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91.
Leopoldo Cruz-López Bernardino Díaz-Díaz Julio C. Rojas 《Arthropod-Plant Interactions》2016,10(2):151-159
The coffee berry borer (CBB), Hypothenemus hampei (Ferrari), is the most important insect pest of coffee worldwide. In this study, we used headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry to sample and identify volatile compounds from Robusta coffee berries, Coffea canephora Pierre ex Froehner, infested with CBB and with mechanical damage. Furthermore, we evaluated the behavioral responses of the CBB and two of its parasitoids, Prorops nasuta Waterstone and Phymastichus coffea LaSalle, to three selected coffee volatile compounds in a Y-tube olfactometer. We found in the effluvia of red coffee berry compounds not previously reported for this coffee species. Our results show that Robusta coffee berries release induced volatiles either by insect herbivory or by mechanical damage. Small amount of butyl acetate, unknown compound 2, α-longipinene, longiborneol and longiborneol acetate are produced only in infested coffee berries fruits. Quantitatively, nine compounds account for the difference between healthy berries, infested, or mechanically damaged berries. Trans-ocimene, 4,8-dimethyl-3,7-nonadien-2-ol, α-copaene and kaurene increased amount levels in infested berries, while amount of methyl salicylate and linalool increased in mechanically damaged coffee berries. The olfactometric bioassays showed that CBB females and its two parasitoids were attracted to methyl salicylate. In addition, H. hampei and P. nasuta were attracted to linalool, and P. nasuta and P. coffea were attracted to trans-ocimene. 相似文献
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93.
Julio Casta?o Cristina Morera Borja Sesé Stephanie Boue Carles Bonet-Costa Merce Martí Alicia Roque Albert Jordan Maria J. Barrero 《PloS one》2016,11(2)
The successful use of specialized cells in regenerative medicine requires an optimization in the differentiation protocols that are currently used. Understanding the molecular events that take place during the differentiation of human pluripotent cells is essential for the improvement of these protocols and the generation of high quality differentiated cells. In an effort to understand the molecular mechanisms that govern differentiation we identify the methyltransferase SETD7 as highly induced during the differentiation of human embryonic stem cells and differentially expressed between induced pluripotent cells and somatic cells. Knock-down of SETD7 causes differentiation defects in human embryonic stem cell including delay in both the silencing of pluripotency-related genes and the induction of differentiation genes. We show that SETD7 methylates linker histone H1 in vitro causing conformational changes in H1. These effects correlate with a decrease in the recruitment of H1 to the pluripotency genes OCT4 and NANOG during differentiation in the SETD7 knock down that might affect the proper silencing of these genes during differentiation. 相似文献
94.
Carlos Navarro-Retamal Carlos Gaete-Eastman Raúl Herrera Julio Caballero Jans H. Alzate-Morales 《PloS one》2016,11(4)
Aroma and flavor are important factors of fruit quality and consumer preference. The specific pattern of aroma is generated during ripening by the accumulation of volatiles compounds, which are mainly esters. Alcohol acyltransferase (AAT) (EC 2.3.1.84) catalyzes the esterification reaction of aliphatic and aromatic alcohols and acyl-CoA into esters in fruits and flowers. In Fragaria x ananassa, there are different volatiles compounds that are obtained from different alcohol precursors, where octanol and hexanol are the most abundant during fruit ripening. At present, there is not structural evidence about the mechanism used by the AAT to synthesize esters. Experimental data attribute the kinetic role of this enzyme to 2 amino acidic residues in a highly conserved motif (HXXXD) that is located in the middle of the protein. With the aim to understand the molecular and energetic aspects of volatiles compound production from F. x ananassa, we first studied the binding modes of a series of alcohols, and also different acyl-CoA substrates, in a molecular model of alcohol acyltransferase from Fragaria x ananassa (SAAT) using molecular docking. Afterwards, the dynamical behavior of both substrates, docked within the SAAT binding site, was studied using routine molecular dynamics (MD) simulations. In addition, in order to correlate the experimental and theoretical data obtained in our laboratories, binding free energy calculations were performed; which previous results suggested that octanol, followed by hexanol, presented the best affinity for SAAT. Finally, and concerning the SAAT molecular reaction mechanism, it is suggested from molecular dynamics simulations that the reaction mechanism may proceed through the formation of a ternary complex, in where the Histidine residue at the HXXXD motif deprotonates the alcohol substrates. Then, a nucleophilic attack occurs from alcohol charged oxygen atom to the carbon atom at carbonyl group of the acyl CoA. This mechanism is in agreement with previous results, obtained in our group, in alcohol acyltransferase from Vasconcellea pubescens (VpAAT1). 相似文献
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96.
Differential effect of shade,water and soil type on emergence and early survival of three dominant species of the Atacama Desert 下载免费PDF全文
Understanding the regeneration niche of species may allow us to gain insight into how communities are structured. In deserts, the regeneration niche is usually related to spaces beneath shrubs where shade cast by shrubs creates microenvironments that benefit seedlings and where even small amounts of rain may favour germination and establishment. Shade and water may also interact with different types of soils. However, species may have different requirements for germination and seedling survival. We could expect that shrub species with different drought tolerances exhibit different responses to the combination of these factors. We ask if responses of dominant species of the Atacama Desert to abiotic factors (shade, water and soil type) are related to their drought tolerance, a topic not exhaustively explored in shrubs growing in true deserts. We conducted two factorial experiments. The first one was designed to evaluate how shade (microhabitat) in combination with water may affect germination (emergence) and early survival. In the second experiment, we assessed the influence of shade in relation to soil type. Each species responded distinctively to the three variables under study, but in general, their emergence responses were more influenced by water (more water, greater emergence) than by microhabitat or soil type. Survival was influenced both by microhabitat and by water and was higher under shade and abundant water. Soil type affected only one of our species in terms of emergence. Species responses in general depended on their tolerance to stress. In one species, there was indication of a seed–seedling conflict. Our results show similar species responses to environmental constraints but also more or less unique responses that are related to their tolerance to drought and which may ultimately permit species coexistence. We found that shade may not be important for germination but may be crucial for survival in dry years. 相似文献
97.
Felipe Couñago Ana Aurora Díaz Gavela Gemma Sancho Irene Ortiz Francisco José Marcos Manuel Recio Julio Fernández Raquel Cano Mar Jiménez Israel J. Thuissard David Sanz-Rosa Juan Castro Nováis Eduardo Pardo Yolanda Molina Hugo Pérez García Elia del Cerro 《Reports of Practical Oncology and Radiotherapy》2019,24(5):472-480
AimTo analyse the efficacy and toxicity of postprostatectomy SRT in patients with a BCR evaluated with mpMRI.BackgroundMultiparametric magnetic resonance imaging (mpMRI) has the ability to detect the site of pelvic recurrence in patients with biochemical recurrence (BCR) after radical prostatectomy (RP). However, we do not know the oncological outcomes of mpMRI-guided savage radiotherapy (SRT).ResultsLocal, lymph node, and pelvic bone recurrence was observed in 13, 4 and 2 patients, respectively. PSA levels were significantly lower in patients with negative mpMRI (0.4 ng/mL [0.4]) vs. positive mpMRI (2.2 ng/mL [4.1], p = 0.003). Median planning target volume doses in patients with visible vs. non-visible recurrences were 76 Gy vs. 70 Gy. Overall, mean follow-up was 41 months (6–81). Biochemical relapse-free survival (bRFS) at 3 years was 82.3% and 82.5%, respectively, for the negative and positive mpMRI groups (p = 0.800). Three-year rates of late grade ≥2 urinary and rectal toxicity were 14.8% and 1.9%, respectively; all but one patient recovered without sequelae.ConclusionSRT to the macroscopic recurrence identified by mpMRI is a feasible and well-tolerated option. In this study, there were no differences in bRFS between MRI-positive and MRI-negative patients, indicating effective targeting of MRI-positive lesions. 相似文献
98.
Lau Yan Ng Julio C.Y. Liu Xiner Huang Nelson Lee Randy Y.C. Poon 《Cell cycle (Georgetown, Tex.)》2019,18(2):238-248
Characterizing the functions of essential cell cycle control genes requires tight and rapid inducible gene inactivation. Drawbacks of current conditional depletion approaches include slow responses and incomplete depletion. We demonstrated that by integrating the tetracycline-controlled promoter system and the auxin-inducible degron (AID) system together, AID-tagged proteins can be downregulated more efficiently than the individual technology alone. When used in conjunction with CRISPR-Cas9-mediated disruption of the endogenous locus, this system facilitates the analysis of essential genes by allowing rapid and tight conditional depletion, as we have demonstrated using several cell cycle-regulatory genes including cyclin A, CDK2, and TRIP13. The vectors constructed in this study allow expression of AID-fusion proteins under the control of tetracycline-controlled promoters and should be useful in studies requiring rapid and tight suppression of gene expression in mammalian cells. 相似文献
99.
Iker Falces-Romero María Pilar Romero-Gómez Julio García-Rodríguez Emilio Cendejas-Bueno 《Revista iberoamericana de micología》2019,36(3):142-146
BackgroundIn Spain, data of candidemia are limited to surveys conducted in specific areas or tertiary care centers. Also, in recent years, attention has shifted toward episodes of candidemia in non-ICU wards.AimsWe reviewed the cases of Candida isolates recovered from the blood of patients admitted to the Emergency Room (ER) in our tertiary care hospital.MethodsThe patients selected for this study had an isolation of Candida in the blood culture. All data were collected retrospectively from the clinical records of a 11-year period.ResultsCandida albicans and other species of the genus were present in 10 and 18 patients, respectively. The patients did not present different clinical features in comparison with other reports of hospitalized patients. All patients had several risk factors for candidemia. Only two patients had received previous antifungal therapy before admission. All the isolates of C. albicans, Candida glabrata and the only isolate of Candida tropicalis were susceptible to all the antifungal agents tested. Only one isolate of Candida parapsilosis was susceptible dose-dependent to fluconazole, and the only isolate of Candida metapsilosis was resistant to fluconazole.ConclusionsIt is essential to evaluate the risk factors, underlying conditions and clinical features in non-hospitalized patients in order to determine whether an empirical treatment for candidemia is appropriate. 相似文献
100.
Regime shifts of Mediterranean forest carbon uptake and reduced resilience driven by multidecadal ocean surface temperatures 总被引:1,自引:0,他引:1
Jofre Carnicer Cristina Domingo‐Marimon Miquel Ninyerola Jesus Julio Camarero Ana Bastos Jorge Lpez‐Parages Laura Blanquer Beln Rodríguez‐Fonseca Timothy M. Lenton Vasilis Dakos Montserrat Ribas Emilia Gutirrez Josep Peuelas Xavier Pons 《Global Change Biology》2019,25(8):2825-2840
The mechanisms translating global circulation changes into rapid abrupt shifts in forest carbon capture in semi‐arid biomes remain poorly understood. Here, we report unprecedented multidecadal shifts in forest carbon uptake in semi‐arid Mediterranean pine forests in Spain over 1950–2012. The averaged carbon sink reduction varies between 31% and 37%, and reaches values in the range of 50% in the most affected forest stands. Regime shifts in forest carbon uptake are associated with climatic early warning signals, decreased forest regional synchrony and reduced long‐term carbon sink resilience. We identify the mechanisms linked to ocean multidecadal variability that shape regime shifts in carbon capture. First, we show that low‐frequency variations of the surface temperature of the Atlantic Ocean induce shifts in the non‐stationary effects of El Niño Southern Oscillation (ENSO) on regional forest carbon capture. Modelling evidence supports that the non‐stationary effects of ENSO can be propagated from tropical areas to semi‐arid Mediterranean biomes through atmospheric wave trains. Second, decadal changes in the Atlantic Multidecadal Oscillation (AMO) significantly alter sea–air heat exchanges, modifying in turn ocean vapour transport over land and land surface temperatures, and promoting sustained drought conditions in spring and summer that reduce forest carbon uptake. Third, we show that lagged effects of AMO on the winter North Atlantic Oscillation also contribute to the maintenance of long‐term droughts. Finally, we show that the reported strong, negative effects of ocean surface temperature (AMO) on forest carbon uptake in the last decades are unprecedented over the last 150 years. Our results provide new, unreported explanations for carbon uptake shifts in these drought‐prone forests and review the expected impacts of global warming on the profiled mechanisms. 相似文献