Self-assembly of rigid building blocks with explicit shape and symmetry is substantially influenced by the geometric factors and remains largely unexplored. We report the selective assembly behaviors ...of a class of precisely defined, nanosized giant tetrahedra constructed by placing different polyhedral oligomeric silsesquioxane (POSS) molecular nanoparticles at the vertices of a rigid tetrahedral framework. Designed symmetry breaking of these giant tetrahedra introduces precise positional interactions and results in diverse selectively assembled, highly ordered supramolecular lattices including a Frank-Kasper A15 phase, which resembles the essential structural features of certain metal alloys but at a larger length scale. These results demonstrate the power of persistent molecular geometry with balanced enthalpy and entropy in creating thermodynamically stable supramolecular lattices with properties distinct from those of other self-assembling soft materials.
The gut microbiota of insects plays a vital role in digestion, nutrient acquisition, metabolism of dietary toxins, pathogen immunity and maintenance of gut homeostasis. Bacillus thuringinensis (Bt) ...poisons target insects through its toxins that are activated in the insect gut. The effects of Bt toxins on gut microbiota of insects and their underlying mechanisms are not well understood. In this study, we found that Cry1Ab/2Ab toxins significantly changed the gut bacterial community’s structure and reduced the total load of gut bacteria in the Locusta migratoria. In addition, Cry toxins significantly increased the level of reactive oxygen species (ROS) in the gut of locusts. Our results also showed that Cry1Ab/2Ab toxins induced the host gut’s immune response by up-regulating of key genes in the Immune deficiency (IMD) and Toll pathway. RNA interference showed that knocking down Relish could narrow the difference in the load, diversity, and composition in gut bacteria caused by Cry toxins. Our findings suggest that Bt potentially influences the gut bacterial community of L. migratoria through host immune response.
•Bt toxins disrupt the homeostasis of gut microbes in Locusta migratoria.•Changes in gut microbes trigger a cascade that further alters the gut environment.•Bt toxins influence the gut microbes of locusts through the immune response.
This study was conducted to explore specific chill models and the mechanisms underlying rhizome bud dormancy break in Polygonatum kingianum. Rhizome buds were subjected to various chilling ...temperatures for different duration and then transferred to warm conditions for germination and subsequent evaluation of their response to temperature and chilling requirements. A CUkingianum model was constructed to describe the contribution of low temperature to the chill unit, and it was suggested that 2.97°C was the optimum temperature and that 11.54°C was the upper limit for bud release. The CASkingianum model showed the relationship between chilling accumulation and sprouting percentage; therefore, rhizome bud development could be predicted through the model. Weighted correlation network analysis (WGCNA) of transcriptomic data of endo-, eco- and nondormant rhizome buds generated 33 gene modules, 6 of which were significantly related to bud sprouting percentage. In addition, 7 significantly matched transcription factors (TFs) were identified from the promoters of 17 "real" hub genes, and DAG2 was the best matched TF that bound to AAAG element to regulate gene expression. The current study is valuable for developing a highly efficient strategy for seedling cultivation and provides strong candidates for key genes related to rhizome bud dormancy in P. kingianum.
Epimedium brevicornu Maxim. is a herbal plant with various therapeutic effects, and its aboveground tissues contain flavonol compounds such as icaritin that can be used to produce new drugs for the ...treatment of advanced liver cancer. Previous studies have shown that ultraviolet-B (UV-B, 280–315 nm) stress can increase the levels of flavonoid substances in plants. In the current study, we observed the microstructure of E. brevicornu leaves after 0, 5, 10, 15, and 20 d of UV-B radiation (60 μw·cm−2) and quality formation mechanism of E. brevicornu leaves after 0, 10, and 20 d of UV-B radiation by LC‒ESI‒MS/MS. The contents of flavonols such as icariside I, wushanicaritin, icaritin, and kumatakenin were significantly upregulated after 10 d of radiation. The results indicated that UV-B radiation for 10 d inhibited the morphological development of E. brevicornu but increased the content of active medicinal components, providing a positive strategy for epimedium quality improvement.
Transgenic maize expressing the Cry1Ab and Cry2Ab protein simultaneously from
Bacillus thuringiensis
(Bt-maize) has been grown for farm-scale study to investigate its potential impact to non-target ...arthropod (NTA). The trials were conducted between Bt maize 2A-7 and its parental line (B73-329) in Beijing, China, over 3 years. Richness (
C
), Shannon index (
H
), Pielou index (
J
), Simpson index (
D
), and Bray-Curtis index were used to evaluate the population dynamics and biodiversity of the dominant arthropods from per 50 plants in crop field. The mainly abundant groups were Aphidoidea, Araneae, Coccinellidae, Anthocoridae, and Thripidae which represented about 90% of the total number of NTA. Although the abundance of NTA varied from year to year, there is no significant difference between Bt maize and non-Bt maize field. Fluctuations were found at individual sample dates, but the trend of these descriptors remained consistent. Further analysis showed the biodiversity indexes of the dominant arthropods
C
,
H
,
J
,
D
, and Bray-Curtis dissimilarity between Bt maize producing Cry1Ab and Cry2Ab toxin simultaneously and its parental line had no significant difference except for some sampling dates. These results suggested that Bt maize is compatible with the NTAs and provides further evidence of the ecological impact of genetically modified maize.
Root rot caused by the pathogenic fungi of the
genus poses a great threat to the yield and quality of medicinal plants. The application of Agricultural Jiaosu (AJ), which contains beneficial microbes ...and metabolites, represents a promising disease control strategy. However, the action-effect of AJ on
root rot disease remains unclear. In the present study, we evaluated the characteristics and antifungal activity of AJ fermented using waste leaves and stems of medicinal plants, and elucidated the mechanisms of AJ action by quantitative real-time PCR and redundancy analysis. The effects of AJ and antagonistic microbes isolated from it on disease suppression were further validated through a pot experiment. Our results indicate that the AJ was rich in beneficial microorganisms (
,
, and
), organic acids (acetic, formic, and butyric acids) and volatile organic compounds (alcohols and esters). It could effectively inhibit
and the half-maximal inhibitory concentration (IC
) was 13.64%. The antifungal contribution rate of the microbial components of AJ reached 46.48%. Notably, the redundancy analysis revealed that the
and
genera occupied the main niche during the whole inhibition process. Moreover, the abundance of the
,
, and
genera were positively correlated with the pH-value, lactic, formic and butyric acids. The results showed that the combined effects of beneficial microbes and organic acid metabolites increased the efficacy of the AJ antifungal activity. The isolation and identification of AJ's antagonistic microbes detected 47 isolates that exhibited antagonistic activities against
. In particular,
and
presented the strongest antifungal activity. In the pot experiment, the application of AJ and these two
species significantly reduced the disease incidence of
root rot and promoted the growth of
. The present study provides a cost-effective method to control of
root rot disease, and establishes a whole-plant recycling pattern to promote the sustainable development of medicinal plant cultivation.
The roots of
var.
(AMM) and A. membranaceus (AM) are widely used in traditional Chinese medicine. Although AMM has higher yields and accounts for a larger market share, its cultivation is fraught ...with challenges, including mixed germplasm resources and widespread adulteration of commercial seeds. Current methods for distinguishing Astragalus seeds from similar (SM) seeds are time-consuming, laborious, and destructive. To establish a non-destructive method, AMM, AM, and SM seeds were collected from various production areas. Machine vision and hyperspectral imaging (HSI) were used to collect morphological data and spectral data of each seed batch, which was used to establish discriminant models through various algorithms. Several preprocessing methods based on hyperspectral data were compared, including multiplicative scatter correction (MSC), standard normal variable (SNV), and first derivative (FD). Then selection methods for identifying informative features in the above data were compared, including successive projections algorithm (SPA), uninformative variable elimination (UVE), and competitive adaptive reweighted sampling (CARS). The results showed that support vector machine (SVM) modeling of machine vision data could distinguish Astragalus seeds from SM with >99% accuracy, but could not satisfactorily distinguish AMM seeds from AM. The FD-UVE-SVM model based on hyperspectral data reached 100.0% accuracy in the validation set. Another 90 seeds were tested, and the recognition accuracy was 100.0%, supporting the stability of the model. In summary, HSI data can be applied to discriminate among the seeds of AMM, AM, and SM non-destructively and with high accuracy, which can drive standardization in the Astragalus production industry.
The rhizome of Polygonatum kingianum Coll. et Hemsl (P. kingianum) is a crucial traditional Chinese medicine, but severe bud dormancy occurs during early rhizome development. Low temperature is a ...positive factor affecting dormancy release, whereas the variation in carbohydrates during dormancy release has not been investigated systematically. Therefore, the sugar content, related metabolic pathways and gene co-expression were analysed to elucidate the regulatory mechanism of carbohydrates during dormancy release in the P. kingianum rhizome bud.
During dormancy transition, starch and sucrose (Suc) exhibited opposing trends in the P. kingianum rhizome bud, representing a critical indicator of dormancy release. Galactose (Gal) and raffinose (Raf) were increased in content and synthesis. Glucose (Glc), cellulose (Cel), mannose (Man), arabinose (Ara), rhamnose (Rha) and stachyose (Sta) showed various changes, indicating their different roles in breaking rhizome bud dormancy in P. kingianum. At the beginning of dormancy release, Glc metabolism may be dominated by anaerobic oxidation (glycolysis followed by ethanol fermentation). After entering the S3 stage, the tricarboxylic acid cycle (TCA) and pentose phosphate pathway (PPP) were may be more active possibly. In the gene co-expression network comprising carbohydrates and hormones, HYD1 was identified as a hub gene, and numerous interactions centred on STS/SUS were also observed, suggesting the essential role of brassinosteroids (BRs), Raf and Suc in the regulatory network.
We revealed cold-responsive genes related to carbohydrate metabolism, suggesting regulatory mechanisms of sugar during dormancy release in the P. kingianum rhizome bud. Additionally, gene co-expression analysis revealed possible interactions between sugar and hormone signalling, providing new insight into the dormancy release mechanism in P. kingianum rhizome buds.
Epimedium brevicornu Maxim is a traditional Chinese medicinal plant with important value for curing several diseases, including liver cancer. Seed germination, field seedling emergence, and ...morphological and physiological traits were measured in developing seeds of E. brevicornu, which were collected at 7, 14, 21, 28, and 35 days after flowering. The results showed that with the fruit pericarp changing from lime green to dark red, the seed volume increased. Furthermore, the dry mass of seeds gradually increased from 0.011 g at 7 d to 0.275 g at 35 d, which was a significantly positive correlation with seed vigour (r = 0.980). The soluble protein content initially increased and then decreased to 11.09 mg/g and presented a maximum at 28 d; however, the soluble sugar content gradually declined to a minimum of 30.45 mg/g at 35 d, which was also significantly negatively correlated with seed vigour (r = −0.915). Furthermore, the unsaturated fatty acids (oleic acid and linoleic acid) increase with seed development. Abscisic acid (ABA) reached a maximum value of 18.45 ng/g at 28 d, and gibberellin (GA3), 3-Indoleacetic acid (IAA) and zeatin-riboside (ZR) initially increased and then decreased. These results suggest that the vigour of E. brevicornu seeds is closely associated with their stage of development, with the highest vigour observed at 28~35 d after flowering.
This paper reports a facile, modular, and efficient approach to the synthesis of shape amphiphiles with a hydrophobic polymer chain as the tail and a polar, compact, functional polyhedral oligomeric ...silsequioxane (POSS) nanoparticle as the headgroup. A poly(l-lactide) (PLLA) chain was grown from monohydroxyl-functionalized heptavinyl POSS (VPOSS−OH) with controlled molecular weight and narrow polydispersity by stannous octoate-mediated ring-opening polymerization of l-lactide. To impart tunable polarity and functionality to the headgroup, various functional groups, such as carboxylic acids, hydroxyl groups, and sugars, were attached to the POSS cage in high efficiency by thiol−ene “click” chemistry, which provides a straightforward and effective approach to synthesize shape amphiphiles with diverse head surface chemistry. The polymers have been fully characterized by 1H NMR, 13C NMR, FT-IR spectroscopy, MALDI-TOF mass spectrometry, and size exclusion chromatography. These functional POSS can serve as versatile nanobuilding blocks in the “bottom-up” construction of nanoscale structures and assemblies that may exhibit rich self-assembling behavior and potentially useful physical properties.
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