<i>In vitro</i> Antibacterial Activity of <i>Moringa oleifera</i> Ethanolic Extract against Tomato Phytopathogenic Bacteria

The tomato (Solanum lycopersicum L.) is one of the world’s most important vegetable crops. Still, phytopathogenic bacteria affect the yield and quality of tomato cultivation, like Agrobacterium tumefeciens (At), Clavibacter michiganensis subsp. michiganensis (Cmm), Pseudomonas syringae pv. tomato (Pst), Ralstonia solanacearum (Rs), and Xanthomonas axonopodis (Xa). Synthetic chemical products are used mostly on disease plant control, but overuse generates resistance to bacterial control. This study aimed to evaluate the in vitro antibacterial activity of the ethanolic extract of Moringa oleifera Lam. leaves against At, Cmm, Pst, Rs, and Xa, as well as information about this plant species’ chemical composition. Antibacterial activity against pathogens observed by microplate technique, phytochemical screening, and FTIR analysis revealed different bio-active compounds on ethanolic extracts with antibacterial activity. The growth inhibition rate ranged between 0.08% and 99.94%. The inhibitory concentration, IC50, required to inhibit 50% of At, Cmm, Pst, Rs, and Xa bacterial growth, was 276.67, 350.48, 277.85, 351.49, and 283.22 mg/L, respectively. Inhibition of phytopathogen bacteria’s growth increased as the concentrations of the extract also increased. Moringa oleifera extract can be recommended as a potent bio-bactericide.     

Anti-atherogenic and anti-angiogenic activities of polyphenols from propolis

Propolis is a polyphenol-rich resinous substance extensively used to improve health and prevent diseases. The effects of polyphenols from different sources of propolis on atherosclerotic lesions and inflammatory and angiogenic factors were investigated in LDL receptor gene (LDLr?/?) knockout mice. The animals received a cholesterol-enriched diet to induce the initial atherosclerotic lesions (IALs) or advanced atherosclerotic lesions (AALs). The IAL or AAL animals were divided into three groups, each receiving polyphenols from either the green, red or brown propolis (250 mg/kg per day) by gavage. After 4 weeks of polyphenol treatment, the animals were sacrificed and their blood was collected for lipid profile analysis. The atheromatous lesions at the aortic root were also analyzed for gene expression of inflammatory and angiogenic factors by quantitative real-time polymerase chain reaction and immunohistochemistry. All three polyphenol extracts improved the lipid profile and decreased the atherosclerotic lesion area in IAL animals. However, only polyphenols from the red propolis induced favorable changes in the lipid profiles and reduced the lesion areas in AAL mice. In IAL groups, VCAM, MCP-1, FGF, PDGF, VEGF, PECAM and MMP-9 gene expression was down-regulated, while the metalloproteinase inhibitor TIMP-1 gene was up-regulated by all polyphenol extracts. In contrast, for advanced lesions, only the polyphenols from red propolis induced the down-regulation of CD36 and the up-regulation of HO-1 and TIMP-1 when compared to polyphenols from the other two types of propolis. In conclusion, polyphenols from propolis, particularly red propolis, are able to reduce atherosclerotic lesions through mechanisms including the modulation of inflammatory and angiogenic factors.     

Analysis of polyadenylated RNA from brain synaptosomes and mitochondria

We have isolated RNA from sheep brain synaptosomes and mitochondria separated by an aqueous two-phase system composed of dextran and poly(ethylene glycol). RNA was fractionated through oligo(dT)-cellulose columns and analyzed by electrophoresis through agarose slab gels containing methylmercuric hydroxide and stained with ethidium bromide. The electrophoretic patterns of the poly(A)-containing RNA fraction from synaptosomes and mitochondria are very similar although some high molecular weight RNA species, clearly visible in the synaptosomal fraction, are scarcely detected in the mitochondrial preparations. The electrophoretic analysis of a cleaner RNA preparation from digitonin-treated free mitochondria (mitoplasts) showed that all the poly (A)-RNA species of the synaptosomal preparation are also present in mitoplast. These results strongly suggest that all the discrete poly(A)-RNA species identified in brain synaptosomes are of mitochondrial origin.     

Differential effect of shade,water and soil type on emergence and early survival of three dominant species of the Atacama Desert

Understanding the regeneration niche of species may allow us to gain insight into how communities are structured. In deserts, the regeneration niche is usually related to spaces beneath shrubs where shade cast by shrubs creates microenvironments that benefit seedlings and where even small amounts of rain may favour germination and establishment. Shade and water may also interact with different types of soils. However, species may have different requirements for germination and seedling survival. We could expect that shrub species with different drought tolerances exhibit different responses to the combination of these factors. We ask if responses of dominant species of the Atacama Desert to abiotic factors (shade, water and soil type) are related to their drought tolerance, a topic not exhaustively explored in shrubs growing in true deserts. We conducted two factorial experiments. The first one was designed to evaluate how shade (microhabitat) in combination with water may affect germination (emergence) and early survival. In the second experiment, we assessed the influence of shade in relation to soil type. Each species responded distinctively to the three variables under study, but in general, their emergence responses were more influenced by water (more water, greater emergence) than by microhabitat or soil type. Survival was influenced both by microhabitat and by water and was higher under shade and abundant water. Soil type affected only one of our species in terms of emergence. Species responses in general depended on their tolerance to stress. In one species, there was indication of a seed–seedling conflict. Our results show similar species responses to environmental constraints but also more or less unique responses that are related to their tolerance to drought and which may ultimately permit species coexistence. We found that shade may not be important for germination but may be crucial for survival in dry years.     

Inhibitory effect of a defensin gene from the Andean crop maca (Lepidium meyenii) against Phytophthora infestans

In this study, we report the isolation of a defensin gene, lm-def, isolated from the Andean crop 'maca' (Lepidium meyenii) with activity against the pathogen Phytophthora infestans responsible of late blight disease of the potato and tomato crops. The lm-def gene has been isolated by polymerase chain reaction (PCR) using degenerate primers corresponding to conserved regions of 13 plant defensin genes of the Brassicaceae family assuming that defensin genes are highly conserved among cruciferous species. The lm-def gene belongs to a small multigene family of at least 10 members possibly including pseudogenes as assessed by genomic hybridization and nucleotide sequence analyses. The deduced mature Lm-Def peptide is 51 amino acids in length and has 74-94% sequence identity with other plant defensins of the Brassicaceae family. The Lm-Def peptide was produced as a fusion protein using the pET-44a expression vector and purified using an immobilized metal ion affinity chromatography. The recombinant protein (NusA:Lm-Def) exhibited in vitro activity against P. infestans. The NusA:Lm-Def protein caused growth inhibition and hyphal damage at concentration not greater than 0.4 microM. In contrast, the NusA protein alone expressed and purified similarly did not show any activity against P. infestans. Therefore, these results indicate that the lm-def gene isolated from maca belong to the plant defensin family with activity against P. infestans. Its expression in potato, as a transgene, might help to control the late blight disease caused by P. infestans with the advantage of being of plant origin.     

Multiparametric magnetic resonance imaging-guided salvage radiotherapy in prostate cancer

AimTo analyse the efficacy and toxicity of postprostatectomy SRT in patients with a BCR evaluated with mpMRI.BackgroundMultiparametric magnetic resonance imaging (mpMRI) has the ability to detect the site of pelvic recurrence in patients with biochemical recurrence (BCR) after radical prostatectomy (RP). However, we do not know the oncological outcomes of mpMRI-guided savage radiotherapy (SRT).ResultsLocal, lymph node, and pelvic bone recurrence was observed in 13, 4 and 2 patients, respectively. PSA levels were significantly lower in patients with negative mpMRI (0.4 ng/mL [0.4]) vs. positive mpMRI (2.2 ng/mL [4.1], p = 0.003). Median planning target volume doses in patients with visible vs. non-visible recurrences were 76 Gy vs. 70 Gy. Overall, mean follow-up was 41 months (6–81). Biochemical relapse-free survival (bRFS) at 3 years was 82.3% and 82.5%, respectively, for the negative and positive mpMRI groups (p = 0.800). Three-year rates of late grade ≥2 urinary and rectal toxicity were 14.8% and 1.9%, respectively; all but one patient recovered without sequelae.ConclusionSRT to the macroscopic recurrence identified by mpMRI is a feasible and well-tolerated option. In this study, there were no differences in bRFS between MRI-positive and MRI-negative patients, indicating effective targeting of MRI-positive lesions.     

Lysyl Hydroxylase 3 Localizes to Epidermal Basement Membrane and Is Reduced in Patients with Recessive Dystrophic Epidermolysis Bullosa

Recessive dystrophic epidermolysis bullosa (RDEB) is caused by mutations in COL7A1 resulting in reduced or absent type VII collagen, aberrant anchoring fibril formation and subsequent dermal-epidermal fragility. Here, we identify a significant decrease in PLOD3 expression and its encoded protein, the collagen modifying enzyme lysyl hydroxylase 3 (LH3), in RDEB. We show abundant LH3 localising to the basement membrane in normal skin which is severely depleted in RDEB patient skin. We demonstrate expression is in-part regulated by endogenous type VII collagen and that, in agreement with previous studies, even small reductions in LH3 expression lead to significantly less secreted LH3 protein. Exogenous type VII collagen did not alter LH3 expression in cultured RDEB keratinocytes and we show that RDEB patients receiving bone marrow transplantation who demonstrate significant increase in type VII collagen do not show increased levels of LH3 at the basement membrane. Our data report a direct link between LH3 and endogenous type VII collagen expression concluding that reduction of LH3 at the basement membrane in patients with RDEB will likely have significant implications for disease progression and therapeutic intervention.     

Clues on Syntenic Relationship among Some Species of Oryzomyini and Akodontini Tribes (Rodentia: Sigmodontinae)

Sigmodontinae rodents represent one of the most diverse and complex components of the mammalian fauna of South America. Among them most species belongs to Oryzomyini and Akodontini tribes. The highly specific diversification observed in both tribes is characterized by diploid complements, which vary from 2n = 10 to 86. Given this diversity, a consistent hypothesis about the origin and evolution of chromosomes depends on the correct establishment of synteny analyzed in a suitable phylogenetic framework. The chromosome painting technique has been particularly useful for identifying chromosomal synteny. In order to extend our knowledge of the homeological relationships between Akodontini and Oryzomyini species, we analyzed the species Akodon montensis (2n = 24) and Thaptomys nigrita (2n = 52) both from the tribe Akodontini, with chromosome probes of Hylaeamys megacephalus (2n = 54) of the tribe Oryzomyini. The results indicate that at least 12 of the 26 autosomes of H. megacephalus show conserved synteny in A. montensis and 14 in T. nigrita. The karyotype of Akodon montensis, as well as some species of the Akodon cursor species group, results from many chromosomal fusions and therefore the syntenic associations observed probably represent synapomorphies. Our finding of a set of such associations revealed by H. megacephalus chromosome probes (6/21; 3/25; 11/16/17; and, 14/19) provides phylogenetic information for both tribes. An extension of these observations to other members of Akodontini and Oryzomyini tribes should improve our knowledge about chromosome evolution in both these groups.     

Two related low-temperature-inducible genes of Arabidopsis encode proteins showing high homology to 14-3-3 proteins,a family of putative kinase regulators

We have isolated two Rare Cold-Inducible (RCI1 and RCI2) cDNAs by screening a cDNA library prepared from cold-acclimated etiolated seedlings of Arabidopsis thaliana with a subtracted probe. RNA-blot hybridizations revealed that the expression of both RCI1 and RCI2 genes is induced by low temperature independently of the plant organ or the developmental stage considered. However, RCI1 mRNA accumulates faster and at higher levels than the RCI2 one indicating that these genes have differential responsiveness to cold stress. Additionally, when plants are returned to room temperature, RCI1 mRNA decreases faster than RCI2. In contrast to most of the cold-inducible plant genes characterized, the expression of RCI1 and RCI2 is not induced by ABA or water stress. The nucleotide sequences of RCI1 and RCI2 cDNAs predict two acidic polypeptides of 255 and 251 amino acids with molecular weights of 29 and 28 kDa respectively. The alignment of these polypeptides indicates that they have 181 identical amino acids suggesting that the corresponding genes have a common origin. Sequence comparisons reveal no similarities between the RCI proteins and any other cold-regulated plant protein so far described. Instead, they demonstrate that the RCI proteins are highly homologous to a family of proteins, known as 14-3-3 proteins, which are thought to be involved in the regulation of multifunctional protein kinases.