Perspective of Monitoring Heavy Metals by Moss Visible Chlorophyll Fluorescence Parameters

Abstract

Chlorophyll fluorescence measurements have been mainly applied to investigate the functioning of the photosynthetic apparatus in the diagnosis of environmental stress. Moss is sensitive to several abiotic stresses and is considered an environmental indicator. Therefore, moss chlorophyll fluorescence can be as a visual parameter applicable for monitoring heavy metal contaminants in water. Different from previous studies with value changes of chlorophyll fluorescence in mosses, we suggest that phenotypes with anthocyanin accumulation pattern and chlorosis pattern and colors of chlorophyll fluorescence images of the maximum efficiency of PSII photochemistry (Fv/Fm) and the quantum yield of PSII electron transport (ΦPSII) could reflect metal species groups and concentrations roughly. And we further indicated that Cr(III) and Cr(VI) could be monitored distinguishably according to the non-photochemical quenching (NPQ) fluorescence of sporadic purple and sporadic lavender images, respectively. It is interesting that the fluorescence color patterns were nearly the same for all treatment concentrations. This perspective provides additional data of chlorophyll fluorescence changes in moss under cold, heat, salinity, high light or osmotic stress. Only heat stress and high light have significant effects on the fluorescence parameters of Fv/Fm and ΦPSII. In contrast, mosses are less sensitive to short-term cold, salinity, and osmotic stress. While NPQ decreases rapidly under the osmotic stress. Nevertheless, heat stress, high light or osmotic stress does not usually co-occur in the place where the moss grows. Estimation through moss chlorophyll fluorescence color patterns is still a rapid and non-invasive method to monitor heavy metal pollutions in water.

Biosensing the Presence of Metal Nanoparticles by Spectrally- and Time-Resolved Endogenous Fluorescence in Water Moss Fontinalis antipyretica

“…In the present study, we evaluate the sensitivity of endogenous fluorescence to short-term exposure of heavy metal NPs in water bryophyte species Fontinalis antipyretica moss. This green moss is naturally occurring in sweet water lakes and is thus a good choice for the study of environmental pollution in water environments [37,38]. It occurs on submerged rocks and wood in flowing or standing waters, including sweet water lakes, where it forms refuge for fish eggs.…”

“…This moss was found to have good accumulation properties for metals when used in active biomonitoring in the river environment [11]. In addition, the Fontinalis antipyretica moss presents high sensitivity of chlorophyll fluorescence parameters to environmental changes [38] and can adsorb some of the heavy metals (Cd, Zn) [39].…”

“…Inherently quenching metal ions such as Hg 2+ , Cu 2+ , Co 2+ , Ni 2+ , and Fe 3+ can interfere with the fluorescent signal of the sensors in detecting other metals [50]. Non-photochemical quenching of the chlorophyll fluorescence, described in the presence of heavy metals [38,51], can a play role in the observed effect of the decrease in the fluorescence by both Co and Cu, accompanied by a rise in the contribution of the shorter fluorescence lifetime component a1. At the same time, our experiments demonstrate accumulation of the NPs mainly in the intercellular space, while the red fluorescence was derived from chloroplasts inside the cells.…”

Exogenously-Sourced Ethylene Modulates Defense Mechanisms and Promotes Tolerance to Zinc Stress in Mustard (Brassica juncea L.)

“…Plants show concentration-dependent requirement of Zn for optimal plant metabolism; however, excess Zn availability inhibits plant growth and development [24]. It has been reported that HMs induce lipid peroxidation in photosynthetic membranes, distort chloroplast ultrastructure, degrade photosynthetic pigments, inhibit PSII activity and the electron transport chain, and decrease both carboxylation efficiency of Rubisco and net photosynthesis [50,51]. Additionally, plants' fitness to the environment is estimated through chlorophyll fluorescence observations [52].…”

Chlorophyll retention caused by STAY-GREEN (SGR) gene mutation enhances photosynthetic efficiency and yield in soybean hybrid Z1

“…We further determined Chl fluorescence, which is a key measure of photosynthetic activity and performance (Baker 2008, Chen et al 2019. F 0 represents the Chl fluorescence emission intensity of the fully opened chloroplast PSⅡ reaction center (Dąbrowski et al 2015).…”