Publications by authors named "Norio Sahashi"

Homospory represents an intriguing reproductive strategy, including the potential for gametophytic selfing, considered the ultimate form of selfing. The plants of the fern genus Sceptridium (Ophioglossaceae) are generally considered to be predominantly selfing, making them suitable for analyzing speciation patterns and intraspecific variation characteristic of homosporous plants. The Sceptridium species in Japan not only exhibit variations in ploidy, including diploids, tetraploids, and hexaploids, but also pose taxonomic challenges due to morphologically distinctive forms that are difficult to be assigned to previously described species.

View Article and Find Full Text PDF

Brown root rot disease (BRRD) is a highly destructive tree disease. Early diagnosis of BRRD has been challenging because the first symptoms and signs are often observed after extensive tissue colonization. Existing molecular detection methods, all based on the internal transcribed spacer (ITS) region, were developed without testing against global isolates, other wood-decay fungi, or host plant tissues.

View Article and Find Full Text PDF

Brown root rot disease (BRRD), caused by , is an important tree disease in tropical and subtropical areas. To improve chemical control of BRRD and deter emergence of fungicide resistance in . , this study investigated control efficacies and systemic activities of fungicides with different modes of action.

View Article and Find Full Text PDF

Although automated pollen monitoring networks using laser optics are well-established in Japan, it is thought that these methods cannot distinguish between pollen counts when evaluating various pollen taxa. However, a method for distinguishing the pollen counts of two pollen taxa was recently developed. In this study, we applied such a method to field evaluate the data of the two main allergens in Japan, Chamaecyparis obtusa and Cryptomeria japonica.

View Article and Find Full Text PDF

Background: In 1986, the Ministry of Health and Welfare started an airborne pollen survey as part of measures against JC pollinosis. We reported the important tree pollen antigens in 2016. We have now estimated the longitudinal investigated results for successful prevention and treatment for allergic symptoms related to grass and weed pollen in Japan.

View Article and Find Full Text PDF
Article Synopsis
  • The Hymenochaetales order includes aggressive white rot fungi that significantly contribute to tree deaths worldwide, yet their evolutionary paths and transmission remain poorly understood.
  • Recent genomic analyses of several fungi, including Phellinus noxius, revealed gene families related to lignin degradation and highlighted the expansion of specific enzyme genes that may explain fast growth.
  • Population genomics of P. noxius from various Asia Pacific islands showed two genetically distinct lineages exhibiting high genetic diversity and unique patterns of inheritance, laying the groundwork for further studies on the genetic determinants of their virulence and adaptability.
View Article and Find Full Text PDF

Rational: In Japan patients with Japanese Cedar (JC) pollinosis have increased nation widely since the latter of 1970's. The Ministry of Health and Welfare of Japanese Governments has begun to take preventive measures against JC pollinosis and airborne pollen monitoring has begun to investigate as a causative agent since 1986. We have estimated the longitudinal investigation result for successful prevention and treatment against pollinosis in Japan.

View Article and Find Full Text PDF

Phellinus noxius is a pathogenic fungus that causes brown root rot disease in a variety of tree species. This fungus is distributed in tropical and sub-tropical regions of Southeast and East Asia, Oceania, Australia, Central America and Africa. In Japan, it was first discovered on Ishigaki Island in Okinawa Prefecture in 1988; since then, it has been found on several of the Ryukyu Islands.

View Article and Find Full Text PDF

Taphrina fungi are biotrophic plant pathogens that cause plant deformity diseases. We sequenced the genomes of four Taphrina species-Taphrina wiesneri, T. deformans, T.

View Article and Find Full Text PDF

Pine wilt disease is one of the most serious epidemic tree diseases in Japan, and resistant pine trees have been developed through a breeding program. To evaluate resistance of resistant families of Japanese black pine, Pinus thunbergii, to the pinewood nematode, Bursaphelenchus xylophilus, isolated from the field, and to determine whether differentiation of pathogenicity to resistant pine families appears in the nematode isolates, seedlings of five resistant pine families were inoculated with 25 nematode isolates. Disease incidence 18 weeks after inoculation was significantly different among nematode isolates and among pine families but there was no interaction effect between nematode isolate and pine family.

View Article and Find Full Text PDF

Bursaphelenchus xylophilus is the nematode responsible for a devastating epidemic of pine wilt disease in Asia and Europe, and represents a recent, independent origin of plant parasitism in nematodes, ecologically and taxonomically distinct from other nematodes for which genomic data is available. As well as being an important pathogen, the B. xylophilus genome thus provides a unique opportunity to study the evolution and mechanism of plant parasitism.

View Article and Find Full Text PDF

Brown root rot, caused by Phellinus noxius, leads to problems in management of shade, ornamental, and windbreak trees in subtropical regions of the world, and it has been causing serious problems in Japan since 1988. To identify the pathogenicity, host specialization, and virulence of the pathogen, cross inoculation tests were carried out using isolates of the fungus obtained from nine different tree species. P.

View Article and Find Full Text PDF

We determined pollen specific IgE in tears and compared these results to the concentration of specific IgE in serum samples. We obtained tears (using Schirmer strips) and serum samples from subjects with Japanese cedar (Cryptomeria japonica) pollinosis, and tested for C. japonica pollen specific IgE using a quantitative ELISA.

View Article and Find Full Text PDF

Glucagon, a key regulatory element of glycogen metabolism, is known to be effective in the clinical treatment of hypoglycemia and the maintenance of normal circulating glucose levels in patients with total pancreatectomy, however the clinical use of this gut hormone has been restricted to parenteral administration. In this investigation, we prepared dry powder dosage forms of glucagon, which were formulated by mixing micronized glucagon particles and excipients with larger carrier particles. To achieve alveolar deposition for subsequent systemic absorption, a dry powder inhalant (DPI) of glucagon was size-reduced to a mass median diameter between 1 and 6 microm, as measured by laser diffraction analysis.

View Article and Find Full Text PDF