Mucocytes with micronuclei and sowing with the coccoid forms of <Emphasis Type="Italic">Helicobacter pylori</Emphasis> in a mucous membrane of human stomach

In accordance with the solution of IARC, the Helicobacter pylori (H. pylori) refers to carcinogens of the first group. As the carcinogenic factors have a mutagen effect, we have undertaken the cytogenetic testing of 62 patients with chronic nonatrophic gastritis (40 of which have H. pylori-associated gastritis) by account of the micronuclei in mucocytes of tectorial-pit epithelium of the mucous membrane of the antral region of the stomach. The detection of H. pylori cells in the mucous membrane of the stomach (SMM) was performed with the help of immunocytochemical method that permitted us to visualize both the bacillar and coccoid forms, as well as to evaluate the degree of sowing of SMM with the coccoid forms of H. pylori. In the patient group with H. pylori-associated gastritis, the frequency rate of mucocytes with micronuclei in SMM appears to be considerably higher than in the group of patients whose SMM was not infected with H. pylori (P < 0,05). A high scale of sowing with the coccoid forms of H. pylori was accompanied by a significantly heightened level of mucocytes with micronuclei in the SMM. In connection with this and on the basis of modern notions of carcinogenesis, based on mutagen modifications in somatic cells, patients that exhibit high sowing with coccoid forms of H. pylori may be placed in the group of heightened oncologic hazards.     

Metabolomics of groundnut (<Emphasis Type="Italic">Arachis hypogaea</Emphasis> L.) genotypes under varying temperature regimes

Various metabolites were analyzed in groundnut genotypes grown under varying temperature regimes (based on date of sowing). Four contrasting groundnut genotypes viz. ICGS44 (high-temperature tolerant), AK159 and GG7 (moderately-high-temperature tolerant), and DRG1 (high-temperature sensitive) were grown at three different temperature regimes i.e., low (early date of sowing), normal (normal date of sowing) and high temperature (late date of sowing) under field conditions. Untargeted metabolomic analysis of leaf tissue was performed by GC–MS, while targeted metabolite profiling was carried out by HPLC (polyamines) and UPLC-MS/MS (phenolics) at both the pegging and pod filling stages. Untargeted metabolomic profiling revealed exclusive expression/induction of beta-d-galactofuranoside, l-threonine, hexopyranose, d-glucopyranose, stearic acid, 4-ketoglucose, d-gulose, 2-o-glycerol-alpha-d-galactopyranoside and serine in ICGS44 during the pegging stage under high-temperature conditions. During the pod filling stage at higher temperature, alpha-d-galactoside, dodecanedioic acid, 1-nonadecene, 1-tetradecene and beta-d-galactofuranose were found to be higher in both ICGS44 and GG7. Moreover, almost all the metabolites detected by GC–MS were found to be higher in GG7, except beta-d-galactopyranoside, beta-d-glucopyranose, inositol and palmitic acid. Accumulation of putrescine was observed to be higher during low-temperature stress, while agmatine showed constitutive expression in all the genotypes, irrespective of temperature regime and crop growth stage. Interestingly, spermidine was observed only in the high-temperature tolerant genotype ICGS44. In our study, we found a higher accumulation of cinnamic acid, caffeic acid, salicylic acid and vanillic acid in ICGS44 compared to that of other genotypes at the pegging stage, whereas catechin and epicatechin were found during the pod filling stage in response to high-temperature stress, suggesting their probable roles in heat-stress tolerance in groundnut.     

Localized application of NH4 +-N plus P at the seedling and later growth stages enhances nutrient uptake and maize yield by inducing lateral root proliferation

Background and aims

Localized supply of P plus ammonium improves root-proliferation and nutrient-uptake by maize (Zea mays L.) at seedling stage, but it is largely unknown how localized supply of nutrients at both early and late stages influences maize-growth, nutrient-uptake and grain-yield.

Methods

A 2-year field experimentation with maize was conducted with localized application of P plus ammonium as diammonium phosphate (LDAP) or ammonium sulfate plus P (LASP) at sowing or jointing stage, with broadcast urea and P (BURP) or no nitrogen (F0) as controls.

Results

Localized supply of P plus ammonium significantly increased root-proliferation, shoot dry-weight and nutrient-uptake at seedling stage. The positive effect disappeared at 53 days after sowing. However, plant-growth and nutrient-uptake increased again after the second localized application of P plus ammonium at jointing. The density and average length of the first-order lateral roots in local patches increased by 50 % in LDAP and LASP compared with F0 and BURP. Maize-yield increased by 8–10 % compared with BURP. Agronomic N efficiency and N-use efficiency increased by 41–48 % and 25–57 % compared with the BURP.

Conclusions

It is suggested that enhanced root-proliferation in the nutrient-rich patches with localized supply of ammonium and P at sowing and jointing stages is essential for improving nutrient-uptake and ultimately grain-yield.     

Identifying protein complexes based on density and modularity in protein-protein interaction network

Background

Identifying protein complexes is crucial to understanding principles of cellular organization and functional mechanisms. As many evidences have indicated that the subgraphs with high density or with high modularity in PPI network usually correspond to protein complexes, protein complexes detection methods based on PPI network focused on subgraph's density or its modularity in PPI network. However, dense subgraphs may have low modularity and subgraph with high modularity may have low density, which results that protein complexes may be subgraphs with low modularity or with low density in the PPI network. As the density-based methods are difficult to mine protein complexes with low density, and the modularity-based methods are difficult to mine protein complexes with low modularity, both two methods have limitation for identifying protein complexes with various density and modularity.

Results

To identify protein complexes with various density and modularity, including those have low density but high modularity and those have low modularity but high density, we define a novel subgraph's fitness, f _ρ , as f _ρ = (density) ^ρ *(modularity)^1-ρ, and propose a novel algorithm, named LF_PIN, to identify protein complexes by expanding seed edges to subgraphs with the local maximum fitness value. Experimental results of LF-PIN in S.cerevisiae show that compared with the results of fitness equal to density (ρ = 1) or equal to modularity (ρ = 0), the LF-PIN identifies known protein complexes more effectively when the fitness value is decided by both density and modularity (0<ρ<1). Compared with the results of seven competing protein complex detection methods (CMC, Core-Attachment, CPM, DPClus, HC-PIN, MCL, and NFC) in S.cerevisiae and E.coli, LF-PIN outperforms other seven methods in terms of matching with known complexes and functional enrichment. Moreover, LF-PIN has better performance in identifying protein complexes with low density or with low modularity.

Conclusions

By considering both the density and the modularity, LF-PIN outperforms other protein complexes detection methods that only consider density or modularity, especially in identifying known protein complexes with low density or low modularity.

     

Metabotyping of 30 maize hybrids under early-sowing conditions reveals potential marker-metabolites for breeding

Introduction

In Northern Europe, maize early-sowing used to maximize yield may lead to moderate damages of seedlings due to chilling without visual phenotypes. Genetic studies and breeding for chilling tolerance remain necessary, and metabolic markers would be particularly useful in this context.

Objectives

Using an untargeted metabolomic approach on a collection of maize hybrids, our aim was to identify metabolite signatures and/or metabolites associated with chilling responses at the vegetative stage, to search for metabolites differentiating groups of hybrids based on silage-earliness, and to search for marker-metabolites correlated with aerial biomass.

Methods

Thirty genetically-diverse maize dent inbred-lines (Zea mays) crossed to a flint inbred-line were sown in a field to assess metabolite profiles upon cold treatment induced by a modification of sowing date, and characterized with climatic measurements and phenotyping.

Results

NMR- and LC-MS-based metabolomic profiling revealed the biological variation of primary and specialized metabolites in young leaves of plants before flowering-stage. The effect of early-sowing on leaf composition was larger than that of genotype, and several metabolites were associated to sowing response. The metabolic distances between genotypes based on leaf compositional data were not related to the genotype admixture groups, and their variability was lower under early-sowing than normal-sowing. Several metabolites or metabolite-features were related to silage-earliness groups in the normal-sowing condition, some of which were confirmed the following year. Correlation networks involving metabolites and aerial biomass suggested marker-metabolites for breeding for chilling tolerance.

Conclusion

After validation in other experiments and larger genotype panels, these marker-metabolites can contribute to breeding.

     

Genetic and environmental influences on root development in cuttings of selected <Emphasis Type="Italic">Salix</Emphasis> and <Emphasis Type="Italic">Populus</Emphasis> clones – a greenhouse experiment

Aims

This study investigated how genetic determination of adventitious root development compared in experimental hybrid and parental Salix and Populus clones, and how soil bulk density influenced root development.

Methods

Cuttings of 11 Salix clones and 10 Populus clones were grown in pots with water, a low bulk density soil and a high bulk density soil for 4 (water) or 10 weeks (soils). Parameters relating to root development were measured.

Results

Root initiation, total root length (RL), and dry mass (DM), as well as root: shoot relationships in Salix clones exceeded that of Populus clones in all media. For Salix clones RL and DM were highest in S. matsudana?×?pentandra and for Populus clones RL and DM were generally higher in hybrid clones having P. trichocarpa parentage. Mean RL and DM for all clones were generally greater in the low bulk density soil than in the high bulk density soil. There were a greater proportion of thinner roots in the low bulk density soil than in the high bulk density soil.

Conclusions

There were significant differences in root initiation, RL, and DM among clones within each genus. Increasing soil bulk density significantly reduced root development in both Salix and Populus clones. Evaluating cutting root development in pot trials could be a useful clone selection tool in willow and poplar breeding.

     

Density functional studies on photophysical properties and chemical reactivities of the triarylboranes: effect of the constraint of planarity

The geometric and electronic structures, absorption spectra, transporting properties, chemical reactivity indices and electrostatic potentials of the planar three-coordinate organoboron compounds 1-2 and twisted reference compound Mes ₃ B, have been investigated by employing density functional theory (DFT) and conceptual DFT methods to shed light on the planarity effects on the photophysical properties and the chemical reactivity. The results show that the planar compounds 1-2 exhibit significantly lower HOMO level than Mes ₃ B, owing to the stronger electronic induction effect of boron centers. This feature conspicuously induces a blue shifted absorption for 1, although 1 seemingly possesses more extended conjugation framework than Mes ₃ B. Importantly, the reactivity strength of the boron atoms in 1-2 is much lower than that in Mes ₃ B, despite the fact that the tri-coordinate boron centers of 1-2 are completely naked. The interesting and abnormal phenomenon is caused by the strong p-π electronic interactions, that is, the empty p-orbital of boron center is partly filled by π-electron of the neighbor carbon atoms in 1-2, which are confirmed by the analysis of Laplacian of the electron density and natural bond orbitals. Furthermore, the negative electrostatic potentials of the boron centers in 1-2 also interpret that they are not the most preferred sites for incoming nucleophiles. Moreover, it is also found that the planar compounds 1-2 can act as promising electron transporting materials since the internal reorganization energies for electron are really small.

Measurements of the plasma density in the FTU tokamak by a pulsed time-of-flight X-wave refractometer

On-line control over the plasma density in tokamaks (especially, in long-term discharges) requires reliable measurements of the averaged plasma density. For this purpose, a new method of density measurements—a pulsed time-of-flight plasma refractometry—was developed and tested in the T-11M tokamak. This method allows one to determine the averaged density from the measured time delay of nanosecond microwave pulses propagating through the plasma. For an O-wave, the measured time delay is proportional to the line-averaged density and is independent of the density profile (f?f _p ) τ_o ≈ k _o \(\tfrac{1}{{f^2 }}\mathop \smallint \limits_l \) N(x dx. A similar formula is valid for an X-wave: τ_X = ≈ k _x \(\tfrac{{f^2 + f_c^2 }}{{(f^2 - f_c^2 )^2 }}\mathop \smallint \limits_l \) N(x)dx. Here, f is the frequency of the probing wave, f _p is the plasma frequency, l= 4 a is the path length for two-pass probing in the equatorial plane, a is the plasma minor radius, k _O and k _X are numerical factors, f _c is the electron-cyclotron frequency at the axis of the plasma column, and f _p ?f _c , f. Measurements of the time delay provide the same information as plasma interferometry, though they do no employ the effect of interference. When the conditions f _p ?f _c , f are not satisfied, the measured time delay depends on the shape of the density profile. In this case, in order to determine the average density regardless of the density profile, it is necessary to perform simultaneous measurements at several probing frequencies in order to determine the average density. In ITER (Bt ～ 5T), a spectral window between the lower and upper cutoff frequencies in the range of 50–100 GHz can be used for pulsed time-of-flight X-wave refractometry. This appreciably simplifies the diagnostics and eliminates the problem of the first mirror. In this paper, the first results obtained in the FTU tokamak with a prototype of the ITER pulsed time-of-flight refractometer are presented. The geometry and layout of experiments similar to the planned ITER experiments are described. The density measured by pulsed time-of-flight refractometry is shown to agree well with the results obtained in FTU with a two-frequency scanning IR interferometer. The results obtained are analyzed, and the future experiments are discussed.     

Interactive effects of multiple vernalization (<Emphasis Type="Italic">Vrn-1</Emphasis>)- and photoperiod (<Emphasis Type="Italic">Ppd-1</Emphasis>)-related genes on the growth habit of bread wheat and their association with heading and flowering time

Background

The precise identification of Winterness/Springness (growth habit) for bread wheat, which is determined by genes involved in vernalization and photoperiod, will contribute to the effective utilization of bread wheat varieties. Here, 198 varieties from the Yellow and Huai wheat production region (YHW) in China were collected to identify their vernalization (Vrn-1) and photoperiod (Ppd-1) gene composition via a series of functional markers and their association with vernalization and photoperiod requirements at three locations during two years of experiments. The growth habits were measured during the spring sowing season.

Results

The results showed that the semi-winter varieties (grades1–4) were most prevalent in the population. The relative effects of single Vrn alleles on the growth period, such as heading date (HD) and/or flowering date (FD), were as follows: Vrn-B1b?>?Vrn-B1a?>?Vrn-D1b?>?Vrn-D1a?>?vrn-D1?=?vrn-B1. The interactive effects of Vrn-B1 and Vrn-D1 on HD and FD were identical to those of Vrn-B1b. Approximately 35.3% of the cultivars carried Ppd-B1a (photoperiod-insensitive) and exhibited the earliest HD and FD. The Ppd-D1a-insensitive allele (Hapl II) was carried by just 0.5% of the varieties; however, the other two sensitive alleles were present at a higher frequency, and their effects were slightly weaker than those of Ppd-B1a. In addition, strong interactive effects between Ppd-B1 and Ppd-D1 were detected. In terms of mean values among various genotypes, the effects followed the order of Vrn-1?>?Ppd-1.

Conclusions

According to the results of ANOVA and least significant range (LSR) tests, we can conclude that Vrn-1 rather than Ppd-1 played a major role in controlling vernalization and photoperiod responses in this region. This research will be helpful for precisely characterizing and evaluating the HD, FD and even growth habit of varieties in the YHW at molecular levels.

     

Identifying the critical period for waterlogging on yield and its components in wheat and barley

Background and aims

Crop tolerance to waterlogging depends on factors such as species sensitivity and the stage of development that waterlogging occurs. The aim of this study was to identify the critical period for waterlogging on grain yield and its components, when applied during different stages of crop development in wheat and barley.

Methods

Two experiments were carried out (E1: early sowing date, under greenhouse; E2: late sowing date, under natural conditions). Waterlogging was imposed during 15–20 days in 5 consecutive periods during the crop cycle (from Leaf 1 emergence to maturity).

Results

The greatest yield penalties occurred when waterlogging was applied from Leaf 7 appearance on the main stem to anthesis (from 34 to 92 % of losses in wheat, and from 40 to 79 % in barley for E1 and E2 respectively). Waterlogging during grain filling reduced yield to a lesser degree. In wheat, reductions in grain number were mostly explained by reduced grain number per spike while in barley, by variations in the number of spikes per plant.

Conclusions

The time around anthesis was identified as the most susceptible period to waterlogging in wheat and barley. Exposing the crop to more stressful conditions, e.g. delaying sowing date, magnified the negative responses to waterlogging, although the most sensitive stage (around anthesis) remained unchanged.     

Estimates of Leaf Vein Density Are Scale Dependent

Leaf vein density (LVD) has garnered considerable attention of late, with numerous studies linking it to the physiology, ecology, and evolution of land plants. Despite this increased attention, little consideration has been given to the effects of measurement methods on estimation of LVD. Here, we focus on the relationship between measurement methods and estimates of LVD. We examine the dependence of LVD on magnification, field of view (FOV), and image resolution. We first show that estimates of LVD increase with increasing image magnification and resolution. We then demonstrate that estimates of LVD are higher with higher variance at small FOV, approaching asymptotic values as the FOV increases. We demonstrate that these effects arise due to three primary factors: (1) the tradeoff between FOV and magnification; (2) geometric effects of lattices at small scales; and; (3) the hierarchical nature of leaf vein networks. Our results help to explain differences in previously published studies and highlight the importance of using consistent magnification and scale, when possible, when comparing LVD and other quantitative measures of venation structure across leaves.Leaf vein density (LVD), defined as the total length of veins per unit area, has been linked to rates of photosynthesis (Brodribb et al., 2007), plant and leaf hydraulic conductance (Sack and Frole, 2006; Sack and Holbrook, 2006), leaf size and conductance (Scoffoni et al., 2011), and leaf allometry (Price et al., 2012; Sack et al., 2012). Vein density affects the distance that water has to travel through the mesophyll space, thereby providing a mechanism to influence whole-leaf physiological rates (Raven, 1994; Sack and Frole, 2006; Brodribb et al., 2007). Long distances (low vein density) are associated with longer travel times and thus slower physiological rates; conversely, shorter distances (high vein density) are associated with faster rates. It has been suggested that an increase in vein density contributed to the phylogenetic radiation and rise to ecological dominance of the angiosperms. This idea is supported by comparing vein density across basal and more derived angiosperm lineages and also by comparing vein density in fossils spanning the Cretaceous angiosperm radiation (Boyce et al., 2009; Brodribb et al., 2010; Feild et al., 2011). For a recent review of the importance of LVD, see Sack and Scoffoni (2013).While there has been considerable discussion regarding the physiological, ecological, and evolutionary implications of LVD, there has been almost no discussion of methodological issues associated with its estimation. Most studies use magnified images of cleared leaves to estimate LVD. Image magnification levels reported are variable, from 20× (Boyce et al., 2009) to 25× (Blonder et al., 2011) to 40× (Sack and Frole, 2006), or cover a range of 5× to 40× (Sack et al., 2012). Similarly, the area of each leaf sampled varies, such as 1.5 to 1.9 mm² in Sack et al. (2012) or 5 to 12 mm² in Feild et al. (2011). Variation in sample area and magnification corresponds to measurements that cover a variable total number of areoles and total length of veins. Furthermore, none of the aforementioned studies employing microscopes mentioned, or appeared to consider, the effect of microscope resolving power. The resolving power of a microscope determines the scale at which distinct features within the sample are able to be distinguished in the image. A digital camera used to acquire microscope images should have, at minimum, two pixels spanning the resolving power of the microscope. This will ensure that features able to be resolved through the microscope eyepiece will also be resolvable in the associated digital image.The length of individual veins in each image is usually determined by tracing the lengths of veins manually via widely used image-analysis programs such as ImageJ (Schneider et al., 2012). Recently, several semiautomated approaches have also been utilized that employ skeletonization on binary representations of cleared images (Blonder et al., 2011; Price et al., 2011, 2012; Dhondt et al., 2012). The use of semiautomated software has enabled estimates of vein density at the scale of entire leaves (Price et al., 2012), leading to questions and criticisms regarding differences between studies (Sack et al., 2012).The tradeoff between field of view (FOV; i.e. the physical size of the object studied) and the resolution of measurement underlies image analysis in fields ranging from cosmology to biology (Lindeberg, 1998). In the case of microscopes, this tradeoff is expressed fundamentally by the metric known as the space-bandwidth product (Lohmann et al., 1996). In particular, the space-bandwidth product reveals the maximum total number of resolvable pixels that an imaging system can acquire, which is of the same order for nearly all typical light microscopes, such as the one employed in this study. Generally, a microscope will achieve its space-bandwidth product only at its lowest magnification. This is because, for typical microscopes, the FOV is inversely proportional to both magnification and image resolution (i.e. the number of pixels per unit length), yet resolving power is independent of these quantities. Therefore, differences in imaging resolution can lead to differences in the estimation of object dimensions. In a classic example, estimates of the length of the coastline of Britain were found to depend on the scale of measurement, such that finer resolution imaging led to increases in the apparent length of the coastline (Mandelbrot, 1967). One way of overcoming the interdependence of FOV, magnification, and resolution, and to break the space-bandwidth product limit, is to mosaic several microscope images together into a single, large-FOV, high-resolution image (a technique we employ below).Here, we examine the combined effect of FOV and magnification on the estimation of LVD. We demonstrate that LVD has a strong and systematic dependence on magnification level and FOV, due to both theoretical and empirical considerations. This dependence arises due to three related phenomena arranged roughly in order of decreasing effect: (1) a tradeoff between magnification and resolution in imaging; (2) geometric effects of lattices at small FOVs; and (3) the hierarchical nature of veins, specifically that large veins contribute disproportionally to vein area. The first factor has the potential to influence vein density at all scales of measurement, the second factor will be most pronounced at small FOVs, and the third factor has the strongest effect as vein sample sizes get larger, both within an individual leaf and as leaves themselves get bigger. We show how this scale dependence of LVD has the potential to reconcile estimates of LVD previously reported by groups using magnified (Sack et al., 2012) and unmagnified (Price et al., 2012) images.     

Comparison of rice flowering-time genes under paddy conditions

Heading date is one of most important agronomic traits in rice. Flowering regulatory mechanisms have been elucidated in many cultivars through various approaches. Although study about flowering has been extensively examined in rice, but contributions of floral regulators had been poorly understood in a common genetic background for rice grown under paddy conditions. Thus, we compared the expression of 10 flowering-time genes — OsMADS50, OsMADS51, OsVIL2, OsPhyA, OsPhyB, OsPhyC, Ghd7, Hd1, OsGI, and OsTrx1 — in the same genetic background for ‘Dongjin’ rice (Oryza sativa) grown under paddy conditions when days were longer than 13.5 h. Whereas the wild type (WT) rice flowered 105 days after sowing, the latest mutant to do so was ostrx1, flowering 53 d later. This indicated that the gene is the strongest inducer among all of those examined. Mutations in OsMADS50 delayed flowering by 45 d when compared with the WT, suggesting that this MADS gene is another strong positive element. The third positive element was OsVIL2; mutations in the gene caused plants to flower 27 d late. In contrast, the double phytochrome mutant osphyA osphyB flowered 44 d earlier than the WT. The single mutant osphyB and the double mutant osphyB osphyC did the same, although not as early as the osphyA osphyB double mutant. These results demonstrated that phytochromes are major inhibitors under paddy conditions. Mutations in Ghd7 accelerated flowering by 34 d, indicating that the gene is also a major inhibitor. The hd1 mutants flowered 16 d earlier than the WT while a mutation in OsGI hastened flowering by 10 d, suggesting that both are weak flowering repressors. Of the two florigen genes (Hd3a being the other one), RFT1 played a major role under paddy conditions. Its expression was strongly promoted by Ehd1, which was negatively controlled by Ghd7. Here we show that phytochromes strongly inhibit flowering and OsTrx1 and OsMADS50 significantly induce flowering under paddy conditions through Ghd7-Ehd1-RFT1 pathway. Thus, we may be able to control heading date under paddy conditions through manipulating those genes, Ghd7, Ehd1 and RFT1.     

Differences in reward removal efficiency and its consequences for seed germination in the ant-dispersed sedge <Emphasis Type="Italic">Carex tristachya</Emphasis> (Cyperaceae)

Reward removal is an essential step for seed dispersal mutualism because residual rewards inhibit germination. Nevertheless, variation in the reward removal efficiency (RRE) among dispersers and its consequences for germination have rarely been reported. In this study, we compared the RREs of two sympatric seed-dispersing ants, Formica japonica and Pheidole noda, using seeds of the ant-dispersed sedge Carex tristachya. Then, we conducted seed sowing experiments in a non-heated glasshouse to evaluate the effect of RRE on the percentage and speed of germination. The majority (85%) of seeds handled by F. japonica had residual elaiosomes, while elaiosomes were completely removed from all seeds handled by P. noda, demonstrating that P. noda has much higher RRE than F. japonica. The seed sowing experiments revealed that RRE, defined by the presence or absence of residual elaiosomes, was not associated with the percentage germination within a year. However, high RRE seeds with no residual elaiosomes germinated significantly faster than low RRE seeds with residual elaiosomes. Similarly, artificial removal of elaiosomes from C. tristachya seeds accelerated germination speed without affecting germination percentage. These results suggest that RRE is one of the most important parameters determining the effectiveness of a seed dispersal agent.     

Expression of <Emphasis Type="Italic">MAX2</Emphasis> under <Emphasis Type="Italic">SCARECROW</Emphasis> promoter enhances the strigolactone/MAX2 dependent response of <Emphasis Type="Italic">Arabidopsis</Emphasis> roots to low-phosphate conditions

Main conclusion

MAX2/strigolactone signaling in the endodermis and/or quiescent center of the root is partiallysufficient to exert changes in F-actin density and cellular trafficking in the root epidermis, and alter gene expression during plant response to low Pi conditions.Strigolactones (SLs) are a new group of plant hormones that regulate different developmental processes in the plant via MAX2, an F-box protein that interacts with their receptor. SLs and MAX2 are necessary for the marked increase in root-hair (RH) density in seedlings under conditions of phosphate (Pi) deprivation. This marked elevation was associated with an active reduction in actin-filament density and endosomal movement in root epidermal cells. Also, expression of MAX2 under the SCARECROW (SCR) promoter was sufficient to confer SL sensitivity in roots, suggesting that SL signaling pathways act through a root-specific, yet non-cell-autonomous regulatory mode of action. Here we show evidence for a non-cell autonomous signaling of SL/MAX2, originating from the root endodermis, and necessary for seedling response to conditions of Pi deprivation. SCR-derived expression of MAX2 in max2-1 mutant background promoted the root low Pi response, whereas supplementation of the synthetic SL GR24 to these SCR:MAX2 expressing lines further enhanced this response. Moreover, the SCR:MAX2 expression led to changes in actin density and endosome movement in epidermal cells and in TIR1 and PHO2 gene expression. These results demonstrate that MAX2 signaling in the endodermis and/or quiescent center is partially sufficient to exert changes in F-actin density and cellular trafficking in the epidermis, and alter gene expression under low Pi conditions.

     

Impact of plant growth-promoting bacteria on grain yield,protein content,and urea-<Superscript>15</Superscript> N recovery by maize in a Cerrado Oxisol

Background and aims

The inoculation of cereal crops with plant growth-promoting bacteria (PGPB) is a potential strategy to improve fertilizer-N acquisition by crops in soils with low capacity to supply N. A study was conducted to assess the impact of three inoculants on grain yield, protein content, and urea-¹⁵ N recovery in maize (Zea mays L.) under Cerrado soil and climate conditions.

Methods

The main treatments included inoculants containing (i) Azospirillum brasilense strain Sp245, (ii) A. brasilense strains AbV5 + AbV6, (iii) Herbaspirillum seropedicae strain ZAE94, and (iv) a non-inoculated control. The subtreatments were (i) urea-N fertilization (100 kg N ha^?1) at 30 days after sowing and (ii) no N addition at the stage. To determine fertilizer-N recovery, ¹⁵N–labelled urea was applied in microplots.

Results

Inoculants carrying A. brasilense improved urea-¹⁵ N acquisition efficiency in maize and also improved grain yield compared to the non-inoculated control, while urea-N fertilization enhanced grain quality by providing higher protein content.

Conclusion

Our results suggest that the inoculation of maize grains with PGPB represents a strategy to improve fertilizer-N recovery and maize yield in Cerrado soil with a low capacity to supply N.

     

Automated computed tomographic scoring of lung disease in adults with primary ciliary dyskinesia

Background

The present study aimed to develop an automated computed tomography (CT) score based on the CT quantification of high-attenuating lung structures, in order to provide a quantitative assessment of lung structural abnormalities in patients with Primary Ciliary Dyskinesia (PCD).

Methods

Adult (≥18?years) PCD patients who underwent both chest CT and spirometry within a 6-month period were retrospectively included. Commercially available lung segmentation software was used to isolate the lungs from the mediastinum and chest wall and obtain histograms of lung density. CT-density scores were calculated using fixed and adapted thresholds based on various combinations of histogram characteristics, such as mean lung density (MLD), skewness, and standard deviation (SD). Additionally, visual scoring using the Bhalla score was performed by 2 independent radiologists. Correlations between CT scores, forced expiratory volume in 1?s (FEV₁) and forced vital capacity (FVC) were evaluated.

Results

Sixty-two adult patients with PCD were included. Of all histogram characteristics, those showing good positive or negative correlations to both FEV₁ and FVC were SD (R?=???0.63 and???0.67; p?<?0.001) and Skewness (R?=?0.67 and 0.67; p?<?0.001). Among all evaluated thresholds, the CT-density score based on MLD?+?1SD provided the best negative correlation with both FEV₁ (R?=???0.68; p?<?0.001) and FVC (R?=???0.71; p?<?0.001), close to the correlations of the visual score (R?=???0.60; p?<?0.001 for FEV₁ and R?=???0.62; p?<?0.001, for FVC).

Conclusions

Automated CT scoring of lung structural abnormalities lung in primary ciliary dyskinesia is feasible and may prove useful for evaluation of disease severity in the clinic and in clinical trials.

     

Sexual reproduction of clonal dwarf shrubs in a forest–tundra ecotone

Successful sexual reproduction may be more important for regeneration of clonal species in high-latitude and -altitude areas than has been previously suggested. We investigated the potential of Vaccinium myrtillus, V. vitis-idaea and Empetrum nigrum ssp. hermaphroditum (E. hermaphroditum) for sexual reproduction at three sites in the forest–tundra ecotone in Finnish Lapland. We studied whether the potential differs between plant communities, whether disturbance enhances germination, and whether seedling emergence is limited by seed availability. We established a field experiment with disturbance and sowing treatments, and monitored seed and seedling numbers and survival rates for two years. The number of mature seeds of V. myrtillus was higher in plants from the tundra heath than in those from the coniferous and mountain birch forests. The number of mature seeds and seedlings emerging from the seed bank of E. hermaphroditum tended also to be higher in the tundra heath. Disturbance marginally increased the seedling emergence of V. myrtillus and E. hermaphroditum, whereas sowing generally increased the seedling numbers. The seedling number of V. myrtillus was lower in the tundra heath and that of E. hermaphroditum was lower in the coniferous forest than at the other sites. Seedling survival was equal for all plant species at all sites. We conclude that the capacity for sexual reproduction varies among plant communities, and seed availability is a stronger constraint than microsite availability for the studied species. Once the crucial early phase of seedling establishment is overcome, seedling survival enables successful recruitment of V. myrtillus, V. vitis-idaea and E. hermaphroditum in the subarctic area.     

Association analysis of alcohol metabolizing enzymes <Emphasis Type="Italic">ADH1B,ADH7, CYP2E1</Emphasis> gene polymorphism with risk for coronary atherosclerosis

The allele and genotype distribution of two alcohol dehydrogenase genes ADH1B (exon 3 polymorphism A/G (47His)), ADH7 (intron 5 polymorphism G/C) and cytochrome P450 2E1 gene (CYP2E1; 5′-flanking region G/C and intron 6 T/A polymorphisms) were examined in Russian (Tomsk, n = 125) healthy population and in coronary atherosclerosis patients (CA, n = 92). The genotype frequencies followed the Hardy-Weinberg equilibrium and the alleles were in linkage equilibrium or gametic equilibrium in the control sample. Only two CYP2E1 gene polymorphisms were in linkage disequilibrium. The frequencies of the derived alleles at ADH1B ^* G (+MslI) allele, CYP2E1 ^* C2 (+PstI) allele and CYP2E1 ^* C (-DraI) allele were 8.48 ± 1.86, 1.20 ± 0.69, and 10.00 ± 1.90%, respectively. The ADH7 gene polymorphism showed a high level of heterozygosity; the frequency of the ADH7 ^* C (-StyI) allele was 44.58 ± 3.21%. A significantly higher frequency of CYP2E1 PstI C2 allele has been revealed in the CA group (P = 0.043; OR = 4.23; 95% CI 1.03–20.01). The tendency to significant effect of A1A2 genotype in ADH1B MslI polymorphism was observed for systolic blood pressure in the control group (P = 0.068). The statistically significant two-way interaction effects of ADH7 StyI and CYP2E1 DraI on diastolic blood pressure (P = 0.029) and on the serum high density lipoprotein level (P = 0.042) were also revealed. Association of A1A2 genotype in ADH1B MslI polymorphism with reduced amount in a serum of a very low density lipoprotein level (P = 0.045) have also been shown. This may result from multifunctional activity of alcohol metabolizing enzymes and their involvement in many metabolic and free radical reactions in the body.