An Importin α Homolog, MOS6, Plays an Important Role in Plant Innate Immunity

SummaryPlant disease resistance is the consequence of an innate defense mechanism mediated by Resistance (R) genes [1]. The conserved structure of one class of R protein is reminiscent of Toll-like receptors (TLRs) and Nucleotide binding oligomerization domain (NOD) proteins—immune-response perception modules in animal cells [2–4]. The Arabidopsis snc1 (suppressor of npr1-1, constitutive, 1) mutant contains a mutation in a TIR-NBS-LRR-type of R gene that renders resistance responses constitutively active without interaction with pathogens [5]. Few components of the downstream signaling network activated by snc1 are known. To search for regulators of R-gene-mediated resistance, we screened for genetic suppressors of snc1. Three alleles of the mutant mos6 (modifier of snc1, 6) partially suppressed constitutive-resistance responses and immunity to virulent pathogens in snc1. Furthermore, the mos6-1 single mutant exhibited enhanced disease susceptibility to a virulent oomycete pathogen. MOS6, identified by positional cloning, encodes importin α3, one of eight α importins in Arabidopsis [6]. α importins mediate the import of specific proteins across the nuclear envelope. We previously reported that MOS3, a protein homologous to human nucleoporin 96, is required for constitutive resistance in snc1 [7]. Our data highlight an essential role for nucleo-cytoplasmic trafficking, especially protein import, in plant innate immunity

Deleteagene: A Fast Neutron Deletion Mutagenesis-Based Gene Knockout System for Plants

Deleteagene™ (Delete-a-gene) is a deletion-based gene knockout system for plants. To obtain deletion mutants for a specific gene, random deletion libraries created by fast neutron mutagenesis are screened by polymerase chain reaction (PCR) using primers flanking the target gene. By adjusting the PCR extension time to preferentially amplify the deletion alleles, deletion mutants can be identified in pools of DNA samples with each sample representing more than a thousand mutant lines. In Arabidopsis, knockout plants for greater than 80% of targeted genes have been obtained from a population of 51 840 lines. A large number of deletion mutants have been identified and multiple deletion alleles are often recovered for targeted loci. In Arabidopsis, the method is very useful for targeting small genes and can be used to find deletion mutants mutating two or three tandem homologous genes. In addition, the method is demonstrated to be effective in rice as a deletion mutant for a rice gene was obtained with a similar approach. Because fast neutron mutagenesis is applicable to all plant genetic systems, Deleteagene™ has the potential to enable reverse genetics for a wide range of plant species

Role of the conserved aspartate and phenylalanine residues in prokaryotic and mitochondrial elongation factor Ts in guanine nucleotide exchange

AbstractThe guanine nucleotide exchange reaction catalyzed by elongation factor Ts is proposed to arise from the intrusion of the side chains of D80 and F81 near the Mg2+ binding site in EF-Tu. D80A and F81A mutants of E. coli EF-Ts were 2–3-fold less active in promoting GDP exchange with E. coli EF-Tu while the D80AF81A mutant was nearly 10-fold less active. The D84 and F85 mutants of EF-Tsmt were 5–10-fold less active in stimulating the activity of EF-Tumt. The double mutation completely abolished the activity of EF-Tsmt

An empirical study on university students' continuous utilization of fitness apps in China

University students in China faced great health challenges. Fitness apps based on smartphones have the potential to provide an innovative approach to the university students to increase physical activities and conduct health management. This study examined how confirmed usefulness and confirmed ease of use of fitness Apps affect the attitudes, intention of recommendation, and continuous use of fitness apps among Chinese university students. The study took a quantitative approach, using online questionnaire to collect data from 552 university students who had experiences using fitness Apps. All data analyses were conducted in R. Pearson’s correlation and multiple linear regression were used to examine associations.Results. Both confirmed usefulness and confirmed ease of use were positively associated with attitude towards fitness Apps and intention of recommending fitness apps to others. However, only confirmed usefulness was positively related to frequency of using fitness apps. Confirmed ease of use was not significantly related to frequency of using fitness apps. We recommend future app-based health interventions targeting on university students to pay more attention to the functionality of the apps and integrate professional instructions into the program designs to help users achieve their goal more effectively.Peer Reviewe