红掌AaMYB1的表达特征及其在烟草中的过表达

The Expression Pattern of AaMYB1 in Anthurium and Its Overexpression in Tobacco

R2R3-MYB转录因子在观赏植物花青素着色中具有关键性的调控作用。为了进一步明确红掌AaMYB1调控花青素合成的功能,本研究采用序列分析、表达特征分析以及在烟草中异源过表达等方法,对AaMYB1进行了功能分析。结果表明,AaMYB1与单子叶植物中调控花青素合成的R2R3-MYB同源性较高。在品种‘Tropical’中,AaMYB1主要在红掌佛焰苞中表达,各组织中的表达量与花青素苷积累密切相关,但在不同品种不同颜色佛焰苞中的表达与花青素苷积累无相关性。单独过表达AaMYB1的T1代烟草花冠檐部因大量积累花青素苷而使颜色变深,且烟草中花青素苷合成途径上的关键酶基因NtDFR和NtANS以及烟草内源调控花青素苷合成的R2R3-MYB基因NtAn2的表达量得到大幅度上调。以上结果进一步明确了AaMYB1具有调控花青素苷合成的功能。

R2 R3-MYB transcriptional factors play a key role in regulation of anthocyanin pigmentation in ornamental plants. The present study employed sequence analysis, relative expression analysis, and heterologous overexpression in tobacco in order to clarify the regulation function of anthocyanin biosynthesis performed by AaMYB1 from Anthurium andraeanum(Hort.). The results suggested that AaMYB1 had much homology with R2 R3-MYB regulator in monocots. The AaMYB1 primarily expressed in the spathe, and it showed great correlation with anthocyanin accumulation in various tissues of cultivar ’Tropical’. However, the expression of AaMYB1 was not related with anthocyanin accumulation in different spathe with various colors. Overexpression of AaMYB1 alone resulted in the darker color of tobacco corolla limb from T1 transgenic tobacco caused by anthocyanin accumulation. And the expression of key enzyme genes on the anthocyanin biosynthetic pathway, NtDFR and NtANS, as well as the endogenous anthocyanin regulator R2 R3-MYB gene NtAn2 was greatly up-regulated in the T1 tobacco lines. All the results indicated that AaMYB1 had the function of regulating anthocyanin biosynthesis.