Downregulation of putative UDP-glucose: flavonoid 3-O-glucosyltransferase gene alters flower coloring in Phalaenopsis
Downregulation of putative UDP-glucose: flavonoid 3-O-glucosyltransferase gene alters flower coloring in Phalaenopsis
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DOI：
10.1007/s00299-011-1006-1
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发表时间：
2011-06-01
影响因子：
6.2
通讯作者：
Ger, Mang-Jye
中科院分区：
文献类型：
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作者：
Chen, Wen-Huei;Hsu, Chi-Yin;Ger, Mang-Jye
花色素苷是形成红色、紫色和蓝色花的主要色素。UDP葡萄糖：类黄酮3-O-葡萄糖基转移酶（UFGT）通过将葡萄糖基部分从UDP-葡萄糖转移到3-羟基以产生第一稳定色素来增强花青素的溶解性。为探讨UFGT与蝴蝶兰花色形成的关系，采用RT-PCR方法检测了PeUFGT 3等花色相关基因在蝴蝶兰红色和白色花蕾发育过程中的转录活性。与查耳酮合成酶、查耳酮异构酶和花青素合成酶基因相比，PeUFGT 3的转录活性在蝴蝶兰的红色品种中表达更高。PeUFGT 3在蝴蝶兰'Luchia Lady'红色唇瓣中的表达量也高于白色花被。PeUFGT 3在不同蝴蝶兰品种中主要表达于花的红色区域。为了研究PeUFGT 3在蝴蝶兰红色花色形成中的作用，利用RNA干扰技术，通过病毒诱导基因沉默，特异性敲除了蝴蝶兰PeUFGT 3。PeUFGT 3抑制的蝴蝶兰表现出不同程度的花色褪色，这与PeUFGT 3转录活性水平降低的程度密切相关。此外，在PeUFGT 3抑制的蝴蝶兰花中花青素含量显著降低。PeUFGT 3基因沉默导致花色素苷含量下降可能是PeUFGT 3抑制的蝴蝶兰花色褪色的原因。因此，这些结果表明，糖基化相关基因PeUFGT 3在蝴蝶兰红色形成中起着关键作用。
Anthocyanin is the primary pigment contributing to red, violet, and blue flower color formation. The solubility of anthocyanins is enhanced by UDP glucose: flavonoid 3-O-glucosyltransferase (UFGT) through transfer of the glucosyl moiety from UDP-glucose to 3-hydroxyl group to produce the first stable pigments. To assess the possibility that UFGT is involved in the flower color formation in Phalaenopsis, the transcriptional activities of PeUFGT3, and other flower color-related genes in developing red or white flower buds were examined using RT-PCR analysis. In contrast with chalcone synthase, chalcone isomerase, and anthocyanidin synthase genes, PeUFGT3 transcriptional activity was higher expressed in the red color of Phalaenopsis cultivars. In the red labellum of Phalaenopsis 'Luchia Lady', PeUFGT3 also showed higher expression levels than that in the white perianth. PeUFGT3 was predominantly expressed in the red region of flower among various Phalaenopsis cultivars. To investigate the role of PeUFGT3 in red flower color formation, PeUFGT3 was specifically knocked down using RNA interference technology via virus inducing gene silencing in Phalaenopsis. The PeUFGT3-suppressed Phalaenopsis exhibited various levels of flower color fading that was well correlated with the extent of reduced level of PeUFGT3 transcriptional activity. Furthermore, there was a significant decrease in anthocyanin content in the PeUFGT3-suppressed Phalaenopsis flowers. The decrease of anthocyanin content due to PeUFGT3 gene silencing possibly caused the faded flower color in PeUFGT3-suppressed Phalaenopsis. Consequently, these results suggested that the glycosylation-related gene PeUFGT3 plays a critical role in red color formation in Phalaenopsis.