Promotive Effect of Brassinolide on Elongation of Etiolated Squash Hypocotyl Segments

本研究は最も新しく発見された植物ホルモンであるブラシノライドの生理作用の解明を目的としたものである。ブラシノライドの生理作用としては数々の報告があるが,本研究では特に細胞伸長促進作用に的を絞り,同じく伸長促進作用を持つことで知られているオーキシンと比較することにより,ブラシノライド特有の生理作用を解明しようとした。本論文は5章から構成されている

Expression Analysis of an R3-Type MYB Transcription Factor CPC-LIKE MYB4 (TRICHOMELESS2) and CPL4-Related Transcripts in Arabidopsis

The CAPRICE (CPC)-like MYB gene family encodes R3-type MYB transcription factors in Arabidopsis. There are six additional CPC-like MYB sequences in the Arabidopsis genome, including TRYPTICHON (TRY), ENHANCER OF TRY AND CPC1 and 2 (ETC1 and ETC2), ENHANCER OF TRY AND CPC3/CPC-LIKE MYB3 (ETC3/CPL3), and TRICHOMELESS1 and 2 (TCL1 and TCL2). We independently identified CPC-LIKE MYB4 (CPL4), which was found to be identical to TCL2. RT-PCR analysis showed that CPL4 is strongly expressed in shoots, including true leaves, but not in roots. Promoter-GUS analyses indicated that CPL4 is specifically expressed in leaf blades. Although CPC expression was repressed in 35S::ETC1, 35S::ETC2 and 35S::CPL3 backgrounds, CPL4 expression was not affected by ETC1, ETC2 or CPL3 over-expression. Notably, several chimeric transcripts may result from inter-genic alternative splicing of CPL4 and ETC2, two tandemly repeated genes on chromosome II. At least two chimeric transcripts named CPL4-α and CPL4-β are expected to encode complete CPC-like MYB proteins

セルラーゼ ニ ヨル コウトウ ショクブツ ノ サイボウ セイチョウ

京都大学0048新制・課程博士博士(農学)甲第9000号農博第1182号新制||農||821(附属図書館)学位論文||H13||N3519(農学部図書室)UT51-2001-F330京都大学大学院農学研究科森林科学専攻(主査)教授 伊東 隆夫, 教授 酒井 富久美, 教授 島田 幹夫学位規則第4条第1項該当Doctor of Agricultural ScienceKyoto UniversityDA

<Preliminary>Changes in Levels of mRNAs for Cell Wall-related Enzymes in Growing Cotton Cells

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました

Localization of the CAPRICE-ENHANCER OF TRY AND CPC1 chimera protein in Arabidopsis root epidermis

<p>The <i>CAPRICE</i> (<i>CPC</i>) encodes an R3-type MYB transcription factor, which promotes root-hair differentiation. Previously, we showed that the CPC protein moves from the non-hair cell to the neighboring cell and induces root-hair differentiation in <i>Arabidopsis</i>. In addition, we proposed two cell-to-cell movement signal sequences, S1 and S2, in CPC. However, an S1:2xGFP:S2 chimera protein did not move between root epidermal cells. Here, we show that the S1 and S2 sequences do not confer cell-to-cell movement or nuclear localization ability to a GFP protein. The <i>ENHANCER OF TRY AND CPC1</i> (<i>ETC1</i>) gene encodes the <i>CPC</i> homolog R3 MYB; this protein does not possess cell-to-cell movement ability or the S1 sequence. To elucidate whether the S1 sequence can induce cell-to-cell movement ability in ETC1, <i>CPCp:S1:ETC1:2xGFP</i> was constructed and introduced into <i>Arabidopsis</i>. Our results indicate that the addition of the S1 sequence was not sufficient for ETC1 to acquire cell-to-cell movement ability.</p

Arabidopsis CAPRICE (MYB) and GLABRA3 (bHLH) Control Tomato (<i>Solanum lycopersicum</i>) Anthocyanin Biosynthesis

<div><p>In <i>Arabidopsis thaliana</i> the MYB transcription factor CAPRICE (CPC) and the bHLH transcription factor GLABRA3 (GL3) are central regulators of root-hair differentiation and trichome initiation. By transforming the orthologous tomato genes <i>SlTRY</i> (<i>CPC</i>) and <i>SlGL3</i> (<i>GL3</i>) into <i>Arabidopsis</i>, we demonstrated that these genes influence epidermal cell differentiation in Arabidopsis, suggesting that tomato and <i>Arabidopsis</i> partially use similar transcription factors for epidermal cell differentiation. CPC and GL3 are also known to be involved in anthocyanin biosynthesis. After transformation into tomato, <i>35S::CPC</i> inhibited anthocyanin accumulation, whereas <i>GL3::GL3</i> enhanced anthocyanin accumulation. Real-time reverse transcription PCR analyses showed that the expression of anthocyanin biosynthetic genes including <i>Phe-ammonia lyase</i> (<i>PAL</i>), the flavonoid pathway genes <i>chalcone synthase</i> (<i>CHS</i>), <i>dihydroflavonol reductase</i> (<i>DFR</i>), and <i>anthocyanidin synthase</i> (<i>ANS</i>) were repressed in <i>35S::CPC</i> tomato. In contrast, the expression levels of <i>PAL</i>, <i>CHS</i>, <i>DFR</i>, and <i>ANS</i> were significantly higher in <i>GL3::GL3</i> tomato compared with control plants. These results suggest that <i>CPC</i> and <i>GL3</i> also influence anthocyanin pigment synthesis in tomato.</p></div