1,133 research outputs found
Rhizosphere microbial ecological characteristics of strawberry root rot
IntroductionStrawberry (Fragaria × ananassa Duch.) holds a preeminent position among small fruits globally due to its delectable fruits and significant economic value. However, strawberry cultivation is hampered by various plant diseases, hindering the sustainable development of the strawberry industry. The occurrence of plant diseases is closely linked to imbalance in rhizosphere microbial community structure.MethodsIn the present study, a systematic analysis of the differences and correlations among non-culturable microorganisms, cultivable microbial communities, and soil nutrients in rhizosphere soil, root surface soil, and non-rhizosphere soil of healthy and diseased strawberry plants affected by root rot was conducted. The goal was to explore the relationship between strawberry root rot occurrence and rhizosphere microbial community structure.ResultsAccording to the results, strawberry root rot altered microbial community diversity, influenced fungal community composition in strawberry roots, reduced microbial interaction network stability, and enriched more endophytic-phytopathogenic bacteria and saprophytic bacteria. In addition, the number of bacteria isolated from the root surface soil of diseased plants was significantly higher than that of healthy plants.DiscussionIn summary, the diseased strawberry plants changed microbial community diversity, fungal species composition, and enriched functional microorganisms significantly, in addition to reshaping the microbial co-occurrence network. The results provide a theoretical basis for revealing the microecological mechanism of strawberry root rot and the ecological prevention and control of strawberry root rot from a microbial ecology perspective
Plant resistance to tomato yellow leaf curl virus is enhanced by Bacillus amyloliquefaciens Ba13 through modulation of RNA interference
IntroductionTomato yellow leaf curl virus (TYLCV), which is a typical member of the genus Begomovirus, causes severe crop yield losses worldwide. RNA interference (RNAi) is an important antiviral defense mechanism in plants, but whether plant beneficial microbes used as biocontrol agents would modulate RNAi in defense against TYLCV remains unclear.MethodsHere, we employed whole-transcriptome, bisulfite, and small RNA sequencing to decipher the possible role of Bacillus amyloliquefaciens Ba13 as a bacterial biocontrol agent against TYLCV in RNAi modulation.ResultsPotted tomato plants were exposed to whiteflies for natural viral infection 14 days after bacterial inoculation. Compared with non-inoculated controls, the abundance of TYLCV gene in the leaves of inoculated plants decreased by 70.1% at 28 days post-infection, which mirrored the pattern observed for plant disease index. The expression of the ARGONAUTE family genes (e.g., AGO3, AGO4, AGO5, and AGO7) involved in antiviral defense markedly increased by 2.44–6.73-fold following bacterial inoculation. The methylation level at CpG site 228 (in the open reading frame region of the RNA interference suppressing gene AV2) and site 461 (in the open reading frame regions of AV1 and AV2) was 183.1 and 63.0% higher in inoculated plants than in non-inoculated controls, respectively. The abundances of 10 small interfering RNAs matched to the TYLCV genome were all reduced in inoculated plants, accompanied by enhancement of photosystem and auxin response pathways.DiscussionThe results indicate that the application of Ba. amyloliquefaciens Ba13 enhances plant resistance to TYLCV through RNAi modulation by upregulating RNAi-related gene expression and enhancing viral genome methylation
How fast could a proto-pulsar rotate?
According to two estimated relations between the initial period and the
dynamo-generated magnetic dipole field of pulsars, we calculate the statistical
distributions of pulsar initial periods. It is found that proto-pulsars are
very likely to have rotation periods between 20 and 30 ms, and that most of the
pulsars rotate initially at a period < 60 ms.Comment: submitted, or at
http://vega.bac.pku.edu.cn/~rxxu/publications/index_P.ht
Precision Measurement of the Mass of the Lepton
An energy scan near the pair production threshold has been performed
using the BESIII detector. About pb of data, distributed over four
scan points, was collected. This analysis is based on pair decays to
, , , , , , , and
final states, where denotes a charged or . The mass of the
lepton is measured from a maximum likelihood fit to the pair production
cross section data to be )
MeV/, which is currently the most precise value in a single measurement.Comment: 13 pages, 7 figure
Observation of a charged charmoniumlike structure in at GeV
We study the process at a
center-of-mass energy of 4.26GeV using a 827pb data sample obtained with
the BESIII detector at the Beijing Electron Positron Collider. Based on a
partial reconstruction technique, the Born cross section is measured to be
pb. We observe a structure near the
threshold in the recoil mass spectrum, which we denote as the
. The measured mass and width of the structure are
MeV/c and MeV, respectively. Its
production ratio is determined to be . The first uncertainties
are statistical and the second are systematic.Comment: 7 pages, 4 figures, 1 table; version accepted to be published in PR
Precision measurement of the decay branching fractions
Using 482 pb of data taken at GeV, we measure the
branching fractions of the decays of into and
to be \BR(D^{*0} \to D^0\pi^0)=(65.5\pm 0.8\pm 0.5)% and \BR(D^{*0} \to
D^0\gamma)=(34.5\pm 0.8\pm 0.5)% respectively, by assuming that the
decays only into these two modes. The ratio of the two branching fractions is
\BR(D^{*0} \to D^0\pi^0)/\BR(D^{*0} \to D^0\gamma) =1.90\pm 0.07\pm 0.05,
which is independent of the assumption made above. The first uncertainties are
statistical and the second ones systematic. The precision is improved by a
factor of three compared to the present world average values
Search for the Lepton Flavor Violation Process at BESIII
We search for the lepton-flavor-violating decay of the into an
electron and a muon using events
collected with the BESIII detector at the BEPCII collider. Four candidate
events are found in the signal region, consistent with background expectations.
An upper limit on the branching fraction of (90% C.L.) is obtained
Measurement of in oscillation using quantum correlations in at = 3.773\,GeV
We report a measurement of the parameter in
\ensuremath{D^0}\xspace-\ensuremath{\overline{D}^{0}}\xspace oscillations
performed by taking advantage of quantum coherence between pairs of
\ensuremath{D^0}\xspace \ensuremath{\overline{D}^{0}}\xspace mesons produced
in annihilations near threshold. In this work, doubly-tagged
\ensuremath{D^0}\xspace \ensuremath{\overline{D}^{0}}\xspace events, where
one decays to a eigenstate and the other decays in a semileptonic
mode, are reconstructed using a data sample of 2.92\,fb collected with
the BESIII detector at the center-of-mass energy of = 3.773\,GeV. We
obtain , where the first uncertainty is
statistical and the second is systematic. This result is compatible with the
current world average.Comment: 13 pages, 3 figure
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