The conidial germ tube of the fungus Magnaporthe grisea differentiates an infection-specific structure, an appressorium, for penetration into the host plant. Formation of the appressorium is also observed on synthetic solid substrata such as polycarbonate. We found that a plant lectin, concanavalin A, specifically suppressed the appressorium formation without affecting the germling adhesion if ...

Rice blast, caused by the fungus, Magnaporthe grisea, is a common disease of rice in Arkansas. The disease has reached epidemic levels previously in Arkansas on susceptible cultivars. Also, it has been established that artificially infected seeds placed on the soil surface could initiate disease in small plots. The research reported here was conducted in small plots to determine if naturally in...

Protein phosphatases, together with protein kinases, regulate protein phosphorylation and dephosphorylation, and play critical roles in plant growth and biotic stress responses. However, little is known about the biological functions of plant protein tyrosine dual-specificity phosphatase (PFA-DSP) in biotic stresses. Here, we found that OsPFA-DSP2 was mainly expressed in calli, seedlings, roots...

One of the first responses of plants to microbial attack is the production of extracellular superoxide surrounding infection sites. Here, we report that Magnaporthe grisea, the causal agent of rice blast disease, undergoes an oxidative burst of its own during plant infection, which is associated with its development of specialized infection structures called appressoria. Scavenging of these oxy...

Tall fescue (Festuca arundinacea Schreb.) is an open-pollinated, perennial, cool-season turf and forage grass species of great economic importance. The main problems of maintenance of tall fescue, and many other turfgrasses, are two severe fungal diseases: gray leaf spot caused by Magnaporthe grisea, and brown patch caused by Rhizoctonia solani. Three genes from various sources have been introd...

An epidemic of rice (Oryza sativa) blast occurred on cultivars Epagri 108 and 109 in the municipalities of Lagoa da Confusão and Duerê in the State of Tocantins, during the rice-growing season 199899. DNA fingerprinting and virulence phenotype analysis were utilized to determine the diversity of Pyricularia grisea isolates collected from these cultivars in one epidemic year. Rep-PCR analysis of...

Although allelic diversity of genes has been reported to play important roles in different physiological processes, information on allelic diversity of defense-responsive genes in host-pathogen interactions is limited. Here, we report that a pair of allelic genes, OsWRKY45-1 and OsWRKY45-2, which encode proteins with a 10-amino acid difference, play opposite roles in rice (Oryza sativa) resista...

An analysis of siderophores produced by Magnaporthe grisea revealed the presence of one intracellular storage siderophore, ferricrocin, and four coprogen derivatives secreted into the medium under iron depletion. Structural analysis showed that the compounds are coprogen, coprogen B, 2-N-methylcoprogen and 2-N-methylcoprogen B. Siderophore production under low and high iron conditions was quant...