Abstract We systematically explore the origin and evolution of the exceptional points (EP) when a light beam is scattered by a PT-symmetric system using a scattering matrix approach and a full-wave theory. It is demonstrated that the PT-symmetric system switches between symmetry and symmetry-breaking phases at the EPs, giving rise to singular features in the Fresnel coefficients and causing the spin-Hall effect (SHE) near the EPs to exhibit anomalous features such as significantly enhanced transverse spin-Hall shifts and additional in-plane spin-Hall shifts. This exotic SHE can be explained by the significant beam intensity distortion caused by the destructive interference between the spin-maintained normal modes and the spin-reversed abnormal modes in the scattered light. This phenomenon can further be understood in terms of vortex mode decomposition, wherein it can be interpreted as the competition and superposition of three vortex modes with topological charges of −1, 0, and 1, respectively. These findings elucidate the mechanism of the unusual SHE around the EPs and offer potential avenues for EP-based sensing and structured light manipulation.
SUMMARY A fundamental question in developmental biology is how to regulate grain size to improve crop yields. Despite this, little is still known about the genetics and molecular mechanisms regulating grain size in crops. Here, we provide evidence that a putative protein kinase‐like (OsLCD3) interacts with the S‐adenosyl‐L‐methionine synthetase 1 (OsSAMS1) and determines the size and weight of grains. OsLCD3 mutation ( lcd3 ) significantly increased grain size and weight by promoting cell expansion in spikelet hull, whereas its overexpression caused negative effects, suggesting that grain size was negatively regulated by OsLCD3 . Importantly, lcd3 and OsSAMS1 overexpression (SAM1OE) led to large and heavy grains, with increased ethylene and decreased polyamines production. Based on genetic analyses, it appears that OsLCD3 and OsSAMS1 control rice grain size in part by ethylene/polyamine homeostasis. The results of this study provide a genetic and molecular understanding of how the OsLCD3‐OsSAMS1 regulatory module regulates grain size, suggesting that ethylene/polyamine homeostasis is an appropriate target for improving grain size and weight.
Herbaceous peony (Paeonia lactiflora Pall.) is known as the flower phase. This phase is somewhat resistant to drought, but long-term drought and severe water shortage will affect its normal growth and development. In this study, physiological indices and the transcriptome of P. lactiflora were determined to clarify its physiological responses and gene expression changes under drought stress. The results showed that under drought stress, soluble sugar content, peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) activities, and chlorophyll, carotenoid and flavonoid contents were significantly increased, and soluble protein content, superoxide dismutase (SOD), glutathione reductase (GR), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR), ascorbic acid (AsA) and glutathione (GSH) activity first increased and then decreased after day 14. Moreover, drought stress also significantly reduced chlorophyll content, photosynthesis and chlorophyll fluorescence parameters. Transcriptomic analysis revealed that compared with the Control, 10,747 differentially expressed genes (DEGs) were upregulated and 11,835 downregulated under drought stress. These DEGs were classified into three categories and 46 functional groups by GO function classification. The 3,179 DEGs were enriched into 128 pathways by KEGG pathway enrichment. The ROS system, chlorophyll degradation and photosynthetic capacity, as well as secondary pathways of biosynthesis and sugar metabolism were included. Additionally, relevant genes expressed in some metabolic pathways were discovered. These results provide a theoretical basis for understanding the responses of P. lactiflora to drought stress.
Our objective was to study the differentially expressed genes (DEGs) of apple (Malus. sp.) rootstock with different gravitropic setpoint angles (GSAs), during the formation of stem-root GSAs. The annual shoots of eight years hybrid seedlings of Malus pumila'Ralls' and M. sp. were used as experimental materials, and softwood cutting was carried out in mid-May. Different strains of adventitious root GSA were screened and shoot cuttings were carried out again the following year. The cuttings were randomly selected at 24 day after cutting, and then the transcriptome analysis was carried out. The results show that: (1) according to the difference of stem-root GSA of cutting seedlings, the seedlings of apple rootstock were divided into 3 groups: deep root type (SC), intermediate root type (ZC) and shallow root type (QC). (2) Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that 2613 genes from shallow- and deep-rooted rootstock, 2091 from deep- and intermediate-rooted rootstock, and 3114 from intermediate- and shallow-rooted rootstock, were annotated into 125 pathways. Among these pathways, plant hormone signal transduction, biosynthesis of secondary metabolites, and phenylpropanoid biosynthesis pathways were significantly enriched (P < 0.01).
Phytochemical investigation on the leaves and twigs of Toona ciliata has led to the isolation of four new polyynes (1-4) and two knowns (5 and 6). Their structures were determined by extensive spectroscopic analysis (MS, UV, IR, and NMR) and Mosher's method. All compounds were evaluated for their inhibitory activities against HepG2 human tumor cell line but were inactive.
Targeted degradation of membrane proteins represents an attractive strategy for eliminating pathogenesis‐related proteins. Aptamer‐based chimeras hold great promise as membrane protein degraders, however, their degradation efficacy is often hindered by the limited structural stability and the risk of off‐target effects due to the non‐covalent interaction with target proteins. We here report the first design of a covalent aptamer‐based autophagosome‐tethering chimera (CApTEC) for the enhanced autophagic degradation of cell‐surface proteins, including transferrin receptor 1 (TfR1) and nucleolin (NCL). This strategy relies on the site‐specific incorporation of sulfonyl fluoride groups onto aptamers to enable the cross‐linking with target proteins, coupled with the conjugation of an LC3 ligand to hijack the autophagy‐lysosomal pathway for targeted protein degradation. The chemically engineered CApTECs exhibit enhanced on‐target retention and improved structural stability. Our results also demonstrate that CApTECs achieve remarkably enhanced and prolonged degradation of membrane proteins compared to the non‐covalent designs. Furthermore, the CApTEC targeting TfR1 is combined with 5‐fluorouracil (5‐FU) for synergistic tumor therapy in a mouse model, leading to substantial suppression of tumor growth. Our strategy may provide deep insights into the LC3‐mdiated autophagic degradation, affording a modular and effective strategy for membrane protein degradation and precise therapeutic applications.
As a kind of Amaryllidaceae alkaloid which is accumulated in the species of Lycoris plants, lycorine has a range of physiological effects. The biosynthesis pathway of lycorine has been partly revealed, but the transport and accumulation mechanisms of lycorine have rarely been studied. In this study, an ATP-binding cassette (ABC) transporter from Lycoris aurea (L'Hér) Herb., namely LaABCB11, was cloned and functionally characterized. Heterologous expression showed that LaABCB11 transported lycorine in an outward direction, increased the tolerance of yeast cells to lycorine, and caused a lower lycorine accumulation in transformants than control or mutant in yeast. LaABCB11 is associated with the plasma membrane, and in situ hybridization indicated that LaABCB11 was mainly expressed in the phloem of leaves and bulbs, as well as in the cortical cells of roots. These findings suggest that LaABCB11 functions as a lycorine transport and it might be related to the translocation and accumulation of lycorine from the leaves and bulbs to the roots.
Alopecurus japonicus is a weed in summer crop field, which is harmful to wheat crops. The complete plastome of A. japonicus was reported in this study. The genome was 136,408 bp in length, consisting of an 80,512 bp large single-copy region, a 12,836 bp small single-copy region, and two 21,530 bp inverted repeat regions. The GC content of this plastome was 38.3%. A total of 112 genes were annotated for the plastome of A. japonicus, containing 78 protein-coding genes (PCGs), 30 tRNAs, and 4 rRNAs. Phylogenetic analysis showed that A. japonicus was sister to Alopecurus aequalis.
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