Most plant pathogens secrete effector proteins to circumvent host immune responses, thereby promoting pathogen virulence. One such pathogen is the fungus Fusarium graminearum, which causes Fusarium head blight (FHB) disease on wheat and barley. Transcriptomic analyses revealed that F. graminearum expresses many candidate effector proteins during early phases of the infection process, some of which are annotated as proteases. However, the contributions of these proteases to virulence remain poorly defined. Here, we characterize an F. graminearum endopeptidase, FgTPP1 (FGSG_11164), that is highly upregulated during wheat spikelet infection and is secreted from fungal cells. To elucidate the potential role of FgTPP1 in F. graminearum virulence, we generated FgTPP1 deletion mutants (Δ Fgtpp1) and performed FHB infection assays. Deletion of FgTPP1 reduced the virulence of F. graminearum as assessed by spikelet bleaching. Infection with wild-type F. graminearum induced full bleaching in about 50% of the spikes at 10 to 11 days postinfection, whereas this fraction was reduced to between 18 and 27% when using Δ Fgtpp1 mutants. Transient expression of green fluorescent protein-tagged FgTPP1 revealed that FgTPP1 localizes, in part, to chloroplasts and attenuates chitin-mediated activation of mitogen-activated protein kinase signaling, reactive oxygen species production, and cell death induced by an autoactive disease resistance protein when expressed in planta. Notably, the FgTPP1 protein is conserved across the Ascomycota phylum, suggesting that it may be a core effector among ascomycete plant pathogens. These properties make FgTPP1 an ideal candidate for decoy substrate engineering, with the goal of engineering resistance to FHB. [ ] Copyright © 2025 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Fusarium head blight (FHB) is a devastating fungal disease of hexaploid wheat (Triticum aestivum). Several genetic loci were previously identified that control FHB resistance in wheat, including Fhb1. Fhb7, a major QTL conferring resistance to FHB, controlling for mycotoxin deoxynivalenol (DON) production, has been introgressed into soft red winter wheat (SRWW). As an exotic QTL, Fhb7 is associated with linkage drag, affecting agronomic and end-use quality performance. This study outlines a breeding strategy for introducing and pyramiding Fhb7 into SRWW breeding populations that already possessed Fhb1 and harbored some additional disease-resistance genes. In addition to the Fhb1-Fhb7 pyramiding, we developed gene-based markers for both genes and examined them on 57 SRWW breeding lines. Our data showed that 15 out of 57 breeding lines possessed both Fhb1 and Fhb7 resistant alleles. Two years of phenotypic data from the inoculated and misted irrigation field showed that the combination of Fhb1-Fhb7 lowers mycotoxin DON accumulation in kernels, which provides protection for end-users and the milling industry. The Fhb gene-pyramided lines, with the additional regionally important disease resistance genes, produced in this breeding pipeline showed reasonable agronomic traits and can be used in crossing programs for the widespread introgression in elite wheat cultivars.

In the summer of 2020, 127 soybean [Glycine max (L.) Merr] seedlings (V1-V3 stage) with reduced growth vigor were sampled as part of a bulk collection of seedling pathogens from Purdue’s Agronomy C...

Virus induced gene silencing (VIGS) is one of the most potent reverse genetics technologies for gene functional characterisation. This method exploits a dsRNA-mediated antiviral defence mechanism in plants. Using this method allows researchers to generate rapid phenotypic data in a relatively rapid time frame as compared to the generation of stable transformants. Here we describe a simple method for silencing a target gene in barley seedling leaves using vectors based on the Barley Stripe Mosaic Virus (BSMV).

Triticum mosaic virus (TriMV) and High plains virus (HPV), identified recently, have been considered among the major viruses that affect wheat. Carried by the same vector, wheat curl mite, both of these viruses cause yellowing and stunting of plants which are very similar to many other viruses attacking wheat. This makes it difficult to detect these viruses in different wheat lines, posing a major problem in the yield. This paper highlights the addition of these two viruses to a multiplex RT-PCR based method which already detected the presence of barley and cereal yellow dwarf viruses (B/CYDVs), soil-borne wheat mosaic virus (SBWMV), wheat spindle streak mosaic virus (WSSMV), and wheat streak mosaic virus (WSMV). The method uses specific sets of primers that detect the target viruses TriMV and HPV at 560 bp and 490 bp, respectively, in the presence of other distinct viruses such as B/CYDVs -PAV, -MAV, -SGV, -RPV, -RMV, WSSMV, SBWMV, and WSMV at 295, 175, 237, 400, 365, 154, 219, and 193 bp, respectively. The forward primer for each specific virus was fluorescently tagged to detect it in a higher throughput manner in capillary electrophoresis. All ten viruses may be viewed as peaks in an electropherogram from the capillary electrophoresis corresponding to their product sizes in base pairs. This advancement in the protocol allows detection of all ten wheat viruses in a single test, thus improving the diagnostic capability with only a slight increase in cost.

The Hessian fly is a destructive pest of wheat. Employing additional molecular strategies can complement wheat’s native insect resistance. However, this requires functional characterization of Hessian-fly-responsive genes, which is challenging because of wheat genome complexity. The diploid Brachypodium distachyon (Bd) exhibits nonhost resistance to Hessian fly and displays phenotypic/molecular responses intermediate between resistant and susceptible host wheat, offering a surrogate genome for gene characterization. Here, we compared the transcriptomes of Biotype L larvae residing on resistant/susceptible wheat, and nonhost Bd plants. Larvae from susceptible wheat and nonhost Bd plants revealed similar molecular responses that were distinct from avirulent larval responses on resistant wheat. Secreted salivary gland proteins were strongly up-regulated in all larvae. Genes from various biological pathways and molecular processes were up-regulated in larvae from both susceptible wheat and nonhost Bd plants. However, Bd larval expression levels were intermediate between larvae from susceptible and resistant wheat. Most genes were down-regulated or unchanged in avirulent larvae, correlating with their inability to establish feeding sites and dying within 4–5 days after egg-hatch. Decreased gene expression in Bd larvae, compared to ones on susceptible wheat, potentially led to developmentally delayed 2nd-instars, followed by eventually succumbing to nonhost resistance defense mechanisms.