Modori-inducing proteinases (MIPs) in horse mackerel and the effect of sodium citrate on the modori phenomenon were investigated. Cysteine protease caused the modori phenomenon only at 60 ℃, while metalloproteinase caused it at both 60 ℃ and 70 ℃. Moreover, the autolysis of myofibrillar proteins was mainly inhibited by ethylene diamine tetra-acetic acid (EDTA), verifying the existence of insoluble metalloproteinase. From the results comparing thermal gel properties and protease activities, we confirmed that increased activity of insoluble metalloproteinase corresponded to the weakening of the thermal gel. Thus, insoluble metalloproteinase was the major MIP in horse mackerel. Moreover, sodium citrate could markedly inhibit insoluble metalloproteinase activity at 60 ℃. The addition of sodium citrate significantly improved the breaking force of the thermal gel at 60 ℃ and 70 ℃, suggesting that sodium citrate could suppress the modori phenomenon by inhibiting insoluble metalloproteinase. Therefore, it is desirable to use sodium citrate in horse mackerel surimi-based products to prevent the modori phenomenon.
The same mutant allele of eukaryotic initiation factor 4E (eIF4E) that confers resistance to Pea seed-borne mosaic virus (sbm-1) and the white lupine strain of Bean yellow mosaic virus (wlv) also confers resistance to Clover yellow vein virus (ClYVV) in pea. The eIF4E genes from several pea lines were isolated and sequenced. Analysis of the eIF4E amino acid sequences from several resistant
lines revealed that some lines, including PI 378159, have the same sequence as reported for sbm-1 and wlv. When eIF4E from a susceptible pea line was expressed from a ClYVV vector after mechanical inoculation of resistant PI 378159, the virus
caused systemic infection, similar to its effects in susceptible line PI 250438. The resistance to ClYVV in line PI 378159
was characterized through a cross with PI 193835, which reportedly carries cyv-2. Mechanical inoculation of the F1 progeny with ClYVV resulted in no infection, indicating that the resistance gene in PI
378159 is identical to cyv-2 in PI 193835. Furthermore, particle bombardment of pea line PI 193835 with infectious cDNA of ClYVV (pClYVV/C3-S65T) resulted
in the same resistance mode as that described for PI 378159. These results demonstrate that the resistance to ClYVV conferred
by cyv-2 is mediated by eIF4E and that cyv-2 is identical to sbm-1 and wlv. 相似文献
A normal variety of rice (Oryza sativa L.cv. Taichung 65, T65c), its isogenic dwarf line (T65d1), and a semidwarf variety of a different line (Oryza sativa L.cv. IR8, IR8) were studied. The results were compared with those of an isogenic dwarf line (Rhi) of wheat straw, which was previously reported. Expression of the dwarf gene,d1, on the chemical composition and the structural features of lignin present in rice internodes differs from that in an isogenic dwarf line of wheat. The differences include the lignin content, total yield of alkaline nitrobenzene oxidation products, and distribution of wall-bound hydroxycinnamic acids. There was, however, no difference in the syringyl/ guaiacyl nuclei (S/V) molar ratio and neutral sugar composition. The lignin composition of rice straw cell walls, particularly that of the dwarf variety, contained more of the condensed structure and fewer syringyl nuclei than lignin in wheat straw cell walls. It is suggested that crosslinking between lignin and polysaccharides by ester-ether bridges via ferulic acid contributes to the mechanical properties of the cell walls of rice straw. Thus the chemical and structural characteristics of lignin in rice straw differ to some extent from those of other temperate grasses, such as wheat (Triticum aestivum) and phalaris (Phalaris aquatica), as reported previously. This can probably be attributed to the water environment of rapidly growing rice seedlings, but it also depends on the genetic variety of the rice plant. 相似文献
Tension wood was induced inEucalyptus camaldulensis L. by fixing the stem at an angle. Proteins in the differentiating tissue of tension wood were compared to those of normal wood on sodium dodecyl sulfate polyacrylamide gel electrophoresis. An obvious difference was found in the salt-soluble fraction of 14 days after inclination. At least five bands (19,22,37,41, and 55kDa) were specific in the differentiating tissue of tension wood. These proteins were bound to the cell wall, plasma membrane, or both by their electric charge; they were undetectable until 14 days after inclination. Mature tension wood was observed in the tissue at 14 days. Thus, all differentiating tissue at 14 days was produced after inclination. On the other hand, the differentiating zone at 7 days contained the same tissue, as in tension wood estimated by the vessel number and diameter during the early phase; and the tissue was indistinguishable from normal wood during the late phase. The proteins found here were related to the phenomenon occurring in the late stage of xylem differentiation. 相似文献
A feeding experiment was conducted to evaluate the efficacy of, and determine the requirements for dietary AsA (l-ascorbic acid) using its popular derivative l-ascorbyl-2-monophosphate-Mg (APM) for juvenile Pacific bluefin tuna (PBT). The five test diets (with APM-0, -400, -800, -1200 and -1600) were prepared by adding 0, 400, 800, 1200 and 1600 mg of APM kg diet?1, respectively. These diets, together with chopped sand lance (the control diet), were administered, in duplicate to 0.27 g PBT at 25 days after hatching (300 juveniles per 15 m3 tank). The PBT were fed to apparent satiety 6 times a day for 2 weeks. While final body weight, feed conversion and survival showed no differences among diets APM 400–1600, PBT fed APM-0 indicated lower growth performance together with anorexia, dark pigmentation and ataxia from 5 days and reached 80 % mortality at 12 days after the start of the feeding trial. In addition, liver and brain ascorbic acid (AsA) concentrations increased with increasing dietary APM levels, the values were similar in PBT fed diets with APM-1200 and APM-1600, and liver and brain concentrations of AsA were significantly higher in these fish than in the PBT fed the other diets (P < 0.05). The PBT responded to increasing dietary APM, and the fish fed APM-1200 had the highest weight gain, protein and lipid content. The data indicate that PBT can utilize APM as an AsA source and suggest that dietary supplementation with APM-1200 (454 mg AsA kg?1 diet) would result in satisfactory growth. 相似文献
Type I collagen is widely distributed in most organs in teleosts. It plays a role not only in intercellular adhesion, but also in molecular signaling. In this study, Pacific bluefin tuna (PBT) procollagen α1 (I) cDNA was cloned and characterized. The nine fragments of a procollagen α1 (I) chain cDNA clone were prepared and spliced together to create the complete coding region. The resulting amino acid sequence was homologous with that of other teleosts. The mRNA expression profile of PBT procollagen α1 (I) in various tissues and the phylogenetic analysis with other vertebrate procollagen α1 (I) chains suggest that PBT procollagen α1 (I) could be a precursor form of the PBT type I collagen α1 chain. In addition, its level of expression in PBT larvae and early juveniles gradually increased with somatic growth. This increase was related to the standard length, wet body weight, and protein content of each individual fish. Therefore, the expression profile of procollagen α1 (I) may be a useful indicator for somatic growth in fish larvae and juveniles. 相似文献
In the Shiretoko Peninsula, a World Natural Heritage site, the sustainable management of kelp forests has drawn public attention because of the economic and ecological importance of kelp. We spatially estimated the distributions of kelp forests in the Shiretoko Peninsula before and after harvest. Field surveys were conducted in coastal waters (23.74 km2) at the ends of July and August 2008, immediately before and after harvest. Data on the presence or absence and thickness of the kelp forests were collected via acoustic observation. The data were interpolated using geostatistical methods. Before harvest, the kelp forests were continuously distributed over 5.64 km2 (thickness 33–132 cm), especially near the north part of the study area. After harvest, they were sparsely distributed over 2.73 km2 (thickness 35–105 cm). In the southern part of the study area, the influence of harvests was observed as declines in forest area. In addition, relatively thickly forested areas formed the majority of the part most likely to be harvested. Selective harvesting for area and size was confirmed though quantitative mapping of kelp forests. The quantitative mapping of both the distribution and harvest of kelp forests was successful. 相似文献
Talanoa has been defined as ‘talking about nothing in particular’, ‘chat’ or ‘gossip’. It is within the cultural milieu of talanoa that knowledge and emotions are shared and new knowledge is generated. Talanoa has recently been taken up by development researchers and others as a culturally appropriate research method in Pacific contexts. However, talanoa is often treated as synonymous with ‘informal open‐ended interviews’ and tends to gloss over the deep empathic understanding required in such exchanges. Highlighting the connection between talanoa and empathy is vital in ensuring that development practitioners and researchers are implicitly aware of the political dimensions, cultural appropriacy and socio‐ecological impact of their research methods. This connection is also critical in illuminating how talanoa as a method may decolonise research in the Pacific, inform the decolonisation of research in other cultural contexts, and contribute to ethical and empowering development policy and practice. We will argue for the merits of what we refer to here as ‘empathic apprenticeship’: an intentional, embodied, emotional, and intersubjective methodology and process between the researcher and the participant. An empathic apprenticeship has the potential to enhance shared understandings between all human beings and is essential if talanoa is intended as a decolonising research methodology. 相似文献