Rice Pyricularia oryzae

Iron toxicity is a syndrome of disorders associated with large concentrations of Fe + in the soil solution. It is only found in flooded soils. A wide range of concentrations produce the symptoms, from 1000 to only 10mgL in soils with poor nutrient status—especially of P or K—or with respiration inhibitors such as H2S. There are large differences in tolerance between rice varieties. The effects include internal damage of tissues due to excessive uptake of Fe + impaired nutrient uptake, especially of P, K, Ca and Mg and increased diseases associated with imbalanced nutrition, such as brown leaf spot (caused by Helminthospo-rium oryzae), sheath blight (caused by Rhizoctonia solani) and blast (caused by Pyricularia oryzae). 

With respect to five-membered lactones fused to hexopyranose units, some approaches have been reported so far and the exploitation of their synthetic potential has led to the access of new carbohydrate derivatives. Bicyclic derivatives of this type are key intermediates in the synthesis of the epimer at C-3 of the sugar moiety contained in miharamycins [212, 213]. The latter are antibiotics known to inhibit strongly Pyricularia oryzae, which produces the rice blast disease. These compounds are also considered to be a potential bioterrorism agent (Scheme 42). Hence, the 3,3-spiroepoxide 176 was converted into the 3-C-cyanomethyl derivative 177, the hydrolysis of which led to spontaneous cyclization in the presence of... 

OS123 Kono, Y., S. Takeuchi, O. Kodama, and T. Akatsuka. Absolute configuration of Oryzalexin A and structures of its related phytoalexins isolated from rice blast leaves infected with Pyricularia oryzae. Agr Biol Chem 1984 48(1) 253-255. 

Monosubstituted pyrrolo[2,3- ]pyridine derivatives substituted at positions 2 or 6 of the ring system, 26, exhibit antifungal activity against Pyricularia oryzae, a fungus that causes rice blast <1997JFA2345>. 

Edifenphos, O-ethyl 5,5-diphenyl phosphorodithioate, was announced in 1968 and introduced commercially by Bayer AG for the control of rice blast, Pyricularia oryzae. Iprobenfos, 5-benzyl 0,0-diisopropyl phosphorothioate, was introduced by Kumiai Chemical... 

Probenazole is used for the control of Pyricularia oryzae in rice (Figure 4.40). Interestingly, probenazole is ineffective against P. oryzae as a pathogen of barley, implying a dependence upon the metabolism of the natural host, rice, or a different SAR response. 

The organisms Pyricularia oryzae, which causes rice blast, and Helminthosporium oryzae, which causes brown leaf spot, can be controlled with complexes of the ligands 1-phenyl-3-methyl-4-nitroso-2-pyrazolin-5-one (36) and 3-methyl-4-nitroso-2-pyrazolin-5-one (37). The complexes were of the type ML Xj (L = 36, 37 X = C1-, Br, N03 ) or [ML2]Y2 (Y = C104 ). The former were assigned an octahedral or distorted octahedral structure and the latter are tetrahedral. The most active nickel complex was (38).92... 

Uesugi, Y. (1982) Pyricularia oryzae of Rice. In Fungicide Resistance in Crop Protection (editors J. Dekker and S.G. Georgo-poulos), Pudoc, Wageningen, 207-218. 

Schaffrath, U., Scheinpflug, H., Reisener, H.J. An elicitor from Pyricularia oryzae induced resistance responses in rice isolation, Characterization and physiological properties. Physiol Mol Plant Pathol 1995 46 293-307. 

Waspi U, Blanc D, Winkler T, Ruedi P, Dudler R (1998) Syringolin, a novel peptide elicitor from Pseudomonas syringae pv. syringae that induces resistance to Pyricularia oryzae in rice. Mol Plant Microbe Interact 11 727-733... 

Blasticidin S. Blasticidin S is the first successful agricultural antibiotic developed in Japan. It was isolated from the culture filtrates of Streptomyces griseochromogenes by Takeuchi et al. (7), and the potent curative effect of blasticidin S on rice blast was found by Misato et al. (8) Thereafter the benzyl-aminobenzene sulfonate of blasticidin S was reported to be least phytotoxic to the host plant without reducing antifungal activity against Pyricularia oryzae, the pathogen of rice blast (9), and... 

Since increased LPO in man has severe consequences to health, LPO products were investigated for physiological action. Thus it was detected that HODEs generated by reduction of HPODEs induce in mammalians the genesis of cytokines, e.g. interleukine-ip [251], which in turn stimulates smooth muscle cell proliferation [252], they cause swelling of mitochondria [253], induce inflammation [254], and are activators of the proliferation activated receptor protein (PPAR) [255], important for cell differentiation [256,257]. Much less is known on the action of HODEs in plants, nevertheless it was shown that HPODEs, HODEs and epoxy resp. trihydroxy derivatives thereof inhibit conidial germination of the rice blast fungus Pyricularia oryzae [159,237]. 

Melanin Biosynthesis Inhibitors. Among the most desirable targets for selective fungitoxic action are those uniquely associated with fungal pathogenicity such as the polyketide pathway to melanin in the fungus Pyricularia oryzae which causes rice blast disease. 

Various biochemical approaches to the pathogen-ecity of Pyricularia oryzae, a rice blast fungus, have been studied in our laboratory from the stand points of toxins (1,2) and glycosidases produced... 

As described in the former sections, a serologically active heteroglycan has been characterized. We thought the antigenecity of the cell wall of Pyricularia oryzae might be a probe for the specific recognition on the various strains of this rice blast fungus. 

AKATSUKA, T., KODAMA, O., SEKIDO, H., KONO, Y., TAKEUCHI, S., Novel phytoalexins (oryzalexins A, B and C) isolated from rice blast leaves infected with Pyricularia oryzae. Part I isolation, characterization and biological activities of oryzalexins, Biol. Chem., 1985, 49, 1689-1694. 

C4H,N02, Mr 129.16, mp. 240°C (decomp.), [a]o -12.4° (H2O). A non-proteinogenic amino acid in the fruit bodies of Amanita viigineoidesIt inhibits the growth of Escherichia coli as well as spore germination of Pyricularia oryzae (mold as cause of mildew on rice). 

Amongst many other derivatives (by NH-acylation, sulfonylation, alkylation, arylation) a sulfonylaminocarbonyl-triazolinone with the internal code no. BAY DAM 4493 was synthesized in 1985 (Fig. 2.6.3). It showed not only activity against rice blast Pyricularia oryzae) but also phytotoxic symptoms at application rates of 500 g a.i. ha h... 

Common properties of MBI-Rs and MBI-Ds are protective control activity against rice blast and inhibition of appressorium pigmentation of Pyricularia oryzae on agar plates or cellophane membrane [Hattori et al., 1994 Soma et al., 1999 Sie-verding et al., 1998]. Inhibition of spore liberation from leaf lesions is also commonly observed in all known MBI-Rs and MBI-Ds [Kitamura et al., 1976 Okuno... 

Altemaria altemata H-25(rice) Cladosporium cucumerinum H-23(melon) Pyricularia oryzae H-22(rice)... 

---