Deciphering the Metabolic Changes Associated with Diapause Syndrome and Cold Acclimation in the Two-Spotted Spider Mite Tetranychus urticae

Diapause is a common feature in several arthropod species that are subject to unfavorable growing seasons. The range of environmental cues that trigger the onset and termination of diapause, in addition to associated hormonal, biochemical, and molecular changes, have been studied extensively in recent years; however, such information is only available for a few insect species. Diapause and cold hardening usually occur together in overwintering arthropods, and can be characterized by recording changes to the wealth of molecules present in the tissue, hemolymph, or whole body of organisms. Recent technological advances, such as high throughput screening and quantification of metabolites via chromatographic analyses, are able to identify such molecules. In the present work, we examined the survival ability of diapausing and non-diapausing females of the two-spotted spider mite, Tetranychus urticae, in the presence (0 or 5°C) or absence of cold acclimation. Furthermore, we examined the metabolic fingerprints of these specimens via gas chromatography-mass spectrophotometry (GC-MS). Partial Least Square Discriminant Analysis (PLS-DA) of metabolites revealed that major metabolic variations were related to diapause, indicating in a clear cut-off between diapausing and non-diapausing females, regardless of acclimation state. Signs of metabolic depression were evident in diapausing females, with most amino acids and TCA cycle intermediates being significantly reduced. Out of the 40 accurately quantified metabolites, seven metabolites remained elevated or were accumulated in diapausing mites, i.e. cadaverine, gluconolactone, glucose, inositol, maltose, mannitol and sorbitol. The capacity to accumulate winter polyols during cold-acclimation was restricted to diapausing females. We conclude that the induction of increased cold hardiness in this species is associated with the diapause syndrome, rather than being a direct effect of low temperature. Our results provide novel information about biochemical events related to the cold hardening process in the two-spotted spider mite.     

Detection of Contracaecum multipapillatum (Nematoda: Anisakidae) in the indigenous killifish Aphanius hormuzensis (Teleostei; Aphaniidae) and its histopathological effects: A review of Iranian Aphanius species parasites

The present study reports the occurrence of Contracaecum multipapillatum (Nematoda: Anisakidae) in an indigenous small killifish, Aphanius hormuzensis Teimori, Esmaeili, Hamidan, Reichenbacher, 2018 from Southern Iran and shows its histopathology. A total of 110 A. hormuzensis specimens were collected from Shur (Naband) River, Hormuzgan basin in Southern Iran and examined for their possible parasitic infections. Third‐stage larva of C. multipapillatum was extracted for the first time from the body cavity of 19 fish specimens (one male and 18 female) and identified by molecular and morphological methods. In comparison with non‐infected fishes, the melanomacrophage centers were detected in the tissue sections from liver, kidney and spleen of all the parasite infected fishes. To date, 16 parasites belong to nine families have been recorded from six Aphanius species (out of 15 known species) in Iran. Among them, eight and four parasites have been identified from A. vladykovi, and A. hormuzensis respectively. Since Aphanius species are living in different environments, therefore, they seem to be good hosts for the different types of parasites, and more new parasites are expected to be found in these fishes.     

Effects of Stress Modifier Biostimulants on Vegetative Growth,Nutrients, and Antioxidants Contents of Garden Thyme (Thymus vulgaris L.) Under Water Deficit Conditions

The aim of this study is to investigate the effect of stress modulators on vegetative growth, antioxidants, and nutrient content of Thymus vulgaris L. under water deficit stress conditions. A factorial experiment was performed in the form of a randomized complete block design with 10 treatments and 3 replications in the 2019–2020 growing season. The factors were stress modulators at 5 levels (ZN: zinc nano-fertilizer, AA: amino acid, SW: seaweed, HA: humic acid and C: control) and irrigation regime at 2 levels [FIrr: full irrigation (100% field capacity) and DIrr: deficit irrigation (50% field capacity)]. The highest plant height, number of branches, and total dry weight of the garden thyme plant were observed in the foliar application of HA and SW under full irrigation conditions. Relative water content, chlorophyll a and b, and uptake of nutrients (N, P, and K) were reduced under water deficit stress, but the foliar application of stress modulators increased relative water content, chlorophyll content, and nutrient uptake of the garden thyme plant significantly compared with control. The water deficit increased proline content, total flavonoid, and phenol content in the garden thyme plant. So, the highest total flavonoid and phenol content was obtained from plants treated with HA, whereas proline content was higher in the control plants. Soluble sugars and essential oil increased significantly under water deficit stress conditions. The foliar application of HA compared to the control plant increased soluble sugars and essential oil in garden thymes. The activities of catalase, superoxide dismutase, and ascorbate peroxidase enzymes were improved in stress modulator treatments such as HA and SW compared to control plants under water deficit stress conditions. The plants of garden thymes showed a good response to stress modulator treatments under water stress conditions, and HA and SW treatments were found to be more effective.

     

Association between the flap endonuclease 1 gene polymorphisms and cancer susceptibility: An updated meta-analysis

Flap endonuclease 1 (FEN1) has emerged as an important enzyme in the maintenance of genomic instability and preventing carcinogenesis. The relationship between FEN1 −69G>A (rs174538)+4150G>T (rs4246215) polymorphisms and cancer susceptibility has been reported; however, results were inconclusive. In the present study, a meta-analysis of data from eligible reports was carried out to summarize the possible relationship between FEN1 polymorphisms and cancer risk. A total of 11 articles, including 20 studies with 7366 cases and 9028 controls and 18 studies with 6649 cases and 8325 controls for FEN1 rs174538 and FEN1 rs4246215 polymorphisms, respectively, were recruited for meta-analysis. Overall, meta-analyses showed that FEN1 rs174538 and rs4246215 polymorphisms are significantly associated with the decreased risk of cancer. The stratified analysis proposed that both variants were associated with protection against gastrointestinal cancer, breast cancer, hepatocellular cancer, esophageal cancer, gastric cancer, colorectal cancer, and lung cancer. In conclusion, this meta-analysis revealed an association between FEN1 polymorphisms and cancer risk. Additional studies in a larger study population that include subjects from a variety of ethnicities are warranted to further verify our findings.     

Let-7e enhances the radiosensitivity of colorectal cancer cells by directly targeting insulin-like growth factor 1 receptor

Abnormal expression of various microRNAs (miRNAs), as regulators of biological signaling pathways, has a strong association with cancer resistance to chemotherapy and radiotherapy. The let-7 family of miRNAs as tumor suppressors have shown to be downregulated in different types of human malignancies including colorectal cancer (CRC). However, the biological function of let-7 members in the processes of resistance to radiation in CRC has not yet been completely elucidated. Insulin-like growth factor 1 receptor (IGF-1R) signaling pathway is amplified in CRC and leads to its progression, development, and also radiation resistance. So, it seems like an attractive target for anticancer therapy. In this study, by using bioinformatics analysis, it has been revealed that IGF-1R is a direct target of the let-7e member. Consistent with this, we identified that increased levels of let-7e in CRC cells reduced IGF-1R protein level and subsequently its downstream signaling pathways, which resulted in the G1 cell cycle arrest and a significant reduction in the proliferation, survival and also resistance to radiation of CRC cells. Altogether, these results suggested that let-7e by targeting the IGF-1R signaling pathway might serve as therapeutics in anticancer therapy.     

Biotechnological potential of Azolla filiculoides for biosorption of Cs and Sr: Application of micro-PIXE for measurement of biosorption

The presence of Cs and Sr in culture medium of Azolla filiculoides caused about 27.4% and 46.3% inhibition of biomass growth, respectively, in comparison to A. filiculoides control weight which had not metals. Biosorption batch experiments were conducted to determine the Cs and Sr binding ability of native biomass and chemically modified biosorbents derived from Azolla namely ferrocyanide Azolla sorbents type 1 and type 2 (FAS1 and FAS2) and hydrogen peroxide Azolla sorbent (HAS). The best Cs and Sr removal results were obtained when A. filiculoides was treated by 2 M MgCl₂ and 30 ml H₂O₂ 8 mM at pH 7 for 12 h and it was then washed by NaOH solution at pH 10.5 for 6 h. Pretreatment of Azolla have been suggested to modify the surface characteristics which could improve biosorption process. The binding of Cs and Sr on the cell wall of Azolla was studied with micro-PIXE and FT-IR.     

The central role of PhEIN2 in ethylene responses throughout plant development in petunia

The plant hormone ethylene regulates many aspects of growth and development. Loss-of-function mutations in ETHYLENE INSENSITIVE2 (EIN2) result in ethylene insensitivity in Arabidopsis, indicating an essential role of EIN2 in ethylene signaling. However, little is known about the role of EIN2 in species other than Arabidopsis. To gain a better understanding of EIN2, a petunia (Petunia x hybrida cv Mitchell Diploid [MD]) homolog of the Arabidopsis EIN2 gene (PhEIN2) was isolated, and the role of PhEIN2 was analyzed in a wide range of plant responses to ethylene, many that do not occur in Arabidopsis. PhEIN2 mRNA was present at varying levels in tissues examined, and the PhEIN2 expression decreased after ethylene treatment in petals. These results indicate that expression of PhEIN2 mRNA is spatially and temporally regulated in petunia during plant development. Transgenic petunia plants with reduced PhEIN2 expression were compared to wild-type MD and ethylene-insensitive petunia plants expressing the Arabidopsis etr1-1 gene for several physiological processes. Both PhEIN2 and etr1-1 transgenic plants exhibited significant delays in flower senescence and fruit ripening, inhibited adventitious root and seedling root hair formation, premature death, and increased hypocotyl length in seedling ethylene response assays compared to MD. Moderate or strong levels of reduction in ethylene sensitivity were achieved with expression of both etr1-1 and PhEIN2 transgenes, as measured by downstream expression of PhEIL1. These results demonstrate that PhEIN2 mediates ethylene signals in a wide range of physiological processes and also indicate the central role of EIN2 in ethylene signal transduction.     

Serological detection of Sharka quarantine disease (Plum pox virus) on stone fruit trees in Golestan province

Sharka disease is one of the most damaging diseases of fruit trees in the world, which is caused by Plum pox virus (PPV) that belongs to the genus Potyvirus in the family Potyviridae. Each year, this virus decreases the yield and causes substantial economic damages to its host plants worldwide. This virus is quarantined in Iran but in recent years, suspicious symptoms of the disease were observed in different grown areas, such as Golestan province. During 2010, 420 samples with mosaic, chlorosis, necrosis, ring pattern, blotches, etc. symptoms were collected from the gardens in Golestan province that included 100 samples from plum, 100 from peach and 240 from nectarine. These samples were evaluated using a double-antibody sandwich-ELISA (DAS-ELISA) method and a polyclonal antibody. The results of this survey indicated that among the total of 420 samples, none of them showed positive reaction in DAS-ELISA test.     

Effect of salinity on vanadate biosorption by Halomonas sp. GT-83: Preliminary investigation on biosorption by micro-PIXE technique

Thirty-eight soil samples were collected from crude oil contaminated land in south of Iran. Initial screening of a total of 100 bacterial isolates, resulted in the selection of one isolate with maximum adsorption capacity of 52.7 mg vanadate/g dry weight. It was tentatively identified as Halomonas sp. according to morphological and biochemical properties and named strain GT-83. Removal of vanadate by biosorption with Halomonas sp. GT-83 was very sensitive to solution pH. Vanadate adsorption decreased with increasing pH, with maximum adsorption capacities achieved in at pH 3.0 in the absence and in the presence of increasing concentrations of salt. Vanadate-salt biosorption studies were also performed at this pH value. Equilibrium uptakes of vanadate increased with increasing vanadate concentration up to 600 mg/l. Maximum metal removal (91.8%) took place at pH 3.0 with initial vanadate concentration of 100 mg/l, which got reduced (84.8%) in the presence of 50 g/l salt. The equilibrium sorption data were analyzed by using Freundlich isotherm. The specific uptake of vanadate increased at low cell concentration and decreased when cell concentration exceeded 0.75 g/l. The paper also demonstrates the potential value of micro-PIXE in biosorption studies.