Japan Agricultural Research Quarterly: JARQ
Online ISSN : 2185-8896
Print ISSN : 0021-3551
ISSN-L : 0021-3551
最新号
選択された号の論文の8件中1~8を表示しています
REVIEWS
Biotechnology
  • Kazuo SOENO, Akiko SATO, Yukihisa SHIMADA
    原稿種別: review-article
    2024 年 58 巻 1 号 p. 1-11
    発行日: 2024/01/01
    公開日: 2024/02/19
    ジャーナル フリー

    Auxins are plant hormones that play key roles in almost all growth and developmental processes, such as cell division, elongation, differentiation, and environmental responses. However, biosynthetic pathways and regulatory mechanisms remain unclear. The indole-3-pyruvic acid (IPyA) pathway, from L-tryptophan (Trp) via IPyA, is the main biosynthetic pathway of the natural auxin indole-3-acetic acid (IAA). In this pathway, IAA is biosynthesized from Trp through two enzymatic reactions: aminotransferase (TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS1 [TAA1]/ TRYPTOPHAN AMINOTRANSFERASE-RELATED [TARs]) and YUCCAs (YUCs), which are flavin-containing monooxygenases. We developed the inhibitors of TAA1/TARs and YUC and analyzed the physiological functions of the IPyA pathway using the biosynthesis inhibitors as chemical probes. This paper also describes the regulatory mechanism of the two-step enzymatic reactions in auxin biosynthesis, employing the novel IPyA analog compounds.

Animal Science
  • Nobuo ARAI
    原稿種別: review-article
    2024 年 58 巻 1 号 p. 13-23
    発行日: 2024/01/01
    公開日: 2024/02/19
    ジャーナル フリー

    Salmonella enterica subsp. enterica serovar Typhimurium and its monophasic variant (Salmonella 4,[5],12:i:-) are two of the most frequently isolated serovars in food animals worldwide. Especially, human and swine infections by Salmonella 4,[5],12:i:- have increased considerably in Western countries since the mid-1990s. Although bovine and swine salmonellosis by Salmonella 4,[5],12:i:- has been increasing in Japan, the genetic background of the serovar has been unclear. In our study, whole genome sequence (WGS)-based phylogenetic analysis was performed to reveal the characteristics of Salmonella Typhimurium and Salmonella 4,[5],12:i:- isolated in Japan. Nine distinctive clades were identified and clonal replacements were observed several times in the last four decades. Among the nine clades, clade 9, which is a multidrug-resistant and predominant clone after 2010, has similar characteristics to the European clone that has been a major threat to public and animal health worldwide in recent years. Furthermore, the two distinctive clades in clade 9 were identified by phylogenetic analysis. Each clade has diverged through microevolution mediated by the acquisition or deletion of mobile genetic elements such as plasmids, prophages, composite transposons, and integrative and conjugative elements. The present review focuses on WGS-based phylogenetic studies of Salmonella Typhimurium and Salmonella 4,[5],12:i:- isolated from food animals in Japan.

  • Tatsuya NISHI, Katsuhiko FUKAI, Kazuki MORIOKA
    原稿種別: review-article
    2024 年 58 巻 1 号 p. 25-30
    発行日: 2024/01/01
    公開日: 2024/02/19
    ジャーナル フリー

    Foot-and-mouth disease (FMD), the most contagious mammalian disease, causes severe economic damage to the livestock industry. Animals infected with FMD virus (FMDV) typically present with vesicles in the mouth, nostrils, and around the breasts and feet. The pathogenicity and infectivity of FMDV in cattle and swine are strain dependent. To investigate the molecular mechanisms underlying these differences, we examined the molecular basis of the pathogenicity of FMDV using two viral strains isolated from two outbreaks of differing severities in Japan. We demonstrated that the two strains have completely different transmissibility in inoculated cattle and virulence in suckling mice. Our study also indicated that VP1 and 3D proteins are independent genetic determinants of this difference. The selectivity of VP1 for host cell receptors and the fidelity of viral RNA during replication were considered important individual factors in the induction of differences in pathogenicity in the host and the severity of outbreaks in the field. These findings provide new insights into the molecular mechanisms underlying the pathogenicity of FMDV.

ARTICLES
Crop Science
  • Toshinori MATSUNAMI, Ryuji OTANI, Yasuhiro TACHIBANA, Morinobu MATSUO, ...
    原稿種別: research-article
    2024 年 58 巻 1 号 p. 31-37
    発行日: 2024/01/01
    公開日: 2024/02/19
    ジャーナル フリー

    This study aimed to experimentally determine the effectiveness of hill seeding in a well-drained paddy field using plowing and compaction systems by comparing the yield, quality, and lodging resistance under high-fertilizer conditions, to those of direct sowing in rows. The degree of lodging was found to be higher with hill seeding than with row sowing. There was a significant reduction in yield with row seeding. This was related to the lower percentage of ripened grain on the primary and secondary rachis branches of the panicle. Therefore, under high-fertilizer conditions, which promote lodging in rice directly sown in a well-drained paddy field using plowing and compaction systems, hill seeding has superior lodging resistance. This was due to the presence of shorter and thicker lower internodes in hill seeding compared to row seeding. Ripening capability was also maintained, which resulted in a higher yield and improved quality. Therefore, hill seeding is effective in obtaining stable and high yields of rice directly sown in well-drained paddy fields using plowing and compaction systems and of rice directly sown in flooded paddy fields.

  • Yoshitaka HARA
    原稿種別: research-article
    2024 年 58 巻 1 号 p. 39-48
    発行日: 2024/01/01
    公開日: 2024/02/19
    ジャーナル フリー

    The reach time equation, a sigmoidal equation with the same number of parameters as the logistic equation, is derived by adding a concentration factor to the physically theoretical Arrhenius equation and assuming a normally distributed factor. Because this equation provides a good description of the time distribution to germination, it may be applicable as an equation for the time distribution reaching a certain stage in a population. Moreover, as derived from the Arrhenius equation, this equation can also be used to evaluate the effect of temperature. Using this equation, the skewness in the time distribution reaching a certain stage became proportional to the variation coefficient of the concentration factor, indicating that a high variation coefficient for the amount of relevant substrates, such as nutrients and enzymes, caused the skewness in the distribution. Given the theoretical implications of the parameters obtained by fitting this equation, it is predicted that the growth and development of living organisms, including inorganic changes can be theoretically analyzed by fitting and analyzing the parameter values. In addition, owing to the small number of parameters, it will also be useful for simple fitting as a sigmoidal curve.

Food
  • Yoshimasa SUGIURA, Mahiko ABE, Noboru MURASE
    原稿種別: research-article
    2024 年 58 巻 1 号 p. 49-55
    発行日: 2024/01/01
    公開日: 2024/02/19
    ジャーナル フリー

    The functional properties of edible lavers are well-known; however, there is limited information on the marine red alga Pyropia tenuipedalis, an indigenous species found in the Yamaguchi Prefecture area. In the present study, samples of P. tenuipedalis were collected from the Koto River Estuary and cultivated using land-based cultivation techniques. A methanol/chloroform (M/C) extract obtained from naturally grown and land-based cultivated P. tenuipedalis showed antiallergic properties, including suppression of ear swelling in the Institute of Cancer Research mouse model, inhibition of inflammation-associated enzymes (i.e., phospholipase A2, lipoxygenase, cyclooxygenase-2, and hyaluronidase), and anti-degranulation in rat basophilic leukemia-2H3 cells. Chemical composition was determined using thin-layer chromatography. Three glyceroglycolipids, namely digalactosyldiacylglycerol, monogalactosyldiacylglycerol, and sulfoquinovosyldiacylglycerol, were detected in the M/C extracts of natural and cultivated algae and were selected as bioactive candidates. The results demonstrate that glyceroglycolipids in natural and cultivated P. tenuipedalis edible algae have promising potential for the development of antiallergic food.

Horticulture
  • Makoto TONOOKA, Yoshiyuki HOMMA, Hideki NUKUI, Kazuo ICHIMURA
    原稿種別: research-article
    2024 年 58 巻 1 号 p. 57-64
    発行日: 2024/01/01
    公開日: 2024/02/19
    ジャーナル フリー

    Seasonal changes in vase life and the electrical conductivity and turbidity of vase water were studied in cut gerbera using two cultivars, namely, ‘Picture Perfect’ and ‘Pinta.’ Sugars and electrolytes released from cut stems are reported to be high in ‘Picture Perfect’ but lower in ‘Pinta.’ From May to July, when the electrical conductivity and turbidity of vase water were relatively high, the vase life of cut ‘Picture Perfect’ was relatively short. From May to July, the vase life of cut ‘Pinta’ was not reduced. Moreover, the electrical conductivity and turbidity of vase water were relatively low throughout the year. Isothiazolinone germicide (a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one; CMIT/MIT) treatment reduced the turbidity of vase water in ‘Picture Perfect.’ ‘Picture Perfect’ had a large central cavity in the stem, whereas ‘Pinta’ had a very small central cavity. The vase life of cut ‘Picture Perfect’ was found to have a significant seasonal variation. The amounts of compounds, including electrolytes, released by cut ‘Picture Perfect’ stems may explain the variation in vase life.

Fisheries
  • Yuki FUJINAMI, Motomitsu TAKAHASHI, Hiroyuki KUROTA
    原稿種別: research-article
    2024 年 58 巻 1 号 p. 65-74
    発行日: 2024/01/01
    公開日: 2024/02/19
    ジャーナル フリー

    Accurate estimates of fish age and growth are essential for stock assessment and management. We evaluated the differences in aging precision of Japanese sardines (Sardinops melanostictus) from the Sea of Japan and East China Sea determined from the counts of annual rings on scales and otolith observation by two readers. Changes in growth parameters between 2011 and 2018 year-classes were also evaluated. Although the aging precision between readers was relatively precise for both scales and otoliths, otoliths may be more useful for determining the age of this population because of the low discrepancy of the age counts between readers. The average standard length of Japanese sardines aged 2-3 years was relatively stable for 2011-2017 year-classes but declined sharply after 2018 year-class, along with increased stock biomass. Recent (2018 year-class) estimated theoretical asymptotic length also declined compared with those of early 2010s year-classes. Changes in the mean standard length at an age of 2-3 years and theoretical asymptotic length of Japanese sardines in the Sea of Japan and East China Sea may be a density-dependent response to increased stock abundance.

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