Pollen acts as a biological protector for protecting male sperm from various harsh conditions and is covered by an outer cell wall polymer called the exine, a major constituent of which is ...sporopollenin. The tapetum is in direct contact with the developing gametophytes and plays an essential role in pollen wall and pollen coat formation. The precise molecular mechanisms underlying tapetal development remain highly elusive, but molecular genetic studies have identified a number of genes that control the formation, differentiation, and programmed cell death of tapetum and interactions of genes in tapetal development. Herein, several lines of evidence suggest that sporopollenin is built up via catalytic enzyme reactions in the tapetum. Furthermore, as based on genetic evidence, we review the currently accepted understanding of the molecular regulation of sporopollenin biosynthesis and examine unanswered questions regarding the requirements underpinning proper exine pattern formation.
Targeted gene regulation on a genome-wide scale is a powerful strategy for interrogating, perturbing, and engineering cellular systems. Recent advances with the RNA-mediated Cas9 endonuclease derived ...from clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated proteins (Cas) systems have dramatically transformed our ability to specifically modify intact genomes of diverse cells and organisms. The CRISPR–Cas system has been adapted as an efficient, facile, and robust gene-targeting technology with the potential for high-throughput and multiplexed genome engineering. Exciting breakthroughs in understanding the mechanisms of the CRISPR–Cas system and its enormous potential for applications across basic science, agricultural and biotechnology.
Salt, saline‐alkali conditions, and drought are major environmental factors limiting plant growth and productivity. The vacuolar H+‐translocating inorganic pyrophosphatase (V‐H+‐PPase) is an ...electrogenic proton pump that translocates protons into vacuoles in plant cells. Expression of V‐H+‐PPase increases in plants under a number of abiotic stresses, and is thought to have an important role in adaptation to abiotic stress. In this work, we report the isolation and characterization of the gene, ScVP, encoding a vacuolar inorganic pyrophosphatase (V‐H+‐PPase) from the halophyte, Suaeda corniculata. Semi‐quantitative reverse transcription‐polymerase chain reaction analysis showed that ScVP was induced in roots, stems and leaves under treatment with salt, saline‐alkali and drought. Compared with wild‐type (WT) Arabidopsis, transgenic plants overexpressing ScVP accumulated more Na+ in leaves and roots, and showed increased tolerance to high salinity, saline‐alkali and drought stresses. The germination percentage of transgenic Arabidopsis seeds was higher than that of WT seeds under the abiotic stresses. The root length of transgenic plants under salt stress was longer than that of WT plants. Furthermore, the rate of water loss during drought stress was higher in WT than in transgenic plants. Collectively, these results indicate that ScVP plays an important role in plant tolerance to salt, saline‐alkali and drought stress.
Salt, saline–alkali and drought stresses are major environmental constraints for the production and yield of soybean worldwide. To identify genes responsible for stress tolerance, the transcriptional ...profiles of genes in leaves and roots of seedlings (two-leaf stage) of the soybean inbred line HJ-1 were examined after 48h under various stress conditions; salt (120mM NaCl), saline–alkali (70mM NaCl and 50mM NaHCO3) and drought (2% PEG 8000). Gene expression at the transcriptional level was investigated using high-throughput Illumina sequencing technology and bioinformatics tools. Under salt, saline–alkali and drought stress, 874, 1897, and 535 genes, respectively, were up-regulated in leaves, and 1822, 1731 and 1690 genes, respectively, were up-regulated in roots, compared with expression in the corresponding organ in control plants. Comparisons among salt, saline–alkali and drought stress yielded similar results in terms of the percentage of genes classified into each GO category. Moreover, 69 genes differentially expressed in both organs with similar expression patterns clustered together in the taxonomic tree across all conditions. Furthermore, comparison of gene expression among salt, saline–alkali and drought treated plants revealed that genes associated with calcium-signaling and nucleic acid pathways were up-regulated in the responses to all three stresses, indicating a degree of cross-talk among these pathways. These results could provide new insights into the stress tolerance mechanisms of soybean.
► We analyzed gene expression profiling of soybean under stresses. ► Genes were categorized according to the number of expressed transcripts. ► 69 genes were expressed differently under salt, saline-alkali and drought stresses. ► Genes were clustered according to similarities across all stresses. ► The response to stress in soybean is a complex physiological and metabolic pathway.
Soybean (Glycine max L.) is one of the most important oil crops in the world. It is desirable to increase oil yields from soybean, and so this has been a major goal of oilseed engineering. However, ...it is still uncertain how many genes and which genes are involved in lipid biosynthesis.
Here, we evaluated changes in gene expression over the course of seed development using Illumina (formerly Solexa) RNA-sequencing. Tissues at 15 days after flowering (DAF) served as the control, and a total of 11592, 16594, and 16255 differentially expressed unigenes were identified at 35, 55, and 65 DAF, respectively. Gene Ontology analyses detected 113 co-expressed unigenes associated with lipid biosynthesis. Of these, 15 showed significant changes in expression levels (log2fold values ≥ 1) during seed development. Pathway analysis revealed 24 co-expressed transcripts involved in lipid biosynthesis and fatty acid biosynthesis pathways. We selected 12 differentially expressed genes and analyzed their expressions using qRT-PCR. The results were consistent with those obtained from Solexa sequencing.
These results provide a comprehensive molecular biology background for research on soybean seed development, particularly with respect to the process of oil accumulation. All of the genes identified in our research have significance for breeding soybeans with increased oil contents.
Salt and saline-alkali are major environmental factors limiting the growth and productivity of alfalfa, the most economically important forage legume worldwide. In this study, alfalfa plants ...transgenic for both ScNHX1 (encoding vacuolar membrane Na⁺/H⁺ antiporter from Suaeda corniculata) and ScVP (encoding vacuolar H⁺-PPase from S. corniculata) were produced by cross-pollination. Transgenic alfalfa plants coexpressing ScVP/ScNHX1 showed enhanced salt and saline-alkali tolerance to 300 or 200 mM NaCl with 100 mM NaHCO₃ treatments, compared with wild-type plants. In addition, ScVP/ScNHX1-coexpressing alfalfa plants accumulated more Na⁺ in leaves and roots than wild-type plants and showed increased tolerance to higher salt and saline-alkali stress. Using the fluorescent carboxy-SNARF probe, the intracellular pH was visualized in the transgenic and wild-type plants under salt and saline-alkali stress. The results showed that the overnight treatment caused a massive change in pH in ScVP/ScNHX1-coexpressing alfalfa plants and they showed that there was significantly higher vacuolar alkalization under salt stress compared with wild-type plants. However, saline-alkali treatment enhanced vacuolar acidification more in the wild-type plants than in transgenic plants. Taken together, our results indicate that coexpression of multiple, effective genes in transgenic plants can enhance resistance to salt and saline-alkali stress.
Norepinephrine infusion decreases hypotension after spinal anesthesia during cesarean section. This study aimed to compare the efficacy of norepinephrine infusion and ephedrine bolus against ...post-spinal hypotension in parturients.
In this double-blinded, randomized controlled clinical trial, parturients scheduled for elective cesarean section were randomly allocated to receive norepinephrine infusion (0.05 μg·kg-1·min-1) just before spinal anesthesia continuing for 30 min or ephedrine bolus (0.15 mg/kg) just before spinal anesthesia. A rescue bolus (5 μg norepinephrine for the norepinephrine group, and 5 mg ephedrine for the ephedrine group) was administered whenever hypotension occurred. Our primary outcome was the incidence of hypotension within 30 min of spinal anesthesia administration. Secondary outcomes included maternal and neonatal outcomes 30 min after spinal block, and neonatal cerebral oxygenation 10 min after birth.
In total, 190 patients were enrolled; of these patients, 177 were included in the final analysis. Fewer patients suffered hypotension in the norepinephrine group than in the ephedrine group (29.5% vs. 44.9%, odds ratio OR: 0.51, 95% confidence interval CI: 0.28-0.95, P = 0.034). Moreover, the tachycardia frequency was lower in the norepinephrine group than in the ephedrine group (OR: 0.22, 95% CI: 0.11-0.44, P < 0.001), and patients suffered less nausea and vomiting (OR: 0.28, 95% CI: 0.11-0.70, P = 0.004). There was no difference in Apgar scores and umbilical arterial blood gas analysis between the two groups. However, neonatal cerebral regional saturations were significantly higher after birth in the norepinephrine group than in the ephedrine group (mean difference: 2.0%, 95% CI: 0.55%-3.45%, P = 0.008).
In patients undergoing elective cesarean section with spinal anesthesia, norepinephrine infusion compared to ephedrine bolus resulted in less hypotension and tachycardia, and exhibited potential neonatal benefits.
ClinicalTrials.gov, NCT02542748; https://clinicaltrials.gov/ct2/show/record/NCT02542748.
In recent years, S-(alkyl)thianthrenium salts have become an important means of functionalizing alcohol compounds. However, additional transition metal catalysts and/or visible light are required. ...Herein, a direct thioetherification/amination reaction of thianthrenium salts is realized under metal-free conditions. This strategy exhibits good functional-group tolerance, operational simplicity, and an extensive range of compatible substrates.
Most plane warts are recalcitrant to treatment. Both cryotherapy and local hyperthermia have been applied to treat plane warts. However, no direct comparative study on their respective efficacy and ...safety has ever been performed. To assess the efficacy and safety of local hyperthermia at 43 ± 1°C versus liquid nitrogen cryotherapy for plane warts. Sequential patients with plane warts entered the study, either receiving cryotherapy or local hyperthermia therapy at the discretion of the patients and the recommendations of consultants. Cryotherapy with liquid nitrogen was delivered in two sessions 2 weeks apart, while local hyperthermia was delivered on three consecutive days, plus two similar treatments 10 ± 3 days later. The temperature over the treated skin surface was set at 43 ± 1°C for 30 min in each session. The primary outcome was the clearance rates of the lesions 6 months after treatment. Among the 194 participants enrolled, 183 were included in the analysis at 6 months. Local hyperthermia and cryotherapy achieved clearance rates of 35.56% (48/135) and 31.25% (15/48), respectively (p = 0.724); recurrence rates of 16.67% (8/48) and 53.33% (8/15) (p = 0.01); and adverse events rates of 20.74% (28/135) and 83.33% (40/48), respectively (p < 0.001). Cryotherapy had a higher pain score (p < 0.001) and a longer healing time (p < 0.001). Local hyperthermia at 43°C and cryotherapy had similar efficacy for plane warts. Local hyperthermia had a safer profile than cryotherapy but it required more treatment visits during a treatment course. More patients preferred local hyperthermia due to its treatment friendly nature.
Functional constipation (FC) is an intractable disease that carries large financial burden as well as emotional and physical stress. We aimed to assess the efficacy and safety of the newly developed ...smartphone-controlled vibrating capsule (VC) in patients with FC.
From December 2018 to February 2020, we did a multicenter, blinded, placebo-controlled randomised trial in six top general hospitals in China focusing on patients aged 18 to 80 with FC. Patients were randomly assigned in a 1:1 ratio to receive VCs or placebo treatment for six weeks (two capsules per week) after a two-week baseline period. The primary outcome was the responder rate, defined as the proportion of patients with an increase of at least one complete spontaneous bowel movement (CSBM) per week during treatment compared to baseline in the full analysis set. This trial is registered with ClinicalTrials.gov, number NCT04671264, and is completed.
107 patients aged from 18 to 74 were randomly assigned to receive VC (n = 53) or placebo treatment (n = 54). The responder rate in the VC group was significantly higher than that in the placebo group (64·2% vs. 35·8%; difference, 27·7% 95% CI, 10·4–45·1; P = 0·005). More patients in the VC group reported weekly CSBMs ≥ 1 for at least four weeks during treatment (difference, 22·7% 95% CI, 8–46; P = 0·022) and follow-up period (difference, 17.3% 95% CI, 0–35; P = 0·048). The mean Patient Assessment of Constipation-Symptoms score and Patient Assessment of Constipation-Quality of Life score differed significantly from the baseline in both groups (all P < 0·0001). The most common adverse event associated with VC was abdominal discomfort (3·7%).
VCs can promote defecation, as well as ameliorating symptoms and improving the quality of life in patients with FC with sustained efficacy. VC appears to be a potential alternative physical treatment for FC with the exact mechanism and parameters warranting further investigation.
The study was supported by "One hundred leading scientists for 21st century" of Health Department of Shanghai Municipal Government (to ZL, No.2017BR005).
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