Coarser taxonomic resolutions are informative in revealing fish community abundance trends for the world’s warmest coral reefs

Coral Reefs - The Arabian Gulf is a natural laboratory to examine how subtropical coral reef ecosystems might change in responding to recurring heating events because of uniquely high water...     

Foliar application of ascorbic acid enhances salinity stress tolerance in barley (Hordeum vulgare L.) through modulation of morpho-physio-biochemical attributes,ions uptake,osmo-protectants and stress response genes expression

Barley (Hordeum vulgare L.) is a major cereal grain and is known as a halophyte (a halophyte is a salt-tolerant plant that grows in soil or waters of high salinity). We therefore conducted a pot experiment to explore plant growth and biomass, photosynthetic pigments, gas exchange attributes, stomatal properties, oxidative stress and antioxidant response and their associated gene expression and absorption of ions in H. Vulgare. The soil used for this analysis was artificially spiked at different salinity concentrations (0, 50, 100 and 150 mM) and different levels of ascorbic acid (AsA) were supplied to plants (0, 30 and 60 mM) shortly after germination of the seed. The results of the present study showed that plant growth and biomass, photosynthetic pigments, gas exchange parameters, stomatal properties and ion uptake were significantly (p < 0.05) reduced by salinity stress, whereas oxidative stress was induced in plants by generating the concentration of reactive oxygen species (ROS) in plant cells/tissues compared to plants grown in the control treatment. Initially, the activity of antioxidant enzymes and relative gene expression increased to a saline level of 100 mM, and then decreased significantly (P < 0.05) by increasing the saline level (150 mM) in the soil compared to plants grown at 0 mM of salinity. We also elucidated that negative impact of salt stress in H. vulgare plants can overcome by the exogenous application of AsA, which not only increased morpho-physiological traits but decreased oxidative stress in the plants by increasing activities of enzymatic antioxidants. We have also explained the negative effect of salt stress on H. vulgare can decrease by exogenous application of AsA, which not only improved morpho-physiological characteristics, ions accumulation in the roots and shoots of the plants, but decreased oxidative stress in plants by increasing antioxidant compounds (enzymatic and non-enzymatic). Taken together, recognizing AsA's role in nutrient uptake introduces new possibilities for agricultural use of this compound and provides a valuable basis for improving plant tolerance and adaptability to potential salinity stress adjustment.     

DNA barcoding of marine fishes from Saudi Arabian waters of the Gulf

We used the cytochrome oxidase subunit I (coI) gene DNA to barcode 117 endemic Gulf and cosmopolitan Indo–West Pacific fish species belonging to 54 families and 13 orders. Novel DNA barcodes were provided for 18 fish species (Trachinocephalus sp., Nematalosa sp., Herklotsichthys lossei, Upeneus doriae, Trachurus indicus, Apogonichthyoides taeniatus, Verulux cypselurus, Favonigobius sp., Suezichthus gracilis, Sillago sp., Brachirus orientalis, Pegusa sp., Lepidotrigla bispinosa, Lepidotrigla sp., Grammoplites suppositus, Hippichthys sp., Paramonacanthus sp. and Triacanthus sp.). The species delimitation analysis, conducted with Poisson tree processes– Bayesian PTP (PTP–bPTP) and nucleotide-divergence-threshold (NDT) models), found 137 and 119 entities respectively. Overall, NDT method, neighbour-joining species tree and the prior taxonomic assessment provided similar results. Among the 54 families considered, only 10 (Ariommatidae, Ephippidae, Leiognathidae, Nemipteridae, Plotosidae, Pomacanthidae, Pomacentridae, Priacanthidae and Rachycentridae) showed the occurrence of molecular diagnostic pure characters. The DNA barcoding database developed during this study will help ichthyologists to identify and resolve the taxonomic ambiguities they may encounter with the fishes occurring in The Gulf and throughout the region.     

Spatial trend of Foot and Mouth Disease virus (FMDV) serotypes in cattle and buffaloes, Pakistan

The present study describes the frequency of Foot and Mouth Disease (FMD) virus serotypes (O, A and Asia-1) in major regions (all provinces) of Pakistan using Indirect Sandwich ELISA. Also, spatial distribution of various FMD serotypes and their comparison is discussed. A total of 590 samples (Epithelial tissue) have been analyzed during a period of five years (2005–2009). Out of 590 samples, 180 were found positive, giving an overall confirmation of FMDV about 33.2 %. Of the prevalent serotypes, FMDV ‘O’ serotype caused most outbreaks (20.7 %), followed by serotype A (6.6 %) and serotype Asia-1 (4.6 %) while there was no positive case of type ‘C’. The study clearly showed that the disease was more frequent in the agro-climatic zones than in hilly areas. Based on the data of 590 samples (>50 outbreaks), the overall prevalence of FMDV in cattle and buffaloes in Pakistan was 33.2 %, while in cattle alone, it was 37.1 %, higher than in buffalo (28.7 %). There were eight cases of mixed serotypes infection, indicating the presence of endemic state of disease. Another significant feature was the change over time. In phase-I (2005–2007), there was an overall prevalence of 29.4 %, while the occurrence of the serotype O, A and Asia-1 was 20.4 %, 2.9 % and 4.7 %, respectively. During phase-II (2008-2009), the overall prevalence was 59.21 %, while those of serotype O, A and Asia-1 were 22.4 %, 31.6 % and 4.0 %, respectively. This clearly indicated a shift from serotype O to A, which may help to explain the occurrence of more severe outbreaks, despite vaccination.     

Transformation and evaluation of different transgenic lines for Glyphosate tolerance and cane borer resistance genes in sugarcane (<Emphasis Type="Italic">Saccharum officinarum</Emphasis> L.)

The aim of this study was to ensure the systematic protein expression of two genes (GTG and Cry1Ac) under the influence of two different constitutive promoters i.e. Ubiquitin-1 and CaMV 35S promoters in different sugarcane lines. PCR amplification of GTG and Cry1Ac was achieved from putative transgenic plants through gene specific primers. Qualitative comparisons of GTG and Cry1Ac genes expression under two different promoters were obtained through protein dot blot and dipstick assay. The appearance of comparatively dark color dots in dot blot and dark color bands on dipstick with Ubiquitin as compared to light color bands with CaMV35S promoter, qualitatively confirmed high protein expression of two genes under Ubiquitin promoter. In quantitative gene expression comparisons maximum optical density (OD) at 450 nm of UV-light was obtained for GTG (3.7 OD) and Cry1Ac (3 OD) under Ubiquitin promoter, while for GTG (1.6 OD) and Cry1Ac (2.5 OD) with CaMV 35S promoter. The results indicated higher expression of two genes under Ubiquitin-1 promoter in sugarcane was found as compared to CaMV 35S promoter. This study provides a guide for stable and high expression of transgenes with reference to Ubiquitin-1 promoter which can be utilize in sugarcane as well as in other monocots.     

Biochemical and Molecular Characterization of Potential Phosphate-Solubilizing Bacteria in Acid Sulfate Soils and Their Beneficial Effects on Rice Growth

A study was conducted to determine the total microbial population, the occurrence of growth promoting bacteria and their beneficial traits in acid sulfate soils. The mechanisms by which the bacteria enhance rice seedlings grown under high Al and low pH stress were investigated. Soils and rice root samples were randomly collected from four sites in the study area (Kelantan, Malaysia). The topsoil pH and exchangeable Al ranged from 3.3 to 4.7 and 1.24 to 4.25 cmol_c kg⁻¹, respectively, which are considered unsuitable for rice production. Total bacterial and actinomycetes population in the acidic soils were found to be higher than fungal populations. A total of 21 phosphate-solubilizing bacteria (PSB) including 19 N₂-fixing strains were isolated from the acid sulfate soil. Using 16S rRNA gene sequence analysis, three potential PSB strains based on their beneficial characteristics were identified (Burkholderia thailandensis, Sphingomonas pituitosa and Burkholderia seminalis). The isolated strains were capable of producing indoleacetic acid (IAA) and organic acids that were able to reduce Al availability via a chelation process. These PSB isolates solubilized P (43.65%) existing in the growth media within 72 hours of incubation. Seedling of rice variety, MR 219, grown at pH 4, and with different concentrations of Al (0, 50 and 100 µM) was inoculated with these PSB strains. Results showed that the bacteria increased the pH with a concomitant reduction in Al concentration, which translated into better rice growth. The improved root volume and seedling dry weight of the inoculated plants indicated the potential of these isolates to be used in a bio-fertilizer formulation for rice cultivation on acid sulfate soils.     

Life history traits and temporal trends of abundance of the orange-spotted trevally (Carangoides bajad) from Saudi waters of the Gulf

In this study we lay the groundwork for sustainability-oriented fisheries management, by estimating parameters the life history of orange-spotted trevally Carangoides bajad as well as trends of abundance in coral-reef habitats. We observed a new record of maximum size of 720 mm fork length. Carangoides bajad is a moderately long-lived (14 years) and slow-growing (K = 0.085 year⁻¹) carangid species, closer to a K-selection species, with higher vulnerability to fishing and lower rates of recovery when the population level is low. Growth and biological composition in terms of length and age categories do not differ between the sexes, but females become mature faster. Reproductively active months (May–August) overlapped with those from Emirati waters further south. The abundance index showed a pronounced drop during 1990–1993, possibly in connection with habitat deterioration during the Gulf War (1990–1991) oil spill. The index increased gradually from 1994 and has fluctuated close to the reference level of 1985 up to the present. Considering the findings of large-sized and old-age individuals and abundance index from coral reefs close to its level three decades back, the C. bajad stock in the western part of The Gulf appears to be in healthy exploitation status despite growing harvesting rates.     

Fatal Sarcoptes scabiei infection of blue sheep (Pseudois nayaur) in Pakistan

Sarcoptes scabiei was detected for the first time in skin scrapings, hair pluckings, and histologic sections from a blue sheep (Pseudois nayaur) from the Shimshali Pamir in the Karakorum range of the western Himalaya in Pakistan (36 degrees 28'N, 75 degrees 36'E). Local reports suggest many hundred animals have been affected by a severe skin disease over a 10-yr period, but the shy nature of this species and the extreme climate that they inhabit meant only a single affected animal was available for detailed evaluation. The severe skin lesions were confined to the forelegs and brisket, and many Sarcoptes scabiei mites were present in all the samples examined. Histologic preparations of the skin showed hyperkeratotic and parakeratotic hyperkeratosis of the epidermis with a severe exudative dermatosis with many polymorphonuclear neutrophils and gram-positive cocci, yet no eosinophils. These findings might suggest the lack of an appropriate immune response to the parasite or other coping strategies because there has been no abatement of the clinical signs in affected animals over several years. Treatment options are limited due to the behavior of the species and its habitat. The blue sheep is a primary source of prey for the endangered snow leopard (Panthera uncia) and continued depletion could have serious consequences for the survival of the latter.     

Strengths and weaknesses in the long-term sustainability of two sympatric seabreams (Argyrops spinifer and Rhabdosargus haffara,Sparidae)

Argyrops spinifer and Rhabdosargus haffara are two sympatric seabream species making important contributions to fisheries landings in the western Arabian/Persian Gulf. We identified the strengths and weaknesses in the long-term sustainability of A. spinifer and R. haffara stocks by integrating multiple sources of data, including fisheries catch and effort statistics, life history traits, scientific trawl surveys and historical length frequency distribution. Four strengths were identified in A. spinifer: wide distribution of juveniles, positive association to the network of de facto fishing exclusion areas created by hundreds of oil-gas facilities, early maturation and the existence of large and old individuals. A. spinifer suffers from two potential weaknesses: slow growth rate and higher exploitation pressure on the small-sized individuals. R. haffara, on the other hand, has a strength of having a short life span and a fast growth rate, characteristics that make it robust to unfavourable conditions. R. haffara suffers from two weaknesses: the lack of association to the oil and gas facilities, and the preference for nearshore shallow waters with stronger negative anthropogenic impacts. Identified strengths and weaknesses of these two sparids provided a preliminary assessment about their long-term sustainability, as well as a roadmap about how to develop different management strategies to meet specific objectives.     

Identification and antifungal activity analysis of two biocontrol antagonists to Colletotrichum musae

Postharvest anthracnose of banana caused by Colletotrichum musae is one of the major diseases resulting in huge economic losses worldwide. To control this disease using biocontrol agents, two antagonistic strains SD7 and NB20 with significant inhibitory effects on mycelial growth and conidial germination of C. musae were identified and evaluated in this study. The inhibitory effects of cell‐free culture filtrates of SD7 and NB20 on conidial germination of C. musae were both 100%, and those on mycelial growth of C. musae were 97.7 ± 0.9% and 95.0 ± 0.6%, respectively. The antifungal activities of cell‐free culture filtrates of both strains were still stable after they were stored at 4°C for 6 months. The control efficacies of cell‐free culture filtrates of SD7 and NB20 on postharvest anthracnose of banana were 55.9 ± 4.1% and 33.2 ± 3.9%, respectively. The disease severity (mean scale value) in banana fruit fingers was significantly lower after the treatment with a cultural suspension of the bacterial strain SD7 (1.4 ± 0.49) or actinomycete strain NB20 (2.0 ± 0.63), compared to that in the control (4.8 ± 0.40). After subculturing for 10 generations, the antifungal efficiency of NB20 remained stable, whereas that of strain SD7 declined obviously. Lastly, based on the morphological, physio‐biochemical and molecular characteristics, the bacterial strain SD7 was identified as Burkholderia cepacia, while the actinomycete strain NB20 was identified as Streptomyces katrae. The results from this study will provide the basis for developing an effective and novel biofungicide to control banana anthracnose disease.