Are sun- and shade-type anatomy required for the acclimation of Neoregelia cruenta?

Abstract

Sun and shade plants are often discriminated by a number of sun-and shade-type anatomies. Nonetheless, we propose that among tank-bromeliads, changes in rosette architecture satisfy the requirements for coping with contrasting light levels. The tank-bromeliad Neoregelia cruenta naturally colonises sub-habitats ranging from full exposure to direct sunlight, to shaded environments in sand ridge plains. We quantifi ed anatomical and morphological traits of leaves and rosettes of N. cruenta grown under sun and shade conditions. Cells with undulated lateral walls within the water parenchyma are for the fi rst time described for the family. Under high light, leaf blades were wider, shorter, and yellowish. The rosette diameter of sun plants was less than half that of shade plants. Sun leaves overlapped with neighbouring leaves for most of their length, forming a cylindrical rosette where water accumulates. Shade leaves only overlapped in the centre of the rosette. Most anatomical traits were similar under both growth conditions. Stomata were absent from the base of sun leaves, which is probably explained by limited gas exchange at the base of the tight sun-type rosette. Data suggest that the ability of N. cruenta to acclimate to sun and shade is better explained by changes in rosette architecture than by leaf anatomy.

Anatomy of vegetative organs, inflorescence axis and pedicel in the Neoregelia bahiana complex (Bromeliaceae): taxonomic and ecological importance

“…For other Bromelioideae species, such as Billbergia elegans and Neoregelia mucugensis from rocky fields (Pereira et al 2013) and Neoregelia cruenta (R. Graham) L. B. Sm. from the Atlantic Forest (Reinert et al 2013), a statistical difference in leaf size has been documented, with longer and narrower leaves in low-light conditions, similar to what we observed for shade leaves of the N. bahiana complex. Furthermore, Pereira et al (2013) observed a larger area and thickness of the lamina in shade leaves, as well as a higher stomatal density and lower scale density.…”

“…Furthermore, Pereira et al (2013) observed a larger area and thickness of the lamina in shade leaves, as well as a higher stomatal density and lower scale density. Reinert et al (2013) also found larger leaf area and fewer spinescent emergences on the margins of shade leaves. Differences in the plant architecture have also been observed: shade plants have a larger diameter and fewer leaves in the rosette (Reinert et al 2013).…”

“…Reinert et al (2013) also found larger leaf area and fewer spinescent emergences on the margins of shade leaves. Differences in the plant architecture have also been observed: shade plants have a larger diameter and fewer leaves in the rosette (Reinert et al 2013). All of these results show the ability of Bromelioideae species to respond to the environment with morphological adjustments, maximising their light-harvesting capacity and growth in low-light conditions.…”

“…In this context, anatomical characterisation of individuals from different populations of Neoregelia bahiana may provide additional diagnostic characters for the species, and may help ascertain the existence of intraspecific or interpopulational variations related to the environment. The importance of anatomical data for the taxonomic and ecological understanding of Bromeliaceae has already been demonstrated in many studies involving different organs such as roots, stems, leaves and the inflorescence axis (Tomlinson 1969, Sajo et al 1998, Pita and Menezes 2002, Aoyama and Sajo 2003, Segecin and Scatena 2004a, b, Proença and Sajo 2004, 2007, 2008a, b, Scatena and Segecin 2005, Horres et al 2007, Versieux et al 2010, Monteiro et al 2011, Silva and Scatena 2011a, b, Faria et al 2012, Reinert et al 2013, Santos-Silva et al 2014.…”

Adaptive strategies against water stress: a study comparing leaf morphoanatomy of rupicolous and epiphytic species of Gesneriaceae

“…Various tropical plant species have demonstrated their ability to make such adaptations (Reinert et al 2013), particularly the Gesneriaceae species, which are known to inhabit various spots with direct sunlight, such as sunny clearings, river banks and creeks, moisture-dripping vertical rocks, steep slopes, and road-cuts (Wiehler 1983;Perret et al 2013). The diversity of habitat found in the Gesneriaceae family favors comparative studies between rupicolous and epiphyte plants.…”