A proteomics view on the role of drought-induced senescence and oxidative stress defense in enhanced stem reserves remobilization in wheat

Drought is one of the major factors limiting the yield of wheat (Triticum aestivum L.) particularly during grain filling. Under terminal drought condition, remobilization of pre-stored carbohydrates in wheat stem to grain has a major contribution in yield. To determine the molecular mechanism of stem reserve utilization under drought condition, we compared stem proteome patterns of two contrasting wheat landraces (N49 and N14) under a progressive post-anthesis drought stress, during which period N49 peduncle showed remarkably higher stem reserves remobilization efficiency compared to N14. Out of 830 protein spots reproducibly detected and analyzed on two-dimensional electrophoresis gels, 135 spots showed significant changes in at least one landrace. The highest number of differentially expressed proteins was observed in landrace N49 at 20days after anthesis when active remobilization of dry matter was observed, suggesting a possible involvement of these proteins in effective stem reserve remobilization of N49. The identification of 82 of differentially expressed proteins using mass spectrometry revealed a coordinated expression of proteins involved in leaf senescence, oxidative stress defense, signal transduction, metabolisms and photosynthesis which might enable N49 to efficiently remobilized its stem reserves compared to N14. The up-regulation of several senescence-associated proteins and breakdown of photosynthetic proteins in N49 might reflect the fact that N49 increased carbon remobilization from the stem to the grains by enhancing senescence. Furthermore, the up-regulation of several oxidative stress defense proteins in N49 might suggest a more effective protection against oxidative stress during senescence in order to protect stem cells from premature cell death. Our results suggest that wheat plant might response to soil drying by efficiently remobilize assimilates from stem to grain through coordinated gene expression.     

In silico analysis of six known Leishmania major antigens and in vitro evaluation of specific epitopes eliciting HLA-A2 restricted CD8 T cell response

Background

As a potent CD8⁺ T cell activator, peptide vaccine has found its way in vaccine development against intracellular infections and cancer, but not against leishmaniasis. The first step toward a peptide vaccine is epitope mapping of different proteins according to the most frequent HLA types in a population.

Methods and Findings

Six Leishmania (L.) major-related candidate antigens (CPB,CPC,LmsTI-1,TSA,LeIF and LPG-3) were screened for potential CD8⁺ T cell activating 9-mer epitopes presented by HLA-A*0201 (the most frequent HLA-A allele). Online software including SYFPEITHI, BIMAS, EpiJen, Rankpep, nHLApred, NetCTL and Multipred were used. Peptides were selected only if predicted by almost all programs, according to their predictive scores. Pan-A2 presentation of selected peptides was confirmed by NetMHCPan1.1. Selected peptides were pooled in four peptide groups and the immunogenicity was evaluated by in vitro stimulation and intracellular cytokine assay of PBMCs from HLA-A2⁺ individuals recovered from L. major. HLA-A2⁻ individuals recovered from L. major and HLA-A2⁺ healthy donors were included as control groups. Individual response of HLA-A2⁺ recovered volunteers as percent of CD8⁺/IFN-γ⁺ T cells after in vitro stimulation against peptide pools II and IV was notably higher than that of HLA-A2⁻ recovered individuals. Based on cutoff scores calculated from the response of HLA-A2⁻ recovered individuals, 31.6% and 13.3% of HLA-A2⁺ recovered persons responded above cutoff in pools II and IV, respectively. ELISpot and ELISA results confirmed flow cytometry analysis. The response of HLA-A2⁻ recovered individuals against peptide pools I and III was detected similar and even higher than HLA-A2⁺ recovered individuals.

Conclusion

Using in silico prediction we demonstrated specific response to LmsTI-1 (pool II) and LPG-3- (pool IV) related peptides specifically presented in HLA-A*0201 context. This is among the very few reports mapping L. major epitopes for human HLA types. Studies like this will speed up polytope vaccine idea towards leishmaniasis.     

Topical application of aminopeptidase N-neutralizing antibody accelerates wound closure

Upon release from keratinocytes, 14-3-3 sigma (also known as stratifin) acts on the dermal fibroblast and modulates its production of extracellular matrix proteins. Subsequent to the recent identification as a receptor responsible for stratifin-mediated matrix turnover in dermal fibroblasts, aminopeptidase N has been implicated in the regulation of epidermal?Cdermal communication and expression of key matrix proteases and adhesion molecules. In light of the growing importance of aminopeptidase N in modulation of the fibroblast phenotype, the present study evaluates the potential of targeting the ectoenzyme in cutaneous repair, and demonstrates that neutralization of aminopeptidase N led to acceleration of wound closure. This was attributed to at least in part an increase of collagen deposition and fibroblast contractility in the granulation tissue. These findings confirmed the important role of aminopeptidase N in post-injury tissue remodeling and wound contraction.     

Comparative study on the efficacy of neemix and basil oil formulations on the cowpea aphid Aphis craccivora Koch

Both neemix and basil oil had an insecticidal effect against Aphis craccivora Koch when the plant was treated systematically or by contact. The tested compounds caused a significant reduction in fecundity, longevity and the natal period. In addition, neemix and basil oil had a toxic effect on the adult stage of the pest, which was more clear for basil oil than neemix, since the cumulative percent morality reached 100% in all tested concentrations after 7 days for basil treatment and after 8 days for neemix oil treatment, while the mortality did not exceed 36% for the control. The two tested oils also had an antifeedant and aphicidal effect on the nymphal stage, since they caused prolongation of the nymphal duration, high percentage of mortality and only a few young ones can be succeeded to reach to the adult stage. The correlation between the biological effects of the tested compounds and the impairment of the activity of some enzymes (acid phosphatase and alkaline phosphatase) and (aspartate aminotranferase and alanine aminotransferase) as well as protein contents had also been investigated. The results clarified a significant reduction in all the tested enzymes and were more pronounced for basil oil treatment than neemix. This explained the reduction in the reproductive potency of A. craccivora Koch. Concerning the side effect of the tested compounds on faba bean plants, the results indicated that the treatment induced promising effect on the antioxidant enzymes activity (superoxide dismutase, catalase, peroxidase and polyphenol oxidase) of the plants which were treated with basil oil and neemix.     

Identification of a novel missense mutation of PEX7 gene in an Iranian patient with rhizomelic chondrodysplasia punctata type 1

Deficiency in the PTS2 protein import pathway due to mutations in PEX7 gene results in the rhizomelic chondrodysplasia punctata (RCDP) type 1. In the present study, we have reported a novel missense mutation, W75R, in the PEX7 gene in an Iranian patient with the RCDP type 1. The inability of PEX7 protein to transport PTS2 containing proteins including peroxisomal 3-ketoacyl-CoA thiolase and PTS2-EGFP protein to the surface of the peroxisomes showed that the W75R mutation in PEX7 gene severely impaired the function of PEX7 protein and was responsible for RCDP type 1 in this patient.     

The point mutation analysis of Cyp2C9*2 (Arg144Cys C>T), Cyp2C9*3 (Ile359Leu A>C) and VKORC1 (1639G>A) in women with cervical cancer related to HPV: A case-control study

Human papillomavirus (HPV) is the most common sexually transmitted viral infection worldwide. HPV tumorigenesis genotypes are the causative agents of cervical cancer and genital malignancies. The scientific literature has demonstrated that life style, environmental, epigenetic accompanied with HR-HPV genotypes are potential risk factors for cervical cancer progression. The frequencies of the Cyp2C9*², Cyp2C9*³, and vitamin K epoxide reductase complex subunit 1 (VKORC1) genotypes as potential molecular biomarkers have been investigated on Iranian women with cervical malignancy related to HPV genotypes. As a case-control study, the mutations were appraised using a polymerase chain reaction-restriction fragment length polymorphism procedure on women suffering from HPV infection (60 cases), CC (46 cases), and 40 subjects of as healthy control. The outcomes demonstrated that Cyp2C9*³ showed a meaningful relationship between women diagnosed with cervical cancer and the healthy population (AA vs. AC; OR, 7.15; 95% CI, 1.94-26.3; p = .003). It was also observed that the Cyp2C9*³ mutation in women with cervical cancer and VKORC1 in healthy population with HPV (+), did not follow the Hardy–Weinberg equilibrium. Our findings aid understanding the genetic polymorphism distribution of Cyp2C9*², Cyp2C9*³, and VKORC1 in women with genital malignancies. This can also be useful in predicting the susceptibility risk factors for developing cervical cancer. However, allelic discrimination as a molecular biomarker requires further research.     

Analysis of sugar composition and pesticides using HPLC and GC–MS techniques in honey samples collected from Saudi Arabian markets

Honey is a complex foodstuff found in nature which is used without any processing. Honey has been in use in medicine as well as raw food since ancient times. Essentially, it is a blend of sugars especially fructose and glucose. The objectives of the study were to determine major sugar composition as well as pesticides contamination in honey samples. Further, Hydroxy-methyl-furfuraldehyde (HMF) level was also determined to ascertain the freshness of honey samples. A total of 14 samples were collected from local market and tested for fructose, glucose, sucrose, HMF and organochlorine pesticides using HPLC and GC–MS techniques respectively. The total sugars in the 14 honey samples were found ranging between 50.26 and 74.74 g/100 g of honey. The chromatographic results showed the presence of the sugars like fructose and glucose in all honey samples. The honey sample SH–11 was found to contain the highest amount of fructose (40.63%). On the other hand, the lowest amount of fructose with 29.08% was observed in SH–7. The HPLC analysis also revealed the presence of sucrose in two samples but under the permissible limit. The average ratio of fructose to glucose in these honey samples was 1.3. None of the sample has ratio below 1.0 indicating lesser chances for honey to crystallize on storage. Out of 14 honey samples, 13 samples were found negative for the presence of any of the 63 pesticides tested. Only sample No. 13, was found to contain 15.95 ppb hexachlorobenzene per kilogram of honey. The HMF was not detected in four samples but in remaining samples it was well below the maximum permissible limit. No pesticide and sugar adulteration was observed in any of the honey samples. The honeys collected from Saudi Arabian markets were found to confirm the standards set by the regional and international standardization organization, the GSO and Codex Alimentarius Commission respectively.     

Arbuscular mycorrhizal fungi benefit drought-stressed Salsola laricina

Plant Ecology - Due to its contribution to plant drought tolerance, arbuscular mycorrhizae (AM) may play an important role in the revegetation of degraded pastures in semi-arid and arid regions....