Glandular Hairs of Sigesbeckia jorullensis Kunth (Asteraceae): Morphology, Histochemistry and Composition of Essential Oil

Abstract

Long-stalked glandular hairs of outer and inner involucral bracts of Sigesbeckia jorullensis, which are important for epizoic fruit propagation, were investigated using light and scanning electron microscopy. The essential oil secreted by the hairs was analysed by chromatographic methods including gas chromatography/mass spectrometry and with a laser microprobe mass analyser. The glandular hairs consisted of a large multicellular stalk and a multicellular secreting head. The apical layer of glandular head cells was characterized by leucoplasts and calcium oxalate crystals. Below the apical cells there were up to six layers of cells containing many chloroplasts around the nucleus and surrounded by vacuoles filled with flavonoids and tannins. The essential oil originating in the head cells was secreted into the subcuticular space and may be liberated by rupture of the cuticle. It was mainly composed of sesqui- and diterpenes, with the sesquiterpene hydrocarbon germacrene-D as the main component. Monoterpenes, n-alkanes and their derivatives as well as flavonoid aglycones were also detected. The stickiness of the essential oil is probably associated with the high content of oxygenated sesqui- and diterpenes. In addition to long-stalked trichomes, small biseriate trichomes occurred, secreting small quantities of essential oil into a subcuticular space.

Bidirectional Secretions from Glandular Trichomes of Pyrethrum Enable Immunization of Seedlings

“…In the Asteraceae family, glandular trichomes are particularly rich in sesquiterpenoids (Seaman et al, 1980;Heinrich et al, 2002;Göpfert et al, 2005;Bertea et al, 2006). Indeed, apart from pyrethrins, pyrethrum extracts also contain a variety of sesquiterpene lactones (STLs), such as pyrethrosin (chrysanthin) (Barton and Demayo, 1957;Barton et al, 1960), chrysanin, dihydro-b-cyclopyrethrosin, chrysanolide, and b-cyclopyrethrosin (Doskotch and Elferaly, 1969;Doskotch et al, 1971).…”

Anatomia e histoquímica dos órgãos vegetativos de Siegesbeckia orientalis (Asteraceae)

“…A raiz lateral é triarca na região seccionada (Figura 15) e de maturação centrípeta. Não foram evidenciadas estruturas secretoras na raiz, o que confirma os conhecimentos da medicina popular, que indicam somente a utilização da parte aérea nos preparos medicinais (Pudles et al, 1957;Bohlmann et al, 1979;Baruah et al, 1979Baruah et al, , 1980Zdero et al, 1991;Heinrich et al, 2002).…”

“…No Brasil, é considerada planta daninha, freqüentemente encontrada na região Sudeste (Kissmann & Groth, 1992;Bremer, 1994). A parte aérea da planta é utilizada na medicina tradicional chinesa em tratamentos antialérgicos, artrites reumáti-cas, entre outros (Pudles et al, 1957;Baruah et al, 1979Baruah et al, , 1980Hwang et al, 2001), tendo sido isolados diversos compostos, que, além de possuírem princípios ativos medicamentosos, incluem substâncias com atividade alelopática (Pudles et al, 1957;Bohlmann et al, 1979;Baruah et al, 1979Baruah et al, , 1980Zdero et al, 1991;Heinrich et al, 2002).…”

Trichomes and chemical composition of the volatile oil of Trichogonia cinerea (Gardner) R. M. King & H. Rob. (Eupatorieae, Asteraceae)

“…The biseriate vesicular glandular trichomes of T. cinerea are similar to those found on the aerial organs of other Asteraceae species and several aspects of these structures have been investigated (Ascensão and Pais 1987, Figueiredo and Pais 1994, Afolayan and Meyer 1995, Pagni 1995, Castro et al 1997, Ascensão et al 2001, Heinrich et al 2002, Andreucci et al 2008, Oliveira et al 2013, Trindade et al 2014.…”