Occurrence of chrysanthemum virescence caused by “<Emphasis Type="Italic">Candidatus</Emphasis> Phytoplasma aurantifolia” in Okinawa

In 1999, a disease of chrysanthemum [Dendranthema grandiflorum (Ramat.) Kitamura], characterized by virescence of flowers, occurred in Okinawa Prefecture. The causal agent was identified as “Candidatus Phytoplasma aurantifolia” based on 16S rDNA sequencing. The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under accession number AB247462.     

N-terminal domain including conserved flg22 is required for flagellin-induced hypersensitive cell death in <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis>

Flagellin in Pseudomonas syringae is a potent elicitor of defense responses including hypersensitive cell death in dicot plants. The oligopeptides flg22 consisting of 22 conserved amino acids near the N-terminus of flagellins is reported to induce plant defense responses. Because glycosylation of the central domain of flagellin affects its elicitor activity, we investigated whether any peptide sequence in addition to flg22 is required for flagellin-induced hypersensitive reaction. A study of recombinant flagellin polypeptides indicated that the N-terminal domain including the conserved flg22 is required for flagellin-induced hypersensitive cell death in Arabidopsis thaliana.     

Effects of Denapon and Ethrel on thinning grapes

The effectiveness of Denapon and Ethrel as a thinning chemical for ‘Muscat of Alexandria’ grape was examined from 1980 to 1982 with various timings and concentrations of application. Ethrel applied at 50 mg l^?1 by cluster-dipping or shoot-spraying at full bloom, or 6 days after full bloom, resulted in over-thinning and chemical injury, and no thinning effect was found when Ethrel was applied at 10 or 5 mg l^?1 on the same dates. The only treatment which exhibited a desirable thinning effect was shoot-spraying at 50 mg l^?1 12 days after full bloom, but this markedly inhibited berry growth. Denapon applied at 1667 mg l^?1 by shoot-spraying at full bloom, or 6 days after full bloom, reduced the number of berries per cluster almost adequately and consistently without any unfavorable side effects. This chemical applied at 834 mg l^?1 was nearly as effective as when applied at 1667 mg l^?1, but the effectiveness of the former was less consistent than that of the latter. From these results, Denapon is thought to be a promising thinning chemical for ‘Muscat of Alexandria’.     

Continuum contraction of tension wood fiber induced by repetitive hygrothermal treatment

Wood Science and Technology - Tension wood, when kiln-dried, is likely to deform hugely, which is probably caused by a gelatinous layer of the gelatinous fiber. To elucidate the mechanism behind...     

The duality of teleost gonadotropins

The duality of salmon gonadotropins has been proved by biochemical, biological, and immunological characterization of two chemically distinc gonadotropins. GTH I and GTH II were equipotent in stimulating estradiol production, whereas GTH II appears to be more potent in stimulating maturational steroid synthesis. The ratio of plasma levels and pituitary contents of GTHs and the secretory control by a GnRH suggest that GTH I is the predominant GTH during vitellogenesis and early stages of spermatogenesis in salmonids, whereas GTH II is predominant at the time of spermiation and ovulation. GTH I and GTH II are found in distinctly separate cells. In trout, GTH I is expressed first in ontogeny, whereas GTH II cells appear coincident with the onset of spermatogenesis and vitellogenesis, and increase dramatically at the time of final reproductive maturation. Comparison of the amino acid sequences of polypeptides and the base sequences of cDNA revealed that salmon GTH I β is more similar to bovine FSHβ than bovine LHβ and salmon GTH II β shows higher homology to bovine LHβ than to bovine FSHβ. The existence of two pituitary gonadotropins in teleosts as well as tetrapods suggests that the divergence of the GTH gene took place earlier than the time of divergence of teleosts from the main line of evolution leading to tetrapods.     

Salmon gonadotropes secrete free form alpha (α)-subunit: quantitative analysis by the sandwich cell immunoblot assay

The sandwich cell immunoblot assay confirmed that salmon LH-cells secreted the free form α-subunit along with the dimeric LH, but lower in amounts than the LH.     

Molecular diversity of binucleate <Emphasis Type="Italic">Rhizoctonia</Emphasis> AG-A in China

AG-A belongs to the binucleate Rhizoctonia (BNR) anastomosis group (AG) of the Ceratobasidium teleomorph, which parasitizes the roots of many plant species. Ninety nine isolate species of AG-A were obtained from Tibet, Sichuan, and Yunnan Province in China. All isolates were divided into three types based on their cultural characteristics. Type I: abundant aerial mycelia, dense hyphae, loose sclerotia; Type II: abundant aerial mycelia, no sclerotia. Type III: sparse aerial mycelium and no sclerotia. All of the isolates infected the seedlings of Chinese mustard and Chinese cabbage, causing the formation of lesions on the stem and a brown discoloration of the roots. Sequence analysis of the 5.8S rDNA-ITS showed a similarity of 98–100% among the isolates. Inter Simple Sequence Repeat (ISSR) was used to detect genetic variation in binucleate Rhizoctonia spp. Forty two AG-A isolates were amplified using 15 random primers. From a total of 164 bands, 144 bands (87.8%) were polymorphic in the 42 tested isolates. A dendrogram showing genetic relationships between the isolates was constructed using unweighted pair-group averages based on genetic distances. According to the dendrogram, the 42 tested isolates could be aligned into three clusters with a genetic similarity coefficient of 0.29, the first clusters including 27 isolates with III of culture characteristics on PDA; the second clusters included eight isolates with I of cultural characteristics on PDA; the third cluster included seven isolates with II of cultural characteristics on PDA. The results of ISSR analysis showed an association between the hosts of these isolates. Our results showed that ISSR analysis can reveal more molecular variation among isolates of AG-A than sequence analysis using the 5.8S rDNA-ITS.     

Muscle Representation within the Hypoglossal Nucleus of the Chicken Studied by Means of Horseradish Peroxidase

The distribution in the chicken of motoneurons innervating the hyolingual muscles, i.e. the Mm. hyoglossus rostralis (HR), hyoglossus obliquus (HO), ceratoglossus (CG), interceratobranchialis (CB). stylohyoideus (YH), serpihyoideus (PH) and cricohyoideus (CR), and the laryngotracheal muscles, comprising the Mm. tracheolateralis (TL), cleido-hyoideus (CL) and sternotrachealis (ST), was examined by retrograde transport of horseradish peroxidase conjugated with wheat-germ agglutinin. Labelled motoneurons are only found in the hypoglossal nucleus. The rostrocaudal distributions of motoneurons projecting to hyolingual muscles are restricted in the hypoglossal nucleus cranial to the obex, and those projecting to laryngotracheal muscles are distributed in the more caudal part of hypoglossal nucleus. Detailed analysis of the data showed that the most rostrally positioned motoneurons in the hypoglossal nucleus supplied to the PH, followed by the CG, CB. HR, YH, HO, CR, TL, CL and ST in that order, overlapping each other. In the hypoglossal nucleus motoneurons innervating the PH and YH have the smallest perikarya. Of the motoneurons in the hypoglossal nucleus, those supplying the laryngotracheal muscles (CL and TL) have the largest perikarya. Motoneurons innervating the other muscles are intermediate in size.     

Precise, simple screening for resistance in potato varieties to common scab using paper pots

Resistance to common scab pathogen Streptomyces turgidiscabies of seven potato varieties was compared in the field with a newly developed paper pot method. Seedlings raised in soil in paper pots containing inocula at 1 × 10³ to 10⁷cfu/g soil were transplanted into a scab-free field and grown for 3 months. The disease severity of the seven varieties in the field trials differed in iteration and from year to year, even though their resistance levels were approximately similar at the expected levels. With the paper pot method, the seven varieties had different resistance levels, which were almost completely consistent with the results of the field trials, at more than 1 × 10⁵cfu/g soil. Significant differences in disease severity between resistant and susceptible varieties were observed (P = 0.05) for 2 years, and the resistance level of the varieties was elucidated.