Modulation of oxidative damage due to salt stress using salicylic acid in Hordeum vulgare

Oxidative status of salicylic acid (SA) treated barley (Hordeum vulgare) plants grown under saline conditions was examined in a two-year field study during 2012–2013 and 2013–2014 growing seasons. Salinity caused a marked oxidative stress which was manifested as increased concentration of hydrogen peroxide (H₂O₂) and reduced grain yield of barley. Barley plants induced antioxidant system to tolerate salt stress, so that activities of four antioxidant enzymes: peroxidase, catalase, superoxide dismutase and glutathione reductase were enhanced by 22%, 28%, 57% and 44% in the first and by 33%, 20%, 45% and 68% in the second year, respectively. Foliar application of SA in concentration over 0.5 mM enhanced the activities of all four antioxidant enzymes and reduced H₂O₂ content and so enhanced yield. However, higher concentrations of SA reduced grain yield in salt stressed plants in both years, which could be attributed to the negative interaction of antioxidant enzymes with higher concentrations of SA as a non-enzymatic antioxidant. Furthermore, SA is in benzoic acid group and at very higher concentrations can act as an herbicide. It was concluded that SA modulated the oxidative stress through enhanced activities of antioxidant enzymes and reduced the salt-induced adverse effect thereby improving grain yield.     

Development of the New Zealand White Rabbit Eye: I. Pre‐ and Postnatal Development of Eye Tunics

The New Zealand white (NZW) rabbit has been and is right now regularly utilized in ophthalmic surgery evaluation. Inside NZW rabbit eye, the visibility of ocular structures throughout surgical procedure is fantastic. Younger rabbits are used in different ages for the evaluation of ophthalmic surgery. Complete studies of ocular development in the NZW rabbits have not been reported previously. The aim of the present investigation was to describe the major landmarks and the time course of the pre‐ and post‐natal development of the complete eye tunics of the NZW rabbit to give a superb model as well as a fruitful area for further ophthalmological investigations. Serial histological sections of NZW rabbit prenatal (E13–E28) and post‐natal (P1–P14) stages were examined, respectively. The eye of the NZW rabbit developed in a similar manner to that of the human and domestic animals eyes; the principal differences were at the time of occurrence of certain developmental events, absence of pigmentation which represent an exploited benefit for ophthalmic surgery, remarkable Bowman's membrane at E25, poor developed ciliary stroma and juvenile retinal layer until P9. In human, the basic morphogenetic processes of the development of eye tunics are completed towards the end of the first half of gestation period. However, the latter represents the beginning stage of the development of eye tunics in the rabbit. Thus, allowing various extensive ophthalmic researches to be performed.     

Earthworm population and microbial activity temporal dynamics in a Caspian Hyrcanian mixed forest

Few studies have analyzed how tree species within a mixed natural forest affect the dynamics of soil chemical properties and soil biological activity. This study examines seasonal changes in earthworm populations and microbial respiration under several forest species (Carpinus betulus, Ulmus minor, Pterocarya fraxinifolia, Alnus glutinosa, Populus caspica and Quercus castaneifolia) in a temperate mixed forest situated in northern Iran. Soil samplings were taken under six individual tree species (n = 5) in April, June, August and October (a total of 30 trees each month) to examine seasonal variability in soil chemical properties and soil biological activity. Earthworm density/biomass varied seasonally but not significantly between tree species. Maximum values were found in spring (10.04 m^?2/16.06 mg m^?2) and autumn (9.7 m^?2/16.98 mg m^?2) and minimum in the summer (0.43 m^?2/1.26 mg m^?2). Soil microbial respiration did not differ between tree species and showed similar temporal trends in all soils under different tree species. In contrast to earthworm activity, maximum microbial activity was measured in summer (0.44 mg CO₂–C g soil^?1 day^?1) and minimum in winter (0.24 mg CO₂–C g soil^?1 day^?1). This study shows that although tree species affected soil chemical properties (pH, organic C, total N content of mineral soils), earthworm density/biomass and microbial respiration are not affected by tree species but are controlled by tree activity and climate with strong seasonal dynamics in this temperate forest.     

Changes in carbohydrate contents in shoot tips,leaves and roots of strawberry (Fragaria × ananassa Duch.) during flower-bud differentiation

Flowering is an important step in crop production. Under flower-inducing conditions, biochemical or physiological changes can be recognized. Changes in carbohydrates have an important role in flower development in plants; however, carbohydrate changes during flower bud differentiation in strawberry have not been thoroughly investigated. In this study, runner plants potted in 18 cm diameter pots and grown under non-inducing conditions (28 ± 3/22 ± 3 °C day/night; 16 h day length). When the plants were established, half of the plants then were put under inducing conditions (23 ± 3/13 ± 3 °C day/night; 8 h day length). After the induction period of 21 short-day cycles, plants were brought to non-inductive conditions again. In order to evaluate the carbohydrate changes during flower differentiation, shoot tips, leaves and roots were sampled from four replicated plants collected weekly for the period of 7 weeks. Sucrose, glucose and fructose contents were determined by HPLC, and starch by the anthrone method. The results obtained indicated that the most abundant soluble sugar in all organs tested was sucrose. Sucrose in the shoot tips of induced plants at 42, 56 and 70 days after the start of the short-day treatment were significantly higher than corresponding time in non-induced plants. However, the glucose, fructose and starch contents in shoot tips, leaves and roots of non-induced plants in most sampling dates were greater than those of induced plants. In other words, the shoot tips (bud) of induced plants acted as strong ‘utilizing sink’ and preferentially metabolized carbohydrates rather than storing them. It seems that non-structural carbohydrate contents in shoot tips, leaves and roots of strawberry may have an important role in flower-bud differentiation.     

Implementing a multi-colour genetic marker analysis technique for embryology education

Embryology belongs to the basic sciences and is usually an integral part of the anatomy. The subject is traditionally taught by visual inspection of embryonic tissue slides stained with Haematoxylin and Eosin (H&E) to expose the dynamics of tissue histology as development proceeds. While combining in situ hybridization for gene expression analysis and immunostaining for protein expression analysis is an established technique for embryology research, the implementation of this tool in embryology teaching has not been described. The present study was conducted to assess the use of an online multi-colour gene expression analysis technique, alongside histological sections and diagrams, to improve students' understanding of embryology. The participants of this study were bachelor's students of Veterinary Medicine at the University of Khartoum. The method was also evaluated by distributing questionnaire items to Veterinary students via Google forms; subsequently, their responses were analysed qualitatively. The majority of students stated that the new technique was beneficial for their learning of embryology. The multi-colour images proved a more effective means for learning embryology than the traditional H&E image. Results from the students strengthen the belief in applying the multi-colour technique for better embryology course learning.     

The morphological postnatal development of the testis of the Nubian bucks

This study was designed to monitor the morphological development of the reproductive tract of the Nubian bucks in relation to puberty. Thirty-two Nubain male kids were used in the study. The animals were slaughtered at intervals of 2 weeks starting from 1 day old up to 24 weeks of age. Tissue samples were obtained from the testes and processed for ultrastructural studies. The boundary tissue of the newly forming seminiferous tubule adhered closely to the basal lamina. It consisted of a single continuous layer of myoid cells, the outer surface of which was covered by scattered fibroblasts. The ultrastructural study of the boundary of the seminiferous tubule revealed that it consisted of three layers; inner fibrous, middle and outer cellular. The seminiferous tubules at week one were lined by two layers of epithelia; spermatogonia and Sertoli cells in the basal layer, and primary spermatocytes in the second layer. A gradual increase in the diameter of the tubules and epithelial height continued to increase with age. Furthermore, spermatocytes number showed an increase with age. In conclusion, based on the appearance of spermatozoa in the lumina of the seminiferous tubules, puberty age was achieved between weeks 18 and 20.