Activation of antioxidative and detoxificative systems in Brassica juncea L. plants against the toxicity of heavy metals

Plant metal hyperaccumulators, to which Brassica juncea belongs, must have very efficient defence mechanisms that enable growth and development in an environment polluted with various heavy metals. B. juncea (Indiana mustard) v. Małopolska was exposed to the activity of trace elements such as cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) in combinations: CuPb, CuCd, CuZn, PbCd, PbZn, and ZnCd in a concentration of 25 μM each for 96 h during control cultivation. We observed a clear tendency for metal uptake and accumulation in above-ground parts which is characteristic of hyperaccumulators. The combinations of CuCd, CuZn, and PbCd inhibited the development of the seedlings the most. The used metal combinations increased the levels of reactive oxygen species (ROS) such as: hydrogen peroxide (H2O2), superoxide anion (O2.−) and oxidized proteins in B. juncea organs, generating oxidative stress conditions in the cells. We determined the level of transcription of the respective defence proteins of the detoxification and antioxidant systems. We have shown that in the first 24 h of stress condiction, activation of glutamylcysteine-γ synthetase (yECS) and glutathione reductase (GR1) enzymes related to the detoxification of heavy metals is important for B. juncea plants. In addition, the data provide important information on how plants respond to the presence of heavy metals in the first days of stress conditions.

Comparison of the transcriptome in circulating leukocytes in early lactation between primiparous and multiparous cows provides evidence for age-related changes

Background Previous studies have identified many immune pathways which are consistently altered in humans and model organisms as they age. Dairy cows are often culled at quite young ages due to an inability to cope adequately with metabolic and infectious diseases, resulting in reduced milk production and infertility. Improved longevity is therefore a desirable trait which would benefit both farmers and their cows. This study analysed the transcriptome derived from RNA-seq data of leukocytes obtained from Holstein cows in early lactation with respect to lactation number. Results Samples were divided into three lactation groups for analysis: i) primiparous (PP, n = 53), ii) multiparous in lactations 2–3 (MP 2–3, n = 121), and iii) MP in lactations 4–7 (MP > 3, n = 55). Leukocyte expression was compared between PP vs MP > 3 cows with MP 2–3 as background using DESeq2 followed by weighted gene co-expression network analysis (WGCNA). Seven modules were significantly correlated (r ≥ 0.25) to the trait lactation number. Genes from the modules which were more highly expressed in either the PP or MP > 3 cows were pooled, and the gene lists subjected to David functional annotation cluster analysis. The top three clusters from modules more highly expressed in the PP cows all involved regulation of gene transcription, particularly zinc fingers. Another cluster included genes encoding enzymes in the mitochondrial beta-oxidation pathway. Top clusters up-regulated in MP > 3 cows included the terms Glycolysis/Gluconeogenesis, C-type lectin, and Immunity. Differentially expressed candidate genes for ageing previously identified in the human blood transcriptome up-regulated in PP cows were mainly associated with T-cell function (CCR7, CD27, IL7R, CAMK4, CD28), mitochondrial ribosomal proteins (MRPS27, MRPS9, MRPS31), and DNA replication and repair (WRN). Those up-regulated in MP > 3 cows encoded immune defence proteins (LYZ, CTSZ, SREBF1, GRN, ANXA5, ADARB1). Conclusions Genes and pathways associated with lactation number in cows were identified for the first time to date, and we found that many were comparable to those known to be associated with ageing in humans and model organisms. We also detected changes in energy utilization and immune responses in leukocytes from older cows.

Protein S-nitrosation differentially modulates tomato responses to infection by hemi-biotrophic oomycetes of Phytophthora spp.

Regulation of protein function by reversible S-nitrosation, a post-translational modification based on the attachment of nitroso group to cysteine thiols, has emerged among key mechanisms of NO signalling in plant development and stress responses. S-nitrosoglutathione is regarded as the most abundant low-molecular-weight S-nitrosothiol in plants, where its intracellular concentrations are modulated by S-nitrosoglutathione reductase. We analysed modulations of S-nitrosothiols and protein S-nitrosation mediated by S-nitrosoglutathione reductase in cultivated Solanum lycopersicum (susceptible) and wild Solanum habrochaites (resistant genotype) up to 96 h post inoculation (hpi) by two hemibiotrophic oomycetes, Phytophthora infestans and Phytophthora parasitica. S-nitrosoglutathione reductase activity and protein level were decreased by P. infestans and P. parasitica infection in both genotypes, whereas protein S-nitrosothiols were increased by P. infestans infection, particularly at 72 hpi related to pathogen biotrophy–necrotrophy transition. Increased levels of S-nitrosothiols localised in both proximal and distal parts to the infection site, which suggests together with their localisation to vascular bundles a signalling role in systemic responses. S-nitrosation targets in plants infected with P. infestans identified by a proteomic analysis include namely antioxidant and defence proteins, together with important proteins of metabolic, regulatory and structural functions. Ascorbate peroxidase S-nitrosation was observed in both genotypes in parallel to increased enzyme activity and protein level during P. infestans pathogenesis, namely in the susceptible genotype. These results show important regulatory functions of protein S-nitrosation in concerting molecular mechanisms of plant resistance to hemibiotrophic pathogens.

Age Related Changes in the Circulating Leukocyte Transcriptome in Dairy Cows

Background: Previous studies of ageing have identified many pathways which are consistently altered in humans and model organisms. Dairy cows are often culled at quite young ages due to an inability to cope adequately with metabolic and infectious diseases, resulting in reduced milk production and infertility. Improved longevity is therefore a desirable trait which would benefit both farmers and their cows. This study analysed the transcriptome derived from RNA-seq data of leukocytes obtained from Holstein cows in early lactation with respect to lactation number. Results: Samples were divided into three age groups for analysis: i) primiparous (PP, n = 53), ii) multiparous in lactations 2-3 (MP 2-3, n = 121), and iii) MP in lactations 4-7 (MP>3, n = 55). Leukocyte expression was compared between PP vs MP>3 cows with MP 2-3 as background using DESeq2 followed by weighted gene co-expression network analysis (WGCNA). Seven modules were significantly correlated (r ≥ 0.25) to the trait age. Genes from the modules which were more highly expressed in either the PP or MP>3 cows were pooled, and the gene lists subjected to David functional annotation cluster analysis. The top three clusters from modules more highly expressed in the PP cows all involved regulation of gene transcription, particularly zinc fingers. Another cluster included genes encoding enzymes in the mitochondrial beta-oxidation pathway. Top clusters up-regulated in MP>3 cows included the terms Glycolysis/Gluconeogenesis, C-type lectin, and Immunity. Differentially expressed candidate genes for ageing previously identified in the human blood transcriptome up-regulated in PP cows were mainly associated with T-cell function (CCR7, CD27, IL7R, CAMK4, CD28), mitochondrial ribosomal proteins (MRPS27, MRPS9, MRPS31), and DNA replication and repair (WRN). Those up-regulated in MP>3 cows encoded immune defence proteins (LYZ, CTSZ, SREBF1, GRN, ANXA5, ADARB1). Conclusions: Genes and pathways associated with age in cows were identified for the first time to date, and we found that many were comparable to those known to be associated with ageing in humans and model organisms. We also detected changes in energy utilization and immune responses in leukocytes with age.

Spatiotemporal Cellular Networks Maintain Immune Homeostasis in the Lung

A dynamic and intricately connected tissue-resident immune cell network continuously monitors the lungs, which are incessantly subjected to external environmental insults. The lungs are protected by the respiratory epithelium, which not only serves as a physical barrier through mucociliary mechanisms, but also a reactive one that can release cytokines, chemokines, and other defence proteins in response to danger signals. In the maintenance of pulmonary homeostasis in health, the lung-resident immune cell network instructs tolerance to innocuous particulates and can rapidly and efficiently drive immunity and memory to pathogenic antigens. This review examines the spatiotemporal dynamics that underlie the exquisite network of highly specialised immune cells and their mediators in the support of pulmonary tissue homeostasis and effective lung immunity in health. In particular, this review examines the specialised immune cells that reside in distinct populations within the diverse compartments of the lung, and the molecular signals that retain and recruit lung-resident immune cells, to further our understanding of how these can be targeted therapeutically to return inflamed or diseased lungs to homeostasis.

Prophage-encoded phage defence proteins with cognate self-immunity

SummaryTemperate phages are pervasive in bacterial genomes, existing as vertically-inherited islands called prophages. Prophages are vulnerable to the predation of their host bacterium by exogenous phages. Here we identify BstA, a novel family of prophage-encoded phage defence proteins found in diverse Gram-negative bacteria. BstA drives potent suppression of phage epidemics through abortive infection. The bstA-encoding prophage itself is not inhibited by BstA during lytic replication due to a self-immunity mechanism driven by the anti-BstA (aba) element, a short stretch of DNA within the bstA locus. Phage-targeting by distinct BstA proteins from Salmonella, Klebsiella and Escherichia prophages is functionally interchangeable, but each possesses a cognate aba element. The specificity of the aba element ensures that immunity is exclusive to the replicating prophage, and cannot be exploited by heterologous BstA-encoding phages. BstA allows prophages to defend their host cells against exogenous phage attack, without sacrificing their own lytic autonomy.

Expression and function of murine WFDC2 in the respiratory tract

WFDC2/HE4 encodes a poorly characterised secretory protein that shares structural similarity with multifunctional host defence proteins through possession of two conserved Whey Acidic Protein/four disulphide-core (WFDC) domains. WFDC2 is expressed in multiple epithelia and although its’ function remains unresolved, it is also overexpressed in a number of human cancers and has an established role as a cancer marker. Currently, little is known about the distribution of WFDC2 in the mouse and thus we have systematically analysed the mouse wfdc2 gene, its’ expression and distribution. We have used recombinant WFDC2 for functional studies. Wfdc2 is the most highly expressed family member in the lung and is enriched in the nasopharynx. Wfdc2 is the most highly expressed family member in differentiated epithelial cells isolated from the trachea, nasal passages and middle ear. Wfdc2 consists of 5 exons with exon 3 encoding an unstructured linker region that separates the two WFDC domains. This genomic organisation appears to be restricted to the Muridae and Cricetidae families of rodents. Similar to the situation in man, mouse wfdc2 can be alternatively spliced to yield a number of distinct transcripts that have the potential to generate a repertoire of distinct protein isoforms. We used immunohistochemistry to localise the proteins to tissues of the respiratory tract and head and neck regions. Although the protein was limited to epithelial cells of the respiratory tract and nasal and oral cavities, it was expressed in different cells in different regions suggesting expression is governed by a unique regulatory mechanism. Recombinant WFDC2 did not possess antiproteinase activity against trypsin or elastase and had no clear antimicrobial activity.

Transcriptome Analysis Reveals Important Candidate Genes Related to Nutrient Reservoir, Carbohydrate Metabolism, and Defence Proteins during Grain Development of Hexaploid Bread Wheat and Its Diploid Progenitors

Wheat grain development after anthesis is an important biological process, in which major components of seeds are synthesised, and these components are further required for germination and seed vigour. We have made a comparative RNA-Seq analysis between hexaploid wheat and its individual diploid progenitors to know the major differentially expressed genes (DEGs) involved during grain development. Two libraries from each species were generated with an average of 55.63, 55.23, 68.13, and 103.81 million reads, resulting in 79.3K, 113.7K, 90.6K, and 121.3K numbers of transcripts in AA, BB, DD, and AABBDD genome species respectively. Number of expressed genes in hexaploid wheat was not proportional to its genome size, but marginally higher than that of its diploid progenitors. However, to capture all the transcripts in hexaploid wheat, sufficiently higher number of reads was required. Functional analysis of DEGs, in all the three comparisons, showed their predominance in three major classes of genes during grain development, i.e., nutrient reservoirs, carbohydrate metabolism, and defence proteins; some of them were subsequently validated through real time quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR). Further, developmental stage–specific gene expression showed most of the defence protein genes expressed during initial developmental stages in hexaploid contrary to the diploids at later stages. Genes related to carbohydrates anabolism expressed during early stages, whereas catabolism genes expressed at later stages in all the species. However, no trend was observed in case of different nutrient reservoirs gene expression. This data could be used to study the comparative gene expression among the three diploid species and homeologue-specific expression in hexaploid.

Effect of Fungal Infection on Defence Proteins of Musca domestica L. and Variation of Virulence with Temperature

With the current global drive for alternative control measures that are safer in comparison to synthetic insecticides, it was considered necessary to assess some fungal entomopathogens for efficacy against the house fly, Musca domestica. The effect of fungal infection on activity of two detoxification enzymes (esterase [EST] and glutathione-S-transferase [GST]) was determined in the laboratory. Effect of temperature on progression of mycosis was also investigated between 15 and 35℃ to determine the optimum temperature necessary for successful fungal infection. Two Beauveria bassiana strains (ARSEF 1564 and ARSEF 8891), Metarhizium robertsii (ARSEF 1057) and M. anisopliae s.s. (ARSEF 5471) were evaluated in this study as potential sources of mycoinsecticide formulations. The fungal strains infected larval and adult house flies successfully by inhibiting activity of EST and GST with a concomitant insect mortality of > 90%. A significantly higher number of dead specimens (80-100%) had fungal growth between 20 and 25℃ with a noticeable level of mycosis also at 30℃. The evaluated fungal strains showed good insecticidal efficacy and could, therefore, serve as good sources of mycoinsecticide formulations against house fly. If this area of biological control is well explored it would reduce reliance on synthetic insecticide formulations. Keywords: Defence proteins, house fly mortality, mycosis, optimum temperature