Monoterpenes are among the most important volatile aromatic compounds contributing to the flavor and aroma of grapes and wine. However, the molecular basis of monoterpene biosynthesis has not yet ...been fully elucidated. In our study, transcriptomics and gas chromatography-mass spectrometry (GC-MS) were used to mine candidate genes and transcription factors involved in monoterpene biosynthesis between high-monoterpene and zero-monoterpene table grape cultivars. We found that monoterpene biosynthesis was positively correlated by the expression of five genes encoding 1-deoxy-D-xylulose-5-phosphate synthase (VvDXSs), one encoding 4-hydroxy-3-methylbut-2-enyl diphosphate reductase (VvHDR), three hydroxy-3-methylglutaryl-CoA synthases (VvHMGSs) and one mevalonate kinase (VvMVK), whereas the expression of one isopentenyl diphosphate isomerase (VvIDI) and one 3-hydroxy-3-methylglutaryl-CoA reductase (VvHMGR) negatively correlated monoterpene biosynthesis. Of these genes, VvIDI was selected to validate its function in monoterpene accumulation through a transient overexpression experiment, and was shown to inhibit the biosynthesis of grape linalool and alpha-terpineol. Meanwhile, we found that a 64-amino acid extension sequence at the N-terminus can guide the VvIDI protein to target the chloroplast. The findings of this study should help to guide future functional analysis of key genes as well as mining the potential regulatory mechanism of monoterpene biosynthesis in grapes and grape products.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This study investigated the adsorption of humic acid (HA) by bi-functional resin JN-10, which removed the HA more effectively than the commercial resins D-301, D-201, XAD-7, and globe active carbon ...F-400. The difference between the FT-IR spectroscopy and
13C NMR analysis of JN-10 before and after it adsorbing the HA revealed that both hydrophobic interaction and electric attraction were the adsorption force for the HA. The related thermodynamic parameters exhibited that the adsorption of the HA by JN-10 was an endothermic process. The occurring of adsorption was due to the increase of entropy, and the electric attraction was also a main adsorption force. In order to investigate the influence of the molecule weight (MW) of the HA on its removal by JN-10, the HA with the MWs ranging from 2000 to 100,000
Da was divided into six fractions by ultra-filtration. The HA with a medium MW (6000–10,000
Da) was preferentially removed by JN-10 due to the synergistic effect of hydrophilicity, molecular size, and aromaticity of the HA. The adsorption capacity of JN-10 for the HA increased in the presence of low concentration of alkali-earth metal ions Ca
2+ and Mg
2+, which neutralized the negative charges of the HA, but it decreased as the concentration of these ions increased because the hydrates formed by the alkali-earth metal ions occupied the adsorption sites of the resin.
The Tibet Autonomous Region of China constitutes a unique and fragile ecosystem that is increasingly influenced by development and global climate change. To protect biodiversity and ecosystem ...services in Tibet, the Chinese government established a system of nature reserves at a significant cost; however, the effectiveness of nature reserves at protecting both-biodiversity and ecosystem service functions in Tibet is not clear. To determine the success of existing nature reserves, we determined importance areas for the conservation of mammal, plant, bird, amphibian, and reptile species, and for the protection of ecosystem service functions. The results indicated that important conservation areas for endangered plants were mainly distributed in the southern part of Nyingchi City, and for endangered animals, in the southern part of Nyingchi and Shannan Cities. Extremely important conservation areas for ecosystem service functions of carbon sequestration, water and soil protection, and flood regulation were mainly distributed in the southern part of Nyingchi and Shannan Cities, northern and southeastern parts of Nagqu City, and southern part of Ngari area. Based on an analysis of spatial overlap in protection areas, we conclude that existing natural reserves need to be expanded, and new ones need to be established to better protect biodiversity in Tibet Autonomous Region.
Novel Fenton-like catalyst HKUST-1(Cu)/MoS2-3-C with a non-equilibrium-state surface was constructed for selective degradation of phenolic contaminants. Electron-polarized distribution facilitated ...the formation of σ-Cu-ligand between electron-poor Cu centre and phenolic compounds, which not only enhanced radicals generation but also accelerated the Cu(I)/Cu(II) redox. Meanwhile, ≡Mo–OOSO3− complexes formed by the electron-rich Mo centre and peroxymonosulfate (PMS), could directly oxidize phenolic contaminants with the generation of SO4•−. The radical quenching experiments and EPR tests indicated that both SO4•− and •OH played a dominant role in the reaction. Additionally, O2 could be reduced to O2•− by OVs and subsequently converted into 1O2 over the Mo centre. DFT calculation, FT-IR, and in situ Raman spectra analysis results demonstrated that phenolic compounds and PMS were respectively adsorbed by electron-poor Cu centre and electron-rich Mo centre, favouring the electrons transfer from phenolic contaminants to Mo centre for PMS activation. With synergistic effects of σ-Cu-ligand and ≡Mo–OOSO3− complexes, HKUST-1(Cu)/MoS2-3-C achieved a high degradation rate of phenolic contaminants and utilization efficiency of PMS.
Growth-regulating factors (GRFs) are plant-specific transcription factors that control organ size. Nineteen GRF genes were identified in the Populus trichocarpa genome and one was reported to control ...leaf size mainly by regulating cell expansion. In this study, we further characterize the roles of the other poplar GRFs in leaf size control in a similar manner.
The 19 poplar GRF genes were clustered into six groups according to their phylogenetic relationship with Arabidopsis GRFs. Bioinformatic analysis, degradome, and transient transcription assays showed that 18 poplar GRFs were regulated by miR396, with GRF12b the only exception. The functions of PagGRF6b (Pag, Populus alba × P. glandulosa), PagGRF7a, PagGRF12a, and PagGRF12b, representing three different groups, were investigated. The results show that PagGRF6b may have no function on leaf size control, while PagGRF7a functions as a negative regulator of leaf size by regulating cell expansion. By contrast, PagGRF12a and PagGRF12b may function as positive regulators of leaf size control by regulating both cell proliferation and expansion, primarily cell proliferation.
The diversity of poplar GRFs in leaf size control may facilitate the specific, coordinated regulation of poplar leaf development through fine adjustment of cell proliferation and expansion.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Multi-contrast vessel wall cardiovascular magnetic resonance (CMR) has demonstrated its capability for atherosclerotic plaque morphology measurement and component characterization in different ...vasculatures. However, limited coverage and partial volume effect with conventional two-dimensional (2D) techniques might cause lesion underestimation. The aim of this work is to evaluate the performance in a) blood suppression and b) vessel wall delineation of three-dimensional (3D) multi-contrast joint intra- and extracranial vessel wall imaging at 3T.
Three multi-contrast 3D black blood (BB) sequences with T1, T2 and heavy T1 weighting and a custom designed 36-channel neurovascular coil covering the entire intra- and extracranial vasculature have been used and investigated in this study. Two healthy subjects were recruited for sequence parameter optimization and twenty-five patients were consecutively scanned for image quality and blood suppression assessment. Qualitative image scores of vessel wall delineation as well as quantitative Signal-to-Noise Ratio (SNR) and Contrast-to-Noise Ratio (CNR) were evaluated at five typical locations ranging from common carotid arteries to middle cerebral arteries.
The 3D multi-contrast images acquired within 15mins allowed the vessel wall visualization with 0.8 mm isotropic spatial resolution covering intra- and extracranial segments. Quantitative wall and lumen SNR measurements for each sequence showed effective blood suppression at all selected locations (P < 0.0001). Although the wall-lumen CNR varied across measured locations, each sequence provided good or adequate image quality in both intra- and extracranial segments.
The proposed 3D multi-contrast vessel wall technique provides isotropic resolution and time efficient solution for joint intra- and extracranial vessel wall CMR.
•Three new functions were proposed to refine a watershed model under arid conditions.•Each of the added algorithms improve the model accuracy in low-flow months.•These alternative algorithms have ...potential application in other watershed models.
Watershed models play an important role in modern water resource management, increasingly demanding a robust hydrologic data framework to estimate watershed hydrochemical processes. The Generalized Watershed Loading Function (GWLF), a typical watershed model with modest data requirements, has been applied to watershed-scale hydrochemical estimation worldwide. However, while it generally successfully estimates flows in humid regions, the model suffers from a weakness in hydrologic estimation during low-flow periods, which are projected to continue increasing with global climate change in many places. To address this issue, three algorithms describing functional responses of flows to saturated water storage, the segment function approach, linear function approach, and exponential function approach, have been proposed in this paper, integrated with a previous leakage mechanism for unsaturated water storage used in two earlier GWLF versions, and applied to a case study of Shuai Shui River watershed in China. Comparisons of this version, including new algorithms or algorithm linkages, with the earlier GWLF versions, show that all the new algorithms improve model accuracy in low-flow months; the linear function approach linking the leakage process has the best effect. This work refines the framework of GWLF model to address both humid and arid conditions that can be used as alternatives for future applications. These new functional dynamic responses should also have potential application in other similar watershed models.
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