Expression profiles and characterization of microRNAs responding to chitin in Arthrobotrys oligospora.

Extracellular proteases, such as chitinases secreted by Arthrobotrys oligospora (A. oligospora), play a crucial role in the process of nematode infection. However, post-transcriptional regulation of gene expression involving microRNAs (miRNAs) in A. oligospora remains scarcely described. Hereto, transcriptome sequencing was carried out to analyze the expression profiles of chitin-responsive miRNAs in A. oligospora. Based on the RNA-seq data, the differential expression of miRNAs (DEmiRNAs) in response to chitin was screened, identified and characterized in A. oligospora. Meanwhile, the potential target genes were predicted by the online tools miRanda and Targetscan, respectively. Furthermore, the interaction of DEmiRNA with it's target gene was validated by a dual-luciferase reporter assay system. Among 85 novel miRNAs identified, 25 miRNAs displayed significant differences in expression in A. oligospora in response to chitin. Gene Ontology (GO) analysis showed that the potential genes targeted by DEmiRNAs were enriched in the biological processes such as bio-degradation, extracellular components and cell cycle. KEGG analysis revealed that the target genes were mainly involved in Hippo, carbon and riboflavin metabolic pathway. Outstandingly, chitinase AOL_s00004g379, which is involved in the hydrolysis metabolic pathway of chitin, was confirmed to be a target gene of differential miR_70. These findings suggest that chitin-responsive miRNAs are involved in the regulation of cell proliferation, predator hyphae growth and chitinase expression through the mechanisms of post-transcriptional regulation, which provides a new perspective to the molecular mechanisms underlying miRNAs-mediated control of gene expression in A. oligospora.

Preferred Film Orientation to Achieve Stable and Efficient Sn-Pb Binary Perovskite Solar Cells.

The preferred orientation of crystalline films in hybrid perovskite materials is known to influence the performance of perovskite solar cells (PSCs). Although the preferred growth along the (112) directions has been reported to promote charge transport within the Pb-based polycrystalline perovskite films, the preferred orientation growth of this facet is still difficult to be achieved due to the higher formation energy compared with the (110) plane. Herein, Sn-Pb binary perovskite films with a well-controlled orientation along the (224) plane were achieved by introducing a simple ultrasonic treatment (UST) into the additive engineering fabricated method. UST is used to process the perovskite precursor solutions of tartaric acid (TA) modified Sn-Pb binary polycrystalline perovskite films to regulate the interactions between PbI2/SnI2 and TA in the intermediate phases. Meanwhile, TA-modulated MA0.9Cs0.1Pb0.75Sn0.25I3-based perovskite films with a preferred orientation of (224) crystal plane were obtained by precisely controlling the UST time to 15 min. The highest power conversion efficiency (PCE) of 15.59% with less hysteresis and improved stability was achieved, while realizing 8.64 and 25.32% enhancements of PCE compared with that of TA-based and control counterparts with (110) preferred orientation, respectively. Our work provides a promising route to obtain preferred orientation growth of polycrystalline perovskite films. In particular, we have shown that this approach improves the performance of Sn-Pb binary PSCs, while such methodology is quite flexible and could also be applied to other low-/non-toxic PSCs.

Carrier dynamic monitoring of a π-conjugated polymer: a surface-enhanced Raman scattering method.

Here, the carrier dynamics of a π-conjugated polymer is monitored by voltage-dependent surface-enhanced Raman scattering (SERS). The conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is employed as a metal-free SERS substrate. Under different voltage conditions, the SERS performance of the semiconductors' rectification characteristic is discussed. Our results open an unprecedented regime for conducting polymer-based SERS.