Superfície da lâmina foliar de Psychotria nuda (Cham. & Schltdl.) Wawra, P. leiocarpa Cham. & Schltdl., P. stenocalyx Müll. Arg. e P. tenuinervis Müll. Arg. (Rubiaceae)
Abstract:São apresentados dados relativos à micromorfologia da superfície foliar de quatro espécies de Psychotria. O estudo foi realizado em indivíduos que ocorrem na Floresta Pluvial Tropical (Mata Atlântica). Atenção especial é dada ao tipo de cera epicuticular e da escultura da superfície dos estômatos, papilas e demais células epidérmicas.
“…leaves; however, the authors did not present any differences in the occurrence of these epidermal structures in relation to biotic and abiotic factors. Vieira and Gomes ([ 1995 ]) attributed the function to converge light stimuli for the mesophyll to the papillae of the abaxial epidermis from Psychotria leiocarpa Cham. and Schltdl., P. stenocalyx Müll.…”
BackgroundDrimys brasiliensis Miers is native to Brazil, where it is mainly found in montane forests and flooded areas in the South and Southeast regions of the country. The objectives of the present study were to compare the leaf anatomy and the chemical constitution of the essential oils from D. brasiliensis present in two altitude levels (1900 and 2100 m), in a Montane Cloud Forest, in Itamonte, MG, Brazil.ResultsA higher number of sclereids was observed in the mesophyll of the leaves at 1900 m altitude. At 2100 m, the formation of papillae was observed on the abaxial surface of the leaves, as well as an increase in the stomatal density and index, a reduction in leaf tissue thickness, an increase in the abundance of intercellular spaces in the mesophyll and an increase in stomatal conductance and in carbon accumulation in the leaves. Fifty-nine constituents have been identified in the oils, with the predominance of sesquiterpenes. Two trends could be inferred for the species in relation to its secondary metabolism and the altitude. The biosyntheses of sesquiterpene alcohols at 1900 m, and phenylpropanoids and epi-cyclocolorenone at 2100 m, were favored.ConclusionsD. brasiliensis presented a high phenotypic plasticity at the altitude levels studied. In relation to its leaf anatomy, the species showed adaptive characteristics, which can maximize the absorption of CO2 at 2100 m altitude, where a reduction in the partial pressure of this atmospheric gas occurs. Its essential oils presented promising compounds for the future evaluation of biological potentialities.Electronic supplementary materialThe online version of this article (doi:10.1186/s40529-014-0041-y) contains supplementary material, which is available to authorized users.
“…leaves; however, the authors did not present any differences in the occurrence of these epidermal structures in relation to biotic and abiotic factors. Vieira and Gomes ([ 1995 ]) attributed the function to converge light stimuli for the mesophyll to the papillae of the abaxial epidermis from Psychotria leiocarpa Cham. and Schltdl., P. stenocalyx Müll.…”
BackgroundDrimys brasiliensis Miers is native to Brazil, where it is mainly found in montane forests and flooded areas in the South and Southeast regions of the country. The objectives of the present study were to compare the leaf anatomy and the chemical constitution of the essential oils from D. brasiliensis present in two altitude levels (1900 and 2100 m), in a Montane Cloud Forest, in Itamonte, MG, Brazil.ResultsA higher number of sclereids was observed in the mesophyll of the leaves at 1900 m altitude. At 2100 m, the formation of papillae was observed on the abaxial surface of the leaves, as well as an increase in the stomatal density and index, a reduction in leaf tissue thickness, an increase in the abundance of intercellular spaces in the mesophyll and an increase in stomatal conductance and in carbon accumulation in the leaves. Fifty-nine constituents have been identified in the oils, with the predominance of sesquiterpenes. Two trends could be inferred for the species in relation to its secondary metabolism and the altitude. The biosyntheses of sesquiterpene alcohols at 1900 m, and phenylpropanoids and epi-cyclocolorenone at 2100 m, were favored.ConclusionsD. brasiliensis presented a high phenotypic plasticity at the altitude levels studied. In relation to its leaf anatomy, the species showed adaptive characteristics, which can maximize the absorption of CO2 at 2100 m altitude, where a reduction in the partial pressure of this atmospheric gas occurs. Its essential oils presented promising compounds for the future evaluation of biological potentialities.Electronic supplementary materialThe online version of this article (doi:10.1186/s40529-014-0041-y) contains supplementary material, which is available to authorized users.
“…However, according to [14] shady plants present sinuous anticlinal walls. But [15] [7], on sunny plants of a dry environment, the epidermal cells, specially on adaxial side, present straight wall and on shady plants, the occurrence of cells with sinuous walls on both sides of the leaf is commonly observed. Although, in front of the revealing, it is verified that variation on cells shape is common, but since both species are sunny plants, it is believed that other factors may influence on this characteristic, such as altitude [16], hydric stress [17] and CO 2 concentration [18]; [19].…”
Section: Resultsmentioning
confidence: 99%
“…However, as observed on Table 2, papilla size differs significantly on both species; bigger in D. radula The epidermis is papillose on both species, with papilla arranged on the two sides. The papilla presence on abaxial side is uncommon on Rubiaceae family [22], but nevertheless, this was also registered by [23] for P. longepedunculata, [24] for Rustia formosa Klotzsch, [25] for Psychotria tenuinervis and P. stenocalix and [15] for P. leiocarpa, indicating it is a common characteristic for Spermacoceae group. Diodella radula and D. teres presented a significant difference on the papillae size, which may be considered as a diagnostic characteristic so important to separate the two species.…”
Diodella radula (Willd. & Hoffmanns. ex Roem. & Schult.) Delprete e Diodella teres (Walter) Small (Rubiaceae) are weeds found in agricultural areas from Mato Grosso do Sul and it is difficult to identify them on vegetative phase, so the morphologic and anatomic studies are an important instrument for controling the species. This work intended to characterize the leaf morphoanatomy of Diodella radula and D. teres, aiming to promote taxonomic subsidies and determine the structures which may influence on the herbicides absorption. The morphoanatomic studies were carried out with fresh material and fixed. Cross and paradermic sections of leaf blade were obtained. The cutting edges were dyed as an usual methodology and submitted to histochemical tests. These species are distinguished plants because they can stay in the sun; Diodella teres is frequently found on the edge of the roads, on a drier soil while D. radula is mainly found on dirty fields, damp soil and at the river banks. D. radula and D. teres leaves present general characteristics quoted for Rubiaceae family, as for example, unilayered epidermis, paracytic stomata, dorsiventral mesophyll and collateral vascular bundles. The observed characteristics such as epidermic cells, papilla size, glandular trichomes and collenchyma arrangement are distinct for both species and therefore they may be used as characters to bound the two species. The low density of stomata and the cuticle thickness on the adaxial surface observed in D. radula and D. teres seems to be leaf barrier to block the herbicides penetration.
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