Morpho-anatomy and ontogeny of the underground system of Chrysolaena simplex (Less.) Dematt. (Asteraceae)

Abstract

The occurrence of thickened underground systems in Asteraceae is widely reported in the literature. Given the great complexity of underground systems, which may originate from roots, stems, or both, morphoanatomical analyses are essential to ensure the use of correct terminology. The goals of this study were to describe the morpho-anatomy and ontogeny, investigate the occurrence of secondary metabolites and evaluate the effects of seasonality on the underground system of Chrysolaena simplex (Less.) Dematt. Samples were studied using standard protocols of plant anatomy, scanning electron microscopy, histochemical and phytochemical. The underground system of C. simplex was categorised as a rhizophore which started from cotyledonary node. In adult individuals, with rhizophores completely developed, the primary roots degenerated and adventitious radicular systems are formed. The buds in the subterranean portions promote the rhizophore growing, and form aerial stems when exposed to light. Lipophilic droplets were evident in the parenchymatous cells of the cortex and pith, endodermis and buds. Inulin-type fructans were observed in the stem axis and buds of the rhizophore. The presence of buds, secondary metabolites and the storage of fructans and lipids in the rhizophore can be seen as adaptive traits.

Rescue and vegetative propagation of Eremanthus erythropappus (DC.) MacLeish in natural stand

“…Anatomical studies performed on 'candeia' roots confirmed the great capacity of root blossom emission in species belonging to the family Asteraceae (Appezzato-da-Glória et al, 2008). Several authors have attributed this regrowth ability to the presence of fructan-type inulin crystals in the root cells (Assega and Carvalho, 2004;Assega et al, 2011;Santos et al, 2016;Silva et al, 2015). The occurrence of crystals on the walls of the vessel elements of the secondary xylem ( Figure 2F-G) is in accordance with what Tertuliano and Figueiredo-Ribeiro (1993) described for other species of the Asteraceae family.…”

“…Morvan-Bertrand et al (2001) reported a decline in the content of this carbohydrate in the leaf base of Lolium perene L. in the process of elongation, which was accompanied by a peak in the activity of the fructan enzyme: exohydroxylase in the growth zone, shortly after defoliation, suggesting the fructan as the source of carbon responsible for sustaining growth resumption. Santos et al (2016) reported seasonal variation in the amount and location of crystal accumulation in Chrysolaena simplex (Less.) Dematt.…”

MORFO-ANATOMIA DO XILOPíâ??DIO DO GEOARBUSTO Galianthe grandifolia E.L. Cabral (RUBIACEAE) E A OCORRíÅ NCIA INCOMUM DE COLÉTERES SUBTERRíâ??NEOS.

“…Cristais estão presentes nos coléteres de 35 das 108 espécies de Psychotria (Rubiaceae) dos neotrópicos, mas são raros entre as 188 espécies do resto do mundo (Lersten, 1974a (Rizzini & Heringer, 1961;Paviani, 1974;Milanez & Moraes-Dallaqua, 2003;Vilhalva & Appezzatoda-Glória, 2006b;Silva et al, 2015), e não no parênquima amilífero típico de raízes e caules tuberosos. Várias plantas de Cerrado acumulam em seus sistemas subterrâneos carboidratos, tais como amido e frutano, sendo que essas reservas são prontamente utilizadas na produção de gemas, permitindo o rebrotamento de órgãos aéreos perdidos durante a ação do fogo ou seca prolongada (Sajo & Menezes, 1986;Figueiredo-Ribeiro et al, 1991;Tertuliano & Figueiredo-Ribeiro, 1993;Hayashi & Appezzato-da-Glória, 2005;Vilhalva & Appezzato-da-Glória, 2006a, 2006bSilva et al, 2015;Santos et al, 2016).…”