Publishing type：Research paper (scientific journal)  

DOI： 10.1093/pcp/pcae005

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Language：English   Publishing type：Research paper (scientific journal)  

Many biotrophic and hemibiotrophic fungal pathogens use appressoria to directly penetrate the host plant surface. In the cucumber anthracnose fungus Colletotrichum orbiculare, differentiation of appressoria requires a proper G1/S cell cycle progression, regulated by the GTPase-activating protein complex CoBub2-CoBfa1 and its downstream GTPase CoTem1. To explore the mechanisms by which the CoTem1 cascade regulates plant infection, we screened for CoTem1 interaction factors and identified a Niemann-Pick type C2 homolog (CoNpc2). Niemann-Pick type C proteins NPC1 and NPC2 are sterol-binding proteins required for sterol export from lysosomes (vacuoles) in humans and yeasts. We showed that CoNpc2 colocalized with CoNpc1 in late endosomes and vacuoles and that disruption of its gene resulted in aberrant sterol accumulation in vacuoles and loss of sterol membrane localization, indicating that NPC proteins are engaged in sterol transport in C. orbiculare. For appressorium infection, sterol transport and proper distribution mediated by CoNpc1 and CoNpc2 are critical for membrane integrity and membrane curvature with actin assembly, leading to penetration peg emergence and appressorial cone formation. Our results revealed a novel mechanism by which NPC proteins regulate appressorium-mediated plant infection. IMPORTANCE Fungal morphogenesis requires accurate cell cycle progression. Two-component GTPase-activating protein (GAP) CoBub2-CoBfa1 interacts with downstream GTPase CoTem1 and is required for G1/S progression to establish plant infection in Colletotrichum orbiculare. To understand the pathogenicity related functions of CoTem1 downstream, we identified a Niemann-Pick type C2 homolog (CoNpc2) as a novel physical interaction factor with CoTem1. Whereas NPC proteins (NPC1 and NPC2) are essential for sterol homeostasis in humans and yeasts, their functions in plant invasion by pathogenic fungi have remained unclear. In this study, we show that CoNPC1 and CoNPC2 play a critical role in intracellular sterol transport and that appropriate sterol distribution is required for membrane integrity and membrane curvature with actin assembly that leads to appressorium-mediated plant penetration and pathogenicity of C. orbiculare. Our findings suggest the importance of sterol distribution in fungal morphogenesis during plant infection.

DOI： 10.1128/mbio.02236-22

PubMed

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Oxford University Press (OUP)  

<title>Abstract</title>
Plants employ two different types of immune receptors, cell surface pattern recognition receptors (PRRs) and intracellular nucleotide-binding and leucine-rich repeat-containing proteins (NLRs), to cope with pathogen invasion. Both immune receptors often share similar downstream components and responses but it remains unknown whether a PRR and an NLR assemble into the same protein complex or two distinct receptor complexes. We have previously found that the small GTPase OsRac1 plays key roles in the signaling of OsCERK1, a PRR for fungal chitin, and of Pit, an NLR for rice blast fungus, and associates directly and indirectly with both of these immune receptors. In this study, using biochemical and bioimaging approaches, we revealed that OsRac1 formed two distinct receptor complexes with OsCERK1 and with Pit. Supporting this result, OsCERK1 and Pit utilized different transport systems for anchorage to the plasma membrane (PM). Activation of OsCERK1 and Pit led to OsRac1 activation and, concomitantly, OsRac1 shifted from a small to a large protein complex fraction. We also found that the chaperone Hsp90 contributed to the proper transport of Pit to the PM and the immune induction of Pit. These findings illuminate how the PRR OsCERK1 and the NLR Pit orchestrate rice immunity through the small GTPase OsRac1.

DOI： 10.1093/pcp/pcab121

PubMed

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Other Link： https://academic.oup.com/pcp/article-pdf/62/11/1662/42269784/pcab121.pdf

Language：English   Publishing type：Research paper (scientific journal)  

Organophosphate is the commonly used pesticide to control pest outbreak, such as those by aphids in many crops. Despite its wide use, however, necrotic lesion and/or cell death following the application of organophosphate pesticides has been reported to occur in several species. To understand this phenomenon, called organophosphate pesticide sensitivity (OPS) in sorghum, we conducted QTL analysis in a recombinant inbred line derived from the Japanese cultivar NOG, which exhibits OPS. Mapping OPS in this population identified a prominent QTL on chromosome 5, which corresponded to Organophosphate-Sensitive Reaction (OSR) reported previously in other mapping populations. The OSR locus included a cluster of three genes potentially encoding nucleotide-binding leucine-rich repeat (NB-LRR, NLR) proteins, among which NLR-C was considered to be responsible for OPS in a dominant fashion. NLR-C was functional in NOG, whereas the other resistant parent, BTx623, had a null mutation caused by the deletion of promoter sequences. Our finding of OSR as a dominant trait is important not only in understanding the diversified role of NB-LRR proteins in cereals but also in securing sorghum breeding free from OPS.

DOI： 10.1038/s41598-021-98908-7

PubMed

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Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1111/nph.17389

PubMed

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1111/nph.17389

J-GLOBAL

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J-GLOBAL

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J-GLOBAL

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Event date： 2022.9.5 - 2022.9.7

Presentation type：Oral presentation (invited, special)  

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Event date： 2022.8.28 - 2022.9.2

Presentation type：Oral presentation (invited, special)  

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Event date： 2022.3.27 - 2022.3.30

Presentation type：Oral presentation (general)  

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Presentation type：Oral presentation (invited, special)  

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