Summary
The continuing nitrogen (N) deposition observed worldwide alters ecosystem nutrient cycling and ecosystem functioning. Litter decomposition is a key process contributing to these changes, but ...the numerous mechanisms for altered decomposition remain poorly identified.
We assessed these different mechanisms with a decomposition experiment using litter from four abundant species (Achnatherum sibiricum, Agropyron cristatum, Leymus chinensis and Stipa grandis) and litter mixtures representing treatment‐specific community composition in a semi‐arid grassland under long‐term simulation of six different rates of N deposition.
Decomposition increased consistently with increasing rates of N addition in all litter types. Higher soil manganese (Mn) availability, which apparently was a consequence of N addition‐induced lower soil pH, was the most important factor for faster decomposition. Soil C : N ratios were lower with N addition that subsequently led to markedly higher bacterial to fungal ratios, which also stimulated litter decomposition.
Several factors contributed jointly to higher rates of litter decomposition in response to N deposition. Shifts in plant species composition and litter quality played a minor role compared to N‐driven reductions in soil pH and C : N, which increased soil Mn availability and altered microbial community structure. The soil‐driven effect on decomposition reported here may have long‐lasting impacts on nutrient cycling, soil organic matter dynamics and ecosystem functioning.
To investigate the diagnostic value of dermoscopy in defining the tumor margin of basal cell carcinoma (BCC) for the appropriate surgical margin. A total of 107 BCC patients were enrolled for this ...study. The tumor boundaries were observed by naked eye and dermoscope respectively, and 5 mm outward was used as surgical margin according to the dermoscopy‐defined margin. Pathological examinations were performed at 2 mm intervals in the direction previously marked and the effect was assessed accordingly. There were still 16.8% of patients whose visual margin was insufficient to the dermoscopy‐detected margin. With 2 mm excision margin from the dermoscopy‐guided tumor margin, excision range in 12 patients (11.2%) proved to be inadequate, but only 18 surgical margins (4.2%) in the whole 428 excision margin specimens proved to be tumor‐positive. While with 4 mm margin, residual lesion was observed in 2 (0.5%) of 107 BCC patients, and positive margin was found in 2 (0.3%) of 428 margin specimen. There has been no recurrence in our study so far. Dermoscopy is superior to visual inspection for defining BCC tumor margin. Under preoperative dermoscopy detection, a 4 mm excision margin of BCC can achieve a radical resection rate of 98.1%, and 92.3% for a 2 mm excision margin of pigmented BCC.
Phytohormones are key regulators of plant growth, development, and signalling networks involved in responses to diverse biotic and abiotic stresses. Transcriptional reference maps of hormone ...responses have been reported for several model plant species such as Arabidopsis thaliana, Oryza sativa, and Brachypodium distachyon. However, because of species differences and the complexity of the wheat genome, these transcriptome data are not appropriate reference material for wheat studies.
We comprehensively analysed the transcriptomic responses in wheat spikes to seven phytohormones, including indole acetic acid (IAA), gibberellic acid (GA), abscisic acid (ABA), ethylene (ET), cytokinin (CK), salicylic acid (SA), and methyl jasmonic acid (MeJA). A total of 3386 genes were differentially expressed at 24 h after the hormone treatments. Furthermore, 22.7% of these genes exhibited overlapping transcriptional responses for at least two hormones, implying there is crosstalk among phytohormones. We subsequently identified genes with expression levels that were significantly and differentially induced by a specific phytohormone (i.e., hormone-specific responses). The data for these hormone-responsive genes were then compared with the transcriptome data for wheat spikes exposed to biotic (Fusarium head blight) and abiotic (water deficit) stresses.
Our data were used to develop a transcriptional reference map of hormone responses in wheat spikes.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
An efficient one‐pot enzymatic synthesis of cardiac glycosides with varied sugar chain lengths (average yield >80%) was carried out through sequential glycosylation using a steroid ...glycosyltransferase UGT74AN3 from Catharanthus roseus and a cyclodextrin glycosyltransferase from Bacillus licheniformis. A series of cardiac glycosides were obtained and showed enhanced affinity and selectivity for inhibition of the α2 isoform of Na+/K+‐ATPase. These findings demonstrate the significant potential of the one‐pot biocatalytic approach in the synthesis of diverse cardiac glycosides as potentially safer cardiotonic agents.
Artificial selection played an important role in the origin of modern Glycine max cultivars from the wild soybean Glycine soja. To elucidate the consequences of artificial selection accompanying the ...domestication and modern improvement of soybean, 25 new and 30 published whole-genome re-sequencing accessions, which represent wild, domesticated landrace, and Chinese elite soybean populations were analyzed.
A total of 5,102,244 single nucleotide polymorphisms (SNPs) and 707,969 insertion/deletions were identified. Among the SNPs detected, 25.5% were not described previously. We found that artificial selection during domestication led to more pronounced reduction in the genetic diversity of soybean than the switch from landraces to elite cultivars. Only a small proportion (2.99%) of the whole genomic regions appear to be affected by artificial selection for preferred agricultural traits. The selection regions were not distributed randomly or uniformly throughout the genome. Instead, clusters of selection hotspots in certain genomic regions were observed. Moreover, a set of candidate genes (4.38% of the total annotated genes) significantly affected by selection underlying soybean domestication and genetic improvement were identified.
Given the uniqueness of the soybean germplasm sequenced, this study drew a clear picture of human-mediated evolution of the soybean genomes. The genomic resources and information provided by this study would also facilitate the discovery of genes/loci underlying agronomically important traits.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Wild relatives of crops are an important source of genetic diversity for agriculture, but their gene repertoire remains largely unexplored. We report the establishment and analysis of a pan-genome of ...Glycine soja, the wild relative of cultivated soybean Glycine max, by sequencing and de novo assembly of seven phylogenetically and geographically representative accessions. Intergenomic comparisons identified lineage-specific genes and genes with copy number variation or large-effect mutations, some of which show evidence of positive selection and may contribute to variation of agronomic traits such as biotic resistance, seed composition, flowering and maturity time, organ size and final biomass. Approximately 80% of the pan-genome was present in all seven accessions (core), whereas the rest was dispensable and exhibited greater variation than the core genome, perhaps reflecting a role in adaptation to diverse environments. This work will facilitate the harnessing of untapped genetic diversity from wild soybean for enhancement of elite cultivars.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background
Hilar cholangiocarcinoma (HCCA) occurs in the core section of the biliary system and has a strong tendency to broadly invade the surrounding vascular system, perineural tissue and major ...liver parenchyma. Thus, minimally invasive resection can only be achieved in limited cases. This article reviews the current laparoscopic and robotic surgery techniques for HCCA and analyses the difficulties and limitations of the current minimally invasive surgical techniques for HCCA.
Methods
A systematic literature search was conducted using multiple electronic databases. All studies involving minimally invasive resections of HCCA were included (up to November 2017).
Results
Twelve studies were included, of which eight concerned laparoscopic surgery of HCCA and four involved robotic surgery for HCCA. For laparoscopic surgery, most of the surgical procedures were limited to partial hepatectomy or even bile duct resection; the post‐operative morbidity rate was approximately 38.9% (range 0–100%); those with fewer complications were mostly restricted to Bismuth type I or type II carcinomas. For robotic surgery, only one study concerned caudate lobectomy of HCCA, with a reported median operative time of 703 min and post‐operative morbidity of 90%.
Conclusions
Minimally invasive surgery for HCCA is restricted to highly selected cases and is deemed technically achievable in experienced hands. However, technical and instrumental improvement is needed to reduce the relevant morbidity and popularize the use of minimally invasive surgery to treat HCCA.
Background
Gallbladder carcinoma (GBC) is the most common biliary tract malignancy, which is characterized by easy local invasion, lymph nodes metastasis, local vascular invasion. Hence, minimally ...invasive surgery (MIS) can be performed in a limited number of patients. In our study, we reviewed the current studies on laparoscopic surgery (LS) and robotic surgery (RS) for GBC and analysed the limitations and difficulties of MIS for GBC.
Methods
Multiple electronic databases were used for a systematic literature retrieval. All studies involving MIS of GBC were included (up to August 2019).
Results
A total of 24 studies were included, of which 18 studies involved LS for GBC and six studies concerned RS of GBC. For LS, 16 studies contained relevant information of T stage, and 323 patients (98.8%) had T3 or lower stage; the average rate of R0 resection, conversion, postoperative complications and mortality was 95.3% (range 80.5–100%), 1.9% (range 0–16.7%), 13.4% (range 0–33.3%) and 1.0% (range 0–10%), respectively. For RS, four studies contained relevant information of T stage, and all patients were T3 or lower stage; the average rate of R0 resection, conversion and postoperative complications was 96.8% (range 81.8–100%), 5.5% (range 0–14.8%) and11.9% (range 0–36.4%), respectively. In addition, no patient had perioperative mortality.
Conclusions
MIS for GBC is limited to highly selected patients and is considered to be technically feasible in experienced surgeons. However, improvements in technical and instrumental are needed to reduce the associated postoperative complications and implantation metastasis, and to promote MIS in the treatment of GBC.
In our study, we reviewed 24 studies on laparoscopic surgery and robotic surgery for gallbladder carcinoma (GBC) and analysis the limitations and difficulties of minimally invasive surgery (MIS) for GBC. MIS for GBC is limited to highly screened patients and is considered to be technically feasible in experienced surgeons. However, improvements in technical and instrumental are needed to reduce the associated postoperative complications and implantation metastasis, and to promote MIS in the treatment of GBC.
High-molecular-weight glutenin subunits (HMW-GSs) are the most critical grain storage proteins that determine the unique processing qualities of wheat. Although it is a part of the superior HMW-GS ...pair (Dx5+Dy10), the contribution of the Dy10 subunit to wheat processing quality remains unclear. In this study, we elucidated the effect of Dy10 on wheat processing quality by generating and analyzing a deletion mutant (with the Dy10-null allele), and by elucidating the changes to wheat flour following the incorporation of purified Dy10. The Dy10-null allele was transcribed normally, but the Dy10 subunit was lacking. These findings implied that the Dy10-null allele reduced the glutenin:gliadin ratio and negatively affected dough strength (i.e., Zeleny sedimentation value, gluten index, and dough development and stability times) and the bread-making quality; however, it positively affected the biscuit-making quality. The incorporation of various amounts of purified Dy10 into wheat flour had a detrimental effect on biscuit-making quality. The results of this study demonstrate that the Dy10 subunit is essential for maintaining wheat dough strength. Furthermore, the Dy10-null allele may be exploited by soft wheat breeding programs.
De-domestication is a unique evolutionary process during which crops re-acquire wild-like traits to survive and persist in agricultural fields without the need for human cultivation. The ...re-acquisition of seed dispersal mechanisms is crucial for crop de-domestication. Common wheat is an important cereal crop worldwide. Tibetan semi-wild wheat is a potential de-domesticated common wheat subspecies. However, the crucial genes responsible for its brittle rachis trait have not been identified.
Genetic mapping, functional analyses and phylogenetic analyses were completed to identify the gene associated with Qbr.sau-5A, which is a major locus for the brittle rachis trait of Tibetan semi-wild wheat.
The cloned Qbr.sau-5A gene is a new Q allele (Qt
) with a 161-bp transposon insertion in exon 5. Although Qt
is expressed normally, its encoded peptide lacks some key features of the APETALA2 family. The abnormal functions of Q
t in developing wheat spikes result in brittle rachises. Phylogenetic and genotyping analyses confirmed that Qt
originated from Q in common wheat and is naturally distributed only in Tibetan semi-wild wheat populations.
The identification of Qt
provides new evidence regarding the origin of Tibetan semi-wild wheat, and new insights into the re-acquisition of wild traits during crop de-domestication.
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