Search Results (45)

Phytophthora parasitica is a devastating oomycete pathogen that causes significant crop losses worldwide. Identifying master regulators of its virulence is crucial for the development of novel control strategies. Here, we demonstrate that the conserved eukaryotic kinase TOR (target of rapamycin) is essential for both growth and pathogenicity in P. parasitica. Transcriptomic analysis revealed that PpTOR inhibition broadly reprograms the transcriptome of P. parasitica, notably leading to the downregulation of numerous PpRxLR and PpCRN effector genes. Among these genes, the overexpression of PpRxLR3 increased plant susceptibility to P. parasitica by affecting jasmonic acid biosynthesis and signaling. On the basis of the crucial role of PpTOR, we evaluated its potential as a target for intervention. Host-induced gene silencing (HIGS) of PpTOR in Nicotiana benthamiana conferred strong resistance to P. parasitica, which was associated with the downregulation of the expression of PpTOR and key effector genes during P. parasitica infection. Furthermore, small RNA sequencing confirmed the production of PpTOR-specific siRNAs in HIGS plants. Exogenous application of synthetic siRNAs targeting PpTOR effectively reduced P. parasitica virulence. Our findings establish PpTOR as a global regulator of pathogenicity and validate PpTOR as a promising target for RNA-based disease control strategies. Full article

Protein arginine methyltransferases (PRMTs) are key regulators of diverse cellular processes in eukaryotes, including transcriptional regulation, RNA processing, signal transduction and DNA repair. However, the biological functions of PRMTs in Verticillium dahliae remain largely unexplored. In this study, we identified a PRMT1 homolog in V. dahliae. Targeted deletion of VdPRMT1 resulted in severely impaired hyphal growth, sporulation, stress responses and pathogenicity. Subcellular localization analysis showed that VdPRMT1 is distributed in both the nucleus and cytoplasm of hyphae. Host-induced gene silencing (HIGS) of VdPRMT1 in cotton significantly reduced disease severity, supporting its important role in pathogenicity. Furthermore, VdLuc7, a U1 snRNP-associated protein containing multiple RG/RGG motifs, was identified as a putative interacting partner of VdPRMT1 through yeast two-hybrid (Y2H) screening, bimolecular fluorescence complementation (BiFC) and luciferase complementation imaging (LCI) assays. Together, our results demonstrate that VdPRMT1 is required for normal fungal development and full virulence in V. dahliae, and suggest that arginine methylation may contribute to pathogenicity through regulation of RNA processing-related pathways. These findings provide new insights into the molecular mechanisms underlying fungal virulence and identify VdPRMT1 as a potential target for disease control. Full article

Cotton is an economically important cash crop severely affected by Verticillium wilt caused by Verticillium dahliae. Secreted cell-wall-degrading enzymes act as key virulence factors of this pathogen, yet the biological function of glucan 1,3-β-glucosidase remains largely uncharacterized. The gene VDAG_02814 (designated Vdbgl1) was previously found to be strongly induced during host infection. Here, combined approaches including gene knockout, host-induced gene silencing (HIGS), and transcriptomic analysis were utilized to characterize the function of Vdbgl1. The results showed that Vdbgl1 deletion retarded colony growth on PDA medium by 20.1–21.6%, decreased conidial yield by 20.2–46.7%, lowered spore germination rate by 30.7–32.9%, and weakened utilization of diverse carbon sources by 5.0–14.9%. The ΔVdbgl1 mutants also exhibited significantly increased sensitivity to cell wall-perturbing, osmotic, and membrane-damaging agents. Additionally, the ΔVdbgl1 mutants exhibited reduced disease index by approximately 19.1–27.7% and decreased fungal biomass by 42.7–61.8% in cotton; consistently, HIGS-mediated silencing of Vdbgl1 reduced the disease index by 25.7% and 26.7% and decreased fungal biomass by 48.1–71.5%. Transcriptome profiling of cotton roots infected by the ΔVdbgl1 mutant and the wild-type strain revealed 1007 down-regulated genes enriched in carbohydrate metabolism, cell wall degradation, and energy pathways, including 27 carbohydrate-active enzyme genes and 58 genes encoding cysteine-rich secreted proteins. Collectively, these findings indicated that Vdbgl1 coordinates carbon utilization, cell wall remodeling, and stress responses to regulate fungal development and pathogenicity, representing a promising target for cotton Verticillium wilt control. Full article

The grain aphid, Sitobion miscanthi, poses a serious threat to cereal crops worldwide, leading to considerable yield losses and demanding annual insecticide applications during the grain-filling stage. As a sustainable alternative, we explored host-induced gene silencing (HIGS) targeting an aphid-specific gene. In this study, we identified SmDSR32, a novel gene encoding a salivary peptide in S. miscanthi, and validated its suitability for RNAi. Transgenic wheat lines expressing SmDSR32-dsRNA were generated. Aphids feeding on these lines showed a 20-fold reduction in SmDSR32 transcript levels compared with controls. This silencing disrupted normal feeding behavior in electropenetrography (EPG) analyses, characterized by a 1.94-fold prolongation of intercellular probing and a 61% shortening of phloem ingestion. Consequently, aphid performance was severely compromised, with at least a 56.7% decrease in survival, a shortening of 5 days in lifespan, and a reduction of 9–10 individuals in aphid progeny production. Impressively, upon being transferred to wild-type plants, both the surviving aphids and their progeny sustained fitness deficits, with a 30% reduction in survival still observed in the first generation. These findings validate SmDSR32 as a potent RNAi target and establish HIGS targeting essential salivary genes as a promising strategy for sustainable aphid management in wheat. Full article

Penicillium species are major postharvest pathogens of fruits and vegetables, causing significant economic losses and posing serious threats to food safety through mycotoxin contamination. This review systematically summarizes the pathogenic mechanisms, metabolic diversity, and eco-friendly strategies of postharvest Penicillium pathogens. The application of CRISPR-Cas9 technology has enabled precise functional analysis of pathogenicity-related genes (e.g., PacC, PeStuA) and regulatory elements involved in fungicide resistance (e.g., FlbC). RNA interference-based strategies, including host-induced gene silencing (HIGS) and spray-induced gene silencing (SIGS), offer promising non-transgenic approaches for disease control. Additionally, artificial intelligence-assisted species identification and fermentation regulation have improved research efficiency. Future integration of multidisciplinary technologies will facilitate sustainable management of postharvest diseases. Full article

Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), poses a severe threat to global wheat production. The adaptor protein complex AP-1 plays a crucial role in vesicular trafficking, yet its function in rust fungi remains poorly understood. In this study, a gene encoding an AP-1 σ subunit, designated PsAP1, was identified in Pst. The expression of PsAP1 was highly induced during the early infection stage. Heterologous expression of PsAP1 in a Fusarium graminearum mutant partially restored its pathogenic defects. Subcellular localization analysis revealed that PsAP1 localizes to the plasma membrane, cytoplasm, and nucleus. Silencing PsAP1 in wheat using Barley stripe mosaic virus-mediated host-induced gene silencing (BSMV-HIGS) significantly attenuated Pst pathogenicity, reducing hyphal growth by 6.7% (colony diameter), sporulation by 61.6% (lesion length), and pathogen biomass by 66%, along with enhanced accumulation of host reactive oxygen species. Transcriptomic analysis further demonstrated that silencing PsAP1 disrupted multiple pathways, including MAPK signaling, glutathione metabolism, and carbohydrate metabolism. These findings indicate that PsAP1 facilitates Pst infection by modulating vesicular trafficking, suppressing host immunity, and reprogramming host metabolism. This study provides novel insights into the pathogenic mechanisms of rust fungi and suggests a potential target for disease control. Full article

The RNA interference machinery is crucial for regulating the activity of both native and foreign genes across all eukaryotes. The core protein families involved in this process are Dicer-like, Argonaute, and RNA-dependent RNA polymerase. However, plants exhibit remarkable diversity within each family and extensively use RNA interference mechanisms in their intricate immune responses. This review examines the role of RNA interference in plant interactions with various pathogens, including viruses, viroids, fungi, oomycetes, and bacteria. Plant diseases cause an estimated $220 billion in annual damage, with microorganisms accounting for approximately $150 billion. Hence, the focus is on the most severe plant diseases, specifically those caused by fungi and viruses. Additionally, recent biotechnological advancements are discussed, with an emphasis on the application of RNA interference for the development of novel plant defence strategies. Full article

Meloidogyne enterolobii, is a devastating pathogen capable of overcoming conventional resistance genes. This study presents the first investigation into targeting the chitin synthase gene Me-chs-1 in M. enterolobii using host-induced gene silencing (HIGS). Our results demonstrate that HIGS effectively suppresses Me-chs-1 expression, leading to a drastic reduction in nematode reproductive capacity, with the most effective transgenic line showing over 82% decrease in total egg production. Additionally, notable developmental deformities were observed in the nematodes. This study confirms Me-chs-1 as a promising target for controlling M. enterolobii and lays a solid foundation for developing novel resistance breeding strategies and eco-friendly nematicides. Full article

Proteins containing the SQS-PSY domain, which include squalene synthetase (SQS), phytoene synthetase (PSY), and NDUFAF6, are functionally important and widely distributed in plants and animals. However, they have not been previously reported in nematodes. In this study, we identified a gene (Minc31999) encoding an SQS-PSY domain-containing protein in the root-knot nematode Meloidogyne incognita. In silico comparison and enzymatic assays of the recombinant protein indicated that this nematode protein is a putative NDUFAF6 homolog. Phylogenetic analysis revealed that this protein is evolutionarily conserved within the Nematoda phylum. RT-qPCR analysis showed that Minc31999 is highly expressed during the early infection stage of M. incognita. Targeting the nematode gene Minc31999 via host-induced gene silencing (HIGS) significantly hindered nematode development and virulence. In contrast, heterologous expression of Minc31999 in Arabidopsis thaliana disrupted normal plant development and increased host susceptibility to nematode infection. Transcriptomic profiling (RNA-seq) of these transgenic plants prior to infections showed a widespread differential expression of genes across multiple metabolic pathways. We propose that this nematode SQS-PSY domain-containing protein may function as an effector that rewires host secondary metabolism to establish a parasitic relationship. Our study elucidates a novel strategy in nematode–plant interactions and advances our understanding of the functional evolution of SQS-PSY domain-containing proteins. Full article

Sclerotinia sclerotiorum is a globally widespread and vast destructive plant pathogenic fungus that causes significant yield losses in crops. Due to the lack of effective resistant germplasm resources, the control of diseases caused by S. sclerotiorum largely relies on chemical fungicides. However, excessive use of these chemicals not only causes environmental concerns but also leads to the increased development of resistance in S. sclerotiorum. In contrast, trans-kingdom sRNA silencing-based technologies, such as host-induced gene silencing (HIGS) and spray-induced gene silencing (SIGS), offer novel, effective, and environmentally friendly methods for the management of S. sclerotiorum infection. This review summarizes recent advances in the identification of S. sclerotiorum pathogenic genes, target gene selection, categories, and application of trans-kingdom RNA interference (RNAi) technologies targeting this pathogen. Although some challenges, including off-target effects and the efficiency of external sRNA uptake, exist, recent findings have proposed solutions for further improvement. Combined with the latest developments in CRISPR/Cas gene editing and other technologies, trans-kingdom RNAi has significant potential to become a crucial tool in the control of sclerotinia stem rot (SSR), mitigating the impact of S. sclerotiorum on crop production. Full article

In planta RNAi or host-induced gene silencing (HIGS) has undergone significant advancements that have rendered it efficient and stable at the transgenerational level in plants for regulating host genes and targeting genes of insect pests and plant pathogens. Similarly, topical RNAi or spray-induced gene silencing (SIGS) has garnered considerable attention as an environmentally sustainable, selective, and alternative approach to chemical control of insect pests and plant pathogens. Several biotechnology companies and startups have focused their efforts on RNAi-based solutions for topical application in agriculture. Nevertheless, further technological advancements are required to enhance the efficacy of topical RNAi in agriculture, including improved dsRNA delivery systems, better target gene selection, and addressing biosafety regulatory issues. Herein, this review discusses key advances and bottlenecks in RNAi, and summarizes successful applications of these RNAi-based technologies in agriculture focusing on in planta and topical RNAi to control insect pests and plant pathogens. Furthermore, this review delves into the patenting landscape, biosafety considerations, risk evaluations, and the current regulatory status of RNAi in Latin America. Finally, it explores the contributions of RNAi to plant science, food production, and fostering a more sustainable form of agriculture. Full article

This review highlights the emerging role of cross-kingdom RNA interference in plant–microbe interactions, particularly the transfer of sRNAs from microbes to plants and vice versa, emphasizing the importance of this mechanism in both mutualistic and pathogenic contexts. As plants adapted to terrestrial life, they formed symbiotic relationships with microbes, essential for nutrient uptake and defense. Emerging evidence underscores sRNAs, including small interfering RNAs (siRNAs) and microRNAs (miRNAs), as critical regulators of gene expression and immune responses in plant–microbe interactions. In mutualistic symbioses, such as mycorrhizal fungi and nitrogen-fixing bacteria associations, sRNAs are hypothesized to regulate nutrient exchange and symbiotic stability. In pathogenic scenarios, microbes utilize sRNAs to undermine plant defenses, while plants employ strategies like host-induced gene silencing (HIGS) to counteract these threats. We further explore the emerging role of extracellular vesicles (EVs) in sRNA transport, which is critical for facilitating interspecies communication in both pathogenic and mutualistic contexts. Although the potential of ckRNAi in mutualistic interactions is promising, the review highlights the need for further experimental validation to establish its true significance in these relationships. By synthesizing current research, this review highlights the intricate molecular dialogues mediated by sRNAs in plant–microbe interactions and identifies critical gaps, proposing future research directions aimed at harnessing these mechanisms for agricultural advancements. Full article

Maize is one of the major crops that are susceptible to Aspergillus flavus infection and subsequent aflatoxin contamination, which poses a serious health threat to humans and domestic animals. Here, an RNA interference (RNAi) approach called Host-Induced Gene Silencing (HIGS) was employed to suppress the O-methyl transferase gene (omtA, also called aflP), a key gene involved in aflatoxin biosynthesis. An RNAi vector carrying part of the omtA gene was introduced into the B104 maize line. Among the six transformation events that were positive for containing the omtA transgene, OmtA-6 and OmtA-10 were self-pollinated from T1 to T4, and OmtA-7 and OmtA-12 to the T6 generation. These four lines showed at least an 81.3% reduction in aflatoxin accumulation at the T3 generation under laboratory conditions. When screened under field conditions with artificial inoculation, OmtA-7 at T5 and T6 generations and OmtA-10 at T4 generation showed a reduction in aflatoxin contamination between 60% and 91% (p < 0.02 to p < 0.002). In order to develop commercial maize lines with enhanced aflatoxin resistance, the omtA transgene in OmtA-7 was introduced into three elite inbred lines through crossing, and the resulting crosses also exhibited significantly lower aflatoxin accumulation compared to crosses with non-transgenic controls (p < 0.04). In addition, high levels of omtA-specific small RNAs were only detected in the transgenic kernel and leaf tissues. These results demonstrate that suppression of omtA through HIGS can enhance maize resistance to aflatoxin contamination, and this resistance can be transferred to elite backgrounds, providing a viable and practical approach to reduce aflatoxin contamination in maize. Full article

Cotton is often threatened by Verticillium wilt caused by V. dahliae. Understanding the molecular mechanism of V. dahlia–cotton interaction is important for the prevention of this disease. To analyze the transcriptome profiles in V. dahliae and cotton simultaneously, the strongly pathogenic strain Vd592 was inoculated into cotton, and the infected cotton roots at 36 h and 3 d post infection were subjected to dual RNA-seq analysis. For the V. dahliae, transcriptomic analysis identified 317 differentially expressed genes (DEGs) encoding classical secreted proteins, which were up-regulated at least at one time point during infection. The 317 DEGs included 126 carbohydrate-active enzyme (CAZyme) and 108 small cysteine-rich protein genes. A pectinesterase gene (VDAG_01782) belonging to CAZyme, designated as VdPE1, was selected for functional validation. VdPE1 silencing by HIGS (host-induced gene silencing) resulted in reduced disease symptoms and the increased resistance of cotton to V. dahliae. For the cotton, transcriptomic analysis found that many DEGs involved in well-known disease resistance pathways (flavonoid biosynthesis, plant hormone signaling, and plant–pathogen interaction) as well as PTI (pattern-triggered immunity) and ETI (effector-triggered immunity) processes were significantly down-regulated in infected cotton roots. The dual RNA-seq data thus potentially connected the genes encoding secreted proteins to the pathogenicity of V. dahliae, and the genes were involved in some disease resistance pathways and PTI and ETI processes for the susceptibility of cotton to V. dahliae. These findings are helpful in the further characterization of candidate genes and breeding resistant cotton varieties via genetic engineering. Full article

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), stands out as one of the most devastating epidemics impacting wheat production worldwide. Resistant wheat varieties had swiftly been overcome due to the emergence of new virulent Pst strains. Effectors secreted by Pst interfere with plant immunity, and verification of their biological function is extremely important for controlling wheat stripe rust. In this study, we identified an effector, Pst-18220, from Puccinia striiformis f. sp. tritici (Pst), which was induced during the early infection stage of Pst. Silencing the expression of Pst-18220 through virus-mediated host-induced gene silencing (HIGS) resulted in a decreased number of rust pustules. In Nicotiana benthamiana, it significantly suppressed cell death induced by Pseudomonas syringae pv. tomato (Pto) DC3000. In Arabidopsis, plants with stable overexpression of Pst-18220 showed increased susceptibility to Pto DC3000, accompanied by a decrease in the expression level of pattern-triggered immunity (PTI)/effector-triggered immunity (ETI)-related genes, namely, AtPCRK1, AtPCRK2, and AtBIK1. These results emphasize the significant role of the Pst candidate effector, Pst-18220, in rust pathogenicity and the suppression of plant defense mechanisms. This broadens our understanding of effectors without any known motif. Full article