The Water Content Drives the Susceptibility of the Lichen Evernia prunastri and the Moss Brachythecium sp. to High Ozone Concentrations

Abstract

The aim of this study was to evaluate the tolerance of lichens (Evernia prunastri) and mosses (Brachythecium sp.) to short-term (1 h), acute (1 ppm) O3 fumigation under different hydration states (dry, <10% water content, metabolism almost inactive; wet, >200% water content, metabolism fully active). We hypothesized that stronger damage would occur following exposure under wet conditions. In addition, we checked for the effect of recovery (1 week) after the exposure. Ozone fumigation negatively affected the content of chlorophyll only in wet samples, but in the moss, such a difference was no longer evident after one week of recovery. Photosynthetic efficiency was always impaired by O3 exposure, irrespective of the dry or wet state, and also after one week of recovery, but the effect was much stronger in wet samples. The antioxidant power was increased in wet moss and in dry lichen, while a decrease was found for wet lichens after 1 week. Our results confirm that the tolerance to O3 of lichens and mosses may be determined by their low water content, which is the case during the peaks of O3 occurring during the Mediterranean summer. The role of antioxidant power as a mechanism of resistance to high O3 concentrations needs to be further investigated.

Foliar Application of Wood Distillate Alleviates Ozone-Induced Damage in Lettuce (Lactuca sativa L.)

“…Ozone-induced ROS can affect photosynthesis by either damaging structurally the chloroplast, as evident by ultrastructural changes [26,55], and/or activating cascade signals which lead to stomatal closure and, in turn, generate further reductions in net photosynthesis, CO 2 assimilation, and plant growth [2,44]. As a result, however, reductions in carbon assimilation may induce increases in the electron transfer with the consequent increase in unwanted ROS overproduction [56].…”

“…200 mg) were homogenized with 4 mL of 80% ethanol and then centrifuged at 15,000 rpm for five minutes. The supernatant (100 µL) was then added to 1 mL of a DPPH solution prepared following the protocol reported by Vannini et al [26]. After the reaction (ca.…”

Ozonized Water in Microbial Control: Analysis of the Stability, In Vitro Biocidal Potential, and Cytotoxicity

“…The antimicrobial action of O 3 herein showed is related to its powerful oxidizing action. O 3 has been widely used as an antimicrobial, in both its gaseous and aqueous form, due to its wide range of microbiological, cleaning, and metabolic activities [6,13,15,16,24,34,45,52,53]. The antimicrobial action of O 3 is related to its powerful oxidizing action.…”

Accumulation and Phytotoxicity of Two Commercial Biocides in the Lichen Evernia prunastri and the Moss Brachythecium sp.

“…Total chlorophyll content was measured using a chlorophyll content meter (CCM-300, Opti-Science, Hudson, NJ, USA), which provides results on a surface basis (mg/m 2 ). The effectiveness of this instrument for the quantification of the chlorophyll content on both E. prunastri and Brachythecium samples has been investigated by Vannini et al [47].…”