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MicroRNAs (miRNAs) are widely involved in various biological processes of plants and contribute to plant resistance against various pathogens. In this study, upon sugarcane mosaic virus (SCMV) infection, the accumulation of maize (Zea mays) miR398b (ZmmiR398b) was significantly reduced in resistant inbred line Chang7‐2, while it was increased in susceptible inbred line Mo17. Degradome sequencing analysis coupled with transient co‐expression assays revealed that ZmmiR398b can target Cu/Zn‐superoxidase dismutase2 (ZmCSD2), ZmCSD4, and ZmCSD9 in vivo, of which the expression levels were all upregulated by SCMV infection in Chang7‐2 and Mo17. Moreover, overexpressing ZmmiR398b (OE398b) exhibited increased susceptibility to SCMV infection, probably by increasing reactive oxygen species (ROS) accumulation, which were consistent with ZmCSD2/4/9‐silenced maize plants. By contrast, silencing ZmmiR398b (STTM398b) through short tandem target mimic (STTM) technology enhanced maize resistance to SCMV infection and decreased ROS levels. Interestingly, copper (Cu)‐gradient hydroponic experiments demonstrated that Cu deficiency promoted SCMV infection while Cu sufficiency inhibited SCMV infection by regulating accumulations of ZmmiR398b and ZmCSD2/4/9 in maize. These results revealed that manipulating the ZmmiR398b‐ZmCSD2/4/9‐ROS module provides a prospective strategy for developing SCMV‐tolerant maize varieties. [ABSTRACT FROM AUTHOR]

Based on four degrees of freedom cartesian transfer robot structural model,the method of parametric modeling of the main part and component of the cartesian robot are studied.Considering the actual needs of different production lines,and combined with CATIA virtual design technology and knowledge engineering techniques,the issues of cartesian robot three-dimensional model rapid generation is solved.The three-dimensional standard part and component library is built by CATIA V5R19.The selection of components and automatic generation are achieved,the designer can obtain the structural parameters by considering the user requirements and do some design calculations relevant to the selected design parameter.

Summary: Chloride channel (CLC) proteins are important anion transporters conserved in organisms ranging from bacteria and yeast to plants and animals. According to sequence comparison, some plant CLCs are predicted to function as Cl−/H+ antiporters, but not Cl− channels. However, no direct evidence was provided to verify the role of these plant CLCs in regulating the pH of the intracellular compartment. We identified tobacco CLC‐Nt1 interacting with the Potato virus Y (PVY) 6K2 protein. To investigate its physiological function, homologous genes of CLC‐Nt1 in Nicotiana benthamiana were knocked out using the CRISPR/Cas9 system. Complementation experiments were subsequently performed by expression of wild‐type or point‐mutated CLC‐Nt1 in knockout mutants. The data presented herein demonstrate that CLC‐Nt1 is localized at endoplasmic reticulum (ER). Using a pH‐sensitive fluorescent protein (pHluorin), we found that loss of CLC‐Nt1 function resulted in a decreased ER luminal pH. Secreted GFP (secGFP) was retained mostly in ER in knockout mutants, indicating that CLC‐Nt1 is also involved in protein secretion. PVY infection induced a rise in ER luminal pH, which was dependent on functional CLC‐Nt1. By contrast, loss of CLC‐Nt1 function inhibited PVY intracellular replication and systemic infection. We propose that PVY alters ER luminal pH for infection in a CLC‐Nt1‐dependent manner. [ABSTRACT FROM AUTHOR]

Maize chlorotic mottle virus (MCMV) is one of the main viruses causing significant losses in maize. N 6 -methyladenosine (m 6 A) RNA modification has been proven to play important regulatory roles in plant development and stress response. In this study, we found that MCMV infection significantly up-regulated the m 6 A level in maize, and methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA sequencing (RNA-seq) were performed to investigate the distribution of m 6 A modified peaks and gene expression patterns in MCMV-infected maize plants. The results showed that 1325 differentially methylated genes (DMGs) and 47 differentially methylated and expressed genes (DMEGs) were identified and analyzed. Moreover, the results of virus-induced gene silencing (VIGS) assays showed that ZmECT18 and ZmGST31 were required for MCMV infection, while silencing of ZmMTC , ZmSCI1 or ZmTIP1 significantly promoted MCMV infection in maize. Our findings provided novel insights into the regulatory roles of m 6 A modification in maize response to MCMV infection.