Disentangling hydroxynitrile glucoside biosynthesis in a barley (Hordeum vulgare) metabolon provides access to elite malting barleys for ethyl carbamate-free whisky production

Barley produces several specialized metabolites, including five α-, β-, and γ-hydroxynitrile glucosides (HNGs). In malting barley, presence of the α-HNG epiheterodendrin gives rise to undesired formation of ethyl carbamate in the beverage production, especially after distilling. Metabolite-GWAS identified QTLs and underlying gene candidates possibly involved in the control of the relative and absolute content of HNGs, including an undescribed MATE transporter. By screening 325 genetically diverse barley accessions, we discovered three H. vulgare ssp. spontaneum (wild barley) lines with drastic changes in the relative ratios of the five HNGs. Knock-out (KO)-lines, isolated from the barley FIND-IT resource and each lacking one of the functional HNG biosynthetic genes (CYP79A12, CYP71C103, CYP71C113, CYP71U5, UGT85F22 and UGT85F23) showed unprecedented changes in HNG ratios enabling assignment of specific and mutually dependent catalytic functions to the biosynthetic enzymes involved. The highly similar relative ratios between the five HNGs found across wild and domesticated barley accessions indicate assembly of the HNG biosynthetic enzymes in a metabolon, the functional output of which was reconfigured in the absence of a single protein component. The absence or altered ratios of the five HNGs in the KO-lines did not change susceptibility to the fungal phytopathogen Pyrenophora teres causing net blotch. The study provides a deeper understanding of the organization of HNG biosynthesis in barley and identifies a novel, single gene HNG-0 line in an elite spring barley background for direct use in breeding of malting barley, eliminating HNGs as a source of ethyl carbamate formation in whisky production.</p

Mechanical properties during healing of Achilles tendon ruptures to predict final outcome: A pilot Roentgen stereophotogrammetric analysis in 10 patients

<p>Abstract</p> <p>Background</p> <p>There are presently few methods described for in vivo monitoring of the mechanics of healing human tendon ruptures, and no methods for prediction of clinical outcome. We tested if Roentgen stereophotogrammetric analysis (RSA) can be used to follow the restoration of mechanical properties during healing of ruptured Achilles tendons, and if early measurements can predict clinical results.</p> <p>Methods</p> <p>Achilles tendon repair was studied with RSA in 10 patients with a total rupture. Tantalum beads were implanted in conjunction with surgical repair. The patients were evaluated at 6, 12 and 18 weeks, and after 1 year. RSA was performed with two different mechanical loadings, and the strain induced by increasing load was measured. The transverse area was determined by ultrasound. CT scan at 12 weeks confirmed that the tantalum beads were located within the tendons. Functional testing was done after 1 year. A heel raise index was chosen as primary clinical outcome variable.</p> <p>Results</p> <p>The strain was median 0.90, 0.32 and 0.14 percent per 100 N tendon force at 6 weeks, 18 weeks and one year respectively. The error of measurement was 0.04 percent units at 18 weeks. There was a large variation between patients, which appears to reflect biological variation. From 6 to 18 weeks, there was a negative correlation between increase in transverse area and increase in material properties, suggesting that healing is regulated at the organ level, to maximize stiffness. Modulus of elasticity during this time correlated with a heel raise index at one year (Rho = 0.76; p = 0.02).</p> <p>Conclusion</p> <p>We conclude that the RSA method might have potential for comparing different treatments of Achilles tendon ruptures.</p

Structural variation in the pangenome of wild and domesticated barley

Pangenomes are collections of annotated genome sequences of multiple individuals of a species1. The structural variants uncovered by these datasets are a major asset to genetic analysis in crop plants2. Here we report a pangenome of barley comprising long-read sequence assemblies of 76 wild and domesticated genomes and short-read sequence data of 1,315 genotypes. An expanded catalogue of sequence variation in the crop includes structurally complex loci that are rich in gene copy number variation. To demonstrate the utility of the pangenome, we focus on four loci involved in disease resistance, plant architecture, nutrient release and trichome development. Novel allelic variation at a powdery mildew resistance locus and population-specific copy number gains in a regulator of vegetative branching were found. Expansion of a family of starch-cleaving enzymes in elite malting barleys was linked to shifts in enzymatic activity in micro-malting trials. Deletion of an enhancer motif is likely to change the developmental trajectory of the hairy appendages on barley grains. Our findings indicate that allelic diversity at structurally complex loci may have helped crop plants to adapt to new selective regimes in agricultural ecosystems.</p

Patellar tendon properties distinguish elite from non-elite soccer players and are related to peak horizontal but not vertical power

Purpose: The aims of our study were to investigate differences in tendon properties between elite and non-elite soccer players, and to establish whether tendon properties were related to power assessed during unilateral jumps in different directions. Methods: Elite (n=16; age, 18.1 ± 1.0yrs) and non-elite (n=13; age, 22.3 ± 2.7yrs) soccer players performed three repetitions of each type (unilateral vertical, unilateral horizontal-forward and unilateral medial) of countermovement jump (CMJ) on a force plate. Patellar tendon (PT) cross-sectional area (CSA), elongation, stiffness and Young’s modulus (measured at the highest common force interval) were assessed with ultrasonography and isokinetic dynamometry. Results: Elite soccer players demonstrated greater PT elongation (6.83±1.87 vs. 4.92±1.88 mm, P=0.011) and strain (11.73±3.25 vs. 8.38±3.06 %, P=0.009) than non-elite. Projectile range and peak horizontal power during unilateral horizontal-forward CMJ correlated positively with tendon elongation (r=0.657 and 0.693, P<0.001) but inversely with Young’s modulus (r=-0.376 and -0.402, P=0.044 and 0.031). Peak medial power during unilateral medial CMJ correlated positively with tendon elongation (r=0.658, P=<0.001) but inversely with tendon stiffness (r=-0.368, P=0.050). No tendon property correlated with unilateral vertical CMJ performance (r≤0.168; P≥0.204). Conclusions: Patellar tendon strain was greater in elite vs. non-elite soccer players and can therefore be considered an indicator of elite soccer playing status. Moreover, a more compliant patellar tendon appears to facilitate unilateral horizontal-forward and medial, but not vertical CMJ performance in soccer players. These findings should be considered when prescribing the detail of talent selection and development protocols related to direction-specific power in elite soccer players

Influence of exercise intensity on training-induced tendon mechanical properties changes in older individuals

This study compared the effects of low vs. high intensity training on tendon properties in an elderly population. Participants were pair-matched (gender, habitual physical activity, anthropometrics, and baseline knee extension strength) and then randomly assigned to low (LowR, i.e., ∼40 % 1RM) or high (High R, i.e., ∼80 % 1RM) intensity resistance training programmes for 12 weeks, 3x per week (LowR, n = 9, age 74 ± 5 years; HighR, n = 8, age 68 ± 6 years). Patellar tendon properties (stiffness [K], Young's modulus [YM], cross-sectional area [T CSA], and tendon length [T L]) were measured pre and post training using a combination of magnetic resonance imaging (MRI), B-mode ultrasonography, dynamometry, electromyography and ramped isometric knee extensions. With training K showed no significant change in the LowR group while it incremented by 57.7 % in the HighR group (p < 0.05). The 51.1 % group difference was significant (p < 0.05). These differences were still apparent when the data was normalized for T CSA and T L, i.e., significant increase in YM post-intervention in HighR (p < 0.05), but no change in LowR. These findings suggest that when prescribing exercise for a mixed genders elderly population, exercise intensities of ≤40 % 1RM may not be sufficient to affect tendon properties. © 2014 American Aging Association

The role of muscle strength on tendon adaptability in old age.

PURPOSE: The purpose of the study was to determine: (1) the relationship between ankle plantarflexor muscle strength and Achilles tendon (AT) biomechanical properties in older female adults, and (2) whether muscle strength asymmetries between the individually dominant and non-dominant legs in the above subject group were accompanied by inter-limb AT size differences. METHODS: The maximal generated AT force, AT stiffness, AT Young's modulus, and AT cross-sectional area (CSA) along its length were determined for both legs in 30 women (65 ± 7 years) using dynamometry, ultrasonography, and magnetic resonance imaging. RESULTS: No between-leg differences in triceps surae muscle strength were identified between dominant (2798 ± 566 N) and non-dominant limb (2667 ± 512 N). The AT CSA increased gradually in the proximo-distal direction, with no differences between the legs. There was a significant correlation (P < 0.05) of maximal AT force with AT stiffness (r = 0.500) and Young's modulus (r = 0.414), but only a tendency with the mean AT CSA. However, region-specific analysis revealed a significant relationship between maximal AT force and the proximal part of the AT, indicating that this region is more likely to display morphological adaptations following an increase in muscle strength in older adults. CONCLUSIONS: These findings demonstrate that maximal force-generation capabilities play a more important role in the variation of AT stiffness and material properties than in tendon CSA, suggesting that exercise-induced increases in muscle strength in older adults may lead to changes in tendon stiffness foremost due to alterations in material rather than in its size

Identification of manganese efficiency candidate genes in winter barley (Hordeum vulgare) using genome wide association mapping

BACKGROUND: Manganese (Mn) has several essential functions in plants, including a role as cofactor in the oxygen evolving complex (OEC) of photosystem II (PSII). Manganese deficiency is a major plant nutritional disorder in winter cereals resulting in significant yield reductions and winter kill in more severe cases. Among the winter cereals, genotypes of winter barley are known to differ considerably in tolerance to Mn deficiency, but the genes controlling the Mn deficiency trait remains elusive. RESULTS: Experiments were conducted using 248 barley varieties, cultivated in six distinct environments prone to induce Mn deficiency. High-throughput phenotyping for Mn deficiency was performed by chlorophyll a (Chl a) fluorescence analysis to quantify the quantum yield efficiency of PSII. High-throughput phenotyping in combination with ICP-OES based multi-element analyses allowed detection of marker-trait associations by genome wide association (GWA) mapping. Several key candidate genes were identified, including PSII subunit proteins, germin like proteins and Mn superoxide dismutase. The putative roles of the encoded proteins in Mn dependent metabolic processes are discussed. CONCLUSIONS: Fifty-four candidate genes were identified by Chl a fluorescence phenotyping and association genetics. Tolerance of plants to Mn deficiency, which is referred to as Mn efficiency, appeared to be a complex trait involving many genes. Moreover, the trait appeared to be highly dependent on the environmental conditions in field. This study provides the basis for an improved understanding of the parameters influencing Mn efficiency and is valuable in future plant breeding aiming at producing new varieties with improved tolerance to cultivation in soil prone to induce Mn deficiency. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12864-016-3129-9) contains supplementary material, which is available to authorized users