Peltate trichomes on biogenic silvery leaves of Elaeagnus umbellata

Abstract

External and internal features of Elaeagnus umbellata leaves were investigated by optical and electron microscopy. The adaxial (upper) and abaxial (lower) leaf surfaces appeared green and silver in color, respectively. There were peltate trichomes on both the adaxial and abaxial leaf surfaces. The peltate trichomes were 200-300 μm in diameter and shield or umbrella-shaped. They had a central dome and 20-30 radiating rays that were fused to form a circular cap in the center and tapered at the end. The density of peltate trichomes was apparently higher on the abaxial leaf surface than on the adaxial leaf surface. At least two layers of peltate trichomes were commonly observed on the abaxial leaf surface. The epidermal cells on the abaxial leaf surface had convex lens-like shape in cross sections. No distinct chloroplasts were found in the cytoplasm of peltate trichomes. These results suggest that the silver coloration on the abaxial leaf surface is mostly due to structural coloration associated with the profuse overlapping peltate trichomes having a circular cap of radially fused rays. The shrub did not show any pigmentary cellular features associated with the silver coloration. With the silvery leaves as a reflective surface for shaded leaves in canopy, E. umbellata is likely to adapt to the harsh non-native light-demanding environments.

Engineering Themes in Plant Forms and Functions

“…Is the trichome-mediated protection caused by mere occlusion of incident radiation, or do structural features create additional scattering or reflectance? The latter is likely is the case, as structural color is a feature of many haired leaves, such as those of Japanese silverberry Elaeagnus umbellata, whose leaves have silvered surfaces (67). The leaf has peltate (shield-like) trichome structures consisting of multiple radially arranged hairs with a spherical central cap (Figure 4b).…”

Micromorphological considerations on Alyssum nezaketiae Aytaç & H. Duman (Brassicaceae), endemic to gypsum habitats from Turkey: An electron microscopic study

“…Abiotic stress responses of different gypsophyte were extensively studied at the phytochemical and molecular level. Macromorphological and complementary microscope‐based techniques are helpful in interpreting the response of plants to abiotic stress at the anatomical and ultrastructural level (Han et al, 2021; Khan & Khan, 2020; Kim, 2018; Mani, Rasangam, Selvam, & Shekhawat, 2021; Nazir et al, 2021; Nazish et al, 2019; Noor & Ahmad, 2021; Öztürk Çalı & Karavin, 2020; Sadia et al, 2020; Salem‐Fnayou, Bouamama, Ghorbel, & Mliki, 2011; Scocco, Mercati, Tardella, & Catorci, 2016). While plant adaptation to changing environmental conditions can be associated with the organization of leaves, presence of a protective outer layer of the epidermis and cuticle, and properties of the stomata (Salem‐Fnayou et al, 2011), few reports described the anatomical and ultrastructural changes that characterize gypsophytes.…”

Jipsli Habitatlarda Doğal Olarak Yetişen Onobrychis germanicopolitana Hub.-Mor. & Simon (Fabaceae)’nın Ultrayapısal Bulguları ve Uyarlanabilir Yanıtları

“…Supporting macromorphological features with LM and SEM microscope-based processes is very beneficial in interpreting the response of plants to environmental stress (Kim, 2018;Khan and Khan, 2020;Sadia et al, 2020;Han et al, 2021;Mani et al, 2021;Nazir et al, 2021;Noor and Ahmad, 2021). There are recent studies with SEM of members of the Fabaceae family, but SEM studies that interpret adaptation to abiotic stress are insufficient (Bacchetta et al, 2020;Shaheen et al, 2020;Abusaief and Boasoul, 2021;Guerrero et al, 2021;Kashyap et al, 2021;Soares et al, 2021).…”