A new anatomical interpretation for abaxialization in unifacial leaf blade of stone plants (Aizoaceae, Caryophyllales)

Abstract

Unifacial leaves are described in different angiosperm groups, especially in monocotyledons, which show anatomical and molecular evidence of an abaxialization process. Among the structural characters, the anatomy of epidermis and growth tissues has been reported. Special focus has been given to vascularization patterns, such as the presence and organization of peripheral vascular bundles. In the Aizoaceae, peripheral vascular bundles exhibit two patterns: exoscopic and endoscopic bundles; however, studies including an ontogenetic approach with evidence for a unifacial condition in the group are lacking. We investigated eleven Ruschioideae species, including members of two tribes (Ruschieae and Dorotheantheae), which present flat and terete leaves. Our results show that all leaves present a bifacial leaf base, with xylem cells oriented toward the adaxial face present in collateral vascular bundles. However, the occurrence of peripheral endoscopic vascular bundles in the leaf blade in all terete leaves demonstrates a unifacial condition which is present only at the leaf blades. Based on ontogenetics studies, we demonstrate that the peripheral endoscopic bundles begin their differentiation in the abaxial side of the leaf primordia, suggesting the occurrence of an abaxialization process during leaf blade development.

Elastic and collapsible: current understanding of cell walls in succulent plants

“…Although the presence of collapsible cell walls has not been systematically surveyed, histological images from an even broader body of research suggests that collapsible cell walls occur in many more succulent lineages: folding patterns can be observed in succulent tissues of Aizoaceae (e.g. Melo-de-Pinna et al , 2014 ; Ogura et al , 2018 ), Crassulaceae (e.g. Jiménez et al , 1983 ; Sandoval-Zapotitla et al , 2019 ), Bromeliaceae (e.g.…”

Morfo-anatomía e histoquímica de órganos vegetativos de Lycium humile (Solanaceae): rasgos adaptativos a humedales salinos de altura

“…La variación en la morfología y las estrategias desplegadas para alcanzar la suculencia en las hojas de numerosas plantas refleja la diversidad de linajes en los que este carácter ha evolucionado, sin embargo, poco que se conoce sobre la regulación molecular de dicho carácter (Heyduk, 2021). Las observaciones disponibles se limitan a relativamente pocos taxones dentro de las Asteraceae, Oxalidaceae, Portulacineae, Aizoaceae Caryophyllales, y en varias familias de monocotiledóneas como Agavaceae, Iridaceae, Orchidaceae y Xanthorrhoeaceae, donde el desarrollo de la venación tridimensional parece variar según el grupo taxonómico (Heyduk et al 2016;Melo-de-Pinna et al, 2014Hernandes-Lopes et al, 2016;Ogura et al, 2018;Ogburn & Edwards, 2018;Heyduk, 2021).…”