Wheat stripe rust poses substantial challenges to food security in China, and elucidating its epidemic patterns provides a scientific basis for disease management. To investigate the factors underlying its widespread 2020 outbreak and the associated inoculum transmission dynamics, 645 Puccinia striiformis f. sp. tritici samples were collected from 15 provinces across China in this study. By integrating population genetic structure analyses with airflow trajectory simulations, we elucidate for the first time the inoculum transmission dynamics among central Shanxi, north-central Hebei, and south-central Inner Mongolia. Our findings demonstrate that inoculum originated in central Shanxi can traverse the Taihang Mountains to reach central Hebei, while both central Shanxi and northern Hebei serve as primary inoculum sources for south-central Inner Mongolia. Furthermore, inoculum from northwestern and southwestern China can disperse to the Huang-Huai-Hai wheat-growing region via distinct pathways, with northwestern inoculum being predominant. Analysis of meteorological data revealed that ample rainfall and optimal temperatures in the Pst oversummering and overwintering regions during the summer and winter of 2019 resulted in a significant accumulation of inoculum in the subsequent autumn and winter. This accumulation served as the main catalyst for the extensive wheat stripe rust epidemic in 2020. This study further clarifies the epidemic patterns of wheat stripe rust in China and is of great significance for disease forecasting and management.
Abstract Fertilization affects not only plant growth but also the development of soil-borne diseases. However, how fertilization regimes that combine organic and inorganic inputs across vegetative and reproductive stages regulate root rot resistance in Apocynum venetum , a medicinal and fiber crop, remains unclear. In this study, we evaluated the effects of these fertilization treatments on growth and root rot in field-grown A. venetum by integrating physiological, hormonal, and transcriptomic analyses. Organic fertilization promoted plant growth while reducing disease incidence and severity, whereas mineral nitrogen-phosphorus fertilization exacerbated disease. Although both fertilizer types stimulated growth, they differentially regulated plant defense systems: mineral fertilization increased polyphenol oxidase and peroxidase activities, and salicylic acid (SA) accumulation, indicating a shift toward SA-mediated responses, whereas organic-based regimes maintained higher superoxide dismutase and catalase activities, flavonoid levels, and jasmonic acid (JA) accumulation, consistent with enhanced antioxidant capacity and JA-associated defenses. WGCNA identified key co-expression modules and hub genes linked to disease-related traits, revealing fertilization treatment-specific transcriptional networks. These findings indicate that fertilization-mediated variation in root rot is associated with coordinated changes in defense physiology and gene regulation, with organic and mineral fertilization differentially modulating immune and antioxidant systems despite their comparable growth-promoting effects. Together, these results provide a basis for optimizing fertilization strategies for sustainable disease management.
Plant diseases pose threat to global agricultural productivity and food security. Targeting conserved pathogenicity mechanisms offers a sustainable strategy for antifungal development. In plant pathogenic fungi, effectors suppress host immunity to facilitate infection. Given the precise regulation of effector delivery, key components of this secretion pathway emerge as attractive targets for the antifungal agents. Previously, we identified the cargo receptor MoErv29 in Magnaporthe oryzae as a key regulator of effector secretion. Here, in this study, we define MoErv29 cargo recognition mechanism and reveals a critical binding pocket essential for the pathogenicity of M. oryzae. Based on the predicted structure, we discover a small-molecule compound 0442, which inhibits MoErv29 function and reduces the severity of rice blast. The evolutionary conservation of this pocket allowed 0442 to exhibit broad-spectrum activity against a wide range of plant fungal pathogens. Together, these findings establish Erv29 as a validated molecular target and provide a framework for the development of a new class of broad-spectrum antifungal agents.
Viral diseases represent one of the most serious constraints to global maize production, where increasing disease incidence and expanding viral diversity threaten yield stability and food security. Several viruses are recognized as the most economically important pathogens in maize. Maize-infecting viruses employ sophisticated infection strategies that suppress host immunity, manipulate hormonal and redox signaling, and exploit insect vectors to drive rapid and widespread transmission. Synergistic interactions among some co-infecting viruses further intensify disease severity, frequently leading to devastating epidemics. In this review, we highlight the top 10 economically significant maize viruses and summarize key profiles for each. We highlight recent advances in understanding how maize viruses modulate host defenses through RNA-silencing suppressors and regulatory networks involving microRNAs (miRNAs) and reactive oxygen species (ROS) homeostasis. We also discuss progress in diagnostics and genetic tools, including portable detection platforms, next-generation sequencing, CRISPR-based assays, and virus-derived vectors, which are enhancing disease surveillance. Finally, we summarize current control strategies, with an emphasis on RNA interference (RNAi)-based and biotechnology-mediated resistance, and outline critical research gaps concerning resistance mechanisms, vector biology, and viral synergism.
Abstract Kiwifruit bacterial canker (KBC), caused by Pseudomonas syringae pv. actinidiae ( Psa ), severely impacts kiwifruit production. Previous studies show that Psa exhibits enhanced virulence under cool temperatures; however, the underlying regulatory mechanisms remain unclear. Given the crucial role of histidine kinases (HKs) in bacterial responses to environmental signals, bioinformatics analysis predicted a total of 69 HKs in Psa , among which hktS was identified as the key cool-temperature-responsive gene. Structural analysis and co-transcription experiments revealed that HktS and its corresponding response regulator HktR constitute a functional two-component system (TCS). We found that mutations in the key phospho‑related residues of HktS and HktR impair cool temperature sensing and reduce the virulence of Psa . Further research demonstrated that HktR directly interacts with the transcription factor RpoD and binds to a conserved motif in the promoter region of hrpRS , thereby activating expression of the type III secretion system (T3SS). Genetic and expression analyses showed that the HktS‑HktR system displays a conserved cool-temperature-responsive expression pattern across the tested strains and is highly conserved within the genus Pseudomonas . Thus, we identified a histidine kinase essential for Psa virulence under cool temperatures and elucidated the underlying molecular mechanism. Our findings provide a critical theoretical basis and potential molecular targets for developing novel control strategies for KBC.
