An R2R3-MYB transcription factor regulates carotenoid pigmentation in Mimulus lewisii flowers
An R2R3-MYB transcription factor regulates carotenoid pigmentation in Mimulus lewisii flowers
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DOI：
10.1111/nph.13647
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发表时间：
2016-02-01
期刊：
影响因子：
9.4
通讯作者：
Yuan, Yao-Wu
中科院分区：
文献类型：
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作者：
Sagawa, Janelle M.;Stanley, Lauren E.;Yuan, Yao-Wu
类胡萝卜素是黄色、橙子和红色的色素，有助于许多花卉和水果的美丽颜色和营养价值。本研究通过大量分离分析和转基因实验对一株化学诱变的刘氏拟谷盗（Mimulus lewisii）突变体进行分析，鉴定出一个R2 R3-MYB，即类胡萝卜素色素减少1（Reduced Carotenoid Pigmentation 1，RCP 1），RCP 1是花发育过程中第一个正调控类胡萝卜素生物合成的转录因子，RCP 1的功能缺失突变导致所有类胡萝卜素生物合成基因的下调，并导致M. lewisii花，在野生型背景中通过RNA干扰重现的表型。该基因在rcp 1突变体背景中的过表达恢复了类胡萝卜素的产生，出乎意料的是，导致一些转基因株系中花青素苷产量的同时下降，类胡萝卜素生物合成的转录调节因子的鉴定为理解自然界中花色多样化的分子基础和潜在的增强花色素苷生物合成的能力提供了“工具箱”基因。通过基因工程在农作物中生产类胡萝卜素。
Carotenoids are yellow, orange, and red pigments that contribute to the beautiful colors and nutritive value of many flowers and fruits. The structural genes in the highly conserved carotenoid biosynthetic pathway have been well characterized in multiple plant systems, but little is known about the transcription factors that control the expression of these structural genes.By analyzing a chemically induced mutant of Mimulus lewisii through bulk segregant analysis and transgenic experiments, we have identified an R2R3-MYB, Reduced Carotenoid Pigmentation 1 (RCP1), as the first transcription factor that positively regulates carotenoid biosynthesis during flower development.Loss-of-function mutations in RCP1 lead to down-regulation of all carotenoid biosynthetic genes and reduced carotenoid content in M. lewisii flowers, a phenotype recapitulated by RNA interference in the wild-type background. Overexpression of this gene in the rcp1 mutant background restores carotenoid production and, unexpectedly, results in simultaneous decrease of anthocyanin production in some transgenic lines by down-regulating the expression of an activator of anthocyanin biosynthesis.Identification of transcriptional regulators of carotenoid biosynthesis provides the 'toolbox' genes for understanding the molecular basis of flower color diversification in nature and for potential enhancement of carotenoid production in crop plants via genetic engineering.