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HxTx-Hv1h, a neurotoxic peptide derived from spider venom, has been developed for use in commercial biopesticide formulations. Cell Penetrating Peptides (CPPs) are short peptides that facilitate the translocation of various biomolecules across cellular membranes. Here, we evaluated the aphidicidal efficacy of a conjugated peptide, HxTx-Hv1h/CPP-1838, created by fusing HxTx-Hv1h with CPP-1838. Additionally, we aimed to establish a robust recombinant expression system for HxTx-Hv1h/CPP-1838. We successfully achieved the secretory production of HxTx-Hv1h, its fusion with Galanthus nivalis agglutinin (GNA) forming HxTx-Hv1h/GNA and HxTx-Hv1h/CPP-1838 in yeast. Purified HxTx-Hv1h exhibited contact toxicity against Megoura crassicauda, with a 48 h median lethal concentration (LC50) of 860.5 μg/mL. Fusion with GNA or CPP-1838 significantly enhanced its aphidicidal potency, reducing the LC50 to 683.5 μg/mL and 465.2 μg/mL, respectively. The aphidicidal efficacy was further improved with the addition of surfactant, decreasing the LC50 of HxTx-Hv1h/CPP-1838 to 66.7 μg/mL—over four times lower compared to HxTx-Hv1h alone. Furthermore, we engineered HxTx-Hv1h/CPP-1838 multi-copy expression vectors utilizing the BglBrick assembly method and achieved high-level recombinant production in laboratory-scale fermentation. This study is the first to document a CPP fusion strategy that enhances the transdermal aphidicidal activity of a natural toxin like HxTx-Hv1h and opens up the possibility of exploring the recombinant production of HxTx-Hv1h/CPP-1838 for potential applications. [ABSTRACT FROM AUTHOR]

Membrane trafficking is essential for plant growth and responses to external signals. The plant unique FYVE domain-containing protein FREE1 is a component of the ESCRT complex (endosomal sorting complex required for transport). FREE1 plays multiple roles in regulating protein trafficking and organelle biogenesis including the formation of intraluminal vesicles of multivesicular body (MVB), vacuolar protein transport and vacuole biogenesis, and autophagic degradation. FREE1 knockout plants show defective MVB formation, abnormal vacuolar transport, fragmented vacuoles, accumulated autophagosomes, and seedling lethality. To further uncover the underlying mechanisms of FREE1 function in plants, we performed a forward genetic screen for mutants that suppressed the seedling lethal phenotype of FREE1-RNAi transgenic plants. The obtained mutants are termed as suppressors of free1 (sof). To date, 229 putative sof mutants have been identified. Barely detecting of FREE1 protein with M3 plants further identified 84 FREE1-related suppressors. Also 145 mutants showing no reduction of FREE1 protein were termed as RNAi-related mutants. Through next-generation sequencing (NGS) of bulked DNA from F2 mapping population of two RNAi-related sof mutants, FREE1-RNAi T-DNA inserted on chromosome 1 was identified and the causal mutation of putative sof mutant is being identified similarly. These FREE1- and RNAi-related sof mutants will be useful tools and resources for illustrating the underlying mechanisms of FREE1 function in intracellular trafficking and organelle biogenesis, as well as for uncovering the new components involved in the regulation of silencing pathways in plants.

Two-dimensional (2D) van der Waals heterostructures (vdWHs) received intensive interest due to their amazing physical properties and broad applications in fields such as ultrasensitive sensors, transistors, and solar cells. Although remarkable progresses were achieved for the synthesis of 2D vdWHs, great challenges still remain for the easy preparation of 2D vdWHs because of the weak interlayer coupling. As a type of 2D semiconductor, the 2D SnSe film is particularly appealing for optoelectronic and thermoelectric devices because of its high thermoelectric and optoelectronic performance. However, the easy preparation of large-area and high-quality 2D SnSe films remains a great challenge. In this work, we proposed an approach to regulate the preparation of high-quality 2D vdWHs, which employed the polarization field of substrate as a key factor to control the diffusion barriers of the adsorbed Sn and Se atoms. Hexagonally stacking α-In2Se3 was selected as such polarized substrate because this substrate exhibits out-of-plane ferroelectricity with upward or downward polarized states at room temperature, and the two degenerated polarized states can be easily switched by applying an external electric field. It was revealed that the polarization field of α-In2Se3 can substantially influence the diffusion behavior of Sn and Se atoms on polarized α-In2Se3 substrate. So, the film growth property of SnSe film is sensitive to the polarization direction of In2Se3 substrate. Our research provides an ideal method to explore the possibility of building 2D functional nanoelectronic devices. [ABSTRACT FROM AUTHOR]

Gate‐controlled ionic intercalation in the van der Waals gap of 2D layered materials can induce novel phases and unlock new properties. However, this strategy is often unsuitable for densely packed 2D non‐layered materials. The non‐layered rhombohedral Cr2S3 is an intrinsic heterodimensional superlattice with alternating layers of 2D CrS2 and 0D Cr1/3. Here an innovative chemical vapor deposition method is reported, utilizing strategically modified metal precursors to initiate entirely new seed layers, yields ultrathin inclined‐standing grown 2D Cr2S3 nanosheets with edge instead of face contact with substrate surfaces, enabling rapid all‐dry transfer to other substrates while ensuring high crystal quality. The unconventional ordered vacancy channels within the 0D Cr1/3 layers, as revealed by cross‐sectional scanning transmission electron microscope, permitting the insertion of Li+ ions. An unprecedented metal‐insulator transition, with a resistance modulation of up to six orders of magnitude at 300 K, is observed in Cr2S3‐based ionic field‐effect transistors. Theoretical calculations corroborate the metallization induced by Li‐ion intercalation. This work sheds light on the understanding of growth mechanism, structure‐property correlation and highlights the diverse potential applications of 2D non‐layered Cr2S3 superlattice. [ABSTRACT FROM AUTHOR]

High‐speed and highly sensitive infrared photodetectors are regarded as one of the most essential components in modern photonic devices and technology because of constantly emerging application scenarios. In this paper, an ultrafast and extremely low noise mid‐infrared (MIR) photodetector is reported at both room and cryogenic temperatures by leveraging the high‐mobility 2D electron gas (2DEG) at the polar CdTe/PbTe heterostructure interface. The detector simultaneously exhibits a peak detectivity of ≈4.2 × 1011 Jones with rapid response in the order of 10 ns, which is substantially superior to the state‐of‐the‐art 2DEG MIR detectors made of 2D layered materials. The ultrafast response with extremely low noise of the 2DEG photodetector is attributed to the unique band alignment at the interface. The practical infrared imaging application is further showcased using the 2DEG MIR detector by revealing the fine features of a MIR radiation target. This work highlights the promising prospect of utilizing the unique 2DEG interface in the field of high‐speed and highly sensitive MIR detection. [ABSTRACT FROM AUTHOR]

Summary: The endomembrane system consists of various membrane‐bound organelles including the endoplasmic reticulum (ER), Golgi apparatus, trans‐Golgi network (TGN), endosomes, and the lysosome/vacuole. Membrane trafficking between distinct compartments is mainly achieved by vesicular transport. As the endomembrane compartments and the machineries regulating the membrane trafficking are largely conserved across all eukaryotes, our current knowledge on organelle biogenesis and endomembrane trafficking in plants has mainly been shaped by corresponding studies in mammals and yeast. However, unique perspectives have emerged from plant cell biology research through the characterization of plant‐specific regulators as well as the development and application of the state‐of‐the‐art microscopical techniques. In this review, we summarize our current knowledge on the plant endomembrane system, with a focus on several distinct pathways: ER‐to‐Golgi transport, protein sorting at the TGN, endosomal sorting on multivesicular bodies, vacuolar trafficking/vacuole biogenesis, and the autophagy pathway. We also give an update on advanced imaging techniques for the plant cell biology research. [ABSTRACT FROM AUTHOR]

Summary: Pollen tubes have dynamic tubular vacuoles. Functional loss of AP‐3, a regulator of one vacuolar trafficking route, reduces pollen tube growth. However, the role of canonical Rab5 GTPases that are responsible for two other vacuolar trafficking routes in Arabidopsis pollen tubes is obscure.By using genomic editing, confocal microscopy, pollen tube growth assays, and transmission electron microscopy, we demonstrate that functional loss of canonical Rab5s in Arabidopsis, RHA1 and ARA7, causes the failure of pollen tubes to grow through style and thus impairs male transmission.Functional loss of canonical Rab5s compromises vacuolar trafficking of tonoplast proteins, vacuolar biogenesis, and turgor regulation. However, rha1;ara7 pollen tubes are comparable to those of wild‐type in growing through narrow passages by microfluidic assays.We demonstrate that functional loss of canonical Rab5s compromises endocytic and secretory trafficking at the plasma membrane (PM), whereas the targeting of PM‐associated ATPases is largely unaffected. Despite that, rha1;ara7 pollen tubes contain a reduced cytosolic pH and disrupted actin microfilaments, correlating with the mis‐targeting of vacuolar ATPases (VHA). These results imply a key role of vacuoles in maintaining cytoplasmic proton homeostasis and in pollen tube penetrative growth through style. [ABSTRACT FROM AUTHOR]

Arabidopsis plastid antiporters KEA1 and KEA2 are critical for plastid development, photosynthetic efficiency, and plant development. Here, we show that KEA1 and KEA2 are involved in vacuolar protein trafficking. Genetic analyses found that the kea1 kea2 mutants had short siliques, small seeds, and short seedlings. Molecular and biochemical assays showed that seed storage proteins were missorted out of the cell and the precursor proteins were accumulated in kea1 kea2. Protein storage vacuoles (PSVs) were smaller in kea1 kea2. Further analyses showed that endosomal trafficking in kea1 kea2 was compromised. Vacuolar sorting receptor 1 (VSR1) subcellular localizations, VSR–cargo interactions, and p24 distribution on the endoplasmic reticulum (ER) and Golgi apparatus were affected in kea1 kea2. Moreover, plastid stromule growth was reduced and plastid association with the endomembrane compartments was disrupted in kea1 kea2. Stromule growth was regulated by the cellular pH and K+ homeostasis maintained by KEA1 and KEA2. The organellar pH along the trafficking pathway was altered in kea1 kea2. Overall, KEA1 and KEA2 regulate vacuolar trafficking by controlling the function of plastid stromules via adjusting pH and K+ homeostasis. [ABSTRACT FROM AUTHOR]