A review of groundwater fluoride contamination in Pakistan and an assessment of the risk of fluorosis

This study was conducted with the financial support of the Higher Education Commission of Pakistan, and the University of Peshawar, Pakistan. We greatly acknowledge with deep gratitude this financial supportPeer reviewedPublisher PD

Phytochemical Analysis and Antibacterial Activity of Berberis vulgaris Extract

Background: Plants are main source of various bioactive compounds that possess great medicinal importance and have gained much popularity for therapeutics due to their less side effects. A diverse category of plants is present to be explored and evaluated for the treatment of different bacterial infection. In the current work, Berberis vulgaris extract in various solvents was evaluated for its phytochemical properties and antimicrobial potential against six different pathogenic bacterial strains.Methods: Different phytochemical tests were carried out to analyze the plant for active biocomponents. The disc diffusion method was used to screen the plant for different pathogenic bacterial strains. Phytochemical analysis revealed the presence of various plant bioactive compounds (alkaloids, saponins, tannins, flavonoids, terpenoids, carbohydrates, and proteins) in variable amount.Results: Among all solvents extracts, butanoic and aqueous fraction showed abundant presence of bioactive compounds, while n-hexane showed least intensity of various phytochemicals. For antimicrobial potential, methanolic and butanoic fractions showed maximum growth inhibition against all strains tested at 1.5mg disc-1. Ethyl acetate and n-hexane also showed better activity against all tested bacteria at all concentrations. The most susceptible microbe was Bacillus subtilis. These results further revealed that least activity was recorded by water extracted solvent and showed no activity against Staphylococcus aureus at all concentrations.Conclusion: The current work highlights the apparent antimicrobial potential of extract derived from of Berberis vulgaris. This plant may be explored for further activities and can be used for the production of antibiotics

Improving salt stress resistance in cereals

Salinity is a complex environmental stress that affects growth and production of agriculturally important crops world-wide. Tolerance to salt stress is variable for different plants and involves integration of various physiological and biochemical mechanisms. This thesis investigates the role in salt tolerance of various transporter genes in important agricultural cereal crops, i.e. rice and barley. Transgenic lines overexpressing OsTPKa, OsTPKb and OsAKT1 were generated using Agrobacterium mediated rice transformation, while for OsAKT1 a loss of function mutant was also isolated. Transgenic and mutant plants were characterized to study the role of these genes in rice. For barley, transgenic lines overexpressing HvHKT2;1 were obtained and studied for its role in barley salt tolerance. Transgenic rice plants overexpressing TPKa did not show any growth phenotype under salt stress conditions, however, the performance of TPKa overexpressors was better at different K+ stress conditions compared to control lines. In contrast, transgenic lines overexpressing TPKb showed improved growth under all K+ and Na+ stress conditions, suggesting that TPK channels plays a crucial role in K+ nutrition and in maintaining a higher K+/Na+ ratio under different K+ and Na+ stress conditions. Characterization of rice AKT1 mutants and overexpressors showed the involvement of the AKT1 channel in Na+ uptake at low [K+]ext or high [Na+]ext concentrations and both overexpression and loss of function resulted in reduced growth under these conditions. On the other hand, data from experiments with barley HKT2;1 overexpressing lines showed improved growth under salt stress conditions possibly via Na+ exclusion or accumulation of excessive Na+ in the shoots. Overall, the findings point to two important aspects of salt tolerance: firstly, the contribution of TPKa and TPKb to K+ homeostasis, particularly that of TPKb in maintaining ion homeostasis during different K+ and Na+ stress conditions. Secondly, a role of AKT1 and HKT2;1 in Na+ uptake at the root soil boundary is inferred. These findings reconfirm the idea that maintaining a high K+/Na+ ratio is crucial for salt tolerance in both rice and barley. In barley, HvHKT2;1 overexpressors showed improved salt tolerance via Na+ redistribution from shoot to root and accumulation of Na+ in older leaves. The transgenic lines overexpressing TPKs and HKT2;1 and the information gained from this study could be used in future breeding programs or to generate multiple overexpressors to study the additive or synergistic effects of traits that will add to the present knowledge of ion transport in rice and barley

Effect of Different Levels of Zinc and Compost on Yield and Yield Components of Wheat

Management of organic matter and micronutrients is very important for the sustainable improvement of soil health. Poor soil organic matter usually results in lower availability of zinc (Zn) micronutrients in plants. Such deficiency in Zn causes a significant decrease in the growth and yield of crops. The need at the current time is to balance the application of organic amendments with Zn micronutrients to achieve optimum crop yields. Thus, the current study was conducted to investigate wheat, using compost as organic matter and Zn as a micronutrient. There were three levels of compost (i.e., control (0C), 5 t/ha (5C) and 10 t/ha (10C)) and four levels of Zn (control (0Zn), 2.5 kg Zn/ha (2.5Zn), 5.0 kg Zn/ha (5.0Zn) and 10.0 kg Zn/ha (10.0Zn)) applied with three replicates. The addition of 10C under 10.0Zn produced significantly better results for the maximum enhancement in plant height (8.08%), tillers/m2 (21.61%), spikes/m2 (22.33%) and spike length (40.50%) compared to 0C. Significant enhancements in 1000-grain weight, biological yield and grain yield also validated the effectiveness of 10C under 10.0Zn compared to 0C. In conclusion, application of 10C with 10.0Zn showed the potential to improve wheat growth and yield attributes. The addition of 10C with 10.0Zn also regulated soil mineral N, total soil N and extractable soil P. Further investigation is recommended with different soil textures to verify 10C with 10.0Zn as the best amendment for the enhancement of wheat yield in poor organic matter and Zn-deficient soils

Identification and characterization of a novel multi-stress responsive gene in Arabidopsis.

Abiotic stresses especially salinity, drought and high temperature result in considerable reduction of crop productivity. In this study, we identified AT4G18280 annotated as a glycine-rich cell wall protein-like (hereafter refer to as GRPL1) protein as a potential multistress-responsive gene. Analysis of public transcriptome data and GUS assay of pGRPL1::GUS showed a strong induction of GRPL1 under drought, salinity and heat stresses. Transgenic plants overexpressing GRPL1-3HA showed significantly higher germination, root elongation and survival rate under salt stress. Moreover, the 35S::GRPL1-3HA transgenic lines also showed higher survival rates under drought and heat stresses. GRPL1 showed similar expression patterns with Abscisic acid (ABA)-pathway genes under different growth and stress conditions, suggesting a possibility that GRPL1 might act in the ABA pathway that is further supported by the inability of ABA-deficient mutant (aba2-1) to induce GRPL1 under drought stress. Taken together, our data presents GRPL1 as a potential multi-stress responsive gene working downstream of ABA