Investigating the Foliar Uptake and Within-Leaf Migration of Phenanthrene by Moss (Hypnum Cupressiforme) Using Two-Photon Excitation Microscopy with Autofluorescence

Abstract

Mosses have the potential to play a significant role in the global cycling and fate of semivolatile organic compounds (SVOCs), due to their extensive distribution at high latitudes and the long-range atmospheric transport of SVOCs. Unlike vascular plants mosses lack a substantial cuticle, vascular system, or root structure, taking up water, nutrients and SVOCs primarily from the atmosphere. Mosses have thus been effectively used as passive air samplers for many SVOCs in urban and rural locations. The potential differences in atmospheric uptake and within-leaf movement storage and processing of SVOCs between vascular and nonvascular living plants were investigated here by comparing the uptake and behavior of phenanthrene in spinach (Spinacia oleracea) and moss (Hypnum cupressiforme), using two-photon excitation microscopy coupled with autofluorescence. Chemical uptake, movement storage, and compartmentalization of phenanthrene was directly detected, visualized, and monitored over a 12 day period following exposure to gas phase phenanthrene. Species differences in the uptake of phenanthrene between moss and spinach leaves were observed, showing how morphological differences affect the foliar uptake of SVOCs. In spinach, phenanthrene accumulated within the cellular cytoplasm and vacuole. In moss, phenanthrene accumulated predominantly within the cell walls, before later migrating across the cell membrane into adjacent cells and the cellular cytoplasm. The study represents a further demonstration of how different plant species can display different and complex transport and storage pathways for the same chemical, and highlights the importance of the cellular structure and plant morphological and physiological features in controlling this behavior.

Understorey Rhododendron tomentosum and Leaf Trichome Density Affect Mountain Birch VOC Emissions in the Subarctic

“…Lipophilic uncharged VOCs such as terpenes tend to be adsorbed within the hydrophobic cuticular wax layer upon gas deposition 40 , from where they may be taken up into the leaf through the stomata 41,42 . Limonene uptake and re-release by 13 plant species was reported by Noe et al ., (2008) 39 , with the uptake of the monoterpene scaling positively with leaf lipid content.…”

Organic Pollutant Penetration through Fruit Polyester Skin: A Modified Three-compartment Diffusion Model

“…Keyte et al . 11 found that the penetration of phenanthrene (PHE), a typical persistent organic pollutant, was much faster through the surface of moss (which has no typical cuticle) than through that of a spinach leaf (which has a typical cuticle). The cuticle is an essential barrier that hinders the penetration of organic pollutants into the plant, but the contributions of cuticular components to such penetration remain unresolved.…”

Evaluation of toxicity risk of polycyclic aromatic hydrocarbons (PAHs) in crops rhizosphere of contaminated field with sequential extraction

“…The contribution of root uptake for PAHs was only 2.4% in soil spiked with naphthalene, phenanthrene, and pyrene (Su and Zhu 2008). The PAHs in shoot were considered to accumulate from atmosphere directly other than transport from root (Su and Zhu 2008;Keyte et al 2009 Table 5 The loading matrix of partial least squares regression models for oat dissipation in rhizosphere soil was due to biodegradation or biotransformation (Binet et al 2000). This process would be influenced by partition coefficient of different PAHs between soil and root or between atmosphere and shoot.…”