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1.
Front Plant Sci ; 14: 1284403, 2023.
Article in English | MEDLINE | ID: mdl-38093996

ABSTRACT

Plant height (PH) and ear height (EH) are important traits associated with biomass, lodging resistance, and grain yield in maize. There were strong effects of genotype x environment interaction (GEI) on plant height and ear height of maize. In this study, 203 maize inbred lines were grown at five locations across China's Spring and Summer corn belts, and plant height (PH) and ear height (EH) phenotype data were collected and grouped using GGE biplot. Five locations fell into two distinct groups (or mega environments) that coincide with two corn ecological zones called Summer Corn Belt and Spring Corn Belt. In total, 73,174 SNPs collected using GBS sequencing platform were used as genotype data and a recently released multi-environment GWAS software package IIIVmrMLM was employed to identify QTNs and QTN x environment (corn belt) interaction (QEIs); 12 and 11 statistically significant QEIs for PH and EH were detected respectively and their phenotypic effects were further partitioned into Add*E and Dom*E components. There were 28 and 25 corn-belt-specific QTNs for PH and EH identified, respectively. The result shows that there are a large number of genetic loci underlying the PH and EH GEIs and IIIVmrMLM is a powerful tool in discovering QTNs that have significant QTN-by-Environment interaction. PH and EH candidate genes were annotated based on transcriptomic analysis and haplotype analysis. EH related-QEI S10_135 (Zm00001d025947, saur76, small auxin up RNA76) and PH related-QEI S4_4 (Zm00001d049692, mads32, encoding MADS-transcription factor 32), and corn-belt specific QTNs including S10_4 (Zm00001d023333, sdg127, set domain gene127) and S7_1 (Zm00001d018614, GLR3.4, and glutamate receptor 3.4 or Zm00001d018616, DDRGK domain-containing protein) were reported, and the relationship among GEIs, QEIs and phenotypic plasticity and their biological and breeding implications were discussed.

2.
Front Plant Sci ; 14: 1221395, 2023.
Article in English | MEDLINE | ID: mdl-37810381

ABSTRACT

Southern corn rust (SCR) caused by Puccinia polysora Underw is a major disease leading to severe yield losses in China Summer Corn Belt. Using six multi-locus GWAS methods, we identified a set of SCR resistance QTNs from a diversity panel of 140 inbred lines collected from China Summer Corn Belt. Thirteen QTNs on chromosomes 1, 2, 4, 5, 6, and 8 were grouped into three types of allele effects and their associations with SCR phenotypes were verified by post-GWAS case-control sampling, allele/haplotype effect analysis. Relative resistance (RRR) and relative susceptibility (RRs) catering to its inbred carrier were estimated from single QTN and QTN-QTN combos and epistatitic effects were estimated for QTN-QTN combos. By transcriptomic annotation, a set of candidate genes were predicted to be involved in transcriptional regulation (S5_145, Zm00001d01613, transcription factor GTE4), phosphorylation (S8_123, Zm00001d010672, Pgk2- phosphoglycerate kinase 2), and temperature stress response (S6_164a/S6_164b, Zm00001d038806, hsp101, and S5_211, Zm00001d017978, cellulase25). The breeding implications of the above findings were discussed.

3.
Angew Chem Int Ed Engl ; 62(39): e202308858, 2023 Sep 25.
Article in English | MEDLINE | ID: mdl-37462217

ABSTRACT

An asymmetric intramolecular hydroalkylation of unactivated internal olefins with tethered cyclic ketones was realized by the cooperative catalysis of a newly designed chiral amine (SPD-NH2 ) and PdII complex, providing straightforward access to either bridged or fused bicyclic systems containing three stereogenic centers with excellent enantioselectivity (up to 99 % ee) and diastereoselectivity (up to >20 : 1 dr). Notably, the bicyclic products could be conveniently transformed into a diverse range of key structures frequently found in bioactive terpenes, such as Δ6 -protoilludene, cracroson D, and vulgarisins. The steric hindrance between the Ar group of the SPD-NH2 catalyst and the branched chain of the substrate, hydrogen-bonding interactions between the N-H of the enamine motif and the C=O of the directing group MQ, and the counterion of the PdII complex were identified as key factors for excellent stereoinduction in this dual catalytic process by density functional theory calculations.

4.
Biomater Sci ; 11(10): 3726-3736, 2023 May 16.
Article in English | MEDLINE | ID: mdl-37051634

ABSTRACT

The oral delivery of protein-based drugs is of great significance, but faces various obstacles, including the deactivation of proteins by the low pH in the stomach and the high concentration of protease, poor transport through intestinal bio-barriers, etc. Herein, we present an acid-resistant metal-organic framework (MOF), NU-1000, in which insulin (Ins, a model protein) was loaded with high capacity (Ins@NU-1000) through the pseudo second-order kinetic model and Langmuir isotherm model. Ins@NU-1000 protects Ins from deactivation in the stomach acid environment and releases it in the intestine through the transformation of the micro-sized rod particles into spherical nanoparticles. Interestingly, the rod particles exhibit long-term retention in the intestine, and Ins is efficiently transported by the shrunk nanoparticles through intestinal bio-barriers and released into the blood, resulting in significant oral hypoglycemic effects (lasting more than 16 h after a single oral administration). Our findings demonstrate that switching the physical properties of the delivery vehicle, such as the shape and size, can contribute to the success of oral protein administration.


Subject(s)
Metal-Organic Frameworks , Nanoparticles , Metal-Organic Frameworks/chemistry , Drug Delivery Systems/methods , Insulin , Nanoparticles/chemistry , Hypoglycemic Agents , Administration, Oral
5.
Front Microbiol ; 14: 1330538, 2023.
Article in English | MEDLINE | ID: mdl-38264477

ABSTRACT

Whole-plant corn silage (WPCS) has been widely used as the main roughage for ruminant, which promoted the utilization of corn stover for animal feed production. However, rigid cell wall structure of corn stover limits the fiber digestion and nutrients adsorption of WPCS. This study investigated the effect of adding cellulase on improving the fermentation quality of WPCS ensiling with a Bacillus complex inoculant. With the Bacillus (BA), the lactic acid accumulation in the WPCS was significantly higher than that in control (CK). The additive cellulase (BC) increased the lactic acid content to the highest of 8.2% DW at 60 days, which was significantly higher than that in the CK and BA groups, and it reduced the neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents from 42.5 to 31.7% DW and 28.4 to 20.3% DW, respectively, which were significantly lower than that in the CK and BA groups. The crude protein and starch were not obviously lost. Dynamic microbial community analysis showed that the Bacillus inoculant promoted the lactic acid bacteria (LAB) fermentation, because higher abundance of Lactobacillus as the dominant bacteria was observed in BA group. Although the addition of cellulase slowed the Lactobacillus fermentation, it increased the bacterial community, where potential lignocellulolytic microorganisms and more functional enzymes were observed, thus leading to the significant degradation of NDF and ADF. The results revealed the mechanism behind the degradation of NDF and ADF in corn stover, and also suggested the potential of cellulase for improving the nutritional quality of WPCS.

6.
World J Hepatol ; 15(12): 1258-1271, 2023 Dec 27.
Article in English | MEDLINE | ID: mdl-38223416

ABSTRACT

Primary liver cancer is a severe and complex disease, leading to 800000 global deaths annually. Emerging evidence suggests that inflammation is one of the critical factors in the development of hepatocellular carcinoma (HCC). Patients with viral hepatitis, alcoholic hepatitis, and steatohepatitis symptoms are at higher risk of developing HCC. However, not all inflammatory factors have a pathogenic function in HCC development. The current study describes the process and mechanism of hepatitis development and its progression to HCC, particularly focusing on viral hepatitis, alcoholic hepatitis, and steatohepatitis. Furthermore, the roles of some essential inflammatory cytokines in HCC progression are described in addition to a summary of future research directions.

7.
Cancers (Basel) ; 14(19)2022 Sep 25.
Article in English | MEDLINE | ID: mdl-36230594

ABSTRACT

The formation of stress granules (SG) is regarded as a cellular mechanism to temporarily limit protein synthesis and prevent the unfolding of proteins in stressed cells. It has been noted that SG formation can promote the survival of stressed cells. Paradoxically, however, persistent SGs could cause cell death. The underlying molecular mechanism that affects the relationship between SG dynamics and cellular states is not fully understood. Here we found that SG dynamics in cancer cells differ significantly from those in normal cells. Specifically, prolonged stress caused the formation of persistent SGs and consequently resulted in apoptosis in the normal cells. By contrast, cancer cells resolved SGs and survived the prolonged stress. Regarding the mechanism, the knockdown of HSP70 or the inhibition of the HSP70s' ATPase activity caused defective SG clearance, leading to apoptosis in otherwise healthy cancer cells. On the other hand, the knockout of G3BPs to block the formation of SGs allowed cancer cells to escape from the HSP70 inhibition-induced apoptosis. Given the observation that SG dynamics were barely affected by the inhibition of autophagy or proteasome, we propose that SG dynamics are regulated mainly by HSP70-mediated refolding of the unfolded proteins or their removal from SGs. As a result, cancer cells evade stress-induced apoptosis by promoting the HSP70-dependent SG clearance.

8.
Cell Mol Life Sci ; 79(3): 180, 2022 Mar 07.
Article in English | MEDLINE | ID: mdl-35254515

ABSTRACT

Abnormal mossy fiber connections in the hippocampus have been implicated in schizophrenia. However, it remains unclear whether this abnormality in the patients is genetically determined and whether it contributes to the onset of schizophrenia. Here, we showed that iPSC-derived hippocampal NPCs from schizophrenia patients with the A/A allele at SNP rs16864067 exhibited abnormal NPC polarity, resulting from the downregulation of SOX11 by this high-risk allele. In the SOX11-deficient mouse brain, abnormal NPC polarity was also observed in the hippocampal dentate gyrus, and this abnormal NPC polarity led to defective hippocampal neurogenesis-specifically, irregular neuroblast distribution and disrupted granule cell morphology. As granule cell synapses, the mossy fiber pathway was disrupted, and this disruption was resistant to activity-induced mossy fiber remodeling in SOX11 mutant mice. Moreover, these mutant mice exhibited diminished PPI and schizophrenia-like behaviors. Activation of hippocampal neurogenesis in the embryonic brain, but not in the adult brain, partially alleviated disrupted mossy fiber connections and improved schizophrenia-related behaviors in mutant mice. We conclude that disrupted mossy fiber connections are genetically determined and strongly correlated with schizophrenia-like behaviors in SOX11-deficient mice. This disruption may reflect the pathological substrate of SOX11-associated schizophrenia.


Subject(s)
Mossy Fibers, Hippocampal/metabolism , Neurogenesis , SOXC Transcription Factors/physiology , Schizophrenia/metabolism , Animals , Hippocampus/metabolism , Hippocampus/physiopathology , Mice , Mice, Transgenic , Mossy Fibers, Hippocampal/physiopathology , SOXC Transcription Factors/genetics , Schizophrenia/physiopathology , Synapses
9.
Article in English | MEDLINE | ID: mdl-34691203

ABSTRACT

OBJECTIVE: With the constant development of medical technology, the medical-nursing combination mode targeted at elderly chronic diseases has been proposed, and based on this, the study on the nursing mode of elderly chronic diseases under the background of medical-nursing combination was conducted. METHODS: Total of 100 elderly patients with chronic diseases who were admitted to our hospital from April 2019 to April 2020 were selected and divided into a control group and an experimental group by lot drawing, with 50 patients in each group. Continuous nursing was conducted to patients in the control group, and continuous nursing combined with comfort nursing was performed to patients in the experimental group, so as to compare their nursing effective rate, satisfaction with nursing, self-care ability at 6 months after nursing, quality of life (QLI) scores, and blood glucose, pressure, and lipid levels at various periods. RESULTS: Compared with the control group, the experimental group obtained significantly improved nursing effective rate, satisfaction with nursing, Exercise of Self-Care Agency (ESCA) scale scores, QLI scores, and lower blood glucose, pressure, and lipid levels at various periods 6 months after nursing, with statistical significance (P all < 0.05). CONCLUSION: Under the context of medical-nursing combination, the continuous nursing intervention combined with comfort nursing intervention is conductive to promote the self-care ability and nursing effect of elderly patients with chronic diseases and obviously improve their quality of life and psychological state.

10.
Gut Pathog ; 13(1): 59, 2021 Oct 13.
Article in English | MEDLINE | ID: mdl-34645508

ABSTRACT

BACKGROUND: To investigate the antimicrobial profiles and genomic characteristics of MDR-Citrobacter spp. strains isolated from Fennec fox imported from Sudan to China. METHODS: Four Citrobacter spp. strains were isolated from stool samples. Individual fresh stool samples were collected and subsequently diluted in phosphate buffered saline as described previously. The diluted fecal samples were plated on MacConkey agar supplemented with 1 mg/l cefotaxime and incubated for 20 h at 37 °C. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS) was used for identification. Antimicrobial susceptibility testing was performed using the broth microdilution method. Whole-genome sequencing was performed on an Illumina Novaseq-6000 platform. Acquired antimicrobial resistance genes and plasmid replicons were detected using ResFinder 4.1 and PlasmidFinder 1.3, respectively. Comparative genomic analysis of 277 Citrobacter genomes was also performed. RESULTS: Isolate FF141 was identified as Citrobacter cronae while isolate FF371, isolate FF414, and isolate FF423 were identified as Citrobacter braakii. Of these, three C. braakii isolates were further confirmed to be extended-spectrum ß-lactamases (ESBL)-producer. All isolates are all multidrug resistance (MDR) with resistance to multiple antimicrobials. Plasmid of pKPC-CAV1321 belong to incompatibility (Inc) group. Comparative genomics analysis of Citrobacter isolates generated a large core-genome. Genetic diversity was observed in our bacterial collection, which clustered into five main clades. Human, environmental and animal Citrobacter isolates were distributed into five clusters. CONCLUSIONS: To our knowledge, this is the first investigation of MDR-Citrobacter from Fennec Fox. Our phenotypic and genomic data further underscore the threat of increased ESBL prevalence in wildlife and emphasize that increased effort should be committed to monitoring the potentially rapid dissemination of ESBL-producers with one health perspective.

11.
Biomed Res Int ; 2021: 6661520, 2021.
Article in English | MEDLINE | ID: mdl-34195277

ABSTRACT

OBJECTIVE: Oral squamous cell carcinoma (OSCC) is the most common malignant tumor of the head and neck, with strong local invasiveness and cervical lymph node metastasis. The purpose of this study was to investigate the role of LINC01296 in oral squamous cell carcinoma and its possible mechanism. MATERIALS AND METHODS: GEPAI database analysis and clinical samples were used to detect the expression of LINC01296 in head and neck cancer. In vivo experiment, MTT, clone formation assay, and transwell were used to detect the proliferation, migration, and invasion of oral squamous cell carcinoma. The effect of LINC01296 on EMT was detected by western blot and qRT-PCR to measure the expression of epithelial and mesenchymal phenotypic markers. BALB/c nude mice were used to carry out in vitro treatment experiment. In terms of mechanism, the binding relationship between LINC01296 and SRSF1 was predicted and verified by the RBPDB database and RNA pull-down assay. RESULTS: LINC01296 was highly expressed in clinical samples and cell lines of oral squamous cell carcinoma. Overexpression of LINC01296 promoted the proliferation, invasion, and migration of oral squamous cell carcinoma cells and accelerated the formation of xenografts, while silencing LINC01296 inhibited tumor progression. In mechanism, LINC01296 plays a tumor-promoting role by binding to SRSF1 protein. CONCLUSION: LINC01296 promotes malignant lesions in oral squamous cell carcinoma by binding to SRSF1 protein, which provides important experimental data and theoretical basis for the prevention, diagnosis, and treatment of oral squamous cell carcinoma.


Subject(s)
Mouth Neoplasms/metabolism , RNA, Long Noncoding/metabolism , Serine-Arginine Splicing Factors/metabolism , Squamous Cell Carcinoma of Head and Neck/metabolism , Aged , Animals , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation/genetics , Female , Gene Expression Regulation, Neoplastic , Humans , Lymphatic Metastasis , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Middle Aged , Mouth Neoplasms/genetics , Neoplasm Invasiveness , Protein Binding , RNA, Long Noncoding/genetics , Serine-Arginine Splicing Factors/genetics , Squamous Cell Carcinoma of Head and Neck/genetics
12.
Chem Commun (Camb) ; 57(54): 6632-6635, 2021 Jul 06.
Article in English | MEDLINE | ID: mdl-34124740

ABSTRACT

A novel oxyallyl cation promoted semipinacol rearrangement of indole-type allylic alcohols was disclosed for the stereodivergent synthesis of spiro-indolines. A variety of spiro-indolines were obtained with moderate to good yields. Three contiguous stereocenters, two of which are vicinal quaternary centers, were effectively formed with good diastereoselectivity. It is worth noting that two diastereoisomers of rearranged products can be readily achieved by easily regulating the reaction conditions. This method may provide an applicable approach for the synthesis of natural indole alkaloids.

13.
Sci Rep ; 11(1): 8012, 2021 04 13.
Article in English | MEDLINE | ID: mdl-33850169

ABSTRACT

Maize (Zea mays L.) germplasm in China Summer maize ecological region (CSM) or central corn-belt of China is diverse but has not been systematically characterized at molecular level. In this study, genetic variation, genome diversity, linkage disequilibrium patterns, population structure, and characteristics of different heterotic groups were studied using 525,141 SNPs obtained by Genotyping-By-Sequencing (GBS) for 490 inbred lines collected from researchers at CSM region. The SNP density is lower near centromere, but higher near telomere region of maize chromosome, the degree of linkage disequilibrium (r2) vary at different chromosome regions. Majority of the inbred lines (66.05%) show pairwise relative kinship near zero, indicating a large genetic diversity in the CSM breeding germplasm. Using 4849 tagSNPs derived from 3618 haplotype blocks, the 490 inbred lines were delineated into 3 supergroups, 6 groups, and 10 subgroups using ADMIXTURE software. A procedure of assigning inbred lines into heterotic groups using genomic data and tag-SNPs was developed and validated. Genome differentiation among different subgroups measured by Fst, and the genetic diversity within each subgroup measured by GD are both large. The share of heterotic groups that have significant North American germplasm contribution: P, SS, IDT, and X, accounts about 54% of the CSM breeding germplasm collection and has increased significantly in the last two decades. Two predominant types of heterotic pattern in CSM region are: M-Reid group × TSPT group, and X subgroup × Local subgroups.


Subject(s)
Plant Breeding , Polymorphism, Single Nucleotide , Zea mays , China , Gene Frequency , Genotype , Linkage Disequilibrium
14.
Tree Physiol ; 41(7): 1143-1160, 2021 07 05.
Article in English | MEDLINE | ID: mdl-33440427

ABSTRACT

Winter precipitation and soil freeze-thaw events have been predicted to increase in boreal regions with climate change. This may expose tree roots to waterlogging (WL) and soil freezing (Fr) more than in the current climate and therefore affect tree growth and survival. Using a whole-tree approach, we studied the responses of silver birch (Betula pendula Roth.) saplings, growing in mineral soil, to 6-week Fr and WL in factorial combinations during dormancy, with accompanying changes in soil gas concentrations. Physiological activation (dark-acclimated chlorophyll fluorescence and chlorophyll content index) and growth of leaves and shoot elongation and stem diameter growth started earlier in Fr than NoFr (soil not frozen). The starch content of leaves was temporarily higher in Fr than NoFr in the latter part of the growing season. Short and long root production and longevity decreased, and mortality increased by soil Fr, while there were no significant effects of WL. Increased fine root damage was followed by increased compensatory root growth. At the beginning of the growing season, stem sap flow increased fastest in Fr + WL, with some delay in both NoWL (without WL) treatments. At the end of the follow-up growing season, the hydraulic conductance and impedance loss factor of roots were higher in Fr than in NoFr, but there were no differences in above- and belowground biomasses. The concentration of soil carbon dioxide increased and methane decreased by soil Fr at the end of dormancy. At the beginning of the growing season, the concentration of nitrous oxide was higher in WL than in NoWL and higher in Fr than in NoFr. In general, soil Fr had more consistent effects on soil greenhouse gas concentrations than WL. To conclude, winter-time WL alone is not as harmful for roots as WL during the growing season.


Subject(s)
Betula , Soil , Freezing , Gases , Trees
15.
Angew Chem Int Ed Engl ; 60(13): 7061-7065, 2021 03 22.
Article in English | MEDLINE | ID: mdl-33369843

ABSTRACT

A challenging direct asymmetric catalytic aerobic oxidative cross-coupling of 2-naphthylamine and 2-naphthol, using a novel CuI /SPDO system, has been successfully developed for the first time. Enantioenriched 3,3'-disubstituted NOBINs were achieved and could be readily derived to divergent chiral ligands and catalysts. This reaction features high enantioselectivities (up to 96 % ee) and good yields (up to 80 %). The DFT calculations suggest that the F-H interactions between CF3 of L17 and H-1,8 of 2-naphthol, and the π-π stacking between the two coupling partners could play vital roles in the enantiocontrol of this cross-coupling reaction.

16.
Angew Chem Int Ed Engl ; 58(32): 11023-11027, 2019 08 05.
Article in English | MEDLINE | ID: mdl-31131524

ABSTRACT

A novel chiral 1,5-N,N-bidentate ligand based on a spirocyclic pyrrolidine oxazoline backbone was designed and prepared, and it coordinates CuBr in situ to form an unprecedented catalyst that enables efficient oxidative cross-coupling of 2-naphthols. Air serves as an external oxidant and generates a series of C1 -symmetric chiral BINOL derivatives with high enantioselectivity (up to 99 % ee) and good yield (up to 87 %). This approach is tolerant of a broader substrates scope, particularly substrates bearing various 3- and 3'-substituents. A preliminary investigation using one of the obtained C1 -symmetric BINOL products was used as an organocatalyst, exhibiting better enantioselectivity than the previously reported organocatalyst, for the asymmetric α-alkylation of amino esters.

17.
Mol Med ; 25(1): 9, 2019 03 29.
Article in English | MEDLINE | ID: mdl-30922214

ABSTRACT

BACKGROUND: Cell therapy is proposed to be a potential treatment for Parkinson's disease (PD). Although fetal retinal pigment epithelial (RPE) cells have been tested in trials for treating PD patients, controversy has been raised over the issue of whether such cells can be reprogrammed into dopamine-producing cells for therapeutic efficacy. Here, we aim to investigate whether adult human RPE cells can be reprogrammed into dopamine-producing cells both in vitro and in the recipient monkey brain. METHODS: The RPE layer was isolated from frozen posterior eyeball tissue after penetrating keratoplasty surgery. The tumorigenicity of RPE cells was examined by G-banding and a tumor formation assay in nude mice. Immunogenicity was measured using a one-way mixed lymphocyte reaction (MLR) assay. Dopamine-production in chemically reprogrammed RPE cells was measured by HPLC. Finally, RPE cells were grafted into the brains of monkeys with MPTP-induced PD in order to investigate the potential of such cells treating PD patients in the future. RESULTS: RPE cell lines have been successively established from adult human eye tissues. Such cells can be chemically reprogrammed into dopamine-producing cells in vitro. Moreover, after being grafted into the brain caudate putamen of monkeys with MPTP-induced PD, RPE cells became tyrosine hydroxylase-positive cells, and recipient PD monkeys showed significant improvement of clinical conditions. CONCLUSIONS: This preclinical study using a primate model indicates that human adult RPE cells could be a potential cell source for the treatment of PD in the future.


Subject(s)
Brain/cytology , Cell- and Tissue-Based Therapy , Dopamine/metabolism , Parkinsonian Disorders/therapy , Retinal Pigment Epithelium/cytology , Animals , Cell Differentiation , Cell Line , Humans , Lymphocyte Culture Test, Mixed , Macaca fascicularis , Male , Mice, SCID , Middle Aged , Retinal Pigment Epithelium/metabolism
18.
Tree Physiol ; 39(5): 805-818, 2019 05 01.
Article in English | MEDLINE | ID: mdl-30753688

ABSTRACT

Soil waterlogging is predicted to increase in the future climate in boreal regions due to increased precipitation. Snowmelt periods in winter may also become more common and further increase the amount of water in soil. It is not well known how waterlogging and soil freezing during winter affect the physiology, phenology and growth of trees. Our aim was to study the below- and aboveground responses of Scots pine (Pinus sylvestris L.) saplings to waterlogging (WL) in frozen (Fr) and unfrozen (NoFr) soils in a growth chamber experiment. The soil was either -2 °C or +2 °C and either waterlogged or not in a split-plot design for 6 weeks during dormancy, with similar air conditions in all treatments, which were Fr + WL, NoFr + WL, Fr + NoWL and NoFr + NoWL. Needles showed a shift towards a deeper dormancy in frozen than unfrozen soil in terms of chlorophyll fluorescence (Fv/Fm), water potential and apoplastic electrical resistance. In spring, initiation of shoot elongation started earlier if the soil was frozen during dormancy. In Fr + WL, initiation of root growth was delayed by 20 days compared with other treatments; after that, the root growth peaked at the same time as needle elongation. Needles remained smaller in Fr + WL than in the other treatments, indicating that roots formed a strong sink for carbon. Shoot and root biomass were not negatively affected by waterlogging if the soil remained unfrozen. In Fr + WL, survival and growth capacity of new terminal and whorl buds, the number of bud scales and the number of dwarf shoots were reduced. We conclude that soil freezing on sites prone to waterlogging should be considered in management of boreal forests, especially in the face of predicted climate change.


Subject(s)
Floods , Freezing , Pinus sylvestris/growth & development , Soil , Finland , Plant Dormancy , Plant Roots/growth & development , Plant Shoots/growth & development
19.
ACS Omega ; 3(2): 1482-1491, 2018 Feb 28.
Article in English | MEDLINE | ID: mdl-31458474

ABSTRACT

A novel metal-free double SO2 insertion/multicomponent bicyclization cascade of benzene-linked 1,7-diynes has been established by treatment with aryldiazonium tetrafluoroborates and DABCO-bis(sulfur dioxide) under redox-neutral conditions, providing a range of dual sulfone-containing naphtho[1,2-c]thiophene 2,2-dioxides with generally high stereoselectivity. The reaction pathway is proposed to proceed through the sequence of arylsulfonyl-radical-induced 6-exo-dig/5-endo-trig bicyclization, H-abstraction, and diazotization.

20.
Chem Commun (Camb) ; 54(5): 445-448, 2018 Jan 11.
Article in English | MEDLINE | ID: mdl-29199312

ABSTRACT

New radical-triggered multi-component cyclizations of ß-alkynyl propenones have been developed, leading to 50 examples of sulfonated 1-indenones with generally good yields and high levels of stereoselectivity. The oxidant-free azosulfonylation of ß-alkynyl propenones with aryldiazonium salts and DABSO was realized under the neutral-redox conditions where TBHP enabled the direct selenosulfonylation of ß-alkynyl propenones by combining sulfinic acids and diphenyl diselenide. This protocol features a broad substrate scope, high functional group tolerance and mild reaction conditions.

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