Inhibiting pathogen chemotaxis is a promising strategy for reducing disease pressure. However, this strategy is currently in the proof-of-concept stage. Here, Phytophthora sojae was used as a model, as its biflagellated zoospores could sense genistein, a soybean root exudate, to navigate host and initiate infection. We identify P. sojae IRK1 (isoflavone-insensitive receptor kinase 1) as a receptor for genistein, with PsIRK2 functioning as a coreceptor that enhances the binding affinity of PsIRK1 to genistein and regulates chemotaxis by phosphorylating G protein α subunit. Last, we identify an antagonist, esculetin, which disrupts the PsIRK1-genistein interaction, thereby preventing P. sojae infection by repelling zoospores. Our findings reveal the mechanism by which P. sojae senses host genistein and demonstrate a strategy for disease prevention by targeting the chemoreceptor.

Background: The Catharanthus roseus receptor-like kinase 1-like (CrRLK1L) subfamily, a specialized group within receptor-like kinases (RLKs), was initially identified in C. roseus cell cultures. CrRLK1L plays an important role in the growth, development and stress response of plants. Although CrRLK1L genes have been characterized across multiple plant species, their biological and genetic functions in potatoes (Solanum tuberosum) remains poorly elucidated. Methods: a genome-wide investigation, phylogenetic analysis, chromosome localization, exon–intron structure, conserved motifs, stress-responsive cis-elements, tissue-specific expression patterns, and their effects on pathogen associated molecular patterns (PAMPs) induced reactive oxygen species (ROS) production were analyzed. Results: A total of 29 CrRLK1L genes were identified in the S. tuberosum genome, unevenly distributed across 10 chromosomes and divided into three groups. Tissue-specific expression analysis revealed seven genes highly expressed in all tissues, while CrRLK1L13 was specific to stamens and flowers. Under stress conditions (mannitol, salt, hormone, and heat), StCrRLK1L genes exhibited diverse expression patterns. Functional characterization in Nicotiana benthamiana identified seven ROS suppressors and four ROS enhancers, implicating their roles in PAMP-triggered immunity. Conclusions: This study provides valuable insights into the StCrRLK1L gene family, enhancing our understanding of its functions, particularly in plant innate immunity.

Metformin (MET), derived from Galega officinalis, stands as the primary first-line medication for the treatment of type 2 diabetes (T2D). Despite its well-documented benefits in mammalian cellular processes, its functions and underlying mechanisms in plants remain unclear. This study aimed to elucidate MET's role in inducing plant immunity and investigate the associated mechanisms. To investigate the impact of MET on enhancing plant immune responses, we conducted assays measuring defense gene expression, reactive oxygen species (ROS) accumulation, mitogen-activated protein kinase (MAPK) phosphorylation, and pathogen infection. Additionally, surface plasmon resonance (SPR) and microscale thermophoresis (MST) techniques were employed to identify MET targets. Protein-protein interactions were analyzed using a luciferase complementation assay and a co-immunoprecipitation assay. Our findings revealed that MET boosts plant disease resistance by activating MAPKs, upregulating the expression of downstream defense genes, and fortifying the ROS burst. CALCIUM-DEPENDENT PROTEIN KINASE 28 (CPK28) was identified as a target of MET. It inhibited the interaction between BOTRYTIS-INDUCED KINASE 1 (BIK1) and CPK28, blocking CPK28 threonine 76 (T76) transphosphorylation by BIK1, and alleviating the negative regulation of immune responses by CPK28. Moreover, MET enhanced disease resistance in tomato, pepper, and soybean plants. Collectively, our data suggest that MET enhances plant immunity by blocking BIK1-mediated CPK28 phosphorylation.

In this investigation, pinocembrin and galangin were efficiently extracted from the male inflorescence of Populus alba L. × berolinensis K. Koch through an enzymatic pretreatment–ultrasonic-assisted strategy (EP-UAS), and the feasibility of their pilot-scale application was validated. The optimal parameters (ethanol volume fraction, cellulase dosage, incubation temperature, incubation time, pH, liquid‒solid ratio, ultrasonic irradiation power during incubation, duty cycle, ultrasonic irradiation power and time during extraction) affecting pinocembrin and galangin yields were systematically explored. The Box–Behnken design (BBD) results provided optimal parameters for the EP-UAS process. Under the optimal conditions, the actual yields of pinocembrin and galangin were 2158.33 ± 0.13 μg/g and 1257.96 ± 0.06 μg/g, respectively. Stability, recovery and reproducibility were determined under the above optimized conditions to evaluate the proposed EP-UAS method. Moreover, laboratory-scale experimental results revealed that the conditions selected via single-factor and response surface experiments were also applicable to pilot-scale production, facilitating industrialization.

The mitogen-activated protein kinase (MAPK) cascade is a fundamental signaling module that translates environmental stimuli into cellular responses in euka