Gokulan C G, Sohini Deb, Namami Gaur, Apoorva Masade, Niranjan Gattu, Rennya P R, Nisha Sao, Donald James, Ramesh V Sonti, Hitendra K Patel
{"title":"<i>Xanthomonas oryzae</i> pv. <i>oryzae</i> Type-III Effector Tal9b Targets a Broadly Conserved Disease Susceptibility Locus to Promote Pathogenesis in Rice.","authors":"Gokulan C G, Sohini Deb, Namami Gaur, Apoorva Masade, Niranjan Gattu, Rennya P R, Nisha Sao, Donald James, Ramesh V Sonti, Hitendra K Patel","doi":"10.1094/MPMI-10-24-0139-R","DOIUrl":"https://doi.org/10.1094/MPMI-10-24-0139-R","url":null,"abstract":"<p><p><i>Xanthomonas oryzae</i> pv. <i>oryzae</i> (<i>Xoo</i>), the causal agent of bacterial blight of rice, translocates multiple Transcription Activator-Like Effectors (TALEs) into rice cells. The TALEs localize to the host cell nucleus, where they bind to the DNA in a sequence-specific manner and enhance gene expression to promote disease susceptibility. <i>Xoo</i> strain PXO99<sup>A</sup> encodes nineteen TALEs, but the host targets of all these TALEs have not been defined. A meta-analysis of rice transcriptome profiles revealed a gene annotated as flavonol synthase/flavanone-3 hydroxylase (henceforth <i>OsS5H</i>/<i>FNS-03g</i>) to be highly induced upon <i>Xoo</i> infection. Further analyses revealed that this gene is induced by PXO99<sup>A</sup> using Tal9b, a broadly conserved TALE of <i>Xoo</i>. Disruption of <i>tal9b</i> rendered PXO99<sup>A</sup> less virulent. OsS5H/FNS-03g functionally complemented its <i>Arabidopsis</i> homologue AtDMR6, a well-studied disease susceptibility locus. Biochemical analyses suggested that OsS5H/FNS-03g is a bifunctional protein with Salicylic Acid 5' Hydroxylase (S5H) and Flavone Synthase-I (FNS-I) activities. Further, an exogenous application of apigenin on rice leaves, the flavone that is enzymatically produced by OsS5H/FNS-03g, promoted virulence of PXO99<sup>A</sup> <i>tal9b</i>-. Overall, our study suggests that OsS5H/FNS-03g is a bifunctional enzyme and its product apigenin is potentially involved in promoting <i>Xoo</i> virulence.</p>","PeriodicalId":19009,"journal":{"name":"Molecular Plant-microbe Interactions","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144008653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Differential Effects of Local dsRNA Application on Systemic Beet Mosaic Virus (BtMV) Resistance in <i>Nicotiana benthamiana</i> and <i>Beta vulgaris</i>.","authors":"Dennis Rahenbrock, Marieke Bode, Mark Varrelmann","doi":"10.1094/MPMI-01-25-0009-R","DOIUrl":"https://doi.org/10.1094/MPMI-01-25-0009-R","url":null,"abstract":"<p><p>Beet mosaic virus (BtMV) is one of several viruses infecting sugar beets and was managed by controlling the vector <i>Myzus persicae</i> with neonicotinoid seed treatment. Following the ban of this measure in 2019 in Europe, alternative control strategies must be researched. One alternative might be the use of RNA interference (RNAi) as a major antiviral defence system. Here we report the selection of target regions using small RNA high throughput sequencing of BtMV infected <i>Beta vulgaris</i> subsp. <i>vulgaris</i> and <i>Nicotiana benthamiana</i> plants, the production of double-stranded RNA (dsRNA), and its effective use in inducing resistance against the mechanically inoculated virus. Both in <i>Escherichia coli</i> HT115 produced dsRNAs for BtMV P1 and nuclear inclusion body b (NIb) induced a high level of resistance, when sprayed before mechanical BtMV inoculation, resulting in an 80% reduction of symptomatic <i>B. vulgaris</i> and <i>N. benthamiana</i> plants. Stem-loop RT-qPCR showed the systemic distribution of dsRNA derived siRNA molecules, but the applied dsRNA remained at the site of application and did not spread within the plant. However, when the virus was inoculated on the next upward leaf to the dsRNA application site, no protective effect was observed. Despite this limitation, the results demonstrate the potential of dsRNA as an effective tool for viral protection in sugar beets, thereby establishing a basis for future developments in systemic delivery and broader field applications.</p>","PeriodicalId":19009,"journal":{"name":"Molecular Plant-microbe Interactions","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143795710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reinaldo Rodrigues de Souza-Neto, Lidia Nascimento Cavalcante, Isis Gabriela Barbosa Carvalho, Maiara Curtolo, Celso Eduardo Benedetti, Marco Aurelio Takita, Nian Wang, Alessandra Alves de Souza
{"title":"CRISPR/Cas9-Mediated Disruption of <i>CsLIEXP1</i> Reveals Expansin as a Key Susceptibility Factor for Citrus Canker Disease.","authors":"Reinaldo Rodrigues de Souza-Neto, Lidia Nascimento Cavalcante, Isis Gabriela Barbosa Carvalho, Maiara Curtolo, Celso Eduardo Benedetti, Marco Aurelio Takita, Nian Wang, Alessandra Alves de Souza","doi":"10.1094/MPMI-12-24-0151-R","DOIUrl":"https://doi.org/10.1094/MPMI-12-24-0151-R","url":null,"abstract":"<p><p>The <i>Citrus sinensis LATERAL ORGAN BOUNDERIES 1</i> (<i>CsLOB1</i>) gene, which is directly induced by the <i>Xanthomonas citri</i> subsp. <i>citri</i> effector PthA4, functions as a transcription factor and citrus canker susceptibility (S) gene. Genome editing of <i>CsLOB1</i> has been shown to confer resistance to citrus canker disease. Previous studies revealed that the citrus <i>CsLOB1-INDUCED EXPANSIN 1</i> gene (<i>CsLIEXP1</i>) is highly and directly upregulated by <i>CsLOB1</i> in <i>Xanthomonas citri</i> subsp. <i>citri</i>-infected plants. Because expansins are associated with cell wall loosening, potentially facilitating bacterial colonization, the <i>CsLOB1</i>-dependent activation of <i>CsLIEXP1</i> is thought to contribute to canker symptoms and disease progression. Thus, <i>CsLIEXP1</i> likely represents a critical canker susceptibility gene. In this study, we employed CRISPR/Cas9 to disrupt the function of <i>CsLIEXP1</i> by modifying its corresponding coding region in <i>Citrus sinensis</i> cv 'Hamlin' and evaluated the post-infection responses of edited plants. DNA sequencing confirmed edition of <i>CsLIEXP1</i>-edited plant, which exhibited 26.47% of <i>CsLIEXP1</i> edited sequences. Furthermore, <i>CsLIEXP1</i> protein accumulation was reduced in <i>CsLIEXP1</i>-edited plants compared to wild-type when infected with <i>X. citri</i>. Leaves of edited plants inoculated with <i>X. citri</i> showed significant less canker symptoms, with lesions limited to the site of bacterial inoculation and less pronounced cellular hypertrophy compared to control plants. Our results show that <i>CsLIEXP1</i> is a citrus canker S gene that acts downstream of <i>CsLOB1</i>, thus providing new insights into plant-pathogen interactions.</p>","PeriodicalId":19009,"journal":{"name":"Molecular Plant-microbe Interactions","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143772410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pablo A Gutierrez, Joshua Fuller, Sydney Stroschein, Austin VanDenTop, Dennis Halterman, Aurelie M Rakotondrafara
{"title":"<i>Potato Virus Y</i> Restricts <i>Alternaria solani</i> Growth During Co-Infection.","authors":"Pablo A Gutierrez, Joshua Fuller, Sydney Stroschein, Austin VanDenTop, Dennis Halterman, Aurelie M Rakotondrafara","doi":"10.1094/MPMI-03-25-0026-R","DOIUrl":"https://doi.org/10.1094/MPMI-03-25-0026-R","url":null,"abstract":"<p><p>In the environment, multiple microbes can interact with each other in the plant phyllosphere. These associations can shape the plant's development, stress responses, and disease susceptibility, but the molecular mechanisms that govern this process remain unexplained. Of interest are the multiple or successive infections that crop plants are exposed to within a growing season. One of the most common and economically important viruses of potato is potato virus Y (PVY, <i>Potyviridae</i>). We show that PVY infection of potato limited the expansion of foliar necrotic lesions caused by the early blight fungus <i>Alternaria solani</i>. The reduced growth phenotype persisted when the fungal mycelium was transferred to solid growth media. RNAseq analysis of responses in potato and <i>A. solani</i> to the presence of PVY suggested two mechanisms that can explain this interaction. First, in <i>A. solani</i> exposed to PVY-positive leaves, we observed a down-regulation of fungal pathogenicity genes. Second, we found that, in the absence of PVY, <i>A. solani</i> downregulates ethylene-responsive defense in potato, but this effect was eliminated when the host was infected with PVY. Our findings expand our understanding of how pathogen virulence can be affected by other pathogens competing for the same host resources. The observation that PVY can alter <i>A. solani</i> infection illustrates the ecological role of viruses as a potential contributor to the development of disease outbreaks.</p>","PeriodicalId":19009,"journal":{"name":"Molecular Plant-microbe Interactions","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143753605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The <i>Alternaria alternata</i> Mip1/RAPTOR Mediates Virulence by Regulating Toxin Production and Autophagy.","authors":"Yu-Ling Huang, Kuang-Ren Chung, Pei-Ching Wu","doi":"10.1094/MPMI-12-24-0161-R","DOIUrl":"https://doi.org/10.1094/MPMI-12-24-0161-R","url":null,"abstract":"<p><p>The necrotrophic pathogen <i>Alternaria alternata</i> produces a host-selective toxin to attack its host plants. This study characterized the crucial function of the Mip1/RAPTOR ortholog (AaMip1) in toxin production and autophagy formation. AaMip1 physically interacts with the Target of Rapamycin (Tor) protein. In response to nitrogen starvation and H<sub>2</sub>O<sub>2</sub>, AaMip1 binds to Tor and triggers autophagy and oxidative stress detoxification. Deleting the <i>AaMip1</i> gene resulted in a Δ<i>AaMip1</i> strain that increased sensitivity to various oxidants, decreased the expression of two oxidative-stress-response genes, <i>AaYap1</i> and <i>AaNoxA</i>, and had lower catalase activity than the wild type. Δ<i>AaMip1</i> produced lower levels of ACT toxin than the wild type after a 7-day incubation; however, Δ<i>AaMip1</i> produced tricycloalternarene mycotoxins but not ACT after 21 days. The reduction of Δ<i>AaMip1</i> virulence in the host plant is due to low ACT production, defective H<sub>2</sub>O<sub>2</sub> detoxification, impaired autophagy, and slow growth during invasion. However, AaMip1 plays a negative role in maintaining cell wall integrity and lipid body accumulation. Δ<i>AaMip1</i> had thicker cell walls and emitted brighter red fluorescence after staining with the cell-wall disrupting agents Congo red and calcofluor white. Δ<i>AaMip1</i> was more resistant to these compounds than the wild type under nutrient-rich conditions. The observed defects in the Δ<i>AaMip1</i> were restored in the complementation (CP) strain after re-expressing a functional copy of <i>AaMip1</i>. This study increases our understanding of how <i>A. alternata</i> deals with toxic ROS, triggers autophagy formation, maintains normal cell wall integrity, and regulates toxin metabolism via the AaMip1-mediated signaling pathways.</p>","PeriodicalId":19009,"journal":{"name":"Molecular Plant-microbe Interactions","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143584904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Suppression of a Transketolase Mutation Leads to Only Partial Restoration of Symbiosis in <i>Sinorhizobium meliloti</i>.","authors":"Sabhjeet Kaur, Justin P Hawkins, Ivan J Oresnik","doi":"10.1094/MPMI-02-25-0017-R","DOIUrl":"https://doi.org/10.1094/MPMI-02-25-0017-R","url":null,"abstract":"<p><p>The interaction between <i>Sinorhizobium meliloti</i> and alfalfa is a well-studied model system for symbiotic establishment between rhizobia and legume plants. Proper utilization of carbon sources has been linked with effective symbiotic establishment in <i>S. meliloti</i> strain Rm1021. Previous work has shown that mutation of the gene <i>tktA</i>, which encodes a transketolase involved in the pentose phosphate pathway, resulted in a strain impaired in many biological functions, including the inability to establish a symbiosis with alfalfa. Work with this strain revealed the appearance of suppressor mutations which could partially revert the symbiotic phenotype associated with a <i>tktA</i> mutation. Characterization of these suppressor strains revealed that carbon phenotypes associated with a mutation in <i>tktA</i> were no longer present and that the production of succinoglycan was partially restored. Central carbon metabolite pools were observed to be different compared to the wildtype and <i>tktA</i> mutant strains. Multiple independent mutations were identified in the gene <i>SMc02340</i>, a Gnt-type negative regulator upon sequencing. RT-PCR suggests that <i>SMc02340</i> acts as a negative regulator on an operon containing the gene <i>tktB</i>, which becomes upregulated when the suppressor mutation is present or <i>SMc02340</i> is removed. Microscopic analysis revealed a unique symbiotic phenotype. The <i>tktA</i> mutant strain induced root hair curling but could not colonize the apoplastic space. Collectively the data suggests the upregulation of <i>tktB</i> can partially bypass some blocks associated with a lesion in <i>tktA</i>, including the colonization of the curled root hair, but cannot fully compensate for the loss of <i>tktA</i>.</p>","PeriodicalId":19009,"journal":{"name":"Molecular Plant-microbe Interactions","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143586344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lida Derevnina, Ksenia V Krasileva, Benjamin Schwessinger, Richard A Wilson
{"title":"Fine Grain: Molecular, Cellular, and Genomic Details of Cereal Crop Diseases.","authors":"Lida Derevnina, Ksenia V Krasileva, Benjamin Schwessinger, Richard A Wilson","doi":"10.1094/MPMI-04-25-0040-CM","DOIUrl":"https://doi.org/10.1094/MPMI-04-25-0040-CM","url":null,"abstract":"","PeriodicalId":19009,"journal":{"name":"Molecular Plant-microbe Interactions","volume":"38 2","pages":"99-103"},"PeriodicalIF":3.2,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144019973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}