Investigating the impact of insertion sequences and transposons in the genomes of the most significant phytopathogenic bacteria.

Genetic variability in phytopathogens is one of the main problems encountered for effective plant disease control. This fact may be related to the presence of transposable elements (TEs), but little is known about their role in host genomes. Here, we performed the most comprehensive analysis of insertion sequences (ISs) and transposons (Tns) in the genomes of the most important bacterial plant pathogens. A total of 35 692 ISs and 71 transposons were identified in 270 complete genomes. The level of pathogen-host specialization was found to be a significant determinant of the element distribution among the species. Some Tns were identified as carrying virulence factors, such as genes encoding effector proteins of the type III secretion system and resistance genes for the antimicrobial streptomycin. Evidence for IS-mediated ectopic recombination was identified in Xanthomonas genomes. Moreover, we found that IS elements tend to be inserted in regions near virulence and fitness genes, such ISs disrupting avirulence genes in X. oryzae genomes. In addition, transcriptome analysis under different stress conditions revealed differences in the expression of genes encoding transposases in the Ralstonia solanacearum, X. oryzae, and P. syringae species. Lastly, we also investigated the role of Tns in regulation via small noncoding regulatory RNAs and found these elements may target plant-cell transcriptional activators. Taken together, the results indicate that TEs may have a fundamental role in variability and virulence in plant pathogenic bacteria.

Physical Fitness Profile of High-Level Female Portuguese Handball Players.

We characterized the physical and physiological profiles of high-level female Portuguese handball players and examined the relationships between their anthropometric characteristics, general motor performance and cardiopulmonary fitness. Twenty-four high-level female handball players with an average age of 23.6 ± 5.5 years, height of 173.6 ± 5.1 cm and body mass of 72.6 ± 9.1 kg volunteered to participate. A Pearson correlation test was used to assess the relationship between variables. Direct relationships were observed between the players' height and arm span (r = 0.741), as well as between their squat jump and countermovement jump performances with regard to body mass (r = 0.448 and 0.496, respectively). The 9 m jump shot has a large relationship with the 7 m standing throw (r = 0.786) and between left hand dynamometry and body mass index (r = 0.595). The 30 m sprint has a relationship with the 7 m standing throw (r = -0.526) and the 9 m jump throw (r = -0.551). Oxygen uptake has a relationship with the players' height (r = -0.482) and time limit (r = 0.513), while the fitness index has a relation to the players' height (r = -0.488) and arm span (r = -0.422). Our results should be considered when using physical testing to plan optimal physical training regimens in elite team handball.

Intracycle Velocity Variation in Swimming: A Systematic Scoping Review.

Intracycle velocity variation is a swimming relevant research topic, focusing on understanding the interaction between hydrodynamic propulsive and drag forces. We have performed a systematic scoping review to map the main concepts, sources and types of evidence accomplished. Searches were conducted in the PubMed, Scopus and Web of Science databases, as well as the Biomechanics and Medicine in Swimming Symposia Proceedings Book, with manual searches, snowballing citation tracking, and external experts consultation. The eligibility criteria included competitive swimmers' intracycle velocity variation assessment of any sex, distance, pace, swimming technique and protocol. Studies' characteristics were summarized and expressed in an evidence gap map, and the risk of bias was judged using RoBANS. A total of 76 studies, corresponding to 68 trials involving 1440 swimmers (55.2 and 34.1% males and females), were included, with only 20 (29.4%) presenting an overall low risk of bias. The front crawl was the most studied swimming technique and intracycle velocity variation was assessed and quantified in several ways, leading to extremely divergent results. Researchers related intracycle velocity variation to coordination, energy cost, fatigue, technical proficiency, velocity, swimming techniques variants and force. Future studies should focus on studying backstroke, breaststroke and butterfly at high intensities, in young, youth and world-class swimmers, as well as in IVV quantification.

Harnessing Novel Soil Bacteria for Beneficial Interactions with Soybean.

It is claimed that one g of soil holds ten billion bacteria representing thousands of distinct species. These bacteria play key roles in the regulation of terrestrial carbon dynamics, nutrient cycles, and plant productivity. Despite the overwhelming diversity of bacteria, most bacterial species remain largely unknown. Here, we used an oligotrophic medium to isolate novel soil bacteria for positive interaction with soybean. Strictly 22 species of bacteria from the soybean rhizosphere were selected. These isolates encompass ten genera (Kosakonia, Microbacterium, Mycobacterium, Methylobacterium, Monashia, Novosphingobium, Pandoraea, Anthrobacter, Stenotrophomonas, and Rhizobium) and have potential as novel species. Furthermore, the novel bacterial species exhibited plant growth-promoting traits in vitro and enhanced soybean growth under drought stress in a greenhouse experiment. We also reported the draft genome sequences of Kosakonia sp. strain SOY2 and Agrobacterium sp. strain SOY23. Along with our analysis of 169 publicly available genomes for the genera reported here, we demonstrated that these bacteria have a repertoire of genes encoding plant growth-promoting proteins and secondary metabolite biosynthetic gene clusters that directly affect plant growth. Taken together, our findings allow the identification novel soil bacteria, paving the way for their application in crop production.

Shoulder Torque Production and Muscular Balance after Long and Short Tennis Points.

Tennis is an asymmetric sport characterized by a systematic repetition of specific movements that may cause disturbances in muscular strength, power, and torque. Thus, we assessed (i) the torque, power, ratio production, and bilateral asymmetries in the shoulder's external and internal rotations at 90 and 180°/s angular velocities, and (ii) the point duration influence of the above-mentioned variables. Twenty competitive tennis players performed external and internal shoulder rotations; an isokinetic evaluation was conducted of the dominant and non-dominant upper limbs before and after five and ten forehands. A higher torque production in the shoulder's internal rotations at 90 and 180°/s was observed for the dominant vs. non-dominant sides (e.g., 63.1 ± 15.6 vs. 45.9 ± 9.8% and 62.5 ± 17.3 vs. 44.0 ± 12.6% of peak torque/body mass, p < 0.05). The peak torque decreased only after ten forehands (38.3 ± 15.8 vs. 38.2 ± 15.8 and 39.3 ± 16.1 vs. 38.1 ± 15.6 Nm, respectively, p < 0.05), but without impacting speed or accuracy. Unilateral systematic actions of tennis players caused contralateral asymmetries, evidencing the importance of implementing compensatory training. The forehand kinematic assessment suggests that racket and wrist amplitude, as well as speed, are important success determinants in tennis.

Genomic analysis reveals the role of integrative and conjugative elements in plant pathogenic bacteria.

BACKGROUND: ICEs are mobile genetic elements found integrated into bacterial chromosomes that can excise and be transferred to a new cell. They play an important role in horizontal gene transmission and carry accessory genes that may provide interesting phenotypes for the bacteria. Here, we seek to research the presence and the role of ICEs in 300 genomes of phytopathogenic bacteria with the greatest scientific and economic impact. RESULTS: Seventy-eight ICEs (45 distinct elements) were identified and characterized in chromosomes of Agrobacterium tumefaciens, Dickeya dadantii, and D. solani, Pectobacterium carotovorum and P. atrosepticum, Pseudomonas syringae, Ralstonia solanacearum Species Complex, and Xanthomonas campestris. Intriguingly, the co-occurrence of four ICEs was observed in some P. syringae strains. Moreover, we identified 31 novel elements, carrying 396 accessory genes with potential influence on virulence and fitness, such as genes coding for functions related to T3SS, cell wall degradation and resistance to heavy metals. We also present the analysis of previously reported data on the expression of cargo genes related to the virulence of P. atrosepticum ICEs, which evidences the role of these genes in the infection process of tobacco plants. CONCLUSIONS: Altogether, this paper has highlighted the potential of ICEs to affect the pathogenicity and lifestyle of these phytopathogens and direct the spread of significant putative virulence genes in phytopathogenic bacteria.

Intra- and inter-cycle velocity variations in sprint front crawl swimming.

Intra- and inter-cycle velocity variations are of utmost importance for achieving enhanced swimming performances. However, intra-cycle events can impact and interfere with the subsequent cycles, making relevant to study several consecutive cycles allowing a better understanding of this possibility. We have assessed front crawl intra- and inter-cyclic velocity variations and overall biomechanical variables in sprint front crawl swimming. Twenty-seven elite swimmers performed 25 m all-out front crawl, were videotaped using moving cameras placed at the sagittal plane and were grouped according to their sprint mean velocity. Coefficient of variation, root mean square error and mean velocity differences between two consecutive paired cycles allowed assessing intra- and inter-cycle velocity variations. Visual inspection was performed to analyse possible variability causes and independent-measures t-test allowed comparing groups. Sprint front crawl was characterised by intra- (11.12 ± 2.98) and inter-cycle velocity variation (2.27 ± 0.80 of inter-cycle velocity coefficient of variation and 0.031 ± 0.014 of root mean square error), with no differences between fastest and slowest swimmers. Front crawl intra-cycle velocity variation was not related to mean velocity and cycle sequence but considered swimmers' personal strategy. Despite some abnormal oscillations within cycles, inter-cycle velocity variation was not caused by intra-cycle velocity variation, mean velocity or cycle sequence.

Velocity Variability and Performance in Backstroke in Elite and Good-Level Swimmers.

Backstroke swimming, a cyclic and continuous movement, displays a repeating structure due to the repeated action of the limb, presenting similar (but not identical) cycles. Some variability is generated by instabilities, but this may play a functional role in the human performance, allowing individual adaptations to constraints. The current study examined the role of velocity variability in backstroke performance, hypothesizing that this variable is associated with swimmers' performance. Sixteen elite and fifteen good-level swimmers were video recorded in the sagittal plane when performing 25 m backstroke at maximal intensity in order to determine hip velocity and mean velocity, stroke rate, stroke length and indexes of coordination/synchronization. Lyapunov maximal exponent and sample entropy were also calculated for successive cycles. The elite swimmers' performances were more unstable (0.1742 ± 0.1131 versus 0.0831 ± 0.0042, p < 0.001) and complex (0.9222 ± 0.4559 versus 0.3821 ± 0.3096, p < 0.001) than their good-level counterparts, but intracycle velocity variation did not differ (11.98 ± 3.47 versus 12.03 ± 3.16%, p > 0.05). Direct relationships were observed between mean velocity and stability (r = 0.40, p = 0.03), as well as with complexity (r = 0.53, p = 0.002), with intracycle velocity variation and complexity also being related (r = 0.38, p = 0.04). Backstroke performance is associated with velocity variability, with elite swimmers being able to control it through several adaptations, overcoming the high drag and inertia.

Human Diacylglycerol Kinase ε N-Terminal Segment Regulates the Phosphatidylinositol Cycle, Controlling the Rate but Not the Acyl Chain Composition of Its Lipid Intermediates.

Diacylglycerol kinase ε (DGKε), an enzyme of the phosphatidylinositol (PI) cycle, bears a highly conserved hydrophobic N-terminal segment, which was proposed to anchor the enzyme into the membrane. However, the importance of this segment to the DGKε function remains to be determined. To address this question, it is here reported an in silico and in vitro combined research strategy. Capitalizing on the AlphaFold 2.0 predicted structure of human DGKε, it is shown that its hydrophobic N-terminal segment anchors it into the membrane via a transmembrane α-helix. Coarse-grained based elastic network model studies showed that a conformational change in the hydrophobic N-terminal segment determines the proximity between the active site of DGKε and the membrane-water interface, likely regulating its kinase activity. In vitro studies with a purified DGKε construct lacking the hydrophobic N-terminal segment (His-SUMO*-Δ50-DGKε) corroborated the role of the N-terminus in regulating DGKε enzymatic properties. The comparison between the enzymatic properties of DGKε and His-SUMO*-Δ50-DGKε showed that the conserved N-terminal segment markedly inhibits the enzyme activity and its sensitivity to membrane intrinsic negative curvature, while also playing a role in the modulation of the enzyme by phosphatidylserine. On the other hand, this segment did not strongly affect its diacylglycerol acyl chain specificity, the modulation of the enzyme by membrane morphological changes, or the activation by phosphatidic acid-rich lipid domains. Hence, these results suggest that the conservation of the hydrophobic N-terminal segment of DGKε throughout evolution guaranteed not only membrane anchorage but also an efficient and elegant manner to regulate the rate of the PI cycle.

Transposable elements contribute to the genome plasticity of Ralstonia solanacearum species complex.

The extensive genetic diversity of Ralstonia solanacearum, a serious soil-borne phytopathogen, has led to the concept that R. solanacearum encompasses a species complex [R. solanacearum species complex (RSSC)]. Insertion sequences (ISs) are suggested to play an important role in the genome evolution of this pathogen. Here, we identified and analysed transposable elements (TEs), ISs and transposons, in 106 RSSC genomes and 15 Ralstonia spp. We mapped 10 259 IS elements in the complete genome of 62 representative RSSC strains and closely related Ralstonia spp. A unique set of 20 IS families was widespread across the strains, IS5 and IS3 being the most abundant. Our results showed six novel transposon sequences belonging to the Tn3 family carrying passenger genes encoding antibiotic resistance and avirulence proteins. In addition, internal rearrangement events associated with ISs were demonstrated in Ralstonia pseudosolanacearum strains. We also mapped IS elements interrupting avirulence genes, which provided evidence that ISs plays an important role in virulence evolution of RSSC. Additionally, the activity of ISs was demonstrated by transcriptome analysis and DNA hybridization in R. solanacearum isolates. Altogether, we have provided collective data of TEs in RSSC genomes, opening a new path for understanding their evolutionary impact on the genome evolution and diversity of this important plant pathogen.

Regulation of DGKε Activity and Substrate Acyl Chain Specificity by Negatively Charged Phospholipids.

Diacylglycerol kinase ε (DGKε) is a membrane-bound enzyme that catalyzes the ATP-dependent phosphorylation of diacylglycerol to form phosphatidic acid (PA) in the phosphatidylinositol cycle. DGKε lacks a putative regulatory domain and has recently been reported to be regulated by highly curved membranes. To further study the effect of other membrane properties as a regulatory mechanism of DGKε, our work reports the effect of negatively charged phospholipids on DGKε activity and substrate acyl chain specificity. These studies were conducted using purified DGKε and detergent-free phospholipid aggregates, which present a more suitable model system to access the impact of membrane physical properties on membrane-active enzymes. The structural properties of the different model membranes were studied by means of differential scanning calorimetry and 31P-NMR. It is shown that the enzyme is inhibited by a variety of negatively charged phospholipids. However, PA, which is a negatively charged phospholipid and the product of DGKε catalyzed reaction, showed a varied regulatory effect on the enzyme from being an activator to an inhibitor. The type of feedback regulation of DGKε by PA depends on the particular PA molecular species as well as the physical properties of the membrane that the enzyme binds to. In the presence of highly packed PA-rich domains, the enzyme is activated. However, its acyl chain specificity is only observed in liposomes containing 1,2-dioleoyl PA in the presence of Ca2+. It is proposed that to endow the enzyme with its substrate acyl chain specificity, a highly dehydrated (hydrophobic) membrane interface is needed. The presence of an overlap of mechanisms to regulate DGKε ensures proper phosphatidylinositol cycle function regardless of the trigged stimulus and represents a sophisticated and specialized manner of membrane-enzyme regulation.