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The host-virus interactome is increasingly recognized as an important research field to discover new therapeutic targets to treat influenza. Multiple pooled genome-wide CRISPR-Cas screens have been reported to identify new pro- and antiviral host factors of the influenza A virus. However, at present, a comprehensive summary of the results is lacking. We performed a systematic review of all reported CRISPR studies in this field in combination with a meta-analysis using the algorithm of meta-analysis by information content (MAIC). Two ranked gene lists were generated based on evidence in 15 proviral and 4 antiviral screens. Enriched pathways in the proviral MAIC results were compared to those of a prior array-based RNA interference (RNAi) meta-analysis. The top 50 proviral MAIC list contained genes whose role requires further elucidation, such as the endosomal ion channel TPCN1 and the kinase WEE1. Moreover, MAIC indicated that ALYREF, a component of the transcription export complex, has antiviral properties, whereas former knockdown experiments attributed a proviral role to this host factor. CRISPR-Cas-pooled screens displayed a bias toward early-replication events, whereas the prior RNAi meta-analysis covered early and late-stage events. RNAi screens led to the identification of a larger fraction of essential genes than CRISPR screens. In summary, the MAIC algorithm points toward the importance of several less well-known pathways in host-influenza virus interactions that merit further investigation. The results from this meta-analysis of CRISPR screens in influenza A virus infection may help guide future research efforts to develop host-directed anti-influenza drugs. [ABSTRACT FROM AUTHOR]

The fungal pathogen Botrytis cinerea establishes a necrotrophic interaction with its host plants, including lettuce ( Lactuca sativa), causing it to wilt, collapse and eventually dry up and die, which results in serious economic losses. Global expression profiling using RNAseq and the newly sequenced lettuce genome identified a complex network of genes involved in the lettuce- B. cinerea interaction. The observed high number of differentially expressed genes allowed us to classify them according to the biological pathways in which they are implicated, generating a holistic picture. Most pronounced were the induction of the phenylpropanoid pathway and terpenoid biosynthesis, whereas photosynthesis was globally down-regulated at 48 h post-inoculation. Large-scale comparison with data available on the interaction of B. cinerea with the model plant Arabidopsis thaliana revealed both general and species-specific responses to infection with this pathogen. Surprisingly, expression analysis of selected genes could not detect significant systemic transcriptional alterations in lettuce leaves distant from the inoculation site. Additionally, we assessed the response of these lettuce genes to a biotrophic pathogen, Bremia lactucae, revealing that similar pathways are induced during compatible interactions of lettuce with necrotrophic and biotrophic pathogens. [ABSTRACT FROM AUTHOR]

•Previously, it was shown that the Arabidopsis thaliana plant defensins AtPDF1.1 (At1g75830) and AtPDF1.2a (At5g44420) exert in vitro antimicrobial properties and that their corresponding genes are expressed in seeds and induced in leaves upon pathogen attack, respectively. •In this study, the expression profile of both AtPDF1.1 and AtPDF1.2a is analysed in wild-type plants upon different stress-related treatments and the effect of modulation of their expression in transgenic plants is examined in both host and nonhost resistance. • AtPDF1.1, which was originally considered to be seed-specific, is demonstrated to be locally induced in leaves upon fungal attack and exhibits an expression profile distinct from that of AtPDF1.2a, a gene frequently used as marker for the ethylene/jasmonate-mediated signaling pathway. Transgenic plants with modulated AtPDF1.1 or AtPDF1.2a gene expression show no altered phenotype upon Botrytis cinerea inoculation. However, constitutive overexpression of AtPDF1.1 in A. thaliana leads to a reduction in symptoms caused by the nonhost Cercospora beticola causing non-spreading spots on A. thaliana leaves. •These results indicate that AtPDF1.1 and AtPDF1.2a clearly differ regarding their expression profile and functionality in planta. It emphasizes the additional level of complexity and fine-tuning within the highly redundant plant defensin genes in A. thaliana. [ABSTRACT FROM AUTHOR]

The plant growth-promoting soil bacterium Azospirillum brasilense enhances growth of economically important crops, such as wheat, corn and rice. In order to improve plant growth, a close bacterial association with the plant roots is needed. Genes encoded on a 90-MDa plasmid, denoted pRhico plasmid, present in A. brasilense Sp7, play an important role in plant root interaction. Sequencing, annotation and in silico analysis of this 90-MDa plasmid revealed the presence of a large collection of genes encoding enzymes involved in surface polysaccharide biosynthesis. Analysis of the 90-MDa plasmid genome provided evidence for its essential role in the viability of the bacterial cell. [Copyright &y& Elsevier]