Effects of vermicompost on soil microbiological properties in lettuce rhizosphere: An environmentally friendly approach for sustainable green future.

The aim of this study is to investigate the effects of vermicompost on the biological and microbial properties of lettuce rhizosphere in an agricultural field in Samsun, Turkey. The experiment was conducted in a completely randomised design (CRD) and included four vermicompost dosages (0%, 1%, 2%, and 4%) and two application methods (with and without plants). Batavia lettuce was selected as the test plant due to its sensitivity to environmental conditions and nutrient deficiencies. The study evaluated the changes in organic matter (OM), pH, electrical conductivity (EC), carbon dioxide (CO2), dehydrogenase activity (DHA), microbial biomass carbon (MBC), and catalase activity (CA) in the rhizosphere of lettuce plants treated with different vermicompost levels (0%, 1%, 2%, and 4%). The findings showed that vermicompost application significantly increased chlorophyll content in lettuce plants, with the highest content observed in plants treated with V1 compared to the control. Different vermicompost concentrations also influenced chlorophyll b and total chlorophyll levels, with positive effects observed at lower concentrations than the control. Plant height and fresh weight were highest in plants treated with V2, indicating the positive impact of vermicompost on plant growth. Additionally, vermicompost application increased plant dry weight and improved soil properties such as pH, organic matter content, and microbial activity. The findings showed that vermicompost increased the rhizosphere's microbial biomass and metabolic activity, which can be beneficial for plant growth and disease suppression. The study highlights the importance of understanding the effects of organic amendments on soil properties and the microbial community in the rhizosphere, which can contribute to sustainable agricultural practices. Overall, the results suggest that vermicompost can be used as an effective organic amendment for enhancing plant growth and improving soil properties in agricultural fields. Moreover, based on the data, it can be suggested that a dose between 1% and 2% vermicompost is beneficial for the overall growth of plants.

Iron Oxide and Silicon Nanoparticles Modulate Mineral Nutrient Homeostasis and Metabolism in Cadmium-Stressed Phaseolus vulgaris.

The application of nanoparticles (NPs) has been proved as an efficient and promising technique for mitigating a wide range of stressors in plants. The present study elucidates the synergistic effect of iron oxide nanoparticles (IONPs) and silicon nanoparticles (SiNPs) in the attenuation of Cd toxicity in Phaseolus vulgaris. Seeds of P. vulgaris were treated with IONPs (10 mg/L) and SiNPs (20 mg/L). Seedlings of uniform size were transplanted to pots for 40 days. The results demonstrated that nanoparticles (NPs) enhanced growth, net photosynthetic rate, and gas exchange attributes in P. vulgaris plants grown in Cd-contaminated soil. Synergistic application of IONPs and SiNPs raised not only K+ content, but also biosynthesis of polyamines (PAs), which alleviated Cd stress in P. vulgaris seedlings. Additionally, NPs decreased malondialdehyde (MDA) content and electrolyte leakage (EL) in P. vulgaris plants exposed to Cd stress. These findings suggest that stress alleviation was mainly attributed to the enhanced accumulation of K+ content, improved antioxidant defense system, and higher spermidine (Spd) and putrescine (Put) levels. It is suggested that various forms of NPs can be applied synergistically to minimize heavy metal stress, thus increasing crop production under stressed conditions.

The complete chloroplast genome sequence of Vitis davidii Foex strain 'SJTU003'.

In the present study, the complete chloroplast genome of Vitis davidii Foex strain 'SJTU003' was assembled and subjected to phylogenetic analysis. This chloroplast genome of 'SJTU003' was 161,335 bp in length, including two inverted repeat regions (IRa and IRb) that were separated by a large single-copy region (89,570 bp) and a small single-copy region (19,059 bp). The genome contained 133 genes, including 88 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Phylogenetic analysis indicated that V. davidii is most closely related to Vitis flexuosa and Vitis amurensis.

Effects of Different Metals on Photosynthesis: Cadmium and Zinc Affect Chlorophyll Fluorescence in Durum Wheat.

A comparative study of the effects of exposure to high Cd2+ (50 µM) and excess Zn2+ (600 µM) on photosynthetic performance of hydroponically-grown durum wheat seedlings was performed. At day 8, Cd and Zn were added to the nutrient solution. After 7-days exposure, the chosen concentrations of both metals resulted in similar relative growth rate (RGR) inhibitions of about 50% and comparable retardations of the CO2 assimilation rates (about 30%) in the second developed leaf of wheat seedlings. Analysis of chlorophyll a fluorescence indicated that both metals disturbed photosynthetic electron transport processes which led to a 4- to 5-fold suppression of the efficiency of energy transformation in Photosystem II. Non-specific toxic effects of Cd and Zn, which prevailed, were an inactivation of part of Photosystem II reaction centres and their transformation into excitation quenching forms as well as disturbed electron transport in the oxygen-evolving complex. The specificity of the Cd and Zn modes of action was mainly expressed in the intensity of the toxicity effects: despite the similar inhibitions of the CO2 assimilation rates, the wheat photochemistry showed much more sensitivity to Cd than to Zn exposure.

Short-term phytotoxicity in Brassica napus (L.) in response to pre-emergently applied metazachlor: A microcosm study.

In accordance with realistic application approaches, a short-term 1-factorial experiment was set up to investigate the phytotoxic impact of pre-emergent application of the chloroacetamide herbicide metazachlor on Brassica napus. In addition to morphological parameters, the underlying processes that ultimately determine the extent of herbicide-induced phytotoxicity (i.e., herbicide metabolization and cellular antioxidant defense) were examined. The present study demonstrated that metazachlor provoked fasciation of the leaves closely after emergence, which might be linked to its mode of action whereby cell division is impaired through the inhibition of very long chain fatty acid synthesis. The increased activities of antioxidative enzymes and metabolites in leaf tissue indicated the presence of reactive oxygen species under the influence of metazachlor. This resulted in oxidative damage in the form of membrane lipid peroxidation. Simultaneously, the increased activity of glutathione S-transferase and the shift in glutathione redox state suggested activation of the detoxification metabolism. This occurred, however, at the expense of growth, with a temporary reduction in plant height and weight after application. The results indicated that metazachlor disappeared within 3 mo to 4 mo after application, which resulted in the recovery of the crop. In conclusion, metazachlor induces phytotoxicity in the short term, either directly through its mode of action or indirectly through the induction of oxidative stress, which resulted in a temporary reduction in growth. Environ Toxicol Chem 2017;36:59-70. © 2016 SETAC.

Toxic potential of five freshwater Phormidium species (Cyanoprokaryota).

Among the Cyanoprokaryota (blue-green algae), the genus Phormidium has thus far rarely been studied with respect to toxin production and potentially resulting human and environmental health effects. We here show that five previously unexplored freshwater species of this genus (Ph. bijugatum, Ph. molle, Ph. papyraceum, Ph. uncinatum, Ph. autumnale) are indeed capable of producing bioactive compounds. Phormidium extracts caused weight loss as well as neuro/hepatotoxic symptoms in mice, and in the case of Ph. bijugatum even death. Very low levels of saxitoxins and microcystins, as confirmed by ELISA, were insufficient to explain this toxicity and the differing toxic potencies of the Phormidium species. Qualitative HPLC analyses confirmed different substance patterns and in the future could aid in the separation of fractions for more detailed substance characterisation. The results in vivo were confirmed in vitro using cells of human, mouse and fish. The fish cells responded least sensitive but proved useful in studying the temperature dependence of the toxicity by the Phormidium samples. Further, the human cells were more sensitive than the mouse cells thus suggesting that the former may be a more appropriate choice for studying the impact of Phormidium to man. Among the human cells, two cancer cell lines were more responsive to one of the samples than a normal cell line, thereby indicating a potential anti-tumour activity. Thus, the five freshwater Phormidium species should be considered in environmental risk assessment but as well, as a source of therapeutic agents.