Horticultural Therapy May Reduce Psychological and Physiological Stress in Adolescents with Anorexia Nervosa: A Pilot Study.

Studies in psychiatric populations have found a positive effect of Horticultural therapy (HCT) on reductions in stress levels. The main objective of the present pilot study was to evaluate the impact of the addition of HCT to conventional clinical treatment (Treatment as Usual, TaU) in a sample of six female adolescents with anorexia nervosa restricting type (AN-R), as compared to six AN-R patients, matched for sex and age, under TaU only. This is a prospective, non-profit, pilot study on patients with a previous diagnosis of AN-R and BMI < 16, recruited in 2020 in clinical settings. At enrolment (T0) and after treatment completion (TF), psychiatric assessment was performed. At T0, all the patients underwent: baseline electrocardiogram acquisition with a wearable chest strap for recording heart rate and its variability; skin conductance registration and thermal mapping of the individual's face. An olfactory identification test was administered both to evaluate the olfactory sensoriality and to assess the induced stress. One-way analyses of variance (ANOVAs) were performed to analyze modifications in clinical and physiological variables, considering time (T0, TF) as a within-subjects factor and group (experimental vs. control) as between-subjects factors. When the ANOVA was significant, post hoc analysis was performed by Paired Sample T-tests. Only in the HCT group, stress response levels, as measured by the biological parameters, improved over time. The body uneasiness level and the affective problem measures displayed a significant improvement in the HCT subjects. HCT seems to have a positive influence on stress levels in AN-R.

Season-long exposure of bilberry plants to realistic and future ozone pollution improves the nutraceutical quality of fruits.

Ozone (O3) is a phytotoxic air pollutant capable of limiting plant yield and growth, and altering the quality of edible plant products. This study aimed to investigate the effects of long-term O3 exposure at realistic and future concentrations (applied during fruit development) not only on morphological, physiological, and biochemical plant/leaf traits of Vaccinium myrtillus but also on its fruit yield and quality. Three-year-old saplings were grown from May to July under three levels of O3 concentration [1.0, 1.5 and 2.0 times the ambient air concentrations, denoted as AA, 1.5_AA and 2.0_AA], using a new-generation O3 Free Air Controlled Exposure system. Ozone induced oxidative pressure and membrane denaturation as confirmed by the accumulation of anion superoxide, hydrogen peroxide (•O2-: +39 and + 29%; H2O2: +55 and + 59% in 1.5_AA and 2.0_AA, respectively, compared with AA), and malondialdehyde by-product (1.4- and 2.5-fold higher than AA, in 1.5_AA and 2.0_AA, respectively). The observed oxidative burst likely affected several cellular structures interested by photosynthetic processes (e.g., decrease of the maximum rate of carboxylation: -30%). This constraint likely induced a decline in plant vitality and a different partitioning of biomass allocation between above and below organs. An accelerated maturation of bilberries due to O3 was reported, suggesting that plants grown under harsher environmental conditions suffered from metabolic changes associated with early ripening. Increasing O3 concentrations might be responsible for an alteration of the ratio between oxidation and reduction processes mechanisms that was followed by a loss of integrity of membranes, so limiting the availability of energy/resources, triggering enzymatic oxidation of phenols to red/purple pigments, and promoting fruit maturation. To the best of our knowledge, this is the first research showing that long-term O3 exposure during bilberry fruit development influenced not only several plant/leaf traits, but also fruit nutraceutical quality at the time of harvest.

Can nutrient fertilization mitigate the effects of ozone exposure on an ozone-sensitive poplar clone?

We tested the independent and interactive effects of nitrogen (N; 0 and 80 kg ha-1), phosphorus (P; 0, 40 and 80 kg ha-1), and ozone (O3) application/exposure [ambient concentration (AA), 1.5 × AA and 2.0 × AA] for five consecutive months on biochemical traits of the O3-sensitive Oxford poplar clone. Plants exposed to O3 showed visible injury and an alteration of membrane integrity, as confirmed by the malondialdehyde by-product accumulation (+3 and +17% under 1.5 × AA and 2.0 × AA conditions, in comparison to AA). This was probably due to O3-induced oxidative damage, as documented by the production of superoxide anion radical (O2-, +27 and +63%, respectively). Ozone per se, independently from the concentrations, induced multiple signals (e.g., alteration of cellular redox state, increase of abscisic acid/indole-3-acetic acid ratio and reduction of proline content) that might be part of premature leaf senescence processes. By contrast, nutrient fertilization (both N and P) reduced reactive oxygen species accumulation (as confirmed by the decreased O2- and hydrogen peroxide content), resulting in enhanced membrane stability. This was probably due to the simultaneous involvement of antioxidant compounds (e.g., carotenoids, ascorbate and glutathione) and osmoprotectants (e.g., proline) that regulate the detoxification processes of coping with oxidative stress by reducing the O3 sensitivity of Oxford clone. These mitigation effects were effective only under AA and 1.5 × AA conditions. Nitrogen and P supply activated a free radical scavenging system that was not able to delay leaf senescence and mitigate the adverse effects of a general peroxidation due to the highest O3 concentrations.

Effects of nitrogen and phosphorus imbalance on photosynthetic traits of poplar Oxford clone under ozone pollution.

Ozone (O3) pollution and the availability of nitrogen (N) and phosphorus (P) in the soil both affect plant photosynthesis and chlorophyll (Chl) content, but the interaction of O3 and nutrition is unclear. We postulated that the nutritional condition changes plant photosynthetic responses to O3. An O3-sensitive poplar clone (Oxford) was subject to two N levels (N0, 0 kg N ha- 1; N80, 80 kg N ha- 1), two P levels (P0, 0 kg P ha- 1; P80, 80 kg P ha- 1) and three levels of O3 exposure (ambient concentration, AA; 1.5 × AA; 2.0 × AA) over a growing season in an O3 free air controlled exposure (FACE) facility. The daily change of leaf gas exchange and dark respiration (Rd) were investigated at mid-summer (August). Chl a fluorescence was measured three times in July, August and September. At the end of the growing season, Chl content was measured. It was found that Chl content, the maximum quantum yield (Fv/Fm), Chl a fluorescence performance index (PI) and gas exchange were negatively affected by elevated O3. Phosphorus may mitigate the O3-induced reduction of the ratio of photosynthesis to stomatal conductance, while it exacerbated the O3-induced loss of Fv/Fm. Nitrogen alleviated negative effects of O3 on Fv/Fm and PI in July. Ozone-induced loss of net photosynthetic rate was mitigated by N in medium O3 exposure (1.5 × AA). However, such a mitigation effect was not observed in the higher O3 level (2.0 × AA). Nitrogen addition exacerbated O3-induced increase of Rd suggesting an increased respiratory carbon loss in the presence of O3 and N. This may result in a further reduction of the net carbon gain for poplars exposed to O3.