Ailanthus altissimia Desf. is a non-native species spread throughout the Southern Europe as invasive plant. It demonstrated to be very sensitive to ozone and ozone-polluted environment, develops brownish stipples on the upper leaf surface. In the 2001 summer 12 young plants were placed in a site near the city of Florence (Italy), where high levels of ozone were experienced. Six of them were regularly watered and six were watered only when the wilting of their leaves was evident. Regular assessments were done during the experiment. They concerned growth, production of new leaves, dead and shedding of old leaves, visible symptoms of damage, stomatal conductance and CO2 uptake, chlorophyll fluorescence. The results suggest that the sensitivity to ozone of watered plants is connected to their higher growth ratio and stomatal conductance. Ozone plays a more important role than drought in producing foliar stress conditions

Several investigations about air pollution impact on forests have been carried out in Slovenia during last thirty years, mainly using the Norway spruce (Picea abies [L.] Karst.) as the main bioindication species, but there is a lack of information about common beach (Fagus sylvatica L.) condition, the most important forest tree species in Slovenia and in Zasavje area. The assessment of air pollution effect on beech based on stress physiological indicators of foliage, macronutrients level in beech leaves and by assessment of crown defoliation was carried out altogether with necessary soils analyses of the selected beech stands. On the basis of all parameters it can be concluded that the worst condition of beech trees in Zasavje is due to high level of air pollution, mainly by sulphur dioxide and not by deficiency of macronutrients or unfavourable state of soils

Heavy metals and emerging engineered nanoparticles (ENPs) are two current environmental concerns that have attracted considerable attention. Cerium oxide nanoparticles (CeO₂NPs) are now used in a plethora of industrial products, while cadmium (Cd) is a great environmental concern because of its toxicity to animals and humans. Up to now, the interactions between heavy metals, nanoparticles and plants have not been extensively studied. The main objectives of this study were (i) to determine the synergistic effects of Cd and CeO₂NPs on the physiological parameters of Brassica and their accumulation in plant tissues and (ii) to explore the underlying physiological/phenotypical effects that drive these specific changes in plant accumulation using Artificial Neural Network (ANN) as an alternative methodology to modeling and simulating plant uptake of Ce and Cd. The combinations of three cadmium levels (0 [control] and 0.25 and 1 mg/kg of dry soil) and two CeO₂NPs concentrations (0 [control] and 500 mg/kg of dry soil) were investigated. The results showed high interactions of co-existing CeO₂NPs and Cd on plant uptake of these metal elements and their interactive effects on plant physiology. ANN also identified key physiological factors affecting plant uptake of co-occurring Cd and CeO₂NPs. Specifically, the results showed that root fresh weight and the net photosynthesis rate are parameters governing Ce uptake in plant leaves and roots while root fresh weight and Fᵥ/Fₘ ratio are parameters affecting Cd uptake in leaves and roots. Overall, ANN is a capable approach to model plant uptake of co-occurring CeO₂NPs and Cd.

The beneficial uptake of nutrients by wetland plants is countered to some extent by nutrient release back into the aquatic environment due to vegetative die-back. This current study examined whether Leersia oryzoides, a common wetland plant, exhibits luxury uptake of nutrients from simulated farm runoff. The study also tested whether with subsequent decomposition, these nutrients are released back into the water column. When exposed to elevated (>2 mg/L N and P) runoff, L. oryzoides assimilated significantly higher concentrations of nitrogen (p < 0.001) and phosphorus (p < 0.001) in above-ground biomass as compared to non-enriched treatments (<0.05 mg/L N and P). Subsequently, senescence of enriched above-ground biomass yielded significantly higher concentrations of phosphorus (2.19 ± 0.84 mg P/L). Using L. oryzoides as our model, this study demonstrates nitrogen and phosphorus sequestration during the growing season and release of phosphorus in the winter. Release of sequestered nutrients during plant senescence.

Mitigation of air pollution by plants is a well-established phenomenon. Trees planted on the roadside are known to reduce particulate matter pollution by about 25%. In an urban ecosystem, especially in a metropolitan city such as Delhi, roadside trees are constantly exposed to air pollution. We, therefore, evaluated the effect of air pollution on a common Indian roadside tree, Neem (Azadirachta indica), and its associated microbes in areas with high and low levels of particulate matter (PM) pollution in Delhi. We hypothesized that alteration in the air quality index not only influences plant physiology but also its microbiome.A 100-fold increase in the number of epiphytic and 10–100 fold increase in endophytic colonies were found with 1.7 times increase in the level of pollutants. Trees in the polluted areas had an abundance of Salmonella, Proteus and Citrobacter, and showed increased secondary metabolites such as phenols and tannins as well as decreased chlorophyll and carotenoid. The number of unique microbes was positively correlated with increased primary metabolites.Our study thus indicates that, alteration in air quality affects the natural micro-environment of plants. These results may be utilized as sustainable tools for studying plant adaptations to the urban ecosystem.