The floral nectary, first recognized and described by Carl Linnaeus, is a remarkable organ that serves to provide carbohydrate-rich nectar to visiting pollinators in return for gamete transfer between flowers. Therefore, the nectary has indispensable biological significance in plant reproduction and even in evolution. Only two genes, CRC and STY, have been reported to regulate floral nectary development. However, it is still unknown what genes contribute to extrafloral nectary development. Here, we report that a nectary development gene in Gossypium (GoNe), annotated as an APETALA 2/ethylene-responsive factor (AP2/ERF), is responsible for the formation of both floral and extrafloral nectaries. GoNe plants that are silenced via virus-induced gene silencing technology and/or knocked out by Cas9 produce a nectariless phenotype. Point mutation and gene truncation simultaneously in duplicated genes Ne1Ne2 lead to impaired nectary development in tetraploid cotton. There is no difference in the expression of the CRC and STY genes between the nectary TM-1 and the nectariless MD90ne in cotton. Therefore, the GoNe gene responsible for the formation of floral and extrafloral nectaries may be independent of CRC and STY. A complex mechanism might exist that restricts the nectary to a specific position with different genetic factors. Characterization of these target genes regulating nectary production has provided insights into the development, evolution, and function of nectaries and insect-resistant breeding. 相似文献
Summary Single and multisensor field effect transistors (FET) with a pH-sensitive Si/SiO2/Si3N4/Ta2O5-gate and reference electrode (for single sensor) were developed and used for manufacturing the following biological (Bio)-FETs: for glucose analysis, glucose oxidase-FET (GOD-FET); for urea analysis, urease-FET; and for cephalosporin C analysis, cephalosporinase-FET. The GOD-FETs were integrated into flow injection analysis (FIA) of the Eppendorf variables analyser (EVA) system and used for monitoring the glucose concentration in microbial cultivation and production processes with recombinant Escherichia coli K12 MF, recombinant E. coli JM103, Saccharomyces cerevisiae H620, and Candida boidinii. Urease-FET-FIA was used to monitor the urea concentration in a simulated cultivation of Cephalosporium acremonium and urease-FET-FIA and GOD-FET-FIA for the monitoring of urea and glucose concentrations in simulated S. cerevisiae cultivations. 相似文献
Differential scanning calorimetry (DSC) and nuclear magnetic resonance (NMR) spectroscopy are applied to characterize the nonfreezable water molecules in fully hydrated D2O/sphingomyelin at temperatures below 0 degrees C. Upon cooling, DSC thermogram displays two thermal transitions peaked at -11 and -34 degrees C. The high-temperature exothermic transition corresponds to the freezing of the bulk D2O, and the low-temperature transition, which has not previously been reported, can be ascribed to the freezing of the phosphocholine headgroup in the lipid bilayer. The dynamics of nonfreezable water are also studied by 2H NMR T1 (spin-lattice relaxation time) and T2e (spin-spin relaxation time obtained by two pulse echo) measurements at 30.7 MHz and at temperatures down to -110 degrees C. The temperature dependence of the T1 relaxation time is characterized by a distinct minimum value of 2.1 +/- 0.1 ms at -30 degrees C. T2e is discontinuous at temperature around -70 degrees C, indicating another freezing-like event for the bound water at this temperature. Analysis of the relaxation data suggest that nonfreezable water undergoes both fast and slow motions at characteristic NMR time scales. The slow motions are affected when the lipid headgroup freezes. 相似文献
Sapium sebiferum Roxb. is a widespread and economically important multipurpose tree due to its high value in ornamental, and biodiesel production as well as medicine. A highly efficient in vitro plant regeneration system through direct shoot organogenesis was established for the first time from leaves and petioles of S. sebiferum. The results showed that plant growth regulators (PGRs), mechanical damage, explant orientation, explant source, and developmental stage had a strong influence on the in vitro morphogenesis of S. sebiferum. For shoot organogenesis from leaves, the highest adventitious shoot induction rate (96.67%) with 25.67 shoots per explant was obtained when mechanically damaged leaves (the first three leaf explants at the top, leaf #1–3) were cultured with the abaxial surface placed down on Murashige and Skoog (MS) medium containing 0.5 mg L?1 thidiazuron (TDZ). For in vitro morphogenesis of petioles, the combination of 1-naphthylacetic acid (NAA) and 6-benzylainopurine (6-BA) played a key role in cell fate determination. All of the in vitro petioles produced adventitious shoots on MS medium containing 1.0 mg L?1 6-BA and 0.1 mg L?1 NAA, while they produced green calli on medium fortified with 0.5 mg L?1 6-BA and 1.0 mg L?1 NAA. The shoots were subcultured in medium fortified with 0.5 mg L?1 6-BA and 0.1 mg L?1 NAA for multiplication and elongation. The elongated shoots successfully rooted on half-strength MS (1/2 MS) medium fortified with 0.5 mg L?1 indole-butyric acid (IBA) and 0.25 mg L?1 indole-3-acetic acid (IAA), and the regenerated plantlets successfully acclimatized with a survival rate of 92.56% in the greenhouse. The genetic fidelity of in vitro regenerated plants was evaluated using inter simple sequence repeat molecular markers. The in vitro regenerated plants were found to be the true to their mother plant. This study will be beneficial for the large-scale propagation as well as the genetic improvement of S. sebiferum.
Bioprocess and Biosystems Engineering - Currently, some cases about the expression of flavor peptides with microorganisms were reported owing to the obvious advantages of biological expression over... 相似文献
Alzheimer’s disease (AD) is the most common neurodegenerative disease with multifactorial pathologies including Aβ containing senile plaques and neurofibrillary tangles (NFT) consisted of aggregated Tau. Most of the AD patients are sporadic and the familial mutation hereditary patients are composed only 1% of all cases. However, the current AD mouse models employ mutated APP, PS1, or even Tau mutant, in order to display a portion of AD pathologies. Delta-secretase (legumain, or asparaginyl endopeptidase, AEP) simultaneously cleaves both APP and Tau and augments Aβ production and Tau hyperphosphorylation and aggregation, contributing to AD pathogenesis. Here we show that δ-secretase is sufficient to promote prominent AD pathologies in wild-type hAPP/hMAPT double transgenic mice. We crossed hAPP l5 mice and hMAPT mice to generate double transgenic mouse model carrying both human wild-type APP and Tau. Compared to the single transgenic parents, these double transgenic mice demonstrated AD-related pathologies in one-year-old hAPP/hMAPT mice. Notably, overexpression of δ-secretase in hAPP/hMAPT double-transgenic mice evidently accelerated enormous senile plaques and NFT, associated with prominent synaptic defects and cognitive deficits. Hence, δ-secretase facilitates AD pathogenesis independent of any patient-derived mutation.Subject terms: Alzheimer''s disease, Neurological disorders相似文献
The long noncoding RNAs (lncRNAs) have been increasingly appreciated as key players underlying tumourigenesis and hold great potentials as prognostic biomarkers and therapeutic targets. However, their roles in head neck squamous cell carcinoma (HNSCC) have remained incompletely known. Here, we sought to reveal the oncogenic roles and clinical significance of a tumour‐associated lncRNA, zinc finger E‐box binding homeobox 2 antisense RNA 1 (ZEB2‐AS1), in HNSCC. ZEB2‐AS1 was aberrantly overexpressed in a fraction of HNSCC samples. Its overexpression significantly associated with large tumour size, cervical node metastasis and reduced overall and disease‐free survival. Antisense oligonucleotides (ASO)‐mediated ZEB2‐AS1 depletion markedly inhibited cell proliferation, migration and invasion while triggered apoptosis in HNSCC cells in part via modulating ZEB2 mRNA stability. Enforced overexpression of ZEB2 largely attenuated the phenotypic changes resulted from ZEB2‐AS1 inhibition except the impaired cell proliferation. In addition, ZEB2‐AS1 was required for TGF‐β1‐induced epithelial‐mesenchymal transition (EMT) in vitro. Significantly reduced tumour growth and lung metastasis were observed in ZEB2‐AS1‐depleted cells in HNSCC xenograft animal models. Taken together, our findings reveal that overexpression of ZEB2‐AS1 associates with tumour aggressiveness and unfavourable prognosis by serving as a putative oncogenic lncRNA and a novel prognostic biomarker in HNSCC. 相似文献