Elveren, Müjgan; Osma, Etem; Varol, Tuğçe; Yaman, Mehmet; Öztürk, Halil İbrahim

Background: In this study, 75 and 100 ppm tebuconazole was applied to pepper seedlings and stress was created. Applications containing Bacillus subtilis, copper and Bacillus subtilis-copper combination were made to reduce the effect of stress on plants. Results: In both tebuconazole doses, significant decreases were observed in plant height, stem diameter, leaf number, leaf area and dry and fresh weights of plants and roots (63%, 37%, 40%, 45%, 27% and 26% respectively). However, bacteria, copper, and combination applications significantly reduced these negative effects; especially, copper-bacteria combination at 75 ppm (K4) and bacteria-only application at 100 ppm (K6) were the most effective in reducing stress. Tebuconazole applications increased oxidative stress and significant increases were detected in catalase (CAT) and superoxide dismutase (SOD) enzyme activities. The highest CAT activity was recorded in the group treated with bacteria (K6) under 100 ppm stress, indicating that antioxidant defenses were strengthened. Photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophyll and carotenoids) were decreased by tebuconazole stress but were significantly preserved by bacterial and copper treatments. While EC (electrolyte conductivity) value increased due to stress, bacteria and copper applications had a positive effect by decreasing EC values. While tebuconazole stress disrupted the balance of some elements, mineral levels were rebalanced after ameliorative applications, and increases were determined in important elements such as Mn, Mg and B. According to the correlation analysis, significant positive correlations were determined between growth parameters, pigment contents and antioxidant enzyme activities. Conclusions: As a result, Bacillus subtilis and copper applications provided a decrease in toxicity due to stress and increased antioxidant enzyme activity. In addition, ameliorative applications provided protection in photosynthetic pigments and increased cell membrane integrity. These findings indicate that the use of beneficial bacteria such as Bacillus subtilis and micronutrients such as copper (Cu) at appropriate concentrations may be beneficial as sustainable solutions against fungicide stress.

Elveren, Müjgan

In this study, pharmaceutical active ingredients (gemfibrozil, acetaminophen and ciprofloxacin) and artificial sweeteners (aspartame and sucralose) were combined and applied to wheat and barley plants. After 15 days of cultivation, a series of biochemical and physiological parameters were evaluated. These included electrolyte leakage, antioxidant enzyme activities such as superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), chlorophyll levels, total phenolic content (TPC), Ferric Reducing Antioxidant Power (FRAP), total flavonoid content (TFC) and concentrations. The relationship between the control samples and the samples treated with pharmaceutical active ingredients and artificial sweeteners was statistically evaluated at the 95% confidence interval, and significant differences were found. The treatments markedly influenced plant physiology and antioxidant defense mechanisms. Electrolyte leakage increased to 795.71 ± 50.14 µS cm-1 in wheat, while catalase (CAT), peroxidase (POX), and superoxide dismutase (SOD) activities showed significant elevations, reaching 5797.5 ± 115.14, 95176.00 ± 3675.42, and 1766.11 ± 13.97 EU g−1, respectively. In contrast, chlorophyll a + b, carotenoids, total phenolic content (TPC), total flavonoid content (TFC), and FRAP values decreased substantially compared with controls. These findings demonstrate that mixtures of pharmaceuticals and artificial sweeteners can disrupt photosynthetic pigment stability, and impair antioxidant defense in wheat and barley, highlighting potential ecological and agricultural risks associated with emerging contaminant mixtures.

Seyed Hajizadeh, Hanifeh; Bayrami Aghdam, Somayeh; Fakhrghazi, Hadi; Karakus, Sinem; Kaya, Ozkan

Background: The primary challenge in the cut flower industry, specifically in the postharvest phase, is the short vase life of flowers. This issue, along with early leaf yellowing and perianth abscission, significantly diminishes the economic value of flowers due to their accelerated senescence. To tackle this, we conducted a factorial experiment on Alstroemeria cv. Rebecca, utilizing a completely randomized design with three replications. In this experiment the effects of varying concentrations of Salicylic acid (SA) (0, 1.5, and 3 mM) and sucrose (SU) (0% and 3%) were investigated on the postharvest quality of leaves and florets, with systematic evaluations every three days throughout their vase life. Results: This experiment revealed that the specific treatment combination of 1.5 mM SA + 3% SU (T5) markedly improved various parameters, such as vase life, total chlorophyll content, membrane stability index, relative fresh weight, and water uptake of cut flowers. In our analysis, we observed that this preservative solution not only extended the vase life and enhanced water uptake but also effectively preserved total chlorophyll, mitigated the loss of fresh weight, and reduced membrane deterioration in petals. Additionally, our results showed an increase in the activities of catalase (CAT) and peroxidase (POD) enzymes, as well as total protein content, alongside a decrease in malondialdehyde (MDA) and hydrogen peroxide (H2O2) levels. Moreover, this study noted a decrease in microbial populations in solutions containing different concentrations of salicylic acid. Conclusions: Our research demonstrated that alstroemeria flowers maintained in a solution with 1.5 mM SA + 3% SU exhibited a significantly prolonged vase life of up to 21 days, in contrast to the 15 days observed in control flowers kept in water. These results are highly beneficial for manufacturers in the cut flower industry, as they provide a viable method to substantially extend the vase life of cut flowers. Such an enhancement in flower longevity can lead to increased market value and customer satisfaction. Furthermore, the reduction in flower senescence and decay rates can contribute to decreased waste and greater efficiency in cut flower distribution and sales, offering a substantial advantage to manufacturers in this competitive market. The extended vase life and reduced senescence observed in alstroemeria flowers treated with 1.5 mM SA and 3% SU are attributed to SA's role in enhancing endogenous defense responses and sucrose's function as an energy source, collectively improving water uptake, and delaying the natural decay process.