenological insight of Bulbostylis paradoxa (Spreng.) Lindm (Cyperaceae)?

Carbohydrate reserves are an essential key to plant survival from disturbance. Therefore, studying the different storage organs and types of reserves makes it possible to understand the dynamics of singular plants such as Bulbostylis paradoxa (Spreng.) Lindm, which presents flowering triggered by fire in the Cerrado. Physiological response to fire frequency is detailed by measuring the plant's reserves after a fire disturbance and which carbohydrates are more available for its use. It was measured the concentrations of starch, amino acids, total soluble carbohydrates and soluble proteins in leaves (control), flowers (burning) and caudex of B. paradoxa, in unburned individuals (control), and burned individuals (annually and biennially, obtained 48 h and 15 days after fire). Starch concentrations increased at both fire frequencies in all parts of the plant, as did carbohydrate concentrations. In amino acids, an increase in the concentration of flowers from individuals burned biennially 48 h after fire was observed. The protein concentration showed a decrease in burned plants. Furthermore, the two burning frequencies and the days following the fire can influence the storage of such reserves.

Anatomical characters and chemical profile of leaves of three species in Lauraceae family

ABSTRACT The Lauraceae family is widely distributed in tropical and subtropical climates, has more than 2500 species and in the taxonomic point of view, it is one of the most difficult families to identify species. The aim of this study was to analyze the leaf anatomy of three species of Lauraceae (Ocotea indecora (Schott) Mez, Nectandra barbellata Coe-Teix. and Endlicheria paniculata (Spreng.) J.F.Macbr.) and identify the chemical profile of essential oil extracted from the leaves by hydrodistillation method. The leaves of the three species were obtained in "Parque Estadual Intervales", Atlantic Forest, São Paulo state, Brazil. Samples of leaves were fixed, dehydrated, embedded in synthetic resin and sectioned for mounting histological slides for anatomical description of leaf tissues. The essential oil extracted by hydrodistillation method from dried leaves was analyzed by gas chromatography to establish its chemical profile. The leaves are hypostomatic, the epidermis in E. paniculata and N. barbellata present regular cells walls and irregular cells walls in O. indecora in both sides of epidermis. The three species present a dorsiventral mesophyll. Histochemical analyses presented lipid substances in secretory cavity and cuticle; starch, phenolic compounds and mucilage were observed in parenchyma cells of midrib and mesophyll. Ultra structural analyses demonstrated that trichomes in the species E. paniculata and O. indecora are shown only on the abaxial leaf face and species N. barbellata presented trichomes on both sides of the epidermis (abaxial and adaxial). Ocotea indecora essential oil revealed as main compound the bicyclogermacrene and N. barbellata the δ-cadinene. The species showed different morphological characters and different compounds of the essential oil, being these data useful for the differentiation of the species.