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Summary: Leucine‐rich repeat receptor‐like kinases (LRR‐RLKs) comprise the largest class of membrane‐localized receptor‐like kinases in plants. Leucine‐rich repeat receptor‐like kinases are key immune sectors contributing to pattern‐triggered immunity (PTI), but whether LRR‐RLK mediates effector‐triggered immunity (ETI) in plants remains unclear.In this study, we evaluated the function of LRR‐RLKs in regulating ETI by using a virus‐induced gene silencing (VIGS)‐based reverse genetic screening assay, and identified a LRR‐RLK named ETI‐dependent receptor‐like kinase 1 (EDK1) required for ETI triggered by the avirulence effector AVRblb2 secreted by Phytophthora infestans and its cognate receptor Rpi‐blb2. Silencing or knockout of EDK1 compromised immunity mediated by Rpi‐blb2 and the cell death triggered by recognition of AVRblb2.NLR‐required for cell death 4 (NRC4), a signaling component acts downstream of Rpi‐blb2, was identified that interacts with EDK1 using the LC–MS analysis and the interaction was further evaluated by co‐immunoprecipitation. EDK1 promotes protein accumulation of NRC4 in a kinase‐dependent manner and positively regulates resistance to P. infestans in Nicotiana benthamiana.Our study revealed that EDK1 positively regulates plant ETI through modulating accumulation of the NLR signaling component NRC4, representing a new regulatory role of the membrane‐localized LRR‐RLKs in plant immunity. [ABSTRACT FROM AUTHOR]

Summary: The role of cysteine‐rich secretory proteins, antigen 5, and pathogenesis‐related 1 (CAP) superfamily proteins in the innate immune responses of mammals is well characterized. However, the biological function of CAP superfamily proteins in plant–microbe interactions is poorly understood.We used proteomics and transcriptome analyses to dissect the apoplastic effectors secreted by the oomycete Phytophthora sojae during early infection of soybean leaves. By transiently expressing these effectors in Nicotiana benthamiana, we identified PsCAP1, a novel type of secreted CAP protein that triggers immune responses in multiple solanaceous plants including N. benthamiana. This secreted CAP protein is conserved among oomycetes, and multiple PsCAP1 homologs can be recognized by N. benthamiana.PsCAP1‐triggered immune responses depend on the N‐terminal immunogenic fragment (aa 27–151). Pretreatment of N. benthamiana with PsCAP1 or the immunogenic fragment increases plant resistance against Phytophthora. The recognition of PsCAP1 and different homologs requires the leucine‐rich repeat receptor‐like protein RCAP1, which associates with two central receptor‐like kinases BRI1‐associated receptor kinase 1 (BAK1) and suppressor of BIR1‐1 (SOBIR1) in planta.These findings suggest that the CAP‐type apoplastic effectors act as an important player in plant–microbe interactions that can be perceived by plant membrane‐localized receptor to activate plant resistance. [ABSTRACT FROM AUTHOR]

Elicitins are a large family of secreted proteins in Phytophthora. Clade 1 elicitins were identified decades ago as potent elicitors of immune responses in Nicotiana species, but the mechanisms underlying elicitin recognition are largely unknown. Here we identified an elicitin receptor in Nicotiana benthamiana that we named REL for Responsive to ELicitins. REL is a receptor-like protein (RLP) with an extracellular leucine-rich repeat (LRR) domain that mediates Phytophthora resistance by binding elicitins. Silencing or knocking out REL in N. benthamiana abolished elicitin-triggered cell death and immune responses. Domain deletion and site-directed mutagenesis revealed that the island domain (ID) located within the LRR domain of REL is crucial for elicitin recognition. In addition, sequence polymorphism in the ID underpins the genetic diversity of REL homologs in various Nicotiana species in elicitin recognition and binding. Remarkably, REL is phylogenetically distant from the elicitin response (ELR) protein, an LRR–RLP that was previously identified in the wild potato species Solanum microdontum and REL and ELR differ in the way they bind and recognize elicitins. Our findings provide insights into the molecular basis of plant innate immunity and highlight a convergent evolution of immune receptors towards perceiving the same elicitor. [ABSTRACT FROM AUTHOR]

Plant pattern recognition receptors (PRRs) are sentinels at the cell surface sensing microbial invasion and activating innate immune responses. During infection, certain microbial apoplastic effectors can be recognized by plant PRRs, culminating in immune responses accompanied by cell death. However, the intricated relationships between the activation of immune responses and cell death are unclear. Here, we studied the glycoside hydrolase family 12 (GH12) protein, Ps109281, secreted by Phytophthora sojae into the plant apoplast during infection. Ps109281 exhibits xyloglucanase activity, and promotes P. sojae infection in a manner dependent on the enzyme activity. Ps109281 is recognized by the membrane‐localized receptor‐like protein RXEG1 and triggers immune responses in various plant species. Unlike other characterized GH12 members, Ps109281 fails to trigger cell death in plants. The loss of cell death induction activity is closely linked to a sequence polymorphism at the N‐terminus. This sequence polymorphism does not affect the in planta interaction of Ps109281 with the recognition receptor RXEG1, indicating that cell death and immune response activation are determined using different regions of the GH12 proteins. Such GH12 protein also exists in other Phytophthora and fungal pathogens. Taken together, these results unravel the evolution of effector sequences underpinning different immune outputs. [ABSTRACT FROM AUTHOR]

Underwater superoleophobic mesh has been broadly investigated but its mechanical durability was seldom mentioned. Thus, in this work a ZrO-coated stainless steel mesh was prepared for durable oil/water separation by an electrophoretic deposition method using ZrO sol as electrolyte. The ZrO coating is of hierarchical structure, making the Z-SSM superhydrophilic in air and superoleophobic underwater. The mesh exhibited outstanding separation efficiency of above 97.5% for various oil/water mixtures. The separation efficiency of n-hexane/water mixture maintained over 98% after 50 times of recycle separation. Moreover, the coated mesh maintained high separation efficiency after 30 cycles of abrasion, showing good stability. Graphical abstract: [ABSTRACT FROM AUTHOR]

Utilization of disease resistance components from wild potatoes is a promising and sustainable approach to control Phytophthora blight. Here, we combined avirulence (Avr) genes screen with RNA-seq analysis to discover the potential mechanism of resistance in Mexican wild potato species, Solanum pinnatisectum. Histological characterization displayed that hyphal expansion was significantly restricted in epidermal cells and mesophyll cell death was predominant, indicating that a typical defense response was initiated in S. pinnatisectum. Inoculation of S. pinnatisectum with diverse Phytophthora infestans isolates showed distinct resistance patterns, suggesting that S. pinnatisectum has complex genetic resistance to most of the prevalent races of P. infestans in northwestern China. Further analysis by Avr gene screens and comparative transcriptomic profiling revealed the presence and upregulation of multiple plant NBS-LRR genes corresponding to biotic stresses. Six NBS-LRR alleles of R1, R2, R3a, R3b, R4, and Rpi-smira2 were detected, and over 60% of the 112 detected NLR proteins were significantly induced in S. pinnatisectum. On the contrary, despite the expression of the Rpi-blb1, Rpi-vnt1, and Rpi-smira1 alleles, fewer NLR proteins were expressed in susceptible Solanum cardophyllum. Thus, the enriched NLR genes in S. pinnatisectum make it an ideal genetic resource for the discovery and deployment of resistance genes for potato breeding. [ABSTRACT FROM AUTHOR]