Developmental and structural features of secretory canals in root and shoot wood of Copaifera langsdorffii Desf. (Leguminosae–Caesalpinioideae)

Abstract

Copaifera langsdorffii Desf., popularly known as copaíba, is an oleoresin-producing tree has been overexploited in Brazil by the pharmaceutical, cosmetic and varnish industries. Despite the long history of the use of this species, the structural knowledge on the resin-producing sites remains inadequate and is limited to the trunk. The aim of this study was to describe the origin, structure and developmental features of secretory spaces present in shoot and root wood of C. langsdorffii, based on the usual techniques of wood anatomy studies. Both root and shoot wood present secretory canals distributed along the marginal parenchyma bands which delimit growth layers. Secretory canals are constituted by a locally biseriate epithelium and lume that contains terpenes. They are arisen in the cambial zone from fusiform cambial initial cells and, eventually, ray initials. The origin of lumen is schizogenous. The epithelial cells have meristematic potential and are responsible for the locally biseriate epithelium. Mature secretory canals are wider and are separated between themselves only by a row of radial cells. The fusion of these adjacent secretory canals is frequent and results from the radial cell collapse. The finding of an interconnected system of resin canals in C. langsdorffii might be of value in terms of sustainable extraction of the resin and realistically assess its sustainable harvest potential.

Oleoresin glands in copaíba (Copaifera trapezifolia Hayne: Leguminosae), a Brazilian rainforest tree

“…Turner (1999) had previously drawn attention to the misinterpretation of artifacts (result of the employment of some fixatives) as cell lyses and recommended caution in the study of lumen origin. The content found in the lumen of leaf secretory cavities of C. trapezifolia is similar to that found in the stem secretory canals, being oily and resinous, confirming previous studies of other Copaifera species (Veiga and Pinto 2002;Rodrigues and Machado 2009;Rodrigues et al 2011). The phenolic compounds found in the cavity/canal epithelial cells of C. trapezifolia (present work) and C. langsdorffii (Rodrigues et al 2011) deserve future studies of biological activity, since these compounds largely found in legumes have presented medicinal properties (Santos and Mello 2007).…”

“…However, cases of lysogenesis have been described in species of Hymenaea (Paiva and Machado 2007) and Pterodon (Paiva et al 2008). An overlap of schizogenesis and lysogenesis was reported in C. langsdorffii by Rodrigues and Machado (2009) and Rodrigues et al (2011) after ultrastructural and immunohistochemical (TUNEL) studies, which indicated the programmed cell death of epithelial cells. Turner (1999) had previously drawn attention to the misinterpretation of artifacts (result of the employment of some fixatives) as cell lyses and recommended caution in the study of lumen origin.…”

“…The occurrence of canals (elongated lumen) and cavities (isodiametric lumen) was recorded in species of Caesalpinia sensu Bentham (Lersten and Curtis 1994), Copaifera (Alencar 1982;Marcati et al 2001;Rodrigues and Machado 2009;Rodrigues et al 2011), Dahlstedtia (Teixeira and Gabrielli 2000), Hymenaea (Lee and Langenheim 1975;Paiva and Machado 2007), Lonchocarpus , Myrocarpus, Myrospermum, Myroxylon (Sartori and Tozzi 2002), and Pterodon (Paiva et al 2008). Such structures are reported for all plant organs, especially the aerial (Teixeira and Gabrielli 2000;Paiva and Oliveira 2004;Rodrigues and Machado 2009;Rodrigues et al 2011), and originate from protoderm cells (Turner 1986;Paiva and Machado 2007) or ground meristem (Teixeira and Gabrielli 2000;Teixeira and Rocha 2009). The lumen is usually esquizogenously formed (Turner 1986;Marcati et al 2001;Teixeira and Rocha 2009), but can occur lysogenously (Paiva and Machado 2007;Paiva et al 2008).…”

Oil Glands in Pterodon pubescens Benth. (Leguminosae-Papilionoideae): Distribution, Structure, and Secretion Mechanisms

“…Secretory cavities and canals are common in many members of Leguminosae and can occur in vegetative (Lersten and Curtis 1986;Turner 1986;Teixeira et al 2000;Teixeira and Gabrielli 2000;Marcati et al 2001;Paiva and Machado 2007;Rodrigues and Machado 2009;Teixeira and Rocha 2009;Rodrigues et al 2011aRodrigues et al , 2011bMilani et al 2012) or reproductive organs (Paiva et al 2008;Teixeira and Rocha 2009). These structures in legumes have taxonomic (Turner 1986;Lersten and Curtis 1996;Teixeira et al 2000;Gabrielli 2000, 2006), ecological (Langenheim et al 1982;Arrhenius and Langenheim 1983;Langenheim 2003), and economic (Coelho et al 2001;Langenheim 2003;Plowden 2003) aspects.…”

Secretory Structures of Subterranean Organs of Some Species of the Cardueae, and Their Diagnostic Value

“…Most literature deals with the development of diverse secretory reservoirs of single species (e.g., Bennici and Tani, 2004) or concentrates on conifers and legumes, as their gumresins or resins are of commercial importance (Hong Wu and Zheng-hai Hu, 1997;Rodrigues and Machado, 2009;Bollschweiler et al, 2008 and others). Previous literature on the Cardueae deals mainly with the occurrence of secretory ducts or cavities on aerial organs, especially those of leaves and shoots, and the transition between root and shoot (Col, 1903(Col, , 1904.…”