Secretory spaces in species of the clade Dipterygeae (Leguminosae, Papilionoideae)

Abstract

Dipteryx, Pterodon and Taralea are legume genera known for secreting oils, produced in secretory canals and cavities, with medicinal properties. We analyzed the distribution, morphology and histochemistry of these glands in leaves and stems of Dipteryx alata, Pterodon pubescens and Taralea oppositifolia, three Neotropical species, using standard techniques for anatomy and histochemistry. Secretory spaces, i.e. secretory cavities and canals, exhibited a wide lumen and a single layer of epithelium. Digitiform epithelial cells, forming trabeculae protruding into the lumen, were seen in all three species. Secretory cavities with a rounded or oval lumen and secretory canals with an elongated lumen in longitudinal sections were found only in T. oppositifolia. In D. alata and P. pubescens, only secretory cavities were found. In P. pubescens, secretory cavities occurred in the leaf blade margin. In T. oppositifolia, secretory spaces were much more numerous than in the other two species. Terpenes, total lipids, phenolic compounds, alkaloids and polysaccharides were detected in the secretory spaces of the three species. Th e abundance of secretory spaces, the presence of canals in T. oppositifolia and the position of cavities in P. pubescens are features with potential diagnostic value for their respective genera.

Structural and histochemical attributes of secretory ducts and cavities in leaves of four species of Calophyllaceae J. Agardh in Amazonian savannas

“…The exclusivity of ducts in the central rib of the studied species, ducts and cavities in the mesophyll of K. rubriflora and K. coriacea, ducts only in the mesophyll of C. brasiliense and cavities only in the mesophyll of C. densifolia are of diagnostic value for these species. This corroborates other studies on Asteraceae from the Cerrado (Castro et al, 1997;Haratym et al, 2020) and Fabaceae (Palermo et al, 2017) that report diagnostic value for the type and occurrence of these structures.…”

“…Structural and chemical attributes of these structures have been studied in species from various taxonomic groups, such Plant Biology 23 (2021) 1128-1140 © 2021 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands as Myrtaceae (Bezerra et al, 2020), Anacardiaceae (T€ olke et al, 2020), Fabaceae (Palermo et al, 2017), Asteraceae (Bezerra et al, 2018), Burseraceae , Clusiaceae (Alencar et al, 2020), Rutaceae (Machado et al, 2016), Primulaceae (Luna et al, 2018) and Salicaceae (Fernandes et al, 2018), to list just a few. However, for Calophyllaceae, there have been only descriptive and histochemical studies that did not consider aspects of ultrastructure (Caddah et al, 2012;D ıaz 2013).…”

Glandular trichomes of Robinia viscosa Vent. var. hartwigii (Koehne) Ashe (Faboideae, Fabaceae)—morphology, histochemistry and ultrastructure

“…Similar groups of secondary metabolites have been identified in trichome secretions of various Faboideae and Caesalpinioideae members (e.g. Palermo et al 2017;Silva et al 2017). In the present study, we did not observe differences in the composition of the trichome secretion or in the ultrastructure of trichomes collected from the different parts of inflorescences, which suggests that these trichomes served similar functions.…”

Presence of the anther gland is a key feature in pollination of the early‐branching papilionoidsDipteryx alataandPterodon pubescens(Leguminosae)

“…The presence of a sheath around the secretory cavities of the anther glandular appendages is responsible for the continuous secretory activity. This sheath consists of potentially meristematic cells that can substitute for the senescent epithelial cells (Rodrigues et al ; Rodrigues & Machado ; Leite et al ; Palermo et al , present study), thus maintaining the production and release of substances during the flower's lifespan, ca. 10 h in D. alata and 24–48 h in P. pubescens (Afonso ; Oliveira & Sigrist ).…”

“…Secretory cavities and ducts are commonly reported in the Dipterygeae clade in parts of the plant body other than anthers, such as the bracteole, sepal, petal (Leite et al ), pulvine, petiole, rachis (Rodrigues & Machado ), leaf (Palermo et al . ; Silva et al ), stem (Rodrigues et al ), fruit (Paiva et al ) and even early in plant development (Rodrigues & Machado ). Such secretory cavities consist of an isodiametric to elliptical lumen delimited by a secretory uniseriate epithelium and a parenchyma sheath (Rodrigues et al ; Leite et al ).…”