Cold acclimation of SnRK2.2 kinases mutant Chlamydomonas reinhardtii

In Chlamydomonas reinhardtii, plant‐specific serine/threonine kinases (SnRK2 kinases) play a central role in sulfur metabolism. However, their role in environmental stress has not been clearly understood. Cold stress is one of the most important factors that limit the growth, productivity, and development of photosynthetic organisms. In this report, the effect of cold stress on some physiological parameters were investigated in SnRK2.2 mutant and wild type C. reinhardtii culture. Our results showed that cold stress had significantly enhanced lipid peroxidation rate in wild type, while no significant change was observed in SnRK2.2 mutant culture. Our data also indicated a decline in Rubisco protein amount of wild type culture under low temperature exposure. Low temperature reduced glutathione reductase (GR) activity in the wild type, while GR activity was enhanced in SnRK2.2 mutant. This result indicated the potential of SnRK2 kinase in cold acclimation process.     

Raman spectroscopy–based water measurements identify the origin of MRI T2 signal in human articular cartilage zones and predict histopathologic score

We investigated for the first time zonal-dependent water distribution in articular cartilage by Raman spectroscopy (RS). We further investigated the association of histopathologic score with RS- and magnetic resonance imaging (MRI)-based water measurements. Cadaveric human cartilage plugs (N = 16) with different osteoarthritis (OA) severity were used. Water content distribution in cartilage zones was probed using RS- and MRI-based techniques. Histopathologic scoring was performed by two independent observers blindly. Moderate associations existed between RS- and MRI-based water measurements across all cartilage zones. RS-based analysis of different water compartments helped assign the origin of the T2 signal collected from the various cartilage zones. RS-based water parameters significantly correlated with OA-severity score, whereas MRI-based water measurements did not. RS can probe different water compartments in cartilage zones and predict up to 66% of the variation observed in the histopathologic score. RS-based water measurement could be developed further to assess cartilage quality in the clinic.     

The Allelopathic Effects of Sunflower and Wheat Root Exudates on <i>Sinapis arvensis and Sinapis alba</i>

In this study, we aimed to investigate the allelopathic effects of sunflower and wheat root exudates on the common weeds such as wild mustard and white mustard in our region. The root exudates which were obtained by soaking 8 weeks old sunflower and wheat seedlings (20 or 40 seedlings) in 100 mL of distilled water for 3 days were applied to the leaves of wild mustard and white mustard. In order to compare the allelopathic effect, the recommended dose (1 g.da^-1 ) and twice the recommended dose (2 g.da^-1 ) of Gromstor (Tribenuron-methyl), a herbicide preferred by farmers for the chemical control of these weeds was also applied. The allelopathy was performed for wild mustard and white mustard seedlings by the measurement of different physiological and biochemical parameters, such as chlorophyll a, chlorophyll b, total chlorophyll, carotenoid, proline, total protein amounts and superoxide dismutase enzyme activity. The amounts of total chl and carotenoid in wild mustard leaves decreased in all treatment groups compared to control. The highest decrease in total chl (50.93%) and carotenoid (46.69%) was oberved in the treatment of 40 wheat seedlings. 100 mL^-1 distilled water. In the white mustard leaves, the amount of total chl in all treatment groups except the treatment group of Gromstor 2 g.da^-1 and carotenoid in all treatment groups increased compared to the control. The highest increases again were observed in 40 wheat seedlings. 100 mL^-1 distilled water treatment. The proline amounts in wild mustard and white mustard increased in all treatment groups. The highest increase was observed for the treatment of 20 wheat seedlings. 100 mL^-1 distilled water in wild mustard (459.69%) and 40 sunflower seedlings. 100 mL^-1 distilled water in white mustard plant (104.70%). In superoxide dismutase enzyme activities, treatments decreased activity except treatment of 40 sunflower seedling root exudate in wild mustard, while increased activity outside commercial herbicide treatment in white mustard. The results showed that sunflower and wheat root exudates have allelopathic effects on wild mustard and white mustard weeds. It is thought that the study will be a reference for new studies that will enable the use of plant root exudates as bioherbicides or foliar fertilizers and will contribute to the fight against weeds in organic agriculture.     

Evaluation of genotoxicity, cytotoxicity and cytostasis in human lymphocytes exposed to patulin by using the cytokinesis-block micronucleus cytome (CBMN cyt) assay

Patulin (PAT) is a fungal secondary metabolite commonly present in apples and apple products. In the present study, PAT was evaluated for its genotoxic, cytotoxic and cytostatic effects to human peripheral blood lymphocytes by using the cytokinesis-block micronucleus cytome (CBMN Cyt) assay. Lymphocyte cultures were treated with PAT at the following concentrations, 0.1, 0.3, 0.5, 1.0, 2.5, 5.0, and 7.5 μM, as well as 0.5 μM mitomycin c (MMC) as a positive control and dimethyl sulfoxide (DMSO) as a vehicle control. PAT was found to induce nucleoplasmic bridges (NPBs) at 5.0 and 7.5 μM concentrations (P?<?0.05), apoptotic cells at 0.1, 1.0, 5.0 μM (P?<?0.05), 7.5 μM concentrations (P?<?0.01) and necrotic cells at 0.3 and 2.5 μM (P?<?0.05), 5.0 and 7.5 μM (P?<?0.01) concentrations in human lymphocytes. The 2.5, 5.0, and 7.5 μM PAT concentrations also led to a clear decrease in the nuclear division index (NDI) (P?<?0.05). PAT caused a significant dose-dependent increase in the number cells of NPBs, in the frequency of apoptotic and necrotic cells, and a significant dose-dependent decrease in the NDI values in lymphocytes. These results indicate that PAT at high concentrations is genotoxic, cytotoxic and cytostatic in cultured human lymphocytes.