Showing papers by "Saleh A. Al-Farraj published in 2021"

The Global Soil Mycobiome consortium dataset for boosting fungal diversity research

Abstract: Fungi are highly important biotic components of terrestrial ecosystems, but we still have a very limited understanding about their diversity and distribution. This data article releases a global soil fungal dataset of the Global Soil Mycobiome consortium (GSMc) to boost further research in fungal diversity, biogeography and macroecology. The dataset comprises 722,682 fungal operational taxonomic units (OTUs) derived from PacBio sequencing of full-length ITS and 18S-V9 variable regions from 3200 plots in 108 countries on all continents. The plots are supplied with geographical and edaphic metadata. The OTUs are taxonomically and functionally assigned to guilds and other functional groups. The entire dataset has been corrected by excluding chimeras, index-switch artefacts and potential contamination. The dataset is more inclusive in terms of geographical breadth and phylogenetic diversity of fungi than previously published data. The GSMc dataset is available over the PlutoF repository.

Kinetin mitigates Cd-induced damagesto growth, photosynthesis and PS II photochemistry of Trigonella seedlings by up-regulating ascorbate-glutathione cycle.

Abstract: Cytokinins (CKs) plays a key role in plant adaptation over a range of different stress conditions. Here, we analyze the effects of a cytokinin (i.e., kinetin, KN) on the growth, photosynthesis (rate of O2 evolution), PS II photochemistry and AsA-GSH cycle in Trigonella seedlings grown under cadmium (Cd) stress. Trigonella seeds were sown in soil amended with 0, 3 and 9 mg Cd kg-1 soil, and after 15 days resultant seedlings were sprayed with three doses of KN, i.e.,10 μM (low, KNL), 50 μM (medium, KNM) and 100 μM (high, KNH); subsequent experiments were performed after 15 days of KN application, i.e., 30 days after sowing. Cadmium toxicity induced oxidative damage as shown by decreased seedling growth and photosynthetic pigment production (Chl a, Chl b and Car), rates of O2-evolution, and photochemistry of PS II of Trigonella seedlings, all accompanied by an increase in H2O2 accumulation. Supplementation with doses of KN at KNL and KNM significantly improved the growth and photosynthetic activity by reducing H2O2 accumulation through the up-regulation AsA-GSH cycle. Notably, KNL and KNM doses stimulated the rate of enzyme activities of APX, GR and DHAR, involved in the AsA-GSH cycle thereby efficiently regulates the level of AsA and GSH in Trigonella grown under Cd stress. The study concludes that KN can mitigate the damaging effects of Cd stress on plant growth by maintaining the redox status (>ratios: AsA/DHA and GSH/GSSG) of cells through the regulation of AsA-GSH cycle at 10 and 50 μM KN under Cd stress conditions. At 100 μM KN, the down-regulation of AsA-GSH cycle did not support the growth and PS II activity of the test seedlings.

Heavy metal accumulation by roadside vegetation and implications for pollution control.

Abstract: Vehicular emissions cause heavy metal pollution and exert negative impacts on environment and roadside vegetation. Wild plants growing along roadsides are capable of absorbing considerable amounts of heavy metals; thus, could be helpful in reducing heavy metal pollution. Therefore, current study inferred heavy metal absorbance capacity of some wild plant species growing along roadside. Four different wild plant species, i.e., Acacia nilotica L., Calotropis procera L., Ricinus communis L., and Ziziphus mauritiana L. were selected for the study. Leaf samples of these species were collected from four different sites, i.e., Control, New Lahore, Nawababad and Fatehabad. Leaf samples were analyzed to determine Pb2+, Zn2+, Ni2+, Mn2+ and Fe3+ accumulation. The A. nilotica, Z. mauritiana and C. procera accumulated significant amount of Pb at New Lahore site. Similarly, R. communis and A. nilotica accumulated higher amounts of Mn, Zn and Fe at Nawababad and New Lahore sites compared to the rest of the species. Nonetheless, Z. mauritiana accumulated higher amounts of Ni at all sites compared with the other species included in the study. Soil surface contributed towards the uptake of heavy metals in leaves; therefore, wild plant species should be grown near the roadsides to control heavy metals pollution. Results revealed that wild plants growing along roadsides accumulate significant amounts of heavy metals. Therefore, these species could be used to halt the vehicular pollution along roadsides and other polluted areas.

Exogenous application of strigolactone alleviates drought stress in maize seedlings by regulating the physiological and antioxidants defense mechanisms

Abstract: Drought stress is an alarming threat to food security in the climate change scenario. This study was conducted to evaluate the potential of strigolactone for drought tolerance in maize seedlings. The treatments consisted of two water regimes, i.e., (1) well-watered, at 80% water holding capacity (WHC) and (2) drought stress, at 40% WHC which were factorally combined with three Strigolactone concentrations (0, 10 and 20 µM) as foliar spray. Results revealed that drought stress diminishes the seedling growth, plant water relations and photosynthetic activities by producing more reactive oxygen species which lead to higher oxidative damage in maize seedlings. Application of strigolactone improved plant growth attributes by improving the gas exchange parameters, water relations and chlorophyll pigments. Application of strigolactone also enhanced the enzymatic antioxidants activities, including superoxide dismutase, peroxidase, catalase and ascorbate peroxidase in stressed seedlings over control. In conclusion, strigolactone improved the water relations, increased photosynthetic pigments and gas exchange parameters and enhanced antioxidant enzymatic activities to impart drought stress tolerance in maize seedlings. To best of our knowledge, this is the first study on role on strigolactone on drought stress tolerance mechanism in maize seedling.

The protective role of luteolin against the methotrexate-induced hepato-renal toxicity via its antioxidative, anti-inflammatory, and anti-apoptotic effects in rats.

Abstract: Methotrexate (MTX) is frequently used drug in treatment of cancer and autoimmune diseases Unfortunately, MTX has many side effects including the hepato-renal toxicity In this study, we hypothesized that Luteolin (Lut) exhibits protective effect against the MTX-induced hepato-renal toxicity In order to investigate our hypothesis, the experiment was designed to examine the effect of exposure of male rats to MTX (20 mg/kg, ip, at day 9) alone or together with Lut (50 mg/kg, oral for 14 days) compared to the control rats (received saline) The findings demonstrated that MTX treatment induced significant increases in the liver and kidney functions markers in serum samples including Aspartate transaminase (AST), Alanine transaminase (ALT), creatinine, urea and uric acid MTX also mediated an oxidative stress expressed by elevated malondialdehyde (MDA) level and decreased level of reduced glutathione (GSH), antioxidant enzyme activities, and downregulation of the Nrf2 gene expression as an antioxidant trigger Moreover, the inflammatory markers (NF-κB, TNF-α, and IL-1β) were significantly elevated upon MTX treatment In addition, MTX showed an apoptotic response mediated by elevating the pro-apoptotic (Bax) and lowering the anti-apoptotic (Bcl-2) proteins All of these changes were confirmed by the observed alterations in the histopathological examination of the hepatic and renal tissues Lut exposure significantly reversed all the MTX-induced changes in the measured parameters suggesting its potential protective role against the MTX-induced toxicity Finally, our findings concluded the antioxidative, anti-inflammatory and anti-apoptotic effects of Lut as a mechanism of its protective role against the MTX-induced hepato-renal toxicity in rats

Protein expression plasticity contributes to heat and drought tolerance of date palm

Abstract: Climate change is increasing the frequency and intensity of warming and drought periods around the globe, currently representing a threat to many plant species. Understanding the resistance and resilience of plants to climate change is, therefore, urgently needed. As date palm (Phoenix dactylifera) evolved adaptation mechanisms to a xeric environment and can tolerate large diurnal and seasonal temperature fluctuations, we studied the protein expression changes in leaves, volatile organic compound emissions, and photosynthesis in response to variable growth temperatures and soil water deprivation. Plants were grown under controlled environmental conditions of simulated Saudi Arabian summer and winter climates challenged with drought stress. We show that date palm is able to counteract the harsh conditions of the Arabian Peninsula by adjusting the abundances of proteins related to the photosynthetic machinery, abiotic stress and secondary metabolism. Under summer climate and water deprivation, these adjustments included efficient protein expression response mediated by heat shock proteins and the antioxidant system to counteract reactive oxygen species formation. Proteins related to secondary metabolism were downregulated, except for the P. dactylifera isoprene synthase (PdIspS), which was strongly upregulated in response to summer climate and drought. This study reports, for the first time, the identification and functional characterization of the gene encoding for PdIspS, allowing future analysis of isoprene functions in date palm under extreme environments. Overall, the current study shows that reprogramming of the leaf protein profiles confers the date palm heat- and drought tolerance. We conclude that the protein plasticity of date palm is an important mechanism of molecular adaptation to environmental fluctuations.

Thermal and Flame Retardant Behavior of Neem and Banyan Fibers When Reinforced with a Bran Particulate Epoxy Hybrid Composite.

Abstract: Awareness of environmental concerns influences researchers to develop an alternative method of developing natural fiber composite materials, to reduce the consumption of synthetic fibers. This research attempted testing the neem (Azadirachta indica) fiber and the banyan (Ficus benghalensis) fiber at different weight fractions, under flame retardant and thermal testing, in the interest of manufacturing efficient products and parts in real-time applications. The hybrid composite consists of 25% fiber reinforcement, 70% matrix material, and 5% bran filler. Their thermal properties—short-term heat deflection, temperature, thermal conductivity, and thermal expansion—were used to quantify the effect of potential epoxy composites. Although natural composite materials are widely utilized, their uses are limited since many of them are combustible. As a result, there has been a lot of focus on making them flame resistant. The thermal analysis revealed the sample B was given 26% more short-term heat resistance when the presence of banyan fiber loading is maximum. The maximum heat deflection temperature occurred in sample A (104.5 °C) and sample B (99.2 °C), which shows a 36% greater thermal expansion compared with chopped neem fiber loading. In sample F, an increased chopped neem fiber weight fraction gave a 40% higher thermal conductivity, when compared to increasing the bidirectional banyan mat of this hybrid composite. The maximum flame retardant capacity occurred in samples A and B, with endurance up to 12.9 and 11.8 min during the flame test of the hybrid composites.

High salinity gradients and intermediate spatial scales shaped similar biogeographical and co-occurrence patterns of microeukaryotes in a tropical freshwater-saltwater ecosystem

Abstract: Microeukaryotes play key ecological roles in the microbial web of aquatic ecosystems. However, large knowledge gaps urgently need to be filled regarding the biogeography with associated shaping mechanisms and co-occurrence patterns of microeukaryotes under freshwater-saltwater gradients, especially true in tropical regions. Here, we investigated microeukaryotes of six mixed freshwater-saltwater regions in the Pearl River Estuary and surrounding coasts in southern China, with salinity ranging 0.1-32.0% and distances spanned up to 500 km, using molecular ecological methods. Results indicate that the biogeography of abundant and rare microeukaryotic communities was similar, both their co-occurrence patterns and biogeographical patterns were driven by deterministic and stochastic processes. The environmental factors with higher selective pressure than dispersal limitation meant that the role of deterministic process in structuring communities was more significant than that of stochastic process, and salinity played important role in structuring both microeukaryotic communities and networks. The abundant communities had stronger influence on entire microeukaryotic communities and seemed to be more sensitive to environmental changes than their rare counterparts, while rare ones had stronger interspecific relationships. Finally, the geographic scale and environmental gradients of study regions should firstly be clarified in future research on the ecological processes of microeukaryotes before conclusions are drawn.

Soil-Applied Boron Combined with Boron-Tolerant Bacteria (Bacillus sp. MN54) Improve Root Proliferation and Nodulation, Yield and Agronomic Grain Biofortification of Chickpea (Cicer arietinum L.)

Abstract: Chickpea is widely cultivated on calcareous sandy soils in arid and semi-arid regions of Pakistan; however, widespread boron (B) deficiencies in these soils significantly decreases its productivity. Soil application of B could improve chickpea yield and grain-B concentration. However, optimizing suitable B level is necessary due to a narrow deficiency and toxicity range of B. Nonetheless, the co-application of B-tolerant bacteria (BTB) and synthetic B fertilizer could be helpful in obtaining higher chickpea yields and grain-B concentration. Therefore, this study optimized the level of soil applied B along with BTB, (i.e., Bacillus sp. MN54) to improve growth, yield and grain-B concentrations of chickpea. The B concentrations included in the study were 0.00 (control), 0.25, 0.50, 0.75 and 1.00 mg B kg−1 soil combined with or without Bacillus sp. MN54 inoculation. Soil application of B significantly improved root system, nodulation, yield and grain-B concentration, and Bacillus sp. MN54 inoculation further improved these traits. Moreover, B application at a lower dose (0.25 mg B kg−1 soil) with BTB inoculation recorded the highest improvements in root system (longer roots with more roots’ proliferation), growth, nodulation and grain yield. However, the highest grain-B concentration was recorded under a higher B level (0.75 mg B kg−1 soil) included in the study. Soil application of 0.25 mg B kg−1 with Bacillus sp. MN54 inoculation improved growth and yield-related traits, especially nodule population (81%), number of pods plant−1 (38%), number of grains plant−1 (65%) and grain yield (47%) compared with control treatment. However, the grain-B concentration was higher under the highest B level (1.00 mg kg−1 soil) with Bacillus sp. MN54 inoculation. In conclusion, soil application of 0.25 mg B kg−1 with Bacillus sp. MN54 inoculation is a pragmatic option to improve the root system, nodule population, seedling growth, yield and agronomic grain-B biofortification of chickpea.

Studies on Mechanical Properties of Kevlar/Napier Grass Fibers Reinforced with Polymer Matrix Hybrid Composite

Abstract: A percentage of natural fibers is used for developing a composite, the materials are quite increasing in recent trends, and they can be a potential replacement of synthetic fibers in the reinforcement phase of hybrid composite. In this research, the combination of natural fibers and synthetic fibers can be used as reinforcement, and epoxy polymer can be used as matrix material. The fibers of Kevlar and Napier grass are reinforced with epoxy matrix to develop a new composite by using conventional hand layup fabrication process and to quantify the effect of this hybrid composite laminate, with five different sequences following. To identify the mechanical properties of this hybrid composite through tensile, flexural, compression strength, impact strength, and hardness tests, among all five samples, sample A was given the maximum mechanical strength, such that the tensile strength is 210 MPa, flexural strength is 165 MPa, the impact energy absorption is 23 J, the average is 40% over the other samples, and, at the same time, the compression strength of sample E is 19 MPa, revealing the negative influence of hybrid composite. The SEM morphology was carried out to identify the failure mode of the hybrid composites.

Integrative Studies on a New Ciliate Campanella sinica n. sp. (Protista, Ciliophora, Peritrichia) Based on the Morphological and Molecular Data, With Notes on the Phylogeny and Systematics of the Family Epistylididae.

Abstract: During an investigation on freshwater peritrichs, a new colonial sessilid ciliate, Campanella sinica n. sp., was isolated from aquatic plants in an artificial freshwater pond in Qingdao, China. Specimen observations of this species were performed both in vivo and using silver staining. C. sinica n. sp. is characterized by the appearance of the mature colony, which is up to 2 cm high and contains more than 1,000 zooids, the asymmetric horn-shaped zooids, strongly everted and multi-layered peristomial lip, the slightly convex peristomial disc, and the well-developed haplokinety and polykinety, which make more than four circuits of the peristome before descending into the infundibulum. The small subunit ribosomal DNA (SSU rDNA), 5.8s rDNA and its flank internal transcribed spacers (ITS1-5.8s rDNA-ITS2), and large subunit ribosomal DNA (LSU rDNA) are sequenced and used for phylogenetic analyses which reveal that the family Epistylididae Kahl, 1933 is non-monophyletic whereas the genus Campanella is monophyletic and nests within the basal clade of the sessilids. The integrative results support the assertion that the genus Campanella represents a separate lineage from other epistylidids, suggesting a further revision of the family Epistylididae is needed. We revise Campanella including the transfer into this genus of a taxon formerly assigned to Epistylis, which we raise to species rank, i.e., Campanella ovata (Nenninger, 1948) n. grad. & n. comb. (original combination Epistylis purneri f. ovata Nenninger, 1948). In addition, we provide a key to the identification of the species of Campanella.

Early life thermal stress modulates hepatic expression of thermotolerance related genes and physiological responses in two rabbit breeds

Abstract: There are few data about early thermal conditioning (TC) and its effect on later life in rabbits. Therefore, the present study aimed to investigate the impact of exposing two rabbit breeds to early...

Molecular characterization of leaf spot caused by Alternaria alternata on buttonwood (Conocarpus erectus L.) and determination of pathogenicity by a novel disease rating scale

Abstract: The buttonwood (Conocarpus erectus L.) is a mangrove shrub belonging to Combretaceae family. It mostly grows on the shorelines of tropical and subtropical regions in the world. It was introduced to Lasbela University of Water, Agriculture & Marine Sciences (LUWMS), Uthal, Baluchistan as an ornamental plant as it grows well under harsh, temperate and saline conditions. During a routine survey, typical leaf spot symptoms were observed on the leaves of buttonwood plants. A disease severity scale for alternaria leaf spot of buttonwood was developed for the first time through this study. Disease severity according to the scale was 38.97%. The microscopic characterizations was accomplished for the identification of Alternaria alternata and Koch’s postulates were employed to determine the pathogenicity. For molecular identification, 650 bp internal transcribed spacer (ITS) regions (ITS1, 5.8s and ITS2) were amplified from three representative isolates (LUAWMS1, LUAWMS2 and LUAWMS3) through polymerase chain reaction (PCR). The nucleotide sequences from ITS regions of the isolates were submitted to NCBI with GenBank accession numbers MW585375, MW585376 and MW585377, respectively. The phylogenetic tree of 22 A. alternata isolates was computed and representative isolates exhibited 99.98% genetic similarity with mangroves ecosystem isolates. This study reports the incidence of alternaria leaf spot of buttonwood at LUWMS for the first time. It is suspected that the disease may spread further. Therefore, effective management strategies should be opted to halt the further spread of the disease.

Metabolic responses of date palm (Phoenix dactylifera L.) leaves to drought differ in summer and winter climate

Abstract: Drought negatively impacts growth and productivity of plants, particularly in arid and semi-arid regions. Although drought events can take place in summer and winter, differences in the impact of drought on physiological processes between seasons are largely unknown. The aim of this study was to elucidate metabolic strategies of date palms in response to drought in summer and winter season. To identify such differences, we exposed date palm seedlings to a drought-recovery regime, both in simulated summer and winter climate. Leaf hydration, carbon discrimination (${\Delta}$13C), and primary and secondary metabolite composition and contents were analyzed. Depending on season, drought differently affected physiological and biochemical traits of the leaves. In summer, drought induced significantly decreased leaf hydration, concentrations of ascorbate, most sugars, primary and secondary organic acids, as well as phenolic compounds, while thiol, amino acid, raffinose and individual fatty acid contents were increased compared with well-watered plants. In winter, drought had no effect on leaf hydration, ascorbate and fatty acids contents, but resulted in increased foliar thiol and amino acid levels as observed in summer. Compared with winter, foliar traits of plants exposed to drought in summer only partly recovered after re-watering. Memory effects on water relations, and primary and secondary metabolites seem to prepare foliar traits of date palms for repeated drought events in summer. Apparently, a well-orchestrated metabolic network, including the anti-oxidative system, compatible solutes accumulation and osmotic adjustment, and maintenance of cell-membrane stability strongly reduces the susceptibility of date palms to drought. These mechanisms of drought compensation may be more frequently required in summer.

Physiological responses of date palm (Phoenix dactylifera) seedlings to seawater and flooding.

Abstract: In their natural environment along coast lines, date palms are exposed to seawater inundation and, hence, combined stress by salinity and flooding. To elucidate the consequences of this combined stress on foliar gas exchange and metabolite abundances in leaves and roots, date palm seedlings were exposed to flooding with seawater and its major constituents under controlled conditions. Seawater flooding significantly reduced CO2 assimilation, transpiration and stomatal conductance, but did not affect isoprene emission. A similar effect was observed upon NaCl exposure. By contrast, flooding with distilled water or MgSO4 did not affect CO2 /H2 O gas exchange or stomatal conductance significantly, indicating that neither flooding itself, nor seawater sulfate, contributed greatly to stomatal closure. Seawater exposure increased Na and Cl contents in leaves and roots, but did not affect sulfate contents significantly. Metabolite analyses revealed reduced abundances of foliar compatible solutes, such as sugars and sugar alcohols, whereas nitrogen compounds accumulated in roots. Reduced transpiration upon seawater exposure may contribute to controlling the movement of toxic ions to leaves and, therefore, can be seen as a mechanism to cope with salinity. The present results indicate that date palm seedlings are tolerant towards seawater exposure to some extent, and highly tolerant to flooding.

Systematic positions and taxonomy of two new ciliates found in China: Euplotes tuffraui sp. nov. and E. shii sp. nov. (Alveolata, Ciliophora, Euplotida)

Abstract: The morphology and SSU rDNA-based phylogeny of two small marine euplotid species isolated from China, Euplotes tuffraui sp. nov. and E. shii sp. nov., were investigated. Euplotes tuffraui sp. nov. ...

The Morphology, Taxonomy, and Phylogenetic Analyses of Five Freshwater Colonial Peritrich Ciliates (Alveolata, Ciliophora), Including the Descriptions of Two New Species.

Abstract: The morphology and phylogeny of two new sessilid species, Zoothamnium weishanicum n. sp. and Epicarchesium sinense n. sp., two insufficiently known species, Zoothamnium arbuscula Ehrenberg, 1831 and Zoothamnium hentscheli Kahl, 1935, and a well-known species, Carchesium polypinum (Linnaeus, 1767) Ehrenberg, 1838, collected from freshwater habitats of China, were investigated. Zoothamnium weishanicum n. sp. is characterized by its inverted bell-shaped zooids, double-layered peristomial lip, alternately branched stalk, and two different-length rows in infundibular polykinety 3 (P3). Epicarchesium sinense n. sp. is recognized by its asymmetric-pyriform zooids, single-layered peristomial lip, conspicuous cortical blisters on the pellicle, dichotomously branched stalk, and P3 containing one short inner row and two long outer rows. Based on previous and newly obtained data of the three known species, improved diagnoses and redescriptions are provided including, for the first time, data on the infraciliature of Z. arbuscula and Z. hentscheli. In addition, we analyzed the phylogeny of each species based on SSU rDNA sequence data.