Controlling toxigenic Fusarium graminearum (FG) is challenging. A bacterial strain (S76-3, identified as Bacillus amyloliquefaciens) that was isolated from diseased wheat spikes in the field ...displayed strong antifungal activity against FG. Reverse-phase high performance liquid chromatography and electrospray ionization mass spectrometry analyses revealed that S76-3 produced three classes of cyclic lipopeptides including iturin, plipastatin and surfactin. Each class consisted of several different molecules. The iturin and plipastatin fractions strongly inhibited FG; the surfactin fractions did not. The most abundant compound that had antagonistic activity from the iturin fraction was iturin A (m/z 1043.35); the most abundant active compound from the plipastatin fraction was plipastatin A (m/z 1463.90). These compounds were analyzed with collision-induced dissociation mass spectrometry. The two purified compounds displayed strong fungicidal activity, completely killing conidial spores at the minimal inhibitory concentration range of 50 µg/ml (iturin A) and 100 µg/ml (plipastatin A). Optical and fluorescence microscopy analyses revealed severe morphological changes in conidia and substantial distortions in FG hyphae treated with iturin A or plipastatin A. Iturin A caused leakage and/or inactivation of FG cellular contents and plipastatin A caused vacuolation. Time-lapse imaging of dynamic antagonistic processes illustrated that iturin A caused distortion and conglobation along hyphae and inhibited branch formation and growth, while plipastatin A caused conglobation in young hyphae and branch tips. Transmission electron microscopy analyses demonstrated that the cell walls of conidia and hyphae of iturin A and plipastatin A treated FG had large gaps and that their plasma membranes were severely damaged and separated from cell walls.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Summary
Fusarium head blight (FHB) and Fusarium seedling blight (FSB) of wheat, caused by Fusarium pathogens, are devastating diseases worldwide. We report the expression of RNA interference (RNAi) ...sequences derived from an essential Fusarium graminearum (Fg) virulence gene, chitin synthase (Chs) 3b, as a method to enhance resistance of wheat plants to fungal pathogens. Deletion of Chs3b was lethal to Fg; disruption of the other Chs gene family members generated knockout mutants with diverse impacts on Fg. Comparative expression analyses revealed that among the Chs gene family members, Chs3b had the highest expression levels during Fg colonization of wheat. Three hairpin RNAi constructs corresponding to the different regions of Chs3b were found to silence Chs3b in transgenic Fg strains. Co‐expression of these three RNAi constructs in two independent elite wheat cultivar transgenic lines conferred high levels of stable, consistent resistance (combined type I and II resistance) to both FHB and FSB throughout the T3 to T5 generations. Confocal microscopy revealed profoundly restricted mycelia in Fg‐infected transgenic wheat plants. Presence of the three specific short interfering RNAs in transgenic wheat plants was confirmed by Northern blotting, and these RNAs efficiently down‐regulated Chs3b in the colonizing Fusarium pathogens on wheat seedlings and spikes. Our results demonstrate that host‐induced gene silencing of an essential fungal chitin synthase gene is an effective strategy for enhancing resistance in crop plants under field test conditions.
ABSTRACT
The dominant species of a biome can be regarded as its genuine indicator. Evergreen broadleaved forests (EBLFs) in subtropical East Asia harbor high levels of species biodiversity and ...endemism and are vital to regional carbon storage and cycling. However, the historical assembly of this unique biome is still controversial. Fagaceae is the most essential family in East Asian subtropical EBLFs and its dominant species are vital for the existence of this biome. Here, we used the dominant Fagaceae species to shed light on the dynamic process of East Asian subtropical EBLFs over time. Our results indicate high precipitation in summer and low temperature in winter are the most influential climatic factors for the distribution of East Asian subtropical EBLFs. Modern East Asian subtropical EBLFs did not begin to appear until 23 Ma, subsequently experienced a long‐lasting development in the Miocene and markedly deteriorated at about 4 Ma, driven jointly by orogenesis and paleoclimate. We also document that there is a lag time between when one clade invaded the region and when its members become dominant species within the region. This study may improve our ability to predict and mitigate the threats to biodiversity of East Asian subtropical EBLFs and points to a new path for future studies involving multidisciplinary methods to explore the assembly of regional biomes.
Modern East Asian subtropical evergreen broadleaved forests have experienced dynamic evolution since 23 Ma, driven by orogenesis and paleoclimate. A new path for future studies should involve multidisciplinary methods to explore the assembly of regional biomes.
In this paper, we study the FCNC decay processes of
B
and
B
c
meson, in which one invisible particle is emitted. Both the spin-0 and spin-1 cases are considered. The model-independent effective ...Lagrangian is introduced to describe the coupling between the light invisible boson and quarks. The constraints of the coupling coefficients are extracted by experimental upper limits of the missing energy in
B
meson decays. The bounds are used to predict the upper limits of branching fractions of corresponding
B
c
decays, which are of the order of
10
-
6
or
10
-
5
when final meson is pseudoscalar or vector, respectively. The maximum branch ratios are achieved when
m
χ
≈
3.5
–4 GeV, where
m
χ
is the mass of the invisible particle.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Key message
GhDRP1 acts as a negatively regulator to participate in response to drought stress possibly by modulating ABA signaling pathway and flavonoid biosynthesis pathway which affects stomata ...movement and thus water loss, ROS scavenging enzymes, and proline accumulation in cotton.
Type-2C protein phosphatases (PP2C) may play important roles in plant stress signal transduction. Here, we show the evidence that a cotton PP2C protein GhDRP1 participates in plant response to drought stress.
GhDRP1
gene encodes an active type-2C protein phosphatase (PP2C) and its expression is significantly induced in cotton by drought stress. Compared with wild type, the
GhDRP1
overexpression (OE) transgenic cotton and Arabidopsis displayed reduced drought tolerance, whereas
GhDRP1
-silenced (RNAi) cotton showed enhanced drought tolerance. Under drought stress, malondialdehyde content was lower, whereas superoxide dismutase and peroxidase activities, proline content, stomata closure and relative water content were higher in
GhDRP1
RNAi plants compared with those in wild type. In contrast,
GhDRP1
OE plants showed the opposite phenotype under the same conditions. Expression levels of some stress-related and flavonoid biosynthesis-related genes were altered in
GhDRP1
transgenic plants under drought stress. Additionally, GhDRP1 protein could interact with other proteins such as PYLs, SNF1-related protein kinase and GLK1-like protein. Collectively, these data suggest that GhDRP1 participates in plant response to drought stress possibly by modulating ABA signaling pathway and flavonoid biosynthesis pathway which affects stomata movement and thus water loss, ROS scavenging enzymes, and proline accumulation in cotton.
A previous report indicated that collagen hydrolysate fraction (F7) from Spanish mackerel (
) skins showed high reducing power and radical scavenging activities on 2,2-Diphenyl-1-picrylhydrazyl ...(DPPH) (EC
value of 1.57 mg/mL) and hydroxyl (EC
value of 1.20 mg/mL). In this work, eight peptides were isolated from F7 and identified as Gly-Pro-Tyr (GPY, 335.31 Da), Gly-Pro-Thr-Gly-Glu (GPTGE, 459.47 Da), Pro-Phe-Gly-Pro-Asp (PFGPD, 531.52 Da), Gly-Pro-Thr-Gly-Ala-Lys (GPTGAKG, 586.65 Da), Pro-Tyr-Gly-Ala-Lys-Gly (PYGAKG, 591.69 Da), Gly-Ala-Thr-Gly-Pro-Gln-Gly (GATGPQG, 586.61 Da), Gly-Pro-Phe-Gly-Pro-Met (GPFGPM, 604.73 Da), and Tyr-Gly-Pro-Met (YGPM, 466.50 Da), respectively. Among them, PFGPD, PYGAKG, and YGPM exhibited strong radical scavenging activities on DPPH (EC
values of 0.80, 3.02, and 0.72 mg/mL for PFGPD, PYGAKG, and YGPM, respectively), hydroxyl (EC
values of 0.81, 0.66, and 0.88 mg/mL for PFGPD, PYGAKG, and YGPM, respectively), superoxide anion (EC
values of 0.91, 0.80, and 0.73 mg/mL for PFGPD, PYGAKG, and YGPM, respectively), and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) cation (EC
values of 0.86, 1.07, and 0.82 mg/mL for PFGPD, PYGAKG, and YGPM, respectively) in a positive concentration-activity relationship. Furthermore, PFGPD, PYGAKG, and YGPM could effectively reduce Fe
to Fe
and inhibit lipid peroxidation. Hence, eight collagen peptides from hydrolysate of Spanish mackerel skins might be served as antioxidant candidates for various industrial applications.
Mitogen-activated protein kinase kinase kinases (MAPKKKs) are significant components in the MAPK signal pathway and play essential roles in regulating plants against drought stress. To explore MAPKKK ...gene family functioning in cotton response and resistance to drought stress, we conducted a systematic analysis of GhMAPKKKs.
In this study, 157 nonredundant GhMAPKKKs (including 87 RAFs, 46 MEKKs and 24 ZIKs) were identified in cotton (Gossypium hirsutum). These GhMAPKKK genes are unevenly distributed on 26 chromosomes, and segmental duplication is the major way for the enlargement of MAPKKK family. Furthermore, members within the same subfamily share a similar gene structure and motif composition. A lot of cis-elements relevant to plant growth and response to stresses are distributed in promoter regions of GhMAPKKKs. Additionally, these GhMAPKKKs show differential expression patterns in cotton tissues. The transcription levels of most genes were markedly altered in cotton under heat, cold and PEG treatments, while the expressions of some GhMAPKKKs were induced in cotton under drought stress. Among these drought-induced genes, we selected GhRAF4 and GhMEKK12 for further functional characterization by virus-induced gene silencing (VIGS) method. The experimental results indicated that the gene-silenced cotton displayed decreased tolerance to drought stress. Malondialdehyde (MDA) content was higher, but proline accumulation, relative leaf water content and activities of superoxide dismutase (SOD) and peroxidase (POD) were lower in the gene-silenced cotton, compared with those in the controls, under drought stress.
Collectively, a systematic survey of gene structure, chromosomal location, motif composition and evolutionary relationship of MAPKKKs were performed in upland cotton (Gossypium hirsutum). The following expression and functional study showed that some of them take important parts in cotton drought tolerance. Thus, the data presented here may provide a foundation for further investigating the roles of GhMAPKKKs in cotton response and resistance to drought stress.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Wigner solution of the quark gap equation Cui, Zhu-Fang; Xu, Shu-Sheng; Li, Bo-Lin ...
The European physical journal. C, Particles and fields,
09/2018, Letnik:
78, Številka:
9
Journal Article
Recenzirano
Odprti dostop
Solutions and their evolutions of the quark gap equation are studied within the Nambu–Jona–Lasinio model, which is a basic issue for studying the QCD phase structure and locating the possible ...critical end point. It is shown that in the chiral limit case of the vacuum, chiral symmetry will hold if the coupling strength
G
is small, then the system only has the Wigner solution at
M
=
0
. If increasing
G
, two symmetric minima will appear as the positive and “negative” Nambu solutions, however, the solution
M
=
0
now corresponds to a maximum instead of a minimum of the thermodynamical potential, so is not a physically stable state anymore (we call it “pseudo-Wigner solution”). Besides, it is shown that as the current quark mass
m
increases, the pseudo-Wigner solution will become negative, and disappear together with the negative Nambu solution if
m
is large enough. Similar things happen if we increase the temperature or quark chemical potential
μ
. Some interesting phenomenon is, from some
μ
a second local minimum will show up. As
μ
increases gradually, it will be stabler than the Nambu solution, survives even the Nambu solution disappears, and approaches
m
, which are just the features of the Wigner solution we expect.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Circulating tumor DNA (ctDNA) isolated from peripheral blood has recently been shown to be an alternative source to detect gene mutations in primary tumors; however, most previous studies have ...focused on advanced stage cancers, and few have evaluated ctDNA detection in early-stage lung cancer. In the present study, blood and tumor samples were collected prospectively from 58 early-stage non-small lung cancer (NSCLC) patients (stages IA, IB, and IIA) and a targeted sequencing approach was used to detect somatic driver mutations in matched tumor DNA (tDNA) and plasma ctDNA. We identified frequent driver mutations in plasma ctDNA and tDNA in EGFR, KRAS, PIK3CA, and TP53, and less frequent mutations in other genes, with an overall study concordance of 50.4% and sensitivity and specificity of 53.8% and 47.3%, respectively. Cell-free (cfDNA) concentrations were found to be significantly associated with some clinical features, including tumor stage and subtype. Importantly, the presence of cfDNA had a higher positive predictive value than that of currently used protein tumor biomarkers. This study demonstrates the feasibility of identifying plasma ctDNA mutations in the earliest stage lung cancer patients via targeted sequencing, demonstrating a potential utility of targeted sequencing of ctDNA in the clinical management of NSCLC.
The hickory genus (Carya) contains ca. 17 species distributed in subtropical and tropical regions of eastern Asia and subtropical to temperate regions of eastern North America. Previously, the ...phylogenetic relationships between eastern Asian and eastern North American species of Carya were not fully confirmed even with an extensive sampling, biogeographic and diversification patterns had thus never been investigated in a phylogenetic context. We sampled 17 species of Carya and 15 species representing all other genera of the Juglandaceae as outgroups, with eight nuclear and plastid loci to reconstruct the phylogeny of Carya. The phylogenetic positions of seven extinct genera of the Juglandaceae were inferred using morphological characters and the molecular phylogeny as a backbone constraint. Divergence times within Carya were estimated with relaxed Bayesian dating. Biogeographic analyses were performed in DIVA and LAGRANGE. Diversification rates were inferred by LASER and APE packages. Our results support two major clades within Carya, corresponding to the lineages of eastern Asia and eastern North America. The split between the two disjunct clades is estimated to be 21.58 (95% HPD 11.07-35.51) Ma. Genus-level DIVA and LAGRANGE analyses incorporating both extant and extinct genera of the Juglandaceae suggested that Carya originated in North America, and migrated to Eurasia during the early Tertiary via the North Atlantic land bridge. Fragmentation of the distribution caused by global cooling in the late Tertiary resulted in the current disjunction. The diversification rate of hickories in eastern North America appeared to be higher than that in eastern Asia, which is ascribed to greater ecological opportunities, key morphological innovations, and polyploidy.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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