SCR遺伝子は様々な植物において根の内皮及び静止中心に発現することが報告されており、シロイヌナズナにおいては内皮・皮層始原細胞の娘細胞における不等分裂に関与していることが明らかとなっている。
　我々はイネよりOsSCR遺伝子を単離し、その発現パターンを詳しく調べた。根においては他の植物と同様に内皮及び静止中心に発現していたが、地上部においては非常に興味深い発現パターンを示した。若い葉原基（P1, P2）では将来維管束が分化する領域以外のすべての細胞で発現しており、葉原基の発達に伴いOsSCRはL1層のみに発現するようになる。さらに、発達した葉原基の先端側ではある間隔をおいて特定の細胞列、あるいは特定の細胞に発現していた。これ以降の発現パターンからこれらの細胞列が気孔の形成される列であり、気孔形成の初期においては孔辺母細胞と副細胞に発現し、その後、孔辺母細胞が等分裂をするころには副細胞のみに発現することが明らかとなった。これらのことから、OsSCRは内皮の形成のみでなく、気孔の形成における不等分裂（特殊な細胞分裂）にも関与している可能性が考えられる。

抄録全体を表示

　私たちは制御タンパク質の細胞間移行のメカニズムの解明のために、根毛形成の正の制御因子であるCPCタンパク質の移行をモデル系として研究を行っている。これまでに演者らはCPCタンパク質が非根毛細胞から根毛細胞へ移行することをCPC:GFP融合タンパク質をCPCプロモーターで発現させた形質転換シロイヌナズナにより明らかにした。
　次にCPCタンパク質の移行能を担うドメインを同定するためにCPCタンパク質の欠失シリーズをGFPに融合させ発現させた形質転換体を解析した。これまでの結果、CPCタンパク質のアミノ末端及びMYB領域が移行に必要であることが明らかになっている。現在、さらに詳細な欠失シリーズを用い移行に必要な領域化を行っている。
　次に、移行の指向性を検定するために異所的にCPC:GFP融合遺伝子を発現させた。プロモーターで根の内皮に、またbHLH遺伝子であるMYC2プロモーターで根毛細胞に発現させたところGFPの蛍光は根の全ての表皮細胞の核で観察された。この事から、CPCタンパク質は全ての表皮細胞に移行し、そこで核移行する性質を持つことが明らかになった。さらに、細胞間移行の制御因子を同定するためにTwo-hybrid法により、上述の移行に必要なCPCタンパク質の領域と相互作用する因子を探索している。

抄録全体を表示

Characterization of mulberry bending mutant was performed. Mulberry bending mutant ‘Garyu’ has a relatively short internode compared with the wild genotype ‘Ichibei’. The stem bends at the nodal position, and the bending is more apparent in the apical part of the stem. Histological observation showed that the bending occurs from the early developmental stage. Gibberellin (GA₃), natural-type abscisic acid ((S)-(+)-ABA) and their mixture were applied to the winter-dormant stem cutting of ‘Garyu’ and three normal straight-stem types. Dormancy break and growth of stem cutting was not affected by these hormones in ‘Garyu’ and ‘Shin-ichinose’, the hybrid between ‘Ichinose’ and ‘Kokuso 21’, but were affected in straight-stem types ‘Ichibei’ and ‘Ryoumenguwa’. Molecular analysis was done by using PCR with GAI degenerate and specific primers producing a fragment which turned to be 765 bp in length after sequencing. The fragment gene has homology to GRAS (GAI, RGA and SCR) transcription factor gene family, which relates to gibberellin response modulation function. We found two substitutive point mutations in GAI-like gene of mulberry ‘Garyu’ in comparison to mulberry ‘Ichibei’, ‘Shin-ichinose’, ‘Kokuso 16’ and other GRAS family gene on other plants. These mutations have the consequence to the replacement in the amino acid sequence and might have changed in protein function.

抄録全体を表示

Arabidopsis cDNA microarray analysis was performed for 5,722 genes using leaf, stem, root and flower mRNA as targets. We identified 55, 22, 21, and 131 genes expressed specifically in leaves, stems, flowers and roots, respectively. Statistical cluster analysis revealed that the roots were the most distant and the leaves and flowers the most related organs with regards to gene expression. K-means clustering revealed that the clusters for leaf-specific genes tended to mainly have genes for plastid-localized proteins, while the cluster for predominantly root-specific genes was mainly secretory proteins.

抄録全体を表示

This study focuses on small-scale biotopes, which I were found suitable for Japanese kindergarten education after an examination of current conditions of school biotopes in Japanese kindergartens, and its future direction. Furthermore, I narrow the focus down to a type of school biotope, namely, "Mini Paddy Field Biotope", where rice is grown utilizing a water environment that matches the Japanese climate and its natural features. In this study, I examine the practical activities of this type of biotope at a Kindergarten in Tokyo and analyze its educational benefits. In conclusion, I propose some ways in which school biotope can be utilized in the kindergarten education in Japan.

抄録全体を表示

Although it is well known that hierarchical transcriptional networks are essential for various aspects of plant development and environmental response, little has been investigated about whether and how they also regulate the plant cell cycle. Recent studies on cell cycle regulation in Arabidopsis thaliana identified

-LIKE28 (SCL28), a GRAS-type transcription factor, that constitutes a hierarchical transcriptional pathway comprised of MYB3R, SCL28 and SIAMESE-RELATED (SMR). In this pathway, MYB3R family proteins regulate the G2/M-specific transcription of the SCL28 gene, of which products, in turn, positively regulate the transcription of SMR genes encoding a group of plant-specific inhibitor proteins of cyclin-dependent kinases. However, this pathway with a role in cell cycle inhibition is solely demonstrated in A. thaliana, thus leaving open the question of whether and to what extent this pathway is evolutionarily conserved in plants. In this study, we conducted differential display RT-PCR on synchronized Nicotiana tabacum (tobacco) BY-2 cells and identified several M-phase-specific cDNA clones, one of which turned out to be a tobacco ortholog of SCL28 and was designated NtSCL28. We showed that NtSCL28 is expressed specifically during G2/M and early G1 in the synchronized cultures of BY-2 cells. NtSCL28 contains MYB3R-binding promoter elements, so-called mitosis-specific activator elements, and is upregulated by a hyperactive form of NtmybA2, one of the MYB3R proteins from tobacco. Our study indicated that a part of the hierarchical pathway identified in A. thaliana is equally operating in tobacco cells, suggesting the conservation of this pathway across different families in evolution of angiosperm.

抄録全体を表示

During the course of plant evolution, leguminous and a few plants species have established root nodule symbiosis (RNS), one of the nitrogen nutrient acquisition strategies based on mutual interaction between plants and nitrogen-fixing bacteria. In addition to its useful agronomic trait, RNS comprises a unique form of plant lateral organogenesis; dedifferentiation and activation of cortical cells in the root are induced upon bacterial infection during nodule development. In the past few years, the elucidations of the significance of NODULE INCEPTION transcription factor as a potentially key innovative factor of RNS, the details of its function, and the successive discoveries of its target genes have advanced our understanding underlying molecular mechanisms of nodule organogenesis. In addition, a recent elucidation of the role of legume SHORTROOT-

module has provided the insights into the unique properties of legume cortical cells. Here, I summarize such latest findings on the neofunctionalized key players of nodule organogenesis, which may provide clue to understand an evolutionary basis of RNS.

抄録全体を表示

「宗教」の西洋的な定義や解釈は、東洋人の宗教観を軽視ないし軽蔑する傾向にある。本研究は、日本の大学生の異常体験を調査することによって、日本人にも「宗教的」というべき体験があることを証明するだけでなく、「宗教」を東洋的に解釈する必要をも提唱する。大学生の「異常体験」を報告し、そのデータを他国の学生の異常経験比率と比較した。結果的には、宗教を特に信じないという若い日本人も多岐にわたる異常体験を経験しており、他文化の宗教とはさほど異ならない。

抄録全体を表示

Plants subjected to abiotic stress can regulate gene expression post-transcriptionally by means of small RNAs such as microRNAs. Cool-temperature stress causes abnormal tapetum hypertrophy in rice anthers, leading to pollen sterility. As a first step toward understanding the molecular mechanisms of cool tolerance in developing anthers of rice, we report here a comprehensive comparative analysis of microRNAs between cool-sensitive Sasanishiki and cool-tolerant Hitomebore cultivars. High-throughput Illumina sequencing revealed 241 known and 46 novel microRNAs. Interestingly, 15 of these microRNAs accumulated differentially in the two cultivars at the uninucleate microspore stage under cool conditions. Inverse correlations between expression patterns of microRNAs and their target genes were confirmed by quantitative RT-PCR analysis, and cleavage sites of some of the target genes were determined by 5’ RNA ligase-mediated RACE experiments. Thus, our data are useful resources to elucidate microRNA-mediated mechanism(s) of cool tolerance in rice anthers at the booting stage.

抄録全体を表示

Microspore culture is an efficient system to produce haploid and double-haploid plants, and is a useful model system in developmental research. Although many studies have been carried out to understand the mechanism of microspore embryogenesis, the details of molecular events occurring during its developmental process are unclear. During embryogenesis, a marked morphological change occurs just after globular stage embryos. To gain insight into the developmental process of androgenesis in rapeseed (Brassica napus), we isolated the genes expressed differentially during globular stage by suppression subtractive hybridization (SSH). Of 254 ESTs isolated and sequenced, 82 were singletons and the remaining 172 were assembled into 28 groups based on homology to the identical gene, resulting in the identification of 110 non-redundant EST groups, which are potentially up-regulated genes in androgenesis. Survey of the potential function of the genes showed that 96.4% of these genes were homologous to known genes with 42.7% of unclassified proteins and 13.6% of metabolism. To confirm the expression profiles of isolated genes during androgenesis and zygotic embryogenesis, six selected genes were examined by quantitative RT-PCR analysis. All genes were highly expressed in globular and other stages of androgenesis. The expressions of these genes were confirmed in zygotic embryogenesis. These results serve as a starting point for understanding the mechanism of androgenesis and zygotic embryogenesis.

抄録全体を表示

We developed a deer warning device using ultrasonic sound. In general, the electrical deer fencing net using high voltage prevents the deer from invading. The deer warning device will enhance the defense effect by setting in front of the deer fencing net. The warning device sound frequency is around 15kHZ referring to the "deer whistle", and operates for a long term with the solar cell and capacitor. This paper shows the idea of the device using PlC microcomputer and consideration of an animal warning device like a . However, the actual effect of the device for the deer is not yet evaluated.

抄録全体を表示

　アサガオ（Pharbitis nil）の1品種であるシダレアサガオ（weeping）は、地上部における負の重力屈性を欠損している。我々はこれまでに、weepingでは地上部において重力感受に必須とされる内皮細胞の分化が異常であり、茎の回旋転頭運動を欠損していること、内皮細胞分化異常の表現型を示すシロイヌナズナ変異体においても回旋転頭運動が欠損していることを明らかにしている。そこで本研究は、アサガオにおける相同遺伝子（PnSCR）のweeping形質への寄与を、その同定と解析により検証した。まずPnSCR全長を単離し、野生型アサガオとweepingのアミノ酸配列を比較した。その結果weepingにおいて、重力屈性欠損と連鎖する1アミノ酸の挿入変異を見出した。次に、この変異がPnSCRの機能欠損の原因であるか検証するために、シロイヌナズナscr変異体を用いた相補性試験を行った。野生型PnSCRを導入したシロイヌナズナscr変異体では花茎の負の重力屈性と回旋転頭運動が復帰したのに対し、weeping型PnSCRを導入した系統ではその復帰が認められなかった。これらの結果は、weepingにおける重力屈性と回旋転頭運動の欠損が、PnSCRの1アミノ酸挿入による機能欠損に起因し、PnSCRがweepingの変異原因遺伝子であることを強く示唆している。

抄録全体を表示

In higher plants, lateral root (LR) formation is a major contributor to root architecture in the soil. Although it is well known that auxin promotes LR formation, the molecular mechanisms that regulate auxin-mediated LR formation are still largely unknown. Recent molecular genetic studies using Arabidopsis mutants have shown that normal auxin signaling mediated by two families of transcriptional regulators, Aux/IAAs (Auxin/Indole-3-Acetic Acid; repressors of auxin-responsive transcription) and ARFs (Auxin Response Factor; activators or repressors of auxin-responsive transcription), is necessary for LR formation. Auxin-responsive transcription mediated by SLR/IAA14 and ARF7/ARF19 in the root pericycle is particularly important for LR initiation. This review summarizes what is known about the auxin signaling that regulates LR formation in Arabidopsis, and discusses the role of Aux/IAAs and ARFs for LR initiation and subsequent primordial development.

抄録全体を表示