Rice apoplastic CBM1-interacting protein counters blast pathogen invasion by binding conserved carbohydrate binding module 1 motif of fungal proteins

いもち病からイネを守る細胞外タンパク質 (CBMIP) の発見 --CBMIPはイネの細胞壁を守り、いもち病菌の感染を抑える--. 京都大学プレスリリース. 2022-09-30.When infecting plants, fungal pathogens secrete cell wall-degrading enzymes (CWDEs) that break down cellulose and hemicellulose, the primary components of plant cell walls. Some fungal CWDEs contain a unique domain, named the carbohydrate binding module (CBM), that facilitates their access to polysaccharides. However, little is known about how plants counteract pathogen degradation of their cell walls. Here, we show that the rice cysteine-rich repeat secretion protein OsRMC binds to and inhibits xylanase MoCel10A of the blast fungus pathogen Magnaporthe oryzae, interfering with its access to the rice cell wall and degradation of rice xylan. We found binding of OsRMC to various CBM1-containing enzymes, suggesting that it has a general role in inhibiting the action of CBM1. OsRMC is localized to the apoplast, and its expression is strongly induced in leaves infected with M. oryzae. Remarkably, knockdown and overexpression of OsRMC reduced and enhanced rice defense against M. oryzae, respectively, demonstrating that inhibition of CBM1-containing fungal enzymes by OsRMC is crucial for rice defense. We also identified additional CBM-interacting proteins (CBMIPs) from Arabidopsis thaliana and Setaria italica, indicating that a wide range of plants counteract pathogens through this mechanism

A blast fungus zinc-finger fold effector binds to a hydrophobic pocket in host Exo70 proteins to modulate immune recognition in rice

イネがいもち病菌を見つける「目印」の構造を解明. 京都大学プレスリリース. 2022-10-21.Exocytosis plays an important role in plant–microbe interactions, in both pathogenesis and symbiosis. Exo70 proteins are integral components of the exocyst, an octameric complex that mediates tethering of vesicles to membranes in eukaryotes. Although plant Exo70s are known to be targeted by pathogen effectors, the underpinning molecular mechanisms and the impact of this interaction on infection are poorly understood. Here, we show the molecular basis of the association between the effector AVR-Pii of the blast fungus Maganaporthe oryzae and rice Exo70 alleles OsExo70F2 and OsExo70F3, which is sensed by the immune receptor pair Pii via an integrated RIN4/NOI domain. The crystal structure of AVR-Pii in complex with OsExo70F2 reveals that the effector binds to a conserved hydrophobic pocket in Exo70, defining an effector/target binding interface. Structure-guided and random mutagenesis validates the importance of AVR-Pii residues at the Exo70 binding interface to sustain protein association and disease resistance in rice when challenged with fungal strains expressing effector mutants. Furthermore, the structure of AVR-Pii defines a zinc-finger effector fold (ZiF) distinct from the MAX (Magnaporthe Avrs and ToxB-like) fold previously described for a majority of characterized M. oryzae effectors. Our data suggest that blast fungus ZiF effectors bind a conserved Exo70 interface to manipulate plant exocytosis and that these effectors are also baited by plant immune receptors, pointing to new opportunities for engineering disease resistance

Transabdominal Approach for Spontaneous Oesophageal Perforation: A Review of Four Cases

Spontaneous oesophageal perforation is an uncommon and life-threatening disease. Although several methods of treatment have been proposed, surgical treatment is considered the standard procedure. Primary repair using the transthoracic approach is the most common. However, few studies have evaluated the characteristics of the transabdominal approach. This study aimed to investigate the clinical outcomes of spontaneous oesophageal perforation that was surgically treated using the transabdominal approach. We retrospectively reviewed all patients with spontaneous oesophageal perforation who were admitted to the surgical department of our institution between November 2010 and April 2017, and identified a total of four patients. Data including demographic factors (age and sex), location of perforation, time to operation, operative method, complications, length of hospital stay, and postoperative recovery were reviewed. In all four cases, we treated the defect using the transabdominal approach, which provides a good surgical field of view. The aims of operative intervention, namely primary repair and access for enteral feeding, can be achieved using this approach. The most commonly observed complication was pyothorax, and we suggest the addition of intrapleural drainage for its prevention. Dysgraphia was observed in two patients, which improved with conservative treatment. The overall mortality rate was 0%. Our results demonstrate that primary repair using the transabdominal approach is safe and effective for the management of spontaneous oesophageal perforation. Addition of intrapleural drainage can improve the outcome associated with this approach

Disentangling the complex gene interaction networks between rice and the blast fungus identifies a new pathogen effector

Studies focused solely on single organisms can fail to identify the networks underlying host–pathogen gene-for-gene interactions. Here, we integrate genetic analyses of rice (Oryza sativa, host) and rice blast fungus (Magnaporthe oryzae, pathogen) and uncover a new pathogen recognition specificity of the rice nucleotide-binding domain and leucine-rich repeat protein (NLR) immune receptor Pik, which mediates resistance to M. oryzae expressing the avirulence effector gene AVR-Pik. Rice Piks-1, encoded by an allele of Pik-1, recognizes a previously unidentified effector encoded by the M. oryzae avirulence gene AVR-Mgk1, which is found on a mini-chromosome. AVR-Mgk1 has no sequence similarity to known AVR-Pik effectors and is prone to deletion from the mini-chromosome mediated by repeated Inago2 retrotransposon sequences. AVR-Mgk1 is detected by Piks-1 and by other Pik-1 alleles known to recognize AVR-Pik effectors; recognition is mediated by AVR-Mgk1 binding to the integrated heavy metal-associated (HMA) domain of Piks-1 and other Pik-1 alleles. Our findings highlight how complex gene-for-gene interaction networks can be disentangled by applying forward genetics approaches simultaneously to the host and pathogen. We demonstrate dynamic coevolution between an NLR integrated domain and multiple families of effector proteins

ブロモウイルス ノ カンセン ニ ヒツヨウナ ウイルス インシカン オヨビ ウイルス - ショクブツ インシカン ソウゴ サヨウ ノ カイセキ

京都大学0048新制・課程博士博士(農学)甲第10284号農博第1356号新制||農||870(附属図書館)学位論文||H15||N3805(農学部図書室)UT51-2003-H705京都大学大学院農学研究科応用生物科学専攻(主査)教授 奥野 哲郎, 教授 遠藤 隆, 教授 泉井 桂学位規則第4条第1項該当Doctor of Agricultural ScienceKyoto UniversityDA

Acute diffuse peritonitis due to spontaneous rupture of a primary gastrointestinal stromal tumor of the jejunum: A case report

Introduction: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Overt peritonitis caused by GIST rupture is very uncommon. Three types of GIST rupture have been described: closed perforation due to abscess (abscess type), hemoperitoneum leading to rupture of the hematoma capsule in the tumor (hemoperitoneum type), and perforation of the digestive tract via a fistula leading to central necrosis of the tumor (bowel perforation type). This report describes a patient with spontaneous tumor rupture and diffuse peritonitis, a variant of the bowel perforation type of GIST rupture. Presentation of case: A 74-year-old man presented with symptoms of vomiting and abdominal pain. Computed tomography (CT) scan revealed an approximately 10 × 7-cm mass in the pelvis with free air and fluid collection. Emergency laparotomy revealed a tumor in the jejunum, which was ruptured with a hole measuring 5 mm in diameter. The tumor and part of the jejunum were resected. Immunohistochemically, the mass was diagnosed as a GIST originating from the gastrointestinal tract. Despite chemotherapy with imatinib mesylate, the patient died 22 months after surgery. Conclusions: This report describes a patient with acute diffuse peritonitis due to spontaneous rupture of a primary GIST of the jejunum