Trichomes: interaction sites of tomato leaves with biotrophic powdery mildew pathogens

The present study aimed to explore the possibility of using the type I trichomes of tomato (Solanum lycopersicum) to monitor the infection processes of powdery mildews by microscopy. Individual trichome cells of two tomato genotypes were inoculated with pathogenic and non-pathogenic powdery mildew species, Pseudoidium neolycopersici, Erysiphe trifoliorum and Podosphaera xanthii. On the trichome cells of the tomato cultivar Moneymaker, hyphae of the pathogenic Pseudoidium neolycopersici (isolates KTP-03 and KTP-04) grew vigorously; whereas hyphal growth of the non-pathogenic Erysiphe trifoliorum and Podosphaera xanthii ceased after appressorium formation, which was associated with papilla formation and hypersensitive cell death, respectively. Similar infection processes of the tested powdery mildews were seen in Moneymaker epidermal cells. Therefore, tomato trichomes are suitable for analysing, at individual cell level, the infection processes of different pathotypes of powdery mildews and for observing the cytological responses of plants by non-pathogenic powdery mildews. On the other hand, it was observed that both isolates KTP-03 and KTP-04 failed to produce conidiophores on the hyphae elongating on Moneymaker trichomes. Similarly, no conidiophores were produced on the hyphae elongating on trichomes of Solanum peruvianum LA2172, which is resistant to KTP-03 and susceptible to KTP-04. Interestingly, delayed cell death occurred in LA2172 epidermal cells, which were attacked by KTP-03 hyphae elongating from trichomes and conidiophores were formed on new hyphae growing from the leaf epidermal cells. Thus, leaf trichomes and epidermal cells of the wild tomato species LA2172 reacted differently to the avirulent isolate KTP-03.     

Effects of protamine hydrochloride from chum salmon milt on lipid metabolism in rats

Protamine is a basic protein whose sulfate is used in medical applications as a carrier for injectable insulin and as a heparin antagonist, while its hydrochloride is used as an antibacterial ingredient for some food products. We previously showed that protamine hydrochloride derived from chum salmon milt inhibited pancreatic lipase and reduced plasma triacylglycerol levels in an oral fat tolerance test in humans. The present study evaluated the effect of chum protamine hydrochloride on lipid metabolism in rats. The single oral administration of protamine hydrochloride (500 mg/kg) reduced plasma triacylglycerol levels in a corn oil tolerance test, and repeated oral administration at a dose of 0, 150, 500, or 1,500 mg/kg with a high fat diet for 7 weeks significantly reduced body weight gain, liver weight, and epididymal adipose tissue, whereas total calorie intakes were not significantly different. These findings could be caused by the suppression of lipid digestibility leading to a significant increase in fecal lipid excretion due to the fact that protamine hydrochloride could bind with bile acids to make a complex that is difficult to digest. Protamine hydrochloride, with a considerable history as food, can be considered to be promising as an anti-obesity functional food material.     

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.     

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.     

Characteristic odor components of Citrus sphaerocarpa Tanaka (Kabosu) cold-pressed peel oil

The volatile components of Citrus sphaerocarpa Tanaka (Kabosu) cold-pressed peel oil were investigated by chemical and sensory analyses. Monoterpene hydrocarbons (more than 94.6%) were predominant in Kabosu peel oil, with limonene and myrcene accounting for the major proportions (70.5% and 20.2%, respectively). The Kabosu oxygenated fraction was characterized by quantitative abundance in aldehydes and a relatively wide variety of alcohols. The weight percentages of aldehydes, alcohols, and esters in Kabosu cold-pressed oil were 1.3%, 0.1%, and 0.1%, respectively. Aroma extract dilution analysis was employed for determination of the odors of Kabosu volatile components, flavor dilution factors, and relative flavor activities. Gas chromatography/olfactometry using Kabosu cold-pressed oil and its oxygenated fraction completed by a chiral analysis revealed that (R)-(+)-citronellal is a characteristic element of Kabosu peel oil odor. Careful sniff testing demonstrated that aqueous solutions of both 0.25% and 0.016% (R)-(+)-citronellal gave an odor similar to that of Kabosu.     

Food preservative potential of gassericin A‐containing concentrate prepared from cheese whey culture supernatant of Lactobacillus gasseri LA39

Gassericin A (GA) is a circular bacteriocin produced by Lactobacillus gasseri LA39. In this study, GA‐containing concentrate was prepared using a cross‐flow membrane filtration device (30 kDa cut‐off) from the culture supernatant of Lb. gasseri LA39 cultivated in a cheese whey‐based food‐grade medium. The bacteriocin activity titer in the concentrate was 16 times as high as that of the culture supernatant and was completely maintained through each incubation at 4°C for 3 months, 37°C for 2 months, 60°C for 5 h, and 100°C for 30 min. The GA‐containing concentrate was used with glycine powder to make custard creams, and then four representative strains of custard cream spoilage bacteria (Bacillus cereus, Lactococcus lactis subsp. lactis, Achromobacter denitrificans and Pseudomonas fluorescens) were individually inoculated at c. 10³ colony forming units/g in the custard creams. Throughout 30 days of incubation at 30°C, all of the inoculated bacteria were completely inhibited by the combination of 5% (w/w) of the GA‐containing concentrate and 0.5% (w/w) glycine. This is the first highly practical application of GA to foods as a biopreservative, and the concentration method and the bacteriocin concentrate would contribute to biopreservation of several foods.     

Effect of high water temperature during vegetative growth on rice growth and yield under a cool climate

Global warming is likely to increase spring temperatures in regions with a cool climate. To examine the effects of this change on rice productivity, we exposed rice plants to a higher (by +2.7 to +2.8 °C) water temperature (T_w) during the vegetative growth period (for 35-50 days) under three levels of N fertilization. High T_w during vegetative growth made the heading stage occur 4-7 days earlier for all levels of N fertilization in both years. The crop growth rate during the treatment period was greatly enhanced by high T_w: by 51-82% in 2008 and by 49-62% in 2009. There was no T_w × N fertilizer interaction. This increased growth was associated with increased leaf expansion and increased canopy radiation capture rather than with increased radiation-use efficiency. However, the positive effect decreased during subsequent growth stages under all levels of N fertilization, leading to no significant differences in total biomass at maturity. High T_w during vegetative growth greatly reduced SPAD values during the grain-filling stage compared with SPAD values in the control T_w treatment, for all levels of N fertilization, and decreased leaf photosynthesis during the mid-grain filling stage. Grain yield was not significantly affected by high T_w at any N fertilizer level or in either year.     

Changes in morphological phenotypes and essential oil components in lavandin (Lavandula × intermedia Emeric ex Loisel.) transformed with wild-type strains of Agrobacterium rhizogenes

Hairy roots were induced from leaf-derived calli of lavandin (Lavandula × intermedia Emeric ex Loisel.) by infection with wild-type strains of Agrobacterium rhizogenes, A-5 (MAFF 02-10265) and A-13 (MAFF 02-10266). A-5-inoculated calli formed hairy roots more efficiently than A-13 ones. The transgenic shoots could be obtained from hairy root segments mediated by each Agrobacterium strain. However, different plant growth regulators were required for efficient adventitious shoot formation in each strain. In A-5, the most efficient adventitious shoot formation rate of 23.8% was observed in a medium with 4.4 × 10⁻⁶ M of 6-benzylaminopurine. On the other hand, a significantly higher rate of 13.2% was detected in a medium with 4.0 × 10⁻⁷ M of N-(2-chloro-4-pyridyl)-N′-phenylurea in A-13. Most of the regenerated plants showed dwarfism with closed internodes and extensive lateral branching, which were typical characteristics of ‘hairy root syndrome’. On the other hand, only nine of the 45 regenerated plants formed flower buds in early June, a delay of about one month compared with nontransgenic regenerated plants. The floral stalks and spikes of these plants were very short, resulting in a compacted form. Many regenerants showed a significantly lower productivity of essential oil than nontransgenic regenerants. Moreover, the relative percentage of the linalyl-cation-derived compounds, linalool and linalyl acetate, decreased in most of the regenerated plants. Compact plants with the ability of flower bud formation are assumed to be valuable not only for lavandin breeding, but also for clarifying the interaction between rol genes expression and essential oil production.     

Compressive deformation of wood impregnated with low molecular weight phenol formaldehyde (PF) resin IV: Species dependency

Flat-sawn specimens of eight wood species, albizia (Paraserianthes falkata, 0.23 g/cm³), Japanese cedar (Cryptomeria japonica, 0.31 g/cm³), red lauan (Shorea sp., 0.36 g/cm³), European spruce (Picea abies, 0.44 g/cm³), Douglas fir (Pseudotsuga douglasii, 0.50 g/cm³), elm (Ulmus sp., 0.51 g/cm³), Japanese beech (Fagus crenata, 0.64 g/cm³), and Japanese birch (Betula maximowicziana, 0.71 g/cm³), were impregnated with low molecular weight phenol-formaldehyde (PF) resin and their compressive deformations were compared. The volume gain (VG) and weight gain due to 20% resin solution impregnation were different among species. Furthermore, the specific volume gain (VG/specific gravity), indicating the degree of swelling of the cell wall, also varied from 17.7% for European spruce to 26.4% for elm. Oven-dried specimens of each species were compressed using hot plates fixed to an Instron testing machine. The deformation behavior of resin-impregnated wood up to 10MPa was significantly different among the species. Stress development during cell wall collapse for low density wood was minimal. As a consequence, a significant increment of density occurred up to 2MPa for low density wood such as albizia and Japanese cedar. When PF resin-impregnated wood was compressed up to 2MPa and the pressure was kept constant for 30min, the density of Japanese cedar reached 1.18g/cm³, about 30% higher than the density of compressed Japanese birch, which possesses an original density that is 2.5 times higher than that of Japanese cedar. The mechanical properties of resin-impregnated wood, especially low density wood, increased with density. Hence, it is manifested that low density wood species have an advantage as raw materials for obtaining high-strength wood at low pressing pressure.     

Establishment of cell line and in vivo mouse model of canine Langerhans cell histiocytosis

A cell line named FB‐LCH01, derived from a dog diagnosed with Langerhans cell histiocytosis (LCH), was established and characterized. FB‐LCH01 had C‐shaped nucleoli, characterized by modal chromosome aberrations. The original tumour cells as well as established FB‐LCH01 cells were immunopositive for human leukocyte antigen‐DR, Iba‐1 and E‐cadherin, and immunonegative for CD163 and CD204, suggesting Langerhans cell origin. Furthermore, the characteristics of FB‐LCH01 were compared with those of two canine histiocytic sarcoma cell lines (PWC‐HS01 and FCR‐HS02) established previously. Expression of E‐cadherin was detected only in FB‐LCH01, but not in PWC‐HS01 and FCR‐HS02. All (n = 9) the severe combined immunodeficiency mice inoculated with the FB‐LCH01 cells developed subcutaneous tumour masses after 3 weeks. Eight of nine mice also developed metastatic lesions in the lymph nodes (8/8; 100%), lung (5/8; 62.5%), stomach (5/8; 62.5%), heart (4/8; 50%), pancreas (4/8; 50%), kidney (3/8; 37.5%), skin (3/8; 37.5%) and bone marrow (1/8; 12.5%). Tumour cells were pleomorphic and round‐ to polygonal‐shaped with prominent anisocytosis and anisokaryosis. The xenotransplanted tumour cells maintained the immunohistochemical features of the original tumour with persistent E‐cadherin expression at injection site and some visceral organs. In conclusion, the established cell line as well as the mice xenotransplant model in this study reflect the nature of canine LCH and may serve as promising models for investigating the patho‐tumorigenesis and therapy of the disease.