The recently described oomycete pathogen Phytophthora pisi causes root rot on pea and faba bean, while the closely related Phytophthora sojae is the causal agent of soybean root and stem rot. ...Differences in the pathogenicity factor repertoires that enable the two species to have distinct host specificity towards pea and soybean, were studied using tandem mass spectrometry in a global proteome study of hyphae and germinating cysts in P. pisi and P. sojae. In total 2775 proteins from P. pisi and 2891 proteins from P. sojae were identified. Fifty-eight orthologous proteins were more abundant in germinated cysts of both pathogens and thus identified as candidate proteins for the infective stage. Several of these proteins were associated with lipid transport and metabolism, and energy production. Twenty-three orthologous proteins were more abundant in hyphae of both pathogens and thus identified as candidate proteins for vegetative growth. Proteins uniquely present in germinating cysts of either P. pisi or P. sojae were considered as candidates for species-specific pathogenicity factors that may be involved in host specificity. Among these proteins were serine proteases, membrane transporters and a berberine-like protein. These results significantly expand the knowledge of the expressed proteome in P. pisi and P. sojae.
P. sojae and P. pisi are closely related species that specifically cause root rot on soybean and pea, respectively. The pathogenicity factors contributing to their host specificity remained unknown. We carried out a comparative large-scale proteome analysis of vegetative (hyphae) and infective (germinating cysts) life stages in P. pisi and P. sojae. This study provides knowledge of the common factors and mechanism involved in initiation of infection and species-specific proteins that may contribute to the host specificity of these pathogens. This knowledge will lead to a better understanding of the infection biology of these pathogens, allowing new possibilities towards developing alternative and effective plant protection measures.
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•Stored lipid compounds are utilized during cyst germination.•Protein candidates possibly involved in early infection process were identified.•Proteins specific to infective stage of each pathogen were identified.
Phytophthora niederhauserii, P. pisi, P. sojae and P. vignae are closely related species that are pathogenic to various legume plants. While P. sojae and P. vignae are reported to specifically infect ...soybean and cowpea, respectively, P. pisi is reported to attack pea and faba bean. Phytophthora niederhauserii is considered to have a broad host range. Zoospores of some Phytophthora species are chemotactically attracted to the isoflavones that are secreted by their host plants. The focus of the current study was to determine the chemotaxic behaviour of zoospores from closely related legume‐root infecting Phytophthora species and to investigate the correlation, if any, to host preference as determined by greenhouse pathogenicity tests. The results showed that P. sojae and P. vignae were attracted to the non‐soybean isoflavone prunetin as well as to the soybean isoflavones genistein and daidzein, which is in contrast with their host specificity on soybean and cowpea, respectively. On the other hand, P. pisi and P. niederhauserii were only attracted to prunetin, previously reported to be produced by pea, but not to the isoflavones associated with the non‐host soybean. The lack of responsiveness to genistein and daidzein in P. pisi may represent a recent adaptation to the host specialization towards pea. However, the affinity of P. niederhauserii to prunetin shows that this trait can also be present in taxa not specifically associated with legume hosts.
Numerous studies on firm-level data have reported higher average wages in foreign-owned firms than in domestically owned firms. This, however, does not necessarily imply that the individual worker's ...wage increase with foreign ownership. Using detailed matched employer–employee data on the entire Swedish private sector, we examine the effect of foreign ownership on individual wages, controlling for individual and firm heterogeneity as well as for possible selection bias in foreign acquisitions. We distinguish between foreign greenfields and takeovers and compare foreign-owned firms with both domestic multinationals and local firms. Our results show a considerably smaller wage premium in foreign-owned firms than what has been found in studies conducted at a more aggregate level. Moreover, foreign takeovers of Swedish firms tend to have no or even a negative effect on wages.
The
Interface Region Imaging Spectrograph
(IRIS) small explorer spacecraft provides simultaneous spectra and images of the photosphere, chromosphere, transition region, and corona with 0.33 – ...0.4 arcsec spatial resolution, two-second temporal resolution, and 1 km s
−1
velocity resolution over a field-of-view of up to 175 arcsec × 175 arcsec. IRIS was launched into a Sun-synchronous orbit on 27 June 2013 using a Pegasus-XL rocket and consists of a 19-cm UV telescope that feeds a slit-based dual-bandpass imaging spectrograph. IRIS obtains spectra in passbands from 1332 – 1358 Å, 1389 – 1407 Å, and 2783 – 2834 Å, including bright spectral lines formed in the chromosphere (Mg
ii
h 2803 Å and Mg
ii
k 2796 Å) and transition region (C
ii
1334/1335 Å and Si
iv
1394/1403 Å). Slit-jaw images in four different passbands (C
ii
1330, Si
iv
1400, Mg
ii
k 2796, and Mg
ii
wing 2830 Å) can be taken simultaneously with spectral rasters that sample regions up to 130 arcsec × 175 arcsec at a variety of spatial samplings (from 0.33 arcsec and up). IRIS is sensitive to emission from plasma at temperatures between 5000 K and 10 MK and will advance our understanding of the flow of mass and energy through an
interface region
, formed by the chromosphere and transition region, between the photosphere and corona. This highly structured and dynamic region not only acts as the conduit of all mass and energy feeding into the corona and solar wind, it also requires an order of magnitude more energy to heat than the corona and solar wind combined. The IRIS investigation includes a strong numerical modeling component based on advanced radiative–MHD codes to facilitate interpretation of observations of this complex region. Approximately eight Gbytes of data (after compression) are acquired by IRIS each day and made available for unrestricted use within a few days of the observation.
A large matched employer-employee data set for Sweden is used to test several predictions from tournament theory. For white-collar workers a positive and significant effect of intra-firm wage ...dispersion on profits and average pay is found, using various measures of wage dispersion. This result is robust for controlling for firm differences in human capital and firm fixed-effects as well as for instrumenting the wage dispersion variable to take into account endogeneity of wage dispersion. Using data on around 10 000 managers, a positive and significant association between pay dispersion and profits is also found for executives. Further results include a positive relationship between market demand volatility and wage dispersion, measured as coefficient of variation in managerial pay, and a negative effect of the number of managers (contestants) on managerial pay spread. The first two results are in accordance with predictions from tournament theory, while the last one is not.
The
Atmospheric Imaging Assembly
(AIA) provides multiple simultaneous high-resolution full-disk images of the corona and transition region up to 0.5
R
⊙
above the solar limb with 1.5-arcsec spatial ...resolution and 12-second temporal resolution. The AIA consists of four telescopes that employ normal-incidence, multilayer-coated optics to provide narrow-band imaging of seven extreme ultraviolet (EUV) band passes centered on specific lines: Fe
xviii
(94 Å), Fe
viii
,
xxi
(131 Å), Fe
ix
(171 Å), Fe
xii
,
xxiv
(193 Å), Fe
xiv
(211 Å), He
ii
(304 Å), and Fe
xvi
(335 Å). One telescope observes C
iv
(near 1600 Å) and the nearby continuum (1700 Å) and has a filter that observes in the visible to enable coalignment with images from other telescopes. The temperature diagnostics of the EUV emissions cover the range from 6×10
4
K to 2×10
7
K. The AIA was launched as a part of NASA’s
Solar Dynamics Observatory
(SDO) mission on 11 February 2010. AIA will advance our understanding of the mechanisms of solar variability and of how the Sun’s energy is stored and released into the heliosphere and geospace.
Phytophthora niederhauserii
,
P
. pisi
,
P
. sojae
and
P
. vignae
are closely related species that are pathogenic to various legume plants. While
P
. sojae
and
P
. vignae
are reported to specifically ...infect soybean and cowpea, respectively,
P
. pisi
is reported to attack pea and faba bean.
Phytophthora niederhauserii
is considered to have a broad host range. Zoospores of some
P
hytophthora
species are chemotactically attracted to the isoflavones that are secreted by their host plants. The focus of the current study was to determine the chemotaxic behaviour of zoospores from closely related legume‐root infecting
P
hytophthora
species and to investigate the correlation, if any, to host preference as determined by greenhouse pathogenicity tests. The results showed that
P
. sojae
and
P
. vignae
were attracted to the non‐soybean isoflavone prunetin as well as to the soybean isoflavones genistein and daidzein, which is in contrast with their host specificity on soybean and cowpea, respectively. On the other hand,
P
. pisi
and
P
. niederhauserii
were only attracted to prunetin, previously reported to be produced by pea, but not to the isoflavones associated with the non‐host soybean. The lack of responsiveness to genistein and daidzein in
P
. pisi
may represent a recent adaptation to the host specialization towards pea. However, the affinity of
P
. niederhauserii
to prunetin shows that this trait can also be present in taxa not specifically associated with legume hosts.
The potential for field soils to cause
Aphanomyces root rot of pea (
Pisum sativum) was estimated for a large number of samples from commercial pea fields over a period of 5 years, using a greenhouse ...bioassay. The aim of the research project was to gain a mechanistic understanding of soil suppressiveness to the disease. Regression analysis showed that of the measured soil variables (Ca, Mg, K, P, pH), soil Ca concentrations had the strongest (negative) correlation with disease prevalence, and also a significant negative correlation with disease severity in samples with confirmed presence of the disease. Greenhouse bioassays using a set of non-infested soils inoculated with artificially produced oospore inoculum of the casual organism
Aphanomyces euteiches, showed a similar negative correlation between soil Ca content and disease severity. Disease severity was not consistently affected by soil sterilisation, but was lowered by the addition of two different Ca salts. In contrast, addition of sodium bicarbonate to two soils lowered the content of water-soluble Ca in the soils and increased disease severity. Studies of cultures of
A. euteiches exposed to varying Ca concentrations in vitro showed that zoospore production was inhibited at submillimolar concentrations, while mycelial growth was stimulated or unaffected. We conclude that free Ca is a major variable controlling the degree of soil suppressiveness against
A. euteiches, and that inhibition of zoospore production from oospores is a possible mechanism.
The early Empire has become almost a locus celeberrimus for popular histories of same-sex marriage, and the attraction is not difficult to understand. Regardless of polemical allegiance, the activist ...who chooses to focus on the occurrences of such a practice in the early Empire is afforded two advantages. Firstly, Christianity had not yet become an influential moral code in mainstream society, and therefore arguments for the acceptance or rejection of the practice gain extra weight from being non-sectarian. Secondly, the depictions and verbal forms in the extant literature are unambiguous, so there is no need for evidential pleading.
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