岡山大学農学部Acta Medica Okayama2186-77551032014裏表紙・英文目次ENNo potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama2186-77551032014奥付ENNo potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama2186-77551032014公表学術論文等リスト 20134559ENNo potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama2186-77551032014トウガラシにおける新規カプサイシン類似物質・カプシコニノイドの含量3743ENYoshiyukiTanaka In the course of analyses of nonpungent capsaicinoid
analogs named capsinoids, two unknown compounds were
discovered in pepper fruits. These compounds were isolated
from the fruit of ‘CCB’(Capsicum baccatum var.
praetermissum). Their structures were determined to be
coniferyl (E)‒8‒methyl‒6‒nonenoate and coniferyl
8‒methylnonanoate. These novel capsaicin analogs were
named capsiconiate and dihydrocapsiconiate, respectively,
and the coniferyl ester group was named capsiconinoid.
Capsiconinoids have agonist activity for transient receptor
potential vanilloid type 1, and their pungency is very low, as
similar to that of capsinoids. Cultivars containing high
levels of capsiconinoid are considered to be important for
vegetable or dietary supplement. HPLC analysis was
conducted to determine capsiconinoid content in fruits of
54 Capsicum cultivars : 28 cultivars of C. annuum, 9 of
C. baccatum, 12 of C. chinense, 4 of C. frutescens, and 1 of
C. pubescens. Twelve cultivars contained capsiconinoids.
‘CCB’ showed the highest capsiconinoid content level (3314
μg・g‒1 DW) and ‘Charapita’ (C. chinense) had the second
highest (2694 μg・g‒1 DW). The other 10 cultivars contained
much lower capsiconinoid than these two cultivars
(<300 μg・g‒1 DW). Time-course analysis during fruit
development clarified that capsiconinoid content increased
and reached maximum level in green mature fruit.
Capsaicinoid contents also increased, correspondingly. As
fruits matured, capsiconinoid contents decreased rapidly,
while capsaicinoid content either did not change or
decreased slightly.No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama2186-77551032014植物免疫プライミング剤の単離と作用機序解明3136ENYoshiteruNoutoshi Plant disease resistance inducers, so-called plant
activators, are agrochemicals that protect crops from
pathogens. They confer long-lasting resistance against a
broad range of diseases by activating their immune system.
Since plant activators impinge on host plants, unlike
commonly-used pesticides which directly target pathogens,
no drug-resistant microbes for plant activators have been
found so far in the field. They originated from probenazole
(Oryzemate ) and have been widely used over 30 years for
the protection of paddy-field rice from blast fungus and
bacterial leaf blight in East Asia. In spite of the advantages
of plant activators, their application is still limited. The lack
of both knowledge about their modes of action and an
appropriate high-throughput screening system restrict the
isolation of novel compounds. We established a highthroughput
chemical screening procedure to identify plant
immune-priming compounds which increase but do not
directly induce immune responses in Arabidopsis
suspension cells upon infection of the bacterial pathogen,
Pseudomonas syringae pv. tomato DC3000 avrRpm1. From
the screening of a commercially available chemical library
of 10,000 diverse small organic molecules, we identified
seven compounds that prime the immune response and we
designated them ‘imprimatins’ for immune-priming
chemicals. The isolated compound, imprimatin C1 activates
the expression of defense-related genes independent of
pathogen and functions as a weak analog of salicylic acid
(SA). Those originally-isolated three compounds and their
four derivatives were classified into two groups with distinct
molecular structures and they weve named imprimatins A
and B. We found that they conferred disease resistance in
plants by inhibiting both a known and a previously
unknown SA glucosyltransferase (SAGT). Imprimatins and
their targets are useful for the development of practical
plant activators and also their modes of action might give a
clue for novel crop protection technology.No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama2186-77551032014Characterization of a novel retrotransposon TriRe‒1 using nullisomic-tetrasomic lines of hexaploid wheat2130ENYukiMondenTakeruTakaiMakotoTahara Retrotransposons constitute the large fraction (～80%) of the wheat genome where numerous and
diverse retrotransposon families exist, where especially the long terminal repeat (LTR) retrotransposon
family is known to be predominant. Thus, they have been considered to contribute to the genome
expansion, sequence diversification and the genome structure alternation in the wheat genome. In addition,
the insertion polymorphism of the LTR retrotransposon family among the cultivars has been
known to be quite useful for the genetic analysis such as the linkage mapping and the phylogenetic studies.
Here, we report the characteristics of a novel active LTR retrotransposon family TriRe‒1, which
belongs to the Ty1‒copia group in the hexaploid wheat (Triticum aestivum L.) genome. This retroelement
appears to encode all proteins required for the transposition and showed high insertion polymorphism
among the hexaploid wheat cultivars, suggesting its potential of transpositional activity with at least
recent transposition during wheat evolution. We studied the chromosomal localization of the TriRe‒1
insertion site based on the genome-wide comparative analysis using the nullisomic-tetrasomic lines of
the cultivar Chinese Spring. The results showed that although the majority of the TriRe‒1 insertion sites
exist across the homoeologous chromosomes of A, B or D genomes, a higher number of insertions in the
B genome was detected compared to A or D genome, suggesting a specific amplification in the history
of B genome progenitors. In conclusion, a novel LTR retrotransposon TriRe‒1 should be valuable for the
development of molecular markers based on insertion polymorphism among the cultivars, and also the
genome-specific TriRe‒1 insertion site can be utilized to study evolutional history of wheat genomes.No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama2186-77551032014養液栽培イチゴの生育・収量と果実発育に及ぼすカリウム栄養の影響1119ENYuichiYoshidaToshimasaOhmoriTanjuroGotoYoshiyukiTanakaKenjiMurakami Effect of K nutrition on sugar and organic acid concentration in fruit and yield of strawberry
cultivars (Fragaria ×ananassa Duch.; Nyoho, Toyonoka, Sachinoka, Asukarubi, Akihime, Tochiotome,
and Sagahonoka) was investigated. Nutrient solution (NO3 8, NH4 1, P 1, K 4, Ca 2, Mg 1, SO4 1 ; mM)
was modified to contain 0 to 4mM of K by replacing K with Ca and supplied from the beginning of
flowering. K in the drainage decreased to a trace level 3 weeks after the beginning of treatment except
for 4mM‒K solution. Absorption of NO3 apparently decreased in plants supplied 0mM‒K solution, but
little difference was observed among the other 3 solutions. K concentration in petiole decreased linearly
with decrease in K concentration in solutions, but there was little difference between the concentrations
of leaflet of plants supplied with 4 and 2mM‒K solutions. No difference was observed in concentrations
of sugars and organic acids in fruit in primary inflorescence. In the second inflorescence, organic acids
and K concentration in fruit linearly decreased with decrease in K in supplied solutions while sugar
concentration of fruit decreased significantly only in plants supplied 0mM‒K solution. When 0.5 to
4mM‒K solutions were supplied from 2 weeks after planting, marketable fruit yield was smallest in
plants supplied 0.5mM‒K solution followed, by that supplied 1mM‒K solution, and largest in that
supplied with 2mM‒K solution. Almost all K supplied with 2mM‒K solution was absorbed by
strawberry plants and no difference was observed in quality and K concentration of fruit, yield and plant
growth between the plants supplied with 2 and 4mM‒K solutions. It may be suitable to reduce the
concentration of K in nutrient solution by half for substrate production of strawberry.No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama2186-77551032014高基質特異性L-グルタミン酸オキシダーゼより作成した基質特異性改変酵素L-アルギニンオキシダーゼの性質検討59ENRyuichiroNakaiShihokoFujinoTomohiroUtsumiTakashiTamuraHitoshiKusakabeaKenjiInagaki L‒Glutamate oxidase (LGOX) from Streptomyces sp. X‒119‒6 has strict substrate specificity toward
L‒glutamate. Recently, we solved the X‒ray crystal structure of LGOX and this revealed that Arg305 in
the active site is the key residue involved in substrate recognition. Therefore, we created 19 mutant
enzymes of R305X‒LGOX by saturation mutagenesis. One of them R305D‒LGOX, Arg305 substituted
with Asp exhibited oxidase activity for L‒Arg. Optimum pH of R305D‒LGOX mutant enzyme was pH
8.5. Interestingly, the activity of R305D‒LGOX toward L‒Arg was inhibited by phosphate. And furthermore,
the substrate specificity of R305D‒LGOX was affected by using buffer. The results of inhibition
analysis suggest, that phosphate is a competitive inhibitor of R305D‒LGOX when L‒Arg is used as
substrate. Kinetic analysis of R305D‒LGOX showed that Km value and kcat value of R305D‒LGOX toward
l-Arg were 0.68 mM and 6.7 s-1 respectively. In this study, we showed that R305D‒LGOX mutant
enzyme is a novel l-arginine oxidase and useful for l-arginine biosensor.No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama2186-77551032014Changes in Glycinin‒Digesting Protease Activity During Soybean Germination.14ENMd. AkhtaruzzamanMegumiMaedaKeikoKitagawaShigeakiTakagiYoshinobuKimura Changes in glycinin-digesting protease activity during soybean germination have been investigated.
The glycinin-digesting protease activities of imbibed or germinated soybean seed were assayed by
RP‒HPLC using a tryptic peptide from CM‒glycinin or by SDS‒PAGE using CM‒glycinin as the endogenous
substrate. Proteolytic activities of the germinated soybean seeds were found through the whole
period of germination, the activities were maintained significantly unchanged during germination for 4
days, and then those specific activities declined slowly. AE‒HPLC analysis of the glycinin-digesting
protease in the imbibed or germinated soybean seeds showed unchanged peaks corresponding to glycinin-
digesting activity, suggesting that the glycinin-digesting protease was not induced during germination
but had already been synthesized during seed maturation.No potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama2186-77551032014目次ENNo potential conflict of interest relevant to this article was reported.岡山大学農学部Acta Medica Okayama2186-77551032014表紙ENNo potential conflict of interest relevant to this article was reported.