Plant-microbe interactions show distinct dual characteristics: there are mutualistic relationships that promote growth, and there are hostile actions that cause damage. An important driving force of plant evolution is to cleverly balance the harmonious coexistence with symbiotic microorganisms and effectively resist the invasion of pathogens.
It is worth noting that about 71% of vascular plants rely on plant pathogenic fungi to hijack phosphate signals using conservative enzyme effectors to enhance the absorption capacity of inorganic phosphate (Pi) and other minerals. In contrast, pathogenic fungi significantly hinder plant growth, resulting in reduced crop yields, which in turn poses a serious threat to global food security.
The phosphate status in plants profoundly affects their beneficial and harmful interactions with microorganisms. At the eukaryotic cell level, inositol pyrophosphates (PP-InsPs) accurately transmit information about the availability of Pi by binding to the SPX protein domain.
When the Pi level in plant cells is sufficient, the protein complex formed by the binding of PP-InsP and SPX domain inhibits the activity of phosphate starvation response transcription factors (PHRs), thereby suppressing the expression of starvation-induced genes and maintaining cell homeostasis. PHRs are widely present in terrestrial plants and green algae, and the symbiotic regulation between monocotyledonous and dicotyledonous plants and AMF depends on the core signaling pathway of PP-InsP–SPX–PHR.
In addition to regulating PHR activity, PP-InsPs are also deeply involved in regulating the functions of phosphate transporters, ubiquitin ligases, and hormone receptors, efficiently integrating Pi availability information into a variety of cellular metabolic processes, showing its wide application in plant physiological regulation.
In addition, plant pathogens may promote the development of diseases by secreting proteins called effectors that target and interfere with the phosphate signaling pathway of plants, further highlighting the key role of phosphate signaling in plant-microbe interactions.
The pathogenic mechanism of Nudix effectors of pathogenic fungi was discovered.
Recently, researchers from the Australian National University and RWTH Aachen University in Germany jointly published a research paper entitled "Plant pathogenic fungi hijack phosphate signaling with conserved enzymatic effectors" in Science, revealing how plant pathogenic fungi use a conserved enzyme effector to hijack the phosphate signaling pathway of plants, thereby exacerbating the molecular mechanism of disease.
The research team focused on MoNUDIX, a key virulence factor of rice blast fungus. After silencing its double-copy gene through RNA interference technology, it was found that the area of the disease spot was significantly reduced, and the plant's reactive oxygen (ROS) defense response was significantly enhanced.
The double knockout mutant ΔΔMoNUDIX constructed using CRISPR-Cas9 technology reduced its infectivity by more than 50% in rice and barley, but the basic physiological function of the pathogen was not affected.
This indicates that MoNUDIX specifically acts on the penetration process of the appressorium and is a key factor in pathogenicity.
The research team also found that this mechanism is also highly conservative in the anthracnose pathogen C. higginsianum. When the ChNUDIX gene of the anthracnose pathogen was knocked out, the infection symptoms of Arabidopsis were significantly alleviated; and in corn anthracnose pathogens, the lesion area of the CgNUDIX deletion mutant on corn was reduced by nearly 40%.
Cross-species functional complementation experiments further confirmed that the wild-type ChNUDIX of the anthracnose pathogen can successfully restore the virulence of the rice blast mutant, but the enzyme activity defective type is ineffective. These results fully demonstrate the evolutionary conservation of the Nudix effector family among pathogens.
Mechanism studies have shown that Nudix effectors interfere with the conduction of plant immune signals by hydrolyzing the pyrophosphate bonds of nucleoside diphosphates. During the biological nutritional growth stage of pathogens, these effectors can inhibit the host's active oxygen burst and cell wall strengthening, thereby promoting the expansion of hyphae.
The research team used X-ray crystallography to successfully resolve the ultra-high resolution structure of the rice blast fungus MoNUDIX protein and found that it is highly similar to the human HsDIPP1 enzyme structure but has completely different functions. Enzyme activity experiments further confirmed that MoNUDIX only specifically decomposes the plant immune signaling molecule 5-pyrophosphate inositol pentaphosphate (5-PP-InsP5), but has no response to other common substrates.
This discovery reveals the molecular characteristics of the pathogen's "precision attack" on the plant defense system and locks in two key lysine residues as the "fatal weakness" of the pathogen. The high conservation of this attack strategy in rice blast fungus and anthracnose fungus lays a solid foundation for the development of broad-spectrum disease-resistant drugs.
The authors pointed out that inhibitors designed for these conserved sites are expected to block the invasion of multiple pathogens in one fell swoop, becoming a new generation of "plant vaccines" to help rice, wheat and other crops resist a variety of fungal diseases.
Figure 1. Magnaporthe and Colletotrichum Nudix effectors are diphosphoinositol polyphosphate phosphohydrolases. (McCombe, et al., 2025)
In addition, researchers also used natural promoter-driven mRFP labeling technology to verify the co-localization of MoNUDIX protein and known cytoplasmic effector protein MoPwl2 in the bionutrient interface complex (BIC). This discovery reveals the potential role of MoNUDIX in the pathogenic process of pathogens and expands its functional conservation.
The research team also found that Nudix effectors can hydrolyze PP-InsP molecules in plants and reduce their intracellular concentrations, thereby relieving the inhibition of SPX protein on PHR transcription factors. The release of PHR further activates phosphate starvation response genes, causing plants to mistakenly perceive nutrient scarcity, thereby suppressing immune responses and reshaping metabolic pathways, creating a favorable environment for the bionutrient growth of pathogens.
This discovery revealed for the first time the molecular mechanism by which plant pathogens hijack the host's nutrient signaling network through a "metabolic deception" strategy, and clarified the dual function of Nudix effectors as "molecular switches". This study not only enhances the understanding of the pathogenic mechanism of plant pathogenic fungi, but also provides ideas for the development of new disease prevention and control strategies.
| Cat# | Product Name | Size |
| ACC-100 | GV3101 Chemically Competent Cell | 10 tubes (100μL/tube) 20 tubes (100μL/tube) 50 tubes (100μL/tube) 100 tubes (100μL/tube) |
| ACC-103 | EHA105 Chemically Competent Cell | 10 tubes (100μL/tube) 20 tubes (100μL/tube) 50 tubes (100μL/tube) 100 tubes (100μL/tube) |
| ACC-105 | AGL1 Chemically Competent Cell | 10 tubes (100μL/tube) 20 tubes (100μL/tube) 50 tubes (100μL/tube) 100 tubes (100μL/tube) |
| ACC-107 | LBA4404 Chemically Competent Cell | 10 tubes (100μL/tube) 20 tubes (100μL/tube) 50 tubes (100μL/tube) 100 tubes (100μL/tube) |
| ACC-108 | EHA101 Chemically Competent Cell | 10 tubes (100μL/tube) 20 tubes (100μL/tube) 50 tubes (100μL/tube) 100 tubes (100μL/tube) |
| ACC-117 | Ar.Qual Chemically Competent Cell | 10 tubes (100μL/tube) 20 tubes (100μL/tube) 50 tubes (100μL/tube) 100 tubes (100μL/tube) |
| ACC-118 | MSU440 Chemically Competent Cell | 10 tubes (100μL/tube) 20 tubes (100μL/tube) 50 tubes (100μL/tube) 100 tubes (100μL/tube) |
| ACC-119 | C58C1 Chemically Competent Cell | 10 tubes (100μL/tube) 20 tubes (100μL/tube) 50 tubes (100μL/tube) 100 tubes (100μL/tube) |
| ACC-121 | K599 Chemically Competent Cell | 10 tubes (100μL/tube) 20 tubes (100μL/tube) 50 tubes (100μL/tube) 100 tubes (100μL/tube) |
| ACC-122 | Ar.A4 Electroporation Competent Cell | 10 tubes (50μL/tube) 20 tubes (50μL/tube) 50 tubes (50μL/tube) |
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