Analysis of new transposable elements involved in mutations of flower color

从龙胆草（Gentiana triflora）、龙胆草（G. scabra）及其杂种龙胆草（Gentiana triflora）中分离并分析了新的转座因子。1)在粉红色龙胆中发现了一个插入类黄酮3,5 '-羟化酶（F3'5' h）基因的转座元件（dTgt1）。该转座元件具有hat型转座元件的特征，不编码任何蛋白质，因此被认为是一个非自主的转座元件。表达分析显示F3’5’h转录本的积累减少，表明GshAT I的插入导致蓝花龙胆呈现粉红色。2)通过退化PCR分离出龙胆花瓣中调控黄酮类化合物合成的转录因子。其中，一个R2R3 MYB基因被命名为GtMYB3，被认为参与了花青素晚期生物合成基因的调控。序列分析显示，白花龙胆品种GtMYB3基因组序列中有一个插入。该插入片段命名为dTgs2，长度为271，具有hA t型转座元件的特征。Northern blot分析表明，GtMYB3信号在白花品种中比蓝花品种长。在其他白花龙胆品种中也发现了插入GtMYB3基因的转座元件，正在进行详细分析。3)从龙胆草悬浮培养细胞中分离到几个新的转座因子，并对其转座进行了分析。分离出hAT和En/Spm转座元件和ltr型反转座元件。水杨酸、茉莉酸和5-azadC对悬浮培养细胞的诱导分析表明，这些转座因子中的一些可以被这些处理激活。Southern blot分析表明，这些转座因子属于龙胆基因组中拷贝数相对较高的家族成员。本研究分离到的这些转座因子对基础和应用研究都有一定的指导意义，我们将继续对龙胆植物中转座因子的解析进行研究。少

We isolated and analyzed new transposable elements from gentian plants (Gentiana triflora, G. scabra and their hybrids).1) A transposable element (dTgt1) inserted in flavonoid 3, 5'-hydroxylase (F3'5'H) gene was found in a pink-flowered gentian. This transposable element had a feature of hAT-type transposable element and did not encode any protein and thus considered as an nonautonomous one. Expression analysis showed that accumulation of F3'5'H transcripts decreased, suggesting that the insertion of GshAT I caused pink coloration from blue-flowered gentian.2) Several transcriptional factors that regulate flavonoid biosynthesis in gentian petals were isolated by degenerated PCR. Among them, an R2R3 MYB gene, designated as GtMYB3, was considered to be involved in the regulation of late anthocyanin biosynthetic genes. Sequence analysis showed an insertion in GtMYB3 genomic sequence of a white-flowered gentian cultivar. This insertion fragment designated as dTgs2 was 271 by in length and … More had a feature of hA T-type transposable element. Northern blot analysis showed that signal of GtMYB3 was longer in the white-flowered cultivars than blue-flowered cultivar. Other transposable elements inserted in GtMYB3 gene were also found in the another white-flowered gentian cultivars and the detailed analyses are in progress.3) Several new transposable elements were isolated from suspension-cultured cells of gentian and analyzed for their transposition. hAT and En/Spm transposable elements and LTR-type retorotransposable elements were isolated. Induction analysis by salicylic acid, jasmonic acid and 5-azadC using suspension-cultured cells showed that some of these transposable elements could be activated by the treatments. Southern blot analyses indicated that these transposable elements belong to members of a relatively high copy number family in the gentian genome.These isolated transposable elements in this study are useful for basic and applied studies and we are continuously studying the elucidation of the transposable elements in gentian plants. Less