Development and validation of DNA markers linked to Sdvy-1, a common bean gene conferring resistance to the yellowing strain of Soybean dwarf virus

The yellowing strain of Soybean dwarf virus (SbDV-YS) causes yellowing and yield loss in common bean (Phaseolus vulgaris). The most effective control is achieved through breeding for resistance. An indeterminate climbing cultivar with a white seed coat, ‘Oofuku’, is resistant to SbDV-YS in inoculation tests. We crossed ‘Oofuku’ with an elite cultivar, ‘Taisho-Kintoki’, which is SbDV-YS-susceptible, determinate dwarf with a red-purple seed coat, and performed amplified-fragment-length polymorphism analysis of F₃ lines. From nucleotide sequences of the resistant-specific fragments and their flanking regions, we developed five DNA markers, of which DV86, DV386, and DV398 were closely linked to Sdvy-1, a resistance gene. Using the markers, we developed ‘Toiku-B79’ and ‘Toiku-B80’, the near-isogenic lines (NILs) incorporating Sdvy-1 in the background of ‘Taisho-Kintoki’. The NILs had similar growth habit, maturity date and seed shape to those of ‘Taisho-Kintoki’. The quality of boiled beans was also similar, except that the NILs had more seed coat cracking than ‘Taisho-Kintoki’. The NILs showed no SbDV-YS infection in inoculation tests. We suggest that Sdvy-1 is a useful source of SbDV-YS resistance in common bean.     

A Method of Solubilizing and Concentrating Astaxanthin and Other Carotenoids

The valuable marine carotenoid, astaxanthin, is used in supplements, medicines and cosmetics. In this study, crustacyanin, an astaxanthin-binding protein, was used to solubilize and concentrate astaxanthin. The recombinant crustacyanin of European lobster spontaneously formed an inclusion body when it was over-expressed in Escherichia coli. In this study, fusing the NusA-tag to the crustacyanin subunits made it possible to express in a soluble fraction and solubilize astaxanthin in aqueous solution. By cutting off the NusA-tag, the crustacyanin subunits generated the pure insoluble form, and captured and concentrated astaxanthin. Overall, the attaching and releasing NusA-tag method has the potential to supply solubilized carotenoids in aqueous solution and concentrated carotenoids, respectively.     

Bean husks as a supplemental fiber for ruminants: Potential use for activation of fibrolytic rumen bacteria to improve main forage digestion

This study evaluated the suitability of easily digested fiber sources as a supplemental fiber to improve overall fiber digestion in ruminants. First, the degradation of five fibrous feedstuffs and the stimulatory effects on rumen bacteria were examined in situ. Chickpea and lablab bean husks were selected for their potential use due to their large degradable fraction (> 94%), which had a stimulatory effect on fibrolytic rumen bacteria such as Fibrobacter succinogenes. Second, a possible improvement in the digestibility of rice straw diet by husk supplementation was monitored in vivo. Four dietary treatments comprising RS (rice straw and concentrate), CHM (RS supplemented with Myanmar chickpea husk), CHE (RS with Egyptian chickpea husk) and LH (RS with lablab bean husk) were allocated to four wethers. The digestibility of acid detergent fiber was 3.1–5.5% greater in CHM and LH than RS. Total volatile fatty acid concentration was higher in LH than other treatments. Acetate proportion was higher in LH than RS. Ruminal abundance of F. succinogenes was 1.3–1.5 times greater in CHM and LH than RS. These results suggest that bean husk supplementation, especially lablab bean husk, might improve the nutritive value of rice straw diet by stimulating fibrolytic bacteria.     

Functional evaluation of horse chestnut seed and its application in the production of compounded paper for effective utilization of an untapped resource

Many streets in Europe and the US are lined with horse chestnut trees. However, its fruit is inedible and poorly utilized. Therefore, its effective utilization has been a big issue. For recycling of horse chestnut seed, it was separated into “sarcocarp and endodermis” and “outer theca”; each part was finely ground for analysis of its functions. Ground horse chestnut seed showed excellent antibacterial activity toward Staphylococcus aureus, Escherichia coli, and Streptococcus mutans. Antibacterial activity was particularly strong against E. coli, which is a Gram-negative bacterium. The “outer theca” part showed a higher antibacterial activity than did the “sarcocarp and endodermis” part. It was found that the polyphenol content of the “outer theca” of the horse chestnut fruit was approximately three times that of the “sarcocarp and endodermis”; these polyphenols are believed to play a role in the seed’s antioxidation capacity. The ground outer theca of horse chestnut seed showed oxygen radical absorbance capacity (ORAC) of 531 mmol Trolox equivalent (TE)/g. Antioxidant activity was assumed to contribute to the antibacterial activity. In other words, antioxidant activity was assumed to damage the peptidoglycan layer of the bacterial cell wall. For possible recycling of horse chestnut seed, compounded paper containing the ground outer theca blended with pulp fibers was prepared. In this study, compounded paper containing ground “outer theca” was prepared using a traditional Washi paper-making method. The compounded paper was found to retain high deodorizing activity of the ground theca. Furthermore, although mechanical properties deteriorated as the proportion of the ground outer theca increased, these parameters remained adequate for practical applications. The compounded paper may be expected to have a wide range of applications as a highly functional paper with high gas permeability, deodorant activity, and antibacterial activity.     

The effects of chemical components and particle size on the mechanical properties of binderless boards made from oak (<Emphasis Type="Italic">Quercus</Emphasis> spp.) logs degraded by shiitake fungi <Emphasis Type="Italic">(Lentinula edodes</Emphasis>)

Binderless boards are composite boards that rely on self-bonding mechanisms for inter-fibre bonding. Quercus acutissima and Quercus serrata logs degraded by Lentinula edodes (shiitake fungi) were used in this study to investigate whether physical and chemical changes induced by shiitake fungi can enhance board mechanical properties. Binderless boards were manufactured with 0.8 g/cm³ target density, 220 °C pressing temperature, 5 MPa pressure, and pressing duration of 10 min. Boards made from logs degraded for ≥?26 months were stronger than control boards and met modulus of rupture (MOR) and internal bonding (IB) requirements for fibreboards. Chemical composition and particle size distribution of the wood powder used to make the boards were determined to elucidate the drivers of board mechanical properties. The proportion of small particles (<?150 µm) showed a strong positive correlation with MOR for both species and hot water extractives showed a strong positive correlation with IB for Q. acutissima boards. Introduction of shiitake fungi pre-treatment to the production process may enhance the mechanical strength of binderless boards.     

Detoxification of phytotoxic compounds by TiO2 photocatalysis in a recycling hydroponic cultivation system of asparagus

TiO 2 photocatalytic decomposition and detoxification of phytotoxic compounds released by the roots of asparagus ( Asparagus officinalis L.) were investigated from the viewpoint of conservation-oriented cultivation. The phytotoxically active fraction was extracted either from dried asparagus roots or from the recycled nutrient solution of an asparagus hydroponic cultivation system. We found that the phytotoxic activity gradually decreased in the fraction with TiO 2 powder under irradiation with ultraviolet (UV) light at an intensity of 1.0 mW/cm (2). The growth of asparagus plants under actual cultivation conditions was also investigated by comparing asparagus grown in a hydroponic system where recycled waste nutrient solution was photocatalytically treated with solar light and a system with untreated recycled waste nutrient solution. The results showed, as measured by growth indices such as stem length and stem thickness, that asparagus growth in the photocatalytically treated system was superior to the untreated one. Furthermore, the yield of asparagus spears was 1.6-fold greater in the photocatalytically treated system, demonstrating the detoxification effect on the phytotoxic compounds and also the killing effect on pathogenic microorganisms.     

Morphological characterization of skin ganglion-like cells in Djungarian hamsters (Phodopus sungorus)

Characteristic ganglion-like cell proliferation observed in the skin of Djungarian hamsters was investigated using 24 male and 24 female hamsters, 1-6 months of age, to examine the anatomic location of these ganglion-like cells and their morphologic features. One abdominal skin tumor composed of these cells and resembling proliferative fasciitis in humans was also examined. Skin ganglion-like cells were rarely observed in young animals but increased in number and extent with age, especially in males. These cells were frequently seen in the ventral and medial regions of the trunk and legs rather than in the dorsal and lateral regions. Light microscopic examination of these ganglion-like cells revealed abundant vesicular basophilic cytoplasm with delicate intracytoplasmic silver stain-positive fibrils. Ultrastructurally, these cells contained abundant rough endoplasmic reticulum and Golgi complexes with dilated cisternae; intracellular collagen fibrils were present within these cisternae. Heat shock protein 47, beta-tubulin, and androgen receptor were expressed in these cells. The morphologic features of cells of one tumor resembling human proliferative fasciitis were identical to those observed in ganglion-like cells. The results of the present study suggest that these ganglion-like cells are derived from intrinsic undifferentiated mesenchymal cells in the dermis or subcutaneous adipose tissue and that any tumor-like lesion they form should be regarded as an abnormal proliferative lesion of skin ganglion-like cells rather than as proliferative fasciitis or fibroma.     

Conditioned fear-related ultrasonic vocalizations are emitted as an emotional response

Ultrasonic vocalizations (USVs) are observed along with freezing behavior when rats are placed under fearful situation. Coping style with stress is categorized into two forms, namely passive and emotional avoidance and active operant avoidance. In this study, fear-induced USV was compared between two conditioning protocols. Two groups of male Wistar rats were contextually conditioned for 10 days by exposing to the shock box. One group was shock-unavoidable and the other shock-avoidable by operant control of emitting the USVs. They were then proceeded to the extinction phase. As the results, the shock-unavoidable group emitted greater USV in both conditioning and extinction phases. The extinction burst, commonly seen in active learned responses, was not observed in either group. The duration of freezing was also longer in shock-unavoidable conditioned rats. These results suggest that under the shock-unavoidable condition, rats receive more stress and thus emit more USV. It is therefore concluded that fear-induced USV is an emotional and passive response to the stress, rather than being controlled in an operant-way.     

Effects of oral exposure of bisphenol A on mRNA expression of nuclear receptors in murine placentae assessed by DNA microarray

Bisphenol A (BPA), a candidate endocrine disruptor (ED), is considered to bind to estrogen receptors and to regulate expressions of estrogen responsive genes. It has also shown evidence of affecting the reproductive, immunological and nervous systems of mammalian embryos. However, the effects of BPA on placentae, a central organ of feto-maternal interlocution, are still unclear. To reveal the mechanisms of BPA effects on placentae in mammals, we compared the mRNA expression of 20 nuclear receptors between placentae of vehicle controls and those of orally BPA exposed pregnant mice by a DNA microarray technique. In murine placentae, mRNAs of 11 nuclear receptors were not detected. However, greater than 1.5 fold changes in mRNA expression of nine nuclear receptors between vehicle control and BPA treated mice were noted. Moreover, remarkable changes in mRNA expression of six non-nuclear receptor proteins were induced by BPA exposure. There were various differences in the effects of BPA on the expression of these mRNAs between the placentae with male embryos and those with female embryos. Such embryo-sex dependent differences are interesting and important pointers to understanding of the endocrine disrupting effect of BPA. The present data indicate that BPA affects the expression of nuclear receptor mRNAs in placentae and may disrupt the physiological functions of placentae.     

Response of transgenic cucumber expressing a rice class I chitinase gene to two fungal pathogens with different infectivities

A transgenic cucumber line (CR32) over-expressing the rice class I chitinase gene exhibited resistance to Phytophthora rot (Phytophthora nicotianae var. parasitica) but not to Fusarium wilt (Fusarium oxysporum f. sp. cucumerinum). The infection behavior of these fungi on CR32 and nontransgenic plants was examined with an optical microscope. In zoosporangia of P. nicotianae var. parasitica, the rates of germination and penetration on leaves of both CR32 and nontransgenic plants were almost equal. After infection, however, the growth of infection hyphae was markedly suppressed in CR32 compared with their growth in the nontransgenic plants. In F. oxysporum f. sp. cucumerinum, the infection hyphae localized in petiole vessels of both CR32 and nontransgenic plants, and growth did not differ in the two plants. We investigated the antifungal activity of a high-molecular-weight fraction (HF) and a low-molecular-weight fraction (LF) of crude leaf extracts from CR32 and from the nontransgenic line. CR32 HF, which included the rice chitinase, had antifungal activity only against F. oxysporum f. sp. cucumerinum. In contrast, CR32 LF, which did not have the rice chitinase, had strong antifungal activity against the two fungi. These results suggested that a low-molecular-weight antifungal substance(s) was induced in CR32 and might function as a factor of resistance to P. nicotianae var. parasitica, which has cell walls that almost never contain chitin. Because rice chitinase has already been demonstrated not to localize in vessels of CR32, the infection localization of F. oxysporum f. sp. cucumerinum in vessels might enable the fungus to avoid antifungal substance(s), resulting in Fusarium wilt in transgenic cucumber.