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Summary: Arabidopsis RESISTANCE TO POWDERY MILDEW 8.2 (RPW8.2) is specifically induced by the powdery mildew (PM) fungus (Golovinomyces cichoracearum) in the infected epidermal cells to activate immunity. However, the mechanism of RPW8.2‐induction is not well understood.Here, we identify a G. cichoracearum effector that interacts with RPW8.2, named Gc‐RPW8.2 interacting protein 1 (GcR8IP1), by a yeast two‐hybrid screen of an Arabidopsis cDNA library.GcR8IP1 is physically associated with RPW8.2 with its REALLY INTERESTING NEW GENE finger domain that is essential and sufficient for the association. GcR8IP1 was secreted and translocated into the nucleus of host cell infected with PM. Association of GcR8IP1 with RPW8.2 led to an increase in RPW8.2 in the nucleus. In turn, the nucleus‐localized RPW8.2 promoted the activity of the RPW8.2 promoter, resulting in transcriptional self‐amplification of RPW8.2 to boost immunity at infection sites. Additionally, ectopic expression or host‐induced gene silencing of GcR8IP1 supported its role as a virulence factor in PM.Altogether, our results reveal a mechanism of RPW8.2‐dependent defense strengthening via altered partitioning of RPW8.2 and transcriptional self‐amplification triggered by a PM fungal effector, which exemplifies an atypical form of effector‐triggered immunity. [ABSTRACT FROM AUTHOR]

The selection of suitable reference genes (RGs) for data normalization is a crucial step for obtaining reliable results from gene expression analysis using the quantitative real‐time polymerase chain reaction (qRT‐PCR). Expression stability of eleven putative RGs (miR‐100‐5p, miR‐92a‐3p, miR‐998‐3p, miR‐279d‐3p, miR‐305‐5p, miR‐276a‐3p, miR‐275‐3p, miR‐9a‐5p, miR‐2a‐3p, U6 snRNA and 5S rRNA) was assessed by using a web‐based tool: RefFinder, which integrates four algorithms (Delta Ct, geNorm, NormFinder, and BestKeeper), and the best combination number of RGs was calculated by geNorm. Validation of selected RGs was performed by an expression analysis of let‐7‐5p under different experimental conditions. The best combinations of RGs were shown as follows: miR‐100‐5p + miR‐275‐3p for temperature treatment, miR‐100‐5p + miR‐305‐5p for adult tissues, miR‐276a‐3p + miR‐9a‐5p for genders, miR‐2a‐3p + miR‐276a‐3p for days after eclosion, U6 snRNA + miR‐9a‐5p + miR‐2a‐3p for developmental stages, and U6 snRNA + miR‐279d‐3p for all above conditions, and there was no one RG suitable for all experimental conditions. Incorrect RG selection affected the evaluation of let‐7‐5p abundance. Our findings demonstrate that an integrated approach of multiple algorithms is necessary to identify reliable, stable RGs for miRNA evaluation, and provide a basis for further studies on expression and function analysis of miRNAs and their target genes in Galeruca daurica, a new pest with great outbreaks in Inner Mongolia since 2009. [ABSTRACT FROM AUTHOR]

Mutations in the γ‐secretase complex have been well‐described in familial hidradenitis suppurativa (HS). No gene mutations have been identified in sporadic HS, which comprises 60%–70% of all HS cases. Obesity and smoking are risk factors for HS and are closely related to DNA methylation, an essential epigenetic phenomenon. Hence, we hypothesized that epigenetic modifications might be involved in sporadic HS. To investigate genes with aberrant methylation in sporadic HS cases and assess their expression in skin lesions and blood from patients with HS. Skin lesion samples and corresponding normal skin were obtained from three patients with HS and subjected to whole‐genome DNA methylation sequencing. Blood samples were collected from 20 patients with HS and 20 healthy controls (HCs). The HS mouse model was established by applying tamoxifen to NcstnΔKC mice. Target gene expression was analysed by immunohistochemistry, immunofluorescence, western blotting, enzyme‐linked immunosorbent assay (ELISA) and semiquantitative real‐time polymerase chain reaction (RT‐qPCR). Among 10 807 differentially methylated genes, we filtered 2101 genes with hypermethylated promoter regions, and following bioinformatics analyses, we focused on CXC chemokine ligand 16 (CXCL16). Subsequent functional experiments confirmed the downregulation of CXCL16 and its receptor, CXC chemokine receptor (CXCR) 6, in skin tissue from HS patients and NcstnΔKC mice. Serum CXCL16 concentrations were also significantly decreased in patients with HS. Our data revealed the downregulation of CXCL16 and CXCR6 in HS. [ABSTRACT FROM AUTHOR]