Real-Time PCR Assay for the Diagnosis and Quantification of Co-infections by and in Sweet Potato.

Foot rot disease caused by (formerly ) has become a major concern for the production of sweet potato [ (L.) Lam.] in Japan.

Effects of carbon sources and amines on induction of trichothecene production by Fusarium asiaticum in liquid culture.

Fusarium asiaticum infects cereal crops and produces trichothecenes such as deoxynivalenol and nivalenol. To determine the trichothecene induction mechanism, effects of carbon sources on the production of deoxynivalenol, nivalenol, 3-acetyl deoxynivalenol (3ADON), and 4-acetyl nivalenol (4ANIV) were examined in liquid cultures incubated with various strains. Sucrose supported significantly higher levels of acetylated trichothecene production in all strains than did the other carbon sources.

One of two major paralogs of AVR-Pita1 is functional in Japanese rice blast isolates.

We analyzed the avirulence gene AVR-Pita1 in Japanese rice blast isolates to determine how they gain virulence toward rice cultivars containing the Pita resistance gene. An avirulent isolate, OS99-G-7a (G7a), from a Japanese commercial field contained two paralogs of AVR-Pita1, designated as AVR-Pita1(JA) and AVR-Pita1(JB). Analysis of virulent, independent mutants derived from G7a, a single avirulent progenitor strain, indicated that AVR-Pita1(JA) was functional but AVR-Pita1(JB) was nonfunctional.

Molecular cloning and characterization of the AVR-Pia locus from a Japanese field isolate of Magnaporthe oryzae.

In order to clone and analyse the avirulence gene AVR-Pia from Japanese field isolates of Magnaporthe oryzae, a mutant of the M. oryzae strain Ina168 was isolated. This mutant, which was named Ina168m95-1, gained virulence towards the rice cultivar Aichi-asahi, which contains the resistance gene Pia.

Suppression of a phospholipase D gene, OsPLDbeta1, activates defense responses and increases disease resistance in rice.

Phospholipase D (PLD) plays an important role in plants, including responses to abiotic as well as biotic stresses. A survey of the rice (Oryza sativa) genome database indicated the presence of 17 PLD genes in the genome, among which OsPLDalpha1, OsPLDalpha5, and OsPLDbeta1 were highly expressed in most tissues studied. To examine the physiological function of PLD in rice, we made knockdown plants for each PLD isoform by introducing gene-specific RNA interference constructs.

Identification of Magnaporthe oryzae Avirulence Genes to Three Rice Blast Resistance Genes.

The segregation of avirulence/virulence was studied in 115 F progeny isolates of Magnaporthe oryzae from a cross of two field isolates on three Japanese race-differential rice cultivars Kanto 51, Fukunishiki, and Toride 1. The χ tests of goodness-of-fit for a 1:1 ratio indicated that avirulence on cvs. Kanto 51, Fukunishiki, and Toride 1 was under monogenic control.

Biological Control of Cyclamen Soilborne Diseases by Serratia marcescens Strain B2.

Cyclamen plants were treated with a highly chitinolytic bacterium, Serratia marcescens strain B2, and then challenge inoculated with Rhizoctonia solani sclerotia or Fusarium oxysporum f. sp. cyclaminis conidia.

Pectinolytic enzymes from Pseudomonas marginalis MAFF 03-01173.

Two pectinolytic enzymes were purified from the culture broth of Pseudomonas marginalis pv. marginalis MAFF 03-01173 with total 33% recovery of the initial activity. From the substrate specificities against pectin and polygalacturonic acid, the requirement of calcium ion for the enzymatic activity, and the N-terminal sequences, the enzymes were identified as pectin lyase and pectate lyase.