Exogenously applied zinc and copper mitigate salinity effect in maize (Zea mays L.) by improving key physiological and biochemical attributes

Zinc or copper deficiency and salinity are known soil problems and often occur simultaneously in agriculture soils. Plants undergo various changes in physiological and biochemical processes to respond to high salt in the growing medium. There is lack of information on the relation of exogenous application of Zn and Cu with important salinity tolerance mechanisms in plants. Therefore, the present study was conducted to determine the effect of foliar Zn and Cu on two maize cultivars (salt-tolerant cv. Yousafwala Hybrid and salt-sensitive cv. Hybrid 1898). Salinity caused a significant reduction in water and turgor potentials, stomatal conductance, and transpiration and photosynthetic rate, while increase in glycine betaine, proline, total soluble sugars, and total free amino acids was evident in plants under saline regimes. Furthermore, there was significant decline in P, N, Ca, K, Mn, Fe, Zn, and Cu and increase in Na and Cl contents in plants fed with NaCl salinity. Nitrate reductase activity was lower in salt-stressed plants. However, foliar application of Zn and Cu circumvented salinity effect on water relations, photosynthesis, and nutrition and this was attributed to the better antioxidant system and enhanced accumulation of glycine betaine, proline, total free amino acids, and sugars. The results of the present study suggested that Zn application was superior to Cu for mediating plant defense responses under salinity.

Phenological application of selenium differentially improves growth, oxidative defense and ion homeostasis in maize under salinity stress

The underlying mechanism of selenium (Se) mediating plant salt tolerance is not well understood and information on how plant growth and development is regulated by phenological Se application (20 and 40 mg/L) under salinity stress is scarce. In present study, we have appraised the impact of phenological Se application on growth, antioxidant defense system and ionic imbalance in maize under salinity. Salinity (12 dS m^-1) reduced growth, concentration of chlorophyll and K⁺ in root and leaf. Contrarily, salinity increased toxic Na⁺, malondialdehyde (MDA) and H₂O₂ concentration that resulted in oxidative damage. Lower level of Se application (20 mg/L) increased growth and chlorophyll by reducing oxidative damage due to high cell concentrations of MDA and H₂O₂. Se reduced endogenous levels of H₂O₂ and MDA under salinity. Moreover, Se regulated antioxidant defense system by increasing the activities of antioxidant enzymes (SOD, POD and CAT) and influenced the concentrations of non-enzymatic antioxidants (phenolics and flavonoids). Se-induced better antioxidant system protected plants from oxidative damage. We have also recorded substantial increase in K⁺ and decrease in Na⁺ concentration in plants treated with 20 mg/L Se under salinity stress. The impact of Se on plant growth and development is linked with the growth stage of exogenous application. Foliar Se at reproductive and both vegetative and reproductive stages improved salinity tolerance in maize compared with vegetative stage.

Ethnopharmacological Investigations of Phytochemical Constituents Isolated from the Genus Cuscuta

The genus Cuscuta, of the family Cuscutaceae, is present in plants and has been traditionally used medicinally against many diseases and conditions, notably depression, mental illness, headache, spleen disease, jaundice, diabetes mellitus, and hypertension. Large numbers of phytochemical constituents such as alkaloids, flavonoids, lignins, oxygen heterocyclic compounds, steroids, fatty acids, phenolic acids, resin glycosides, and polysaccharides have been isolated from different species of Cuscuta. Ethnopharmacological studies conducted on such constituents have also been shown Cuscuta to possess anticancer, antiviral, antispasmodic, antihypertensive, anticonvulsant, antibacterial, antioxidant, diuretic, and hair-growth activity. Many tribes and traditional communities have long used the different forms of Cuscuta for treatment and prevention of many diseases. In this article, we comprehensively summarize relevant data regarding the phytochemical, ethnopharmacological, and traditional therapeutic uses of Cuscuta. In addition, we review the parts of the plants that are used as traditional therapeutic agents, their regions of existence, and their possible modes of action. To conclude, we provide evidence and new insights for further discovery and development of natural drugs from Cuscuta. We show that further studies are needed to investigate the mechanism of action and safety profile of phytochemical constituents isolated from Cuscuta.

Advances in microbe-assisted reclamation of heavy metal contaminated soils over the last decade: A review

Contamination of agricultural soils with trace metals present lethal consequences in terms of diverse ecological and environmental problems that entail entry of metal in food chain, soil deterioration, plant growth suppression, yield reduction and alteration in microbial community. Metal polluted soils have become a major concern for scientists around the globe. Phytoremediation involves the hyperaccumulation of metals in different plant parts. Phytoremediation of metals from polluted soils could be enhanced through inoculation with metal resistant plant growth promoting (PGP) bacteria. These PGP bacteria not only promote plant growth but also enhance metal uptake by plants. There are a number of reports in the literature where PGP bacterial inoculation improves metal accumulation in different plant parts without influencing plant growth. Therefore, there is a need to select PGP bacterial strains which possess the potential to improve plant growth as well as expedite the phytoremediation of metals. In this review, we have discussed the mechanisms possessed by PGP bacteria to promote plant growth and phytoremediation of metals. The central part of this review deals with the recent advances in microbial assisted-phytoremediation of metals.

Enhancement of external quantum efficiency and quality of heterojunction white LEDs by varying the size of ZnO nanorods

The size of ZnO nanorods (NRs) plays an important role in tuning the external quantum efficiency (EQE) and quality of light generated by white light emitting diodes (LEDs). In this work, we report on the enhancement of EQE and the quality of ZnO NR-based hetrojunction white LEDs fabricated on a p-GaN substrate using a low temperature solution method. Cathodoluminescence spectra demonstrate that ultraviolet (UV) emission decreases and visible deep band emission increases with an increase in the length of the ZnO NRs. The UV emission could be internally reabsorbed by the ZnO NR excitation, thus enhancing the emission intensity of the visible deep band. Photocurrent measurements validated the fact that the EQE depends on the size of ZnO NRs, increasing by 87% with an increase in the length of the ZnO NRs. Furthermore, the quality of white light was measured and clearly indicated an increase in the color rendering indices of the LEDs with an increase in the length of the ZnO NRs, confirming that the quality of light generated by LEDs can be tuned by varying the length of the ZnO NRs. These results suggest that the EQE and visible deep band emission from n-ZnONRs/p-GaN heterojunction LEDs can be effectively controlled by adjusting the length of the ZnO NRs, which can be useful for realizing tunable white LEDs.

Dural Tears In Patients With Depressed Skull Fractures

BACKGROUND

The presence of skull fracture in patients sustaining traumatic brain injury is an important risk factor for intracranial lesions. Assessment of integrity of dura in depressed skull fracture is of paramount importance because if dura is torn, lacerated brain matter may be present in the wound which needs proper debridement followed by water tight dural closure to prevent meningitis, cerebral abscess, and pseudomeningocoele formation. The objective of this study was to determine the frequency of dural tear in patients with depressed skull fractures.

METHODS

This cross-sectional study was conducted at Department of Neurosurgery Ayub Teaching Hospital Abbottabad. All the patients of either patients above 1 year of age with depressed skull fracture were included in this study in consecutive manner. Patients were operated for skull fractures and per-operatively dura in the region of depressed skull fracture was closely observed for any dural tear. The data were collected on a predesigned pro forma.

RESULTS

A total of 83 patients were included in this study out of which 57 (68.7%) were males and 26 (31.3%) were females. The age of the patients ranged from 1-50 (mean 15.71±13.49 years). Most common site of depressed skull fracture was parietal 32 (38.6%), followed by Frontal in 24 (28.9%), 21(25.3%) in temporal region, 5(6.0%) were in occipital region and only 1 (1.2%) in posterior fossa. Dural tear was present in 28 (33.7%) patients and it was absent in 55 (66.3%) of patients.

CONCLUSIONS

In depressed skull fractures, there are high chances of associated traumatic dural tears which should be vigilantly managed.