Melanin biosynthesis in Pyricularia oryzae: Site of tricyclazole inhibition and pathogenicity of melanin-deficient mutants

Woloshuk, Charles P.; Sisler, H. D.; Tokousbalides, M.Chrysayi; Dutky, S. R.

doi:10.1016/0048-3575(80)90032-2

Cited by 133 publications

(43 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The first characterizations suggested catechol precursors to form allomelanin devoid of nitrogen by similarity to plant melanins [8,32]. These initial studies were carried out to study pathogenic molds of rice plants (Pyricularia oryzae), and melanin was identified as a pathogenicity factor [106]. According to that nitrogen economy, L-tyrosine did not stimulate melanin formation.…”

Section: Fungal Melaninmentioning

confidence: 99%

Melanins: Skin Pigments and Much More—Types, Structural Models, Biological Functions, and Formation Routes

Solano

2014

New Journal of Science

443

431

View full text Add to dashboard Cite

This review presents a general view of all types of melanin in all types of organisms. Melanin is frequently considered just an animal cutaneous pigment and is treated separately from similar fungal or bacterial pigments. Similarities concerning the phenol precursors and common patterns in the formation routes are discussed. All melanins are formed in a first enzymatically-controlled phase, generally a phenolase, and a second phase characterized by an uncontrolled polymerization of the oxidized intermediates. In that second phase, quinones derived from phenol oxidation play a crucial role. Concerning functions, all melanins show a common feature, a protective role, but they are not merely photoprotective pigments against UV sunlight. In pathogenic microorganisms, melanization becomes a virulence factor since melanin protects microbial cells from defense mechanisms in the infected host. In turn, some melanins are formed in tissues where sunlight radiation is not a potential threat. Then, their redox, metal chelating, or free radical scavenging properties are more important than light absorption capacity. These pigments sometimes behave as a doubleedged sword, and inhibition of melanogenesis is desirable in different cells. Melanin biochemistry is an active field of research from dermatological, biomedical, cosmetical, and microbiological points of view, as well as fruit technology.

show abstract

Section: Fungal Melaninmentioning

confidence: 99%

Melanins: Skin Pigments and Much More—Types, Structural Models, Biological Functions, and Formation Routes

Solano

2014

New Journal of Science

443

431

View full text Add to dashboard Cite

show abstract

“…8,9) Mycelial pigmentation by P, oyyzae is markedly inhibited by tricyclazole concentrations which effectively inhibit appressorial penetration of plant epidermal barriers. 1,2,8) It was proposed that tricyclazole blocks two reduction steps of the fungal melanin biosynthesis pathway; the conversion of 1, 3,6,8-tetrahydroxynaphthalene (1,3,6,8-THN) to scytalone and 1,3,8-trihydroxynaphthalene (1,3, to vermelone, 8,10) and thus causes abnormal accumulation of 2-hydroxyjuglone (2-HJ), flaviolin and other related intermediates and metabolites. An inhibitory effect of tricyclazole was also demonstrated on appressorial melanization in penetration tests with P. oryzae, 11) Colletotrichum lindemuthianum12) and C. lagenarium.…”

Section: Introductionmentioning

confidence: 99%

Restoration of Appressorial Penetration Ability by Melanin Precursors in <i>Pyricularia oryzae</i> Treated with Antipenetrants and in Melanin-Deficient Mutants

Chida

Sisler

1987

J. Pestic. Sci.

Self Cite

View full text Add to dashboard Cite

The capacity of Pyricularia oyyzae appressoria to penetrate onion epidermal walls was lost in an albino mutant or in wild type strains treated with melanin biosynthesis inhibitors, cerulenin, fthalide and tricyclazole. Melanization and penetration ability of cerulenin treated wild type or untreated albino mutant appressoria were restored with scytalone or 1, 8-dihydroxynaphthalene(1,=8-DHN). Fthalide or tricyclazole nullified the restoration by scytalone, but not by 1, 8-DHN. Penetration ability of wild type appressoria treated with 0. 1 cg/ml of fthalide or tricyclazole was restored by 1,8-DHN, but was not well restored in appressoria treated with 1 or 10 ug/ml of these inhibitors unless cerulenin was also present. This investigation indicates that blocking of the melanin biosynthesis pathway by fthalide or tricyclazole leads to two mechanisms of antipenetrant action (1) interference with melanin synthesis (2) accumulation of inhibitory metabolites.The latter mechanism, which may operate concomitantly with former, is nullified in the presence of cerulenin.

show abstract

“…The melanin biosynthesis plays a crucial role in M. oryzae pathogenic development; the infection structure, appressorium must be melanized. Consequently, 3HNR is the biochemical target of commercial agricultural fungicides (tricyclazole, pyroquilon, and phthalide) to prevent rice blast (Tokousbalides and Sisler, 1978;Woloshuk et al, 1980;Woloshuk and Sisler, 1982). Unlike melanin-deficient mutants of M. oryzae lacking 3HNR and 4HNR expression (Chumley and Valent, 1990), the melanization in MoSDR1 deletion mutant appeared to be normal (data not shown).…”

Section: Discussionmentioning

confidence: 99%

A Short-chain Dehydrogenase/reductase Gene is Required for Infection-related Development and Pathogenicity in Magnaporthe oryzae

Kwon¹,

Kim²,

Lee³

2010

The Plant Pathology Journal

View full text Add to dashboard Cite

The phytopathogenic fungus Magnaporthe oryzae is a major limiting factor in rice production. To understand the genetic basis of M. oryzae pathogenic development, we previously analyzed a library of T-DNA insertional mutants of M. oryzae, and identified ATMT0879A1 as one of the pathogenicity-defective mutants. Molecular analyses and database searches revealed that a single T-DNA insertion in ATMT0879A1 resulted in functional interference with an annotated gene, MGG00056, which encodes a short-chain dehydrogenase/reductase (SDR). The mutant and annotated gene were designated as MoSDR1and MoSDR1, respectively. Like other SDR family members, MoSDR1 possesses both a cofactor-binding motif and a catalytic site. The expression pattern of MoSDR1 suggests that the gene is associated with pathogenicity and plays an important role in M. oryzae development. To understand the roles of MoSDR1, the deletion mutant ΔMosdr1 for the gene was obtained via homology-dependent gene replacement. As expected, ΔMosdr1 was nonpathogenic; moreover, the mutant displayed pleiotropic defects in conidiation, conidial germination, appressorium formation, penetration, and growth inside host tissues. These results suggest that MoSDR1 functions as a key metabolic enzyme in the regulation of development and pathogenicity in M. oryzae.

show abstract

Melanin biosynthesis in Pyricularia oryzae: Site of tricyclazole inhibition and pathogenicity of melanin-deficient mutants

Cited by 133 publications

References 10 publications

Melanins: Skin Pigments and Much More—Types, Structural Models, Biological Functions, and Formation Routes

Melanins: Skin Pigments and Much More—Types, Structural Models, Biological Functions, and Formation Routes

Restoration of Appressorial Penetration Ability by Melanin Precursors in <i>Pyricularia oryzae</i> Treated with Antipenetrants and in Melanin-Deficient Mutants

A Short-chain Dehydrogenase/reductase Gene is Required for Infection-related Development and Pathogenicity in Magnaporthe oryzae

Contact Info

Product

Resources

About