Pine pitch canker (PPC), caused by Fusarium circinatum, affects Pinus species worldwide. Although no effective solutions have yet been found to control it, there is a growing interest in using ...biological control agents (BCA) such as Trichoderma to avoid the application of chemical‐based products. Using species with an increasing level of susceptibility to PPC (Pinus pinea, Pinus pinaster and Pinus radiata), this study aimed to evaluate the effect of Trichoderma viride pre‐inoculation on disease development, assessing several physiological and hormonal parameters. A 2‐week period elapsed between T. viride and F. circinatum inoculation. Sampling for each species was performed independently when at least 50% of the plants of one of the inoculated groups developed disease symptoms. Fusarium circinatum infection reduced water status and photosynthesis, but increased proline, abscisic acid and jasmonic acid concentrations in plants of P. radiata and P. pinaster with symptoms; while in P. pinea water relations were maintained and anthocyanin accumulation occurred in the presence of F. circinatum. In P. radiata, T. viride pre‐inoculation accelerated disease progression, with some PPC‐induced responses augmented (decreased water potential and photosynthesis; increased substomatal CO2 concentration) and novel changes not found in seedlings inoculated exclusively with F. circinatum (increased electrolyte leakage and salicylic acid; decreased relative water content). This suggests that T. viride may be initially recognized as an invading organism, subverting the plant defence mechanisms for successful root colonization. If seedlings are not allowed to recover from this state, pathogen infection may thus be facilitated, highlighting the importance of application timing in BCA strategies.
A
bstract
The European Spallation Source (ESS), presently well on its way to completion, will soon provide the most intense neutron beams for multi-disciplinary science. Fortuitously, it will also ...generate the largest pulsed neutrino flux suitable for the detection of Coherent Elastic Neutrino-Nucleus Scattering (CE
ν
NS), a process recently measured for the first time at ORNL’s Spallation Neutron Source. We describe innovative detector technologies maximally able to profit from the order-of-magnitude increase in neutrino flux provided by the ESS, along with their sensitivity to a rich particle physics phenomenology accessible through high-statistics, precision CE
ν
NS measurements.
A
bstract
The
Neutrino Experiment with a Xenon TPC
(NEXT) searches for the neutrinoless double-beta (0
νββ
) decay of
136
Xe using high-pressure xenon gas TPCs with electroluminescent amplification. ...A scaled-up version of this technology with about 1 tonne of enriched xenon could reach in less than 5 years of operation a sensitivity to the half-life of 0
νββ
decay better than 10
27
years, improving the current limits by at least one order of magnitude. This prediction is based on a well-understood background model dominated by radiogenic sources. The detector concept presented here represents a first step on a compelling path towards sensitivity to the parameter space defined by the inverted ordering of neutrino masses, and beyond.
We present evidence of non-excimer-based secondary scintillation in gaseous xenon, obtained using both the NEXT-White time projection chamber (TPC) and a dedicated setup. Detailed comparison with ...first-principle calculations allows us to assign this scintillation mechanism to neutral bremsstrahlung (NBrS), a process that is postulated to exist in xenon that has been largely overlooked. For photon emission below 1000 nm, the NBrS yield increases from about10−2photon/e−cm−1bar−1at pressure-reduced electric field values of50Vcm−1bar−1to above3×10−1photon/e−cm−1bar−1at500Vcm−1bar−1. Above1.5kVcm−1bar−1, values that are typically employed for electroluminescence, it is estimated that NBrS is present with an intensity around1photon/e−cm−1bar−1, which is about 2 orders of magnitude lower than conventional, excimer-based electroluminescence. Despite being fainter than its excimeric counterpart, our calculations reveal that NBrS causes luminous backgrounds that can interfere, in either gas or liquid phase, with the ability to distinguish and/or to precisely measure low primary-scintillation signals (S1). In particular, we show this to be the case in the “buffer” region, where keeping the electric field below the electroluminescence threshold does not suffice to extinguish secondary scintillation. The electric field leakage in this region should be mitigated to avoid intolerable levels of NBrS emission. Furthermore, we show that this new source of light emission opens up a viable path toward obtaining S2 signals for discrimination purposes in future single-phase liquid TPCs for neutrino and dark matter physics, with estimated yields up to20–50photons/e−cm−1.
SUMMARY
Plants growing under natural conditions experience high light (HL) intensities that are often accompanied by elevated temperatures. These conditions could affect photosynthesis, reduce yield, ...and negatively impact agricultural productivity. The combination of different abiotic challenges creates a new type of stress for plants by generating complex environmental conditions that often exceed the impact of their individual parts. Transcription factors (TFs) play a key role in integrating the different molecular signals generated by multiple stress conditions, orchestrating the acclimation response of plants to stress. In this study, we show that the TF WRKY48 negatively controls the acclimation of Arabidopsis thaliana plants to a combination of HL and heat stress (HL + HS), and its expression is attenuated by jasmonic acid under HL + HS conditions. Using comparative physiological and transcriptomic analyses between wild‐type and wrky48 mutants, we further demonstrate that under control conditions, WRKY48 represses the expression of a set of transcripts that are specifically required for the acclimation of plants to HL + HS, hence its suppression during the HL + HS stress combination contributes to plant survival under these conditions. Accordingly, mutants that lack WRKY48 are more resistant to HL + HS, and transgenic plants that overexpress WRKY48 are more sensitive to it. Taken together, our findings reveal that WRKY48 is a negative regulator of the transcriptomic response of Arabidopsis to HL + HS and provide new insights into the complex regulatory networks of plant acclimation to stress combination.
Significance Statement
Our study reveals that the transcription factor WRKY48 plays a key role as a suppressor of Arabidopsis thaliana tolerance to the combination of high light and heat stress. We further propose that jasmonic acid negatively regulates WRKY48 expression under stress combination.
In Mediterranean regions, severe summers are becoming more common, leading to restrictions to vine productivity and yield quality, requiring sustainable practices to support this sector. We assessed ...the behaviour of three red grapevine varieties from the Douro Region to examine their tolerance to summer climate stress from the perspective that the less common varieties may have potential for increased use in a climate change scenario.
Leaf and fruit biochemical profile, antioxidant activity and fruit colorimetric parameters were assessed at different phenological stages in Aragonez (AR), Tinto Cão (TC) and Touriga Nacional (TN) grape varieties.
All three varieties exhibit significant variability in phenological timing, influenced by genetic and environmental factors. Photosynthetic pigment strategies differed among varieties. Chlorophyll content in AR was high to cope with high radiation, while TN displaying a balanced approach, and TC had lower pigment levels, with higher levels of phenolics, antioxidants, and soluble sugars, particularly during stress. The variations in berry biochemical profile highlight the distinct characteristics of the varieties. TC and TN show potential for coping with climate change, having elevated total acidity, while AR has larger and heavier berries with distinct coloration.
These findings reinforce the need to study the behaviour of different varieties in each Terroir, to understand their diverse strategies to deal with summer climate stress. This will help in selecting the most suitable variety for these conditions under vineyard management in the Douro Region
This research assesses the responses of red grapevines to summer stress in the Douro Valley, highlighting the importance of understanding variety‐specific responses for sustainable viticulture management, particularly in climate change scenarios.
Carotenoids are the pigments responsible for the coloration of the peel and pulp of
Citrus
fruits. Light is one of the major environmental factors influencing coloration and carotenoid content and ...composition of fleshy fruits and therefore their commercial and nutritional quality. Agronomical observations indicate that citrus fruits exposed to sunlight develop a brighter peel coloration than shaded fruit inside the tree canopy. In the present study, the effect of light deprivation on carotenoid profile, and in the expression of genes of carotenoid metabolism and their precursors have been analyzed in fruits of Clemenules mandarin (
Citrus clementine
) and Navelina orange (
Citrus sinensis
). Fruit shading accelerated peel degreening, chlorophyll degradation, and reduced chloroplastic-type carotenoids. Time-course shading experiments revealed that the stage of fruit ripening appears to be determinant for the effect of darkness in carotenoid biosynthesis. Fruit shading produced a down-regulation of the expression of key carotenoids biosynthetic genes (
PSY
,
PDS
,
ZDS1
,
LCY2a
,
LCY2b
, and
CHX
). However, expression of MEP pathway genes (
DXS
,
HDR1
, and
GGPPS1
) and the carotenoid cleavage dioxygenase,
CCD4b1
, responsible of the formation of the apocarotenoid β-citraurin, were not substantially affected by dark-grown conditions. The content of abscisic acid (ABA), an end product of the carotenoid pathway, was not affected by the light regime, suggesting that effect of shading on the precursor’s pool is not sufficient to impair ABA synthesis. A moderate increase in total carotenoid and in the expression of biosynthetic genes was observed in mature dark-grown mandarin and orange fruits. Collectively, results suggest that light stimulates carotenoid biosynthesis in the peel of citrus fruits but a light-independent regulation may also operate.
On the measurement of leptonic CP violation Burguet Castell, J.; Gavela, M.B.; Gómez Cadenas, J.J. ...
Nuclear physics. B,
08/2001, Letnik:
608, Številka:
1
Journal Article
Recenzirano
Odprti dostop
We show that the simultaneous determination of the leptonic CP-odd phase
δ and the angle
θ
13 from the subleading transitions
ν
e
→
ν
μ
and
ν
̄
e→
ν
̄
μ
results generically, at fixed neutrino energy ...and baseline, in two degenerate solutions. In light of this, we refine a previous analysis of the sensitivity to leptonic CP violation at a neutrino factory, in the LMA–MSW scenario, by exploring the full range of
δ and
θ
13. Furthermore, we take into account the expected uncertainties on the solar and atmospheric oscillation parameters and in the average Earth matter density along the neutrino path. An intermediate baseline of
O(3000) km is still the best option to tackle CP violation, although a combination of two baselines turns out to be very important in resolving degeneracies.
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