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In order to study the wearing characters of shield cutters in the sandy and pebble composite stratum with the combination of tearing cutters and scrapers, the characteristics of the cutter wear in the composite stratum mixed with sandy gravel soil and silty clay are analyzed based on the cutter wearing situations during shield tunneling in composite stratum in the project of Tsinghua Garden Shield Tunnel of Beijing-Zhangjiakou High-speed Railway. First, the actual situations of shield opening inspection and the characteristics of the scraper and the tearing knife are summarized. Next, different formation conditions are classified and how the wearing of the tearing knife changes with the length of the cutting path and installation radius is analyzed. The result shows that when the content of silty clay in the ground is more than that of sand and pebble soil, the wearing of cutting tool can be divided into three stages, and the maximum allowable cutting trajectory is 1 500 km; when sand and pebble soil are the majority, the cutting tool wearing is divided into two stages, and the maximum allowable cutting trajectory is less than 800 km. Also, the frequent replacement and abnormal wearing of the outer tearing knife is analyzed, which indicates that the replacement of the outer tearing knife is more likely to cause stress concentration of the tool and aggravate wearing. Finally, corresponding improvement measures for tool replacement and control of tunneling parameters are proposed. [ABSTRACT FROM AUTHOR]

The primary cilium is a microtubule-based organelle that functions in sensory and signalling pathways. Defects in ciliogenesis can lead to a group of genetic syndromes known as ciliopathies (1-3). However, the regulatory mechanisms of primary ciliogenesis in normal and cancer cells are incompletely understood. Here we demonstrate that autophagic degradation of a ciliopathy protein, OFD1 (oral-facial-digital syndrome 1), at centriolar satellites promotes primary cilium biogenesis. Autophagy is a catabolic pathway in which cytosol, damaged organelles and protein aggregates are engulfed in autophagosomes and delivered to lysosomes for destruction (4). We show that the population of OFD1 at the centriolar satellites is rapidly degraded by autophagy upon serum starvation. In autophagy-deficient Atg5or Atg3 null mouse embryonic fibroblasts, OFD1 accumulates at centriolar satellites, leading to fewer and shorter primary cilia and a defective recruitment of BBS4 (Bardet-Biedl syndrome 4) to cilia. These defects are fully rescued by OFD1 partial knockdown that reduces the population of OFD1 at centriolar satellites. More strikingly, OFD1 depletion at centriolar satellites promotes cilia formation in both cycling cells and transformed breast cancer MCF7 cells that normally do not form cilia. This work reveals that removal of OFD1 by autophagy at centriolar satellites represents a general mechanism to promote ciliogenesis in mammalian cells. These findings define a newly recognized role of autophagy in organelle biogenesis., During autophagy, the membrane anchored LC3 (microtubule-associated protein 1 light chain 3, also known as MAP1LC3B) interacts with cargo and cargo-adaptor proteins, recruiting cargoes to the autophagosome for subsequent degradation [...]

Background Vibrio vulnificus, an opportunistic pathogen, is the causative agent of life-threatening septicemia and severe wound infections. However, the pathogenicity and virulence factors of V. vulnificus are not fully understood. Here we report the complete genome sequence of V. vulnificus VV2014DJH, which was isolated from a death case. Results The genome of the V. vulnificus VV2014DJH contains two circular chromosomes with a mean G+C content of 46.8%, but does not consists of any plasmids. The chromosome I and chromosome II consist of 3,303,590 and 1,770,972 bp, respectively. In addition, the genome consists of 4617 protein coding genes, 172 RNA genes and type I, II and III secretion systems were predicted. Conclusions In this study, the genomic information of the V. vulnificus VV2014DJH has been described. The information would contribute to the increasing scope and depth of Vibrio genome database, and provide insights into the pathogenicity and virulence factors of V. vulnificus., Author(s): Junhang Pan[sup.1,2] , Yi Sun[sup.2] , Wenwu Yao[sup.2] , Haiyan Mao[sup.2] , Yanjun Zhang[sup.2] and Muyuan Zhu[sup.1] Introduction Vibrio vulnificus is an opportunistic Gram-negative pathogen, which is widely distributed [...]

Autophagy is essential to maintain cellular homeostasis for normal cell growth and development. In selective autophagy, ATG8 plays a crucial role in cargo target recognition by binding to various adaptors and receptors with the ATG8-interacting motif, also known as the LC3-interacting region (LIR). However, the process of autophagy in the callus, as a proliferating cell type, is largely unknown. In this study, we overexpressed green fluorescent protein (GFP)-ATG8a and GFP-ATG8b transgenic barley callus and checked their autophagic activities. We identified five new ATG8 candidate interactors containing the canonical LIR motif by using immunoprecipitation coupled with mass spectrometry: RPP3, COPE, NCLN, RAE1 and CTSL. The binding activities between these candidate interactors and ATG8 were further demonstrated in the punctate structure. Notably, RPP3 was colocalized in ATG8-labeled autophagosomes under tunicamycin-induced endoplasmic reticulum stress. Glutathione S-transferase pull-down assays showed that the interaction between RPP3 and ATG8 could be prevented by mutating the LIR of RPP3 or the LIR docking site (LDS) of ATG8, suggesting that RPP3 directly interacted with ATG8 in an LIR-dependent manner via the LDS. Our findings would provide the basis for further investigations on novel receptors and functions of autophagy in plants, especially in the physiological state of cell de-differentiation. [ABSTRACT FROM AUTHOR]

Summary: Auxin regulates almost every aspect of plant growth and development and is perceived by the TIR1/AFB auxin co‐receptor proteins differentially acting in concert with specific Aux/IAA transcriptional repressors. Little is known about the diverse functions of TIR1/AFB family members in species other than Arabidopsis.We created targeted OsTIR1 and OsAFB2–5 mutations in rice using CRISPR/Cas9 genome editing, and functionally characterized the roles of these five members in plant growth and development and auxinic herbicide resistance.Our results demonstrated that functions of OsTIR1/AFB family members are partially redundant in grain yield, tillering, plant height, root system and germination. Ostir1, Osafb2 and Osafb4 mutants exhibited more severe phenotypes than Osafb3 and Osafb5. The Ostir1Osafb2 double mutant displays extremely severe defects in plant development. All five OsTIR1/AFB members interacted with OsIAA1 and OsIAA11 proteins in vivo. Root elongation assay showed that each Ostir1/afb2–5 mutant was resistant to 2,4‐dichlorophenoxyacetic acid (2,4‐D) treatment. Notably, only the Osafb4 mutants were strongly resistant to the herbicide picloram, suggesting that OsAFB4 is a unique auxin receptor in rice.Our findings demonstrate similarities and specificities of auxin receptor TIR1/AFB proteins in rice, and could offer the opportunity to modify effective herbicide‐resistant alleles in agronomically important crops. [ABSTRACT FROM AUTHOR]

Background and Aims Most primary auxin response genes are classified into three families: AUX/IAA , GH3 and SAUR genes. Few studies have been conducted on Arabidopsis thaliana SAUR genes, possibly due to genetic redundancy among different subfamily members. Data mining on arabidopsis transcriptional profiles indicates that the SAUR41 subfamily members of SMALL AUXIN UP RNA genes are, strikingly, induced by an inhibitory phytohormone, abscisic acid (ABA). We aimed to reveal the physiological roles of arabidopsis SAUR41 subfamily genes containing SAUR40 , SAUR41 , SAUR71 and SAUR72. Methods Transcriptional responses of arabidopsis SAUR41 genes to phytohormones were determined by quantitative real-time PCR. Knock out of SAUR41 genes was carried out with the CRISPR/Cas9 (clustered regulatory interspaced short palindromic repeats/CRISPR-associated protein 9) genome editing technique. The saur41/40/71/72 quadruple mutants, SAUR41 overexpression lines and the wild type were subjected to ultrastructural observation, transcriptome analysis and physiological characterization. Key Results Transcription of arabidopsis SAUR41 subfamily genes is activated by ABA but not by gibberellic acids and brassinosteroids. Quadruple mutations in saur41/40/71/72 led to reduced cell expansion/elongation in cotyledons and hypocotyls, opposite to the overexpression of SAUR41 ; however, an irregular arrangement of cell size and shape was observed in both cases. The quadruple mutants had increased transcription of calcium homeostasis/signalling genes in seedling shoots, and the SAUR41 overexpression lines had decreased transcription of iron homeostasis genes in roots and increased ABA biosynthesis in shoots. Notably, both the quadruple mutants and the SAUR41 overexpression lines were hypersensitive to salt stress during seedling establishment, whereas specific expression of SAUR41 under the ABA-responsive RD29A (Responsive to Desiccation 29A) promoter in the quadruple mutants rescued the inhibitory effect of salt stress. Conclusions The SAUR41 subfamily genes of arabidopsis are ABA inducible to modulate cell expansion, ion homeostasis and salt tolerance. Our work may provide new candidate genes for improvement of plant abiotic stress tolerance. [ABSTRACT FROM AUTHOR]