Role of the gelatinous layer (G-layer) on the origin of the physical properties of the tension wood of Acer sieboldianum

The tension wood (TW) properties of a 70-year-old specimen of Acer sieboldianum Miq. were analyzed by using the G-fiber model that was proposed in our previous report. The roles of the G-layer on the origins of (1) a high tensile growth stress, (2) a large longitudinal Young’s modulus, and (3) a high longitudinal drying shrinkage in the TW xylem are discussed on the basis of the simulations using the G-fiber model. The results suggest that the G-layer generates a high tensile stress in the longitudinal direction during xylem maturation; the longitudinal Young’s modulus of the green G-layer becomes significantly higher than that of the lignified layer; furthermore, the G-layer tends to shrink extraordinarily more than that of the lignified layer during moisture desorption.This report follows the previous report “Role of the gelatinous layer on the origin of the physical properties of the tension wood.” J Wood Sci (2004) 50:197–208. Part of this paper was presented at the 49th Annual Meeting of the Japan Wood Research Society, Tokyo, April 1999, and at the 2nd International Conference of the European Society for Wood Mechanics, Stockholm, May 2003This revised version was published online in July 2005. On pages 228–230 the character was replaced by a vertical line.     

Structure, allometry, and biomass of plantation Metasequoia glyptostroboides in Japan

We quantified structural features and the aboveground biomass of the deciduous conifer, Metasequoia glyptostroboides (Hu and Cheng) in six plantations in central Japan. In order to derive biomass estimates we dissected 14 M. glyptostroboides trees into three structural components (stem wood, branch wood and foliage) to develop allometric equations relating the mass of these components and of the whole tree to diameter at breast height (DBH). We found robust relationships at the branch and whole tree level that allow accurate prediction of component and whole tree biomass. Dominant tree height was similar within five older (>40 years) plantations (27–33 m) and shorter in a 20-year-old plantation (18 m). Average stem diameter varied from 12.8 cm in the youngest stand to greater than 35 cm in the oldest stand.

Metasequoia have relatively compact crowns distributed over the top 30% of the tree although the youngest stand had the deepest crown relative to tree height (up to 38%). At the individual tree level in older stands, 87% of the aboveground biomass was allocated to the stem, 9% to branch wood and 4% to foliage. We found little difference in the relative distribution of above ground biomass among the stands with the exception of lower foliage biomass in larger diameter trees. Total aboveground biomass of the older stands varied twofold, ranging from a maximum of 450 Mg ha⁻¹ in a 42-year-old stand to a minimum of 196 Mg ha⁻¹ in a 48-year-old stand. Total above ground biomass of the 20-year-old stand was 176 Mg ha⁻¹.     

Mapping of QTLs for leaf developmental behavior in rice (Oryza sativa L.)

Leaf developmental behavior in rice (Oryza sativa L.) is one of the important agronomic characteristics, which not only determines vegetative growth but also influences grain yield. This study was conducted to identify quantitative trait loci (QTLs) for total number of leaves (TNL), days to the emergence of flag-leaf (DEF) and the leaf emergence rates (LER) on main stem, which mainly represent leaf developmental behavior, using recombinant inbred lines (RILs) derived from a cross between a japonica variety, Asominori and an indica variety, IR24, cultivated in 2001 and 2002. The transgressive segregations in both parental directions and continuous variations of all three tested traits were observed. Significant correlations among these traits were detected. A total of fourteen QTLs for leaf development behavior were detected with 289 RFLP markers. Six QTLs controlling TNL were mapped to chromosomes 3, 5, 6, 8, 9, 12, and accounted for 5.615.7% of the total phenotypic variations, and three QTLs for DEF were mapped to chromosome 3, 6, 8 and accounted for 10.735.4% of total phenotype variation and five QTLs for LER were mapped to chromosome 1(two QTLs), 2, 4, 9 and explained 6.217.5% of phenotype variation. The identification of QTLs for leaf developmental behavior in rice may be useful for selection of fast growing genotype before heading using maker-assisted selection.     

Trisomic genetic analysis of aroma in three Japanese native rice varieties (Oryza sativa L.)

Information on the genetics of aroma in rice facilitates breeding and selection of new aromatic varieties with high yield and good quality. Objective of the present study was to make clear the number of genes controlling aroma, and the allelism of aroma genes and the location of aroma gene(s) on the chromosome in three Japanese native aromatic rice varieties (Kabashiko, Shiroikichi and Henroyori). Lack of leaf aroma in all F₁ plants of non-aromatic/aromatic crosses indicated the recessive nature of aroma, and the segregation ratios (3:1) of non-aromatic to aromatic plants in its F₂ populations from Nipponbare/aromatic varieties crosses revealed that each of the three aromatic varieties contains a single recessive gene for aroma. Through trisomic analysis, the segregation of non-aromatic and aromatic plants in all F₂ populations from the crosses between trisomics lines NT8, with an extra chromosome 8, and aromatic varieties deviated significantly from disomic segregation of 3:1 ratios, and fitted to trisomic segregation, however, in other F₂ populations derived from other 7 types of trisomic F₁ plants, the segregation ratios of non-aromatic to aromatic were 3:1, indicating that the single recessive aroma gene was located on chromosome 8 in three aromatic varieties. This revised version was published online in July 2006 with corrections to the Cover Date.     

Microbial community profiles in intercellular fluid of rice

Plants harbor microorganisms that are thought to stimulate plant defense systems or promote plant growth. Individual species in these intercellular microbial communities are often not sufficiently abundant to be easily described, although some endophytic microorganisms amenable to culture have been characterized. To better understand the microbial population of plants, we collected intercellular fluid (IF) from leaf blades and sheaths of rice and subsequently isolated DNA from the IF. Denaturing gradient gel electrophoresis (DGGE) analysis of 16S and 18S rDNA fragments amplified from IF DNA by PCR indicated that these band patterns were distinguishable from those of a leaf surface-wash fluid (SF). Analysis of a set of rDNA fragments amplified from IF DNA of rice with different genotypes, paddies or growth stages for the primary survey of overall microbial community in the IF suggested that this approach is suitable for analyzing microbial diversity in the IF from various plant samples. Actually, comparative analysis of amplified rDNA fragments of rice and other five plant species indicated that the microbial diversity in IF is likely to vary substantially among plant species. We can also use sequence analysis of 16S rDNA fragments amplified from rice IF DNA to identify species including unculturable bacteria and proteobacteria and Xanthomonas and 18S rDNA fragments to identify Tilletiaria anomala, Tilletia iowensis, Ustilago maydis and unculturable eukaryotes. Thus, IF DNA analysis seems to be a good tool to further study the microbial ecology of plants.     

Comparison between immunohistochemistry and genetic clonality analysis for cellular lineage determination in feline lymphomas

Clinical application of genetic clonality analysis by PCR has been available in feline lymphoma. However, it is in under dispute whether the analysis can be applied for cellular lineage determination. To evaluate utility of the analysis for lineage determination, the results between immunohistochemistry and the genetic analysis were compared. Based on the result with immunohistochemistry, sensitivity of the primer for IgH was 89% and specificity was 75%. Sensitivity of the primer for TCRγ was 25% and specificity was 100%. Cross-lineage IgH rearrangement was found in 25% of T-cell lymphomas. The present study suggests that the genetic analysis had better be applied as not a definite but an adjunctive tool for lineage determination in feline lymphomas.     

Experimental H-type bovine spongiform encephalopathy characterized by plaques and glial- and stellate-type prion protein deposits

ABSTRACT: Atypical bovine spongiform encephalopathy (BSE) has recently been identified in Europe, North America, and Japan. It is classified as H-type and L-type BSE according to the molecular mass of the disease-associated prion protein (PrPSc). To investigate the topographical distribution and deposition patterns of immunolabeled PrPSc, H-type BSE isolate was inoculated intracerebrally into cattle. H-type BSE was successfully transmitted to 3 calves, with incubation periods between 500 and 600 days. Moderate to severe spongiform changes were detected in the cerebral and cerebellar cortices, basal ganglia, thalamus, and brainstem. H-type BSE was characterized by the presence of PrP-immunopositive amyloid plaques in the white matter of the cerebrum, basal ganglia, and thalamus. Moreover, intraglial-type immunolabeled PrPSc was prominent throughout the brain. Stellate-type immunolabeled PrPSc was conspicuous in the gray matter of the cerebral cortex, basal ganglia, and thalamus, but not in the brainstem. In addition, PrPSc accumulation was detected in the peripheral nervous tissues, such as trigeminal ganglia, dorsal root ganglia, optic nerve, retina, and neurohypophysis. Cattle are susceptible to H-type BSE with a shorter incubation period, showing distinct and distinguishable phenotypes of PrPSc accumulation.     

Effects of amino acids infused into the vein on ghrelin‐induced GH,insulin and glucagon secretion in lactating cows

To investigate the effects of amino acids on ghrelin‐induced growth hormone (GH), insulin and glucagon secretion in lactating dairy cattle, six Holstein cows were randomly assigned to two infusion treatments in a cross‐over design. Mixture solution of amino acids (AMI) or saline (CON) was continuously infused into the left side jugular vein via catheter for 4 h. At 2 h after the start of infusion, synthetic bovine ghrelin was single injected into the right side jugular vein through the catheter. Ghrelin injection immediately increased plasma GH, glucose and non‐esterified fatty acids (P < 0.05) with no difference between both treatments. Additionally, plasma insulin and glucagon concentrations were increased by ghrelin injection in both treatments. The peak value of plasma insulin concentration was greater in AMI compared with CON (P < 0.05). Plasma glucagon concentration showed no difference in the peak value reached at 5 min between both treatments, and then the plasma levels in AMI compared with CON showed sustained higher values (P < 0.05). After plasma glucose concentration reached the peak, the decline was greater in AMI compared with CON (P < 0.05). These results showed that the increased plasma amino acids may enhance ghrelin action which in turn enhances insulin and glucagon secretions in lactating cows.