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关键词： Antioxidants   Ion homeostasis   Genomics   Germination   Metabolomics   Phytohormones   Proteomics   Transcriptomics  

摘要： Salinity is one of the major threats to sustainable agriculture that globally decreases plant production by impairing various physiological, biochemical, and molecular function. In particular, salinity hampers germination, growth, photosynthesis, transpiration, and stomatal conductance. Salinity decreases leaf water potential and turgor pressure and generates osmotic stress. Salinity enhances reactive oxygen species (ROS) content in the plant cell as a result of ion toxicity and disturbs ion homeostasis. Thus, it imbalances nutrient uptake, disintegrates membrane, and various ultrastructure. Consequently, salinity leads to osmotic and ionic stress. Plants respond to salinity by modulating various morpho-physiological, anatomical, and biochemical traits by regulating ion homeostasis and compartmentalization, antioxidant machinery, and biosynthesis of osmoprotectants and phytohormones, i.e, auxins, abscisic acid, brassinosteroids, cytokinins, ethylene, gibberellins, salicylic acid, jasmonic acid, and polyamines. Thus, this further modulates plant osmoticum, decreases ion toxicity, and scavenges ROS. Plants upregulate various genes and proteins that participate in salinity tolerance. They also promote the production of various phytohormones and metabolites that mitigate the toxic effect of salinity. Based on recent papers, the deleterious effect of salinity on plant physiology is discussed. Furthermore, it evaluates the physiological and biochemical responses of the plant to salinity along with phytohormone response. This review paper also highlights omics (genomics, transcriptomics, proteomics, and metabolomics) approach to understand salt stress tolerance.

关键词： Antioxidant   Carbohydrate   Candidatusphytoplasma aurantifolia   Nutritional status  

摘要： Witches' broom disease of lime (WBDL), caused by 'CandidatusPhytoplasma aurantifolia', is a major limiting factor for Mexican lime (Citrus aurantifoliaSwingle) production in southern Iran. Here, nutritional status and biochemical composition of healthy and infected Mexican lime in a greenhouse were compared between uninoculated (healthy) plants and plants 52 weeks after inoculation with the phytoplasma. Leaves from healthy and infected plants were sampled to measure total phenolics, antioxidant capacity, peroxidase and superoxide dismutase enzymatic activities, soluble carbohydrate, and starch. Macro- and microelements were also measured in leaves, stems, and roots of the plants. The results showed that phytoplasma infection led to a marked increase in soluble carbohydrates and starch in the leaves, but to a reduction in the roots. In leaves and roots, antioxidant capacity, phenolics, and peroxidase activity were enhanced after infection;nitrogen, calcium, boron, and manganese were significantly lower and phosphorus, magnesium, potassium, iron, zinc, and copper significantly higher in the infected leaves. This study provides new insights on metabolic and nutritional changes associated with WBDL in the greenhouse.

关键词： Protein semi-purification   Serine proteases   Protein hydrolysis   Sea catfish   Bagre panamensis  

摘要： The recovery of proteases from fish viscera could be a strategy to reduce environmental problems caused by inadequate disposal of fish by-products. This study reports the biochemical characterization of proteases isolated from chihuil sea catfish (Bagre panamensis) intestines and the evaluation of their stability to different physical and chemical factors. Protein hydrolysates from chihuil muscle and casein were produced using its semi-purified proteases extract (SPE) and alcalase. Assays with specific protease inhibitors indicate that trypsin and chymotrypsin are the main types of serine proteases in SPE. Semi-purified enzymes exhibited proteolytic activity at alkaline pH (9-12), and high stability at low/mild temperatures (10-40 degrees C). A 92% of SPE proteolytic activity was retained in the presence of 30% NaCl. The enzyme extract was stable in reducing agents (2-mercaptoethanol and DTT) but lost about 70% of proteolytic activity in anionic detergents like SDS and tween-80. Organic solvents did not affect the enzyme activity of SPE. Finally, maintaining a same E/S ratio for protein hydrolysates elaboration, chihuil serin proteases exhibited a higher hydrolytic efficiency compared to alcalase when casein and proteins from chihuil muscle were hydrolyzed. Thus, the semi-purification of serine proteases from chihuil viscera provided a low-cost source of enzymes with interesting catalytic features. [GRAPHICS] .

关键词： Hypo-salinity exposure   Clearance rate   Biochemical parameters   HSP genes   Bacterial densities   P   radiata  

摘要： Hypo-salinity exposure is a serious concern for bivalve aquaculture, with profound effects on the animals' physiological condition. The present study aimed to evaluate the influence of low-salinity exposure on the clearance rate, total heterotrophic marine bacteria and totalVibriocount in flesh, as well as the biochemical parameters of hemolymph and heat shock protein (HSP) gene expression, inPinctada radiata. To this end, the oysters were reared for 14 days at salinities of 40 (control group), 35, 30, 25 and 20 PSU. Results indicated that low salinity led to a significantly lower clearance rate, with the lowest clearance rate observed at 20 PSU. However, no significant differences were found among the groups in the total heterotrophic marine bacteria, calcium concentration, aspartate aminotransferase (AST), alanine aminotransferase (ALT) or alkaline phosphatase (ALP) levels. In addition, the results demonstrated that the totalVibriocount increased significantly in oysters exposed to the hypoosmotic condition. A reduction in glucose concentration was observed in the 25 and 20 PSU groups compared to the other experimental groups. In addition, the highest survival rate was found in the 40 and 35 PSU groups. Based on q-RT-PCR results, HSP70 and HSP90 mRNA levels were significantly up-regulated by low-salinity exposure, while the expression of HSP20 mRNA was remarkably down-regulated in the 35 and 30 PSU salinity groups. The present study shows that pearl oysters tolerate a wide range of salinities (40-20 PSU), whereas optimal salinity for oyster culture ranges from 30 to 40 PSU. These results also provide a better understanding of the feeding behavior and physiological changes ofP. radiatain response to salinity changes.

关键词： arginine modification   Ganoderma lucidum   medicinal mushroom   melanin   physicochemical and biochemical properties  

摘要： Melanin is a hydrophobic biomolecule produced widely in fungi. Compared with other fungi, health benefits have been associated with medicinal mushrooms, which may provide an excellent source of natural melanin. Nevertheless, the hydrophobicity of melanin may limit its applications. Consequently, the present study was carried out on isolation of melanin from the medicinal mushroom Ganoderma lucidum (GLM) and modification with arginine to improve its solubility. The physicochemical and biochemical properties of melanin were evaluated including structural characterization, solubility, stability, antioxidant activities, and inhibitory effect on pancreatic lipase activity. Arginine-modified melanin showed better solubility, higher color value, stronger antioxidant activity, and stronger inhibitory effect on pancreatic lipase activity in vitro than GLM. In addition, both have good stability in the dark and natural light. These results opened possibilities for providing an excellent source of natural melanin in health food or food additives fields.

关键词： Tetranychus urticae   Lambda-cyhalothrin   Bifenthrin   Resistance   Inheritance   Biochemical mechanisms  

摘要： Tetranychus urticae (Koch) (Acari: Tetrancyhidae) is one of the most economically important pests among spider mites, due to the number of hosts that it harms in agricultural fields and greenhouses, and to its remarkable ability to develop resistance to chemicals applied in a short time. Pyrethroids are among the most widely used insecticides to control this pest. In this study, the biochemical mechanisms and inheritance mode of lambda cyhalothrin and bifenthrin resistance in T. urticae were investigated. A greenhouse population (BEYDOM) of T. urticae was selected for eight cycles in the laboratory with lambda cyhalothrin and bifenthrin by a spray tower-Petri dish method using the LC90 of a standard susceptible population (GSS). After eight selection cycles, the BEYDOM population was found 18.24-fold resistant to lambda cyhalothrin and 74.23-fold resistant to bifenthrin compared with the GSS based on LC50 values. Reciprocal and backcross studies revealed that the inheritance of lambda cyhalothrin resistance was sex-linked, incompletely dominant, and was probably under the control of more than one gene at lower doses and a single gene at higher doses, while inheritance to bifenthrin resistance was autosomal and incompletely recessive and may be controlled by one gene. Biochemical and synergism experiments suggested that monooxygenases and carboxylesterase enzymes play an essential role in the resistance to these pyrethmids, whereas glutathione S-transferases were not found to have a significant effect. These results provide valuable information in terms of designing an effective resistance management strategy to retard or avoid the development of resistant T. urticae populations.

关键词： active learning   biochemistry   COVID-19   online teaching  

摘要： A biochemistry class was transformed to implement student-centered, active-learning pedagogies to help improve competencies associated with the scientific method. In responding to the COVID-19 pandemic, the course content switched from the biochemistry of nucleic acids to the science of the newly discovered virus, SARS-CoV-2. This provided a unique opportunity to model authentic science inquiry through cycles of questioning, investigating, assessing, and critical thinking on a rapidly evolving, interdisciplinary topic. This learning experience helped enhance science literacy, supported self-directed learning and curiosity, and emphasized the importance of evaluating information sources to recognize misinformation.

关键词： Arsenic   Antimony   Phytoremediation   Vetiveria zizanioides   Antioxidant enzyme  

摘要： Vetiver grass (Vetiveria zizanioides L. Nash) has a great application potential to the phytoremediation of heavy metals pollution. However, few studies explored the bioavailability and distribution of different speciations of As and Sb in V. zizanioides. This study aimed to clarify the allocation and accumulation of two inorganic species arsenic (As(III) and As(V)) and antimony (Sb(III) and Sb(V)) in V. zizanioides, to understand the self-defense mechanisms of V. zizanioides to these metal(loids) elements. Thus, an experiment was conducted under greenhouse conditions to identify distribution of As and Sb in plant roots and shoots. Antioxidant enzymes (superoxide dismutase, SOD) and changes of subcellular structures were tested to evaluate metal(loids) tolerance capacities of V. zizanioides. This study demonstrated that V. zizanioides had higher capacity to accumulate Sb than As. For Sb absorption, Sb(III) content is significantly higher than Sb(V) in tissues of V. zizanioides under all concentration levels, despite the oxidation of Sb(III) on the nutrient solution surface. Additional Sb was mainly accumulated in plant roots due to Sb immobilization by transforming it into precipitates. As was more easily transferred to aerial tissues and had low accumulation rates, probably due to its restricted uptake rather than restricted transport. In many cases, two inorganic species of As and Sb showed almost same biotoxicity to V. zizanioides estimated from its biomass, SOD activity, and MDA content as well as functional groups. In summary, the results of this study provide new insights into understanding allocation, accumulation and phytotoxicity effects of arsenic and antimony in V. zizanioides. [GRAPHICS] .

关键词： Laccase   Purification   Immobilization   Diclofenac transformation   LC-MS  

摘要： An extracellular laccase enzyme secreted fromSphingobacteriumksn-11 was purified to electrophoretic homogeneity, showing a molecular weight of 90 kDa. The purified enzyme was monomeric in nature confirmed by sodium dodecyl gel electrophoresis. The optimum temperature and pH were found to be 40 degrees C and 4.5 respectively. The enzyme showed highest substrate specificity for 2,2 azino-bis (ethylthiozoline-6-sulfonate) (ABTS), followed by syringaldazine. TheK(m)value for ABTS was 2.12 mM with aV(max)value of 33.33 U/mg which was higher when compared with syringaldazine and guaiacol substrates. Sodium azide and EDTA inhibited the activity by 30%, whereas presence of Ca(2+)and iron increased activity by 50%. The purified enzyme was immobilized in sodium alginate-silicon dioxide-polyvinyl alcohol beads and evaluated for diclofenac transformation studies. LC-MS analysis confirmed that immobilized laccase transformed diclofenac to 4-OH diclofenac after 4 h of incubation. 45 % of diclofenac was able to transform even at 3rd cycle of immobilized laccase use. Therefore, immobilized laccase can be used to transform or degrade several recalcitrant compounds from industrial effluents.

摘要： The original version of this article unfortunately contained a mistake in the equation under "Immobilized Laccase Activity and its Storage Stability" section.