Biochemical and Molecular Analysis of Pink Tomatoes: Deregulated Expression of the Gene Encoding Transcription Factor S1MYB12 Leads to Pink Tomato Fruit Color
Biochemical and Molecular Analysis of Pink Tomatoes: Deregulated Expression of the Gene Encoding Transcription Factor S1MYB12 Leads to Pink Tomato Fruit Color
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DOI：
10.1104/pp.109.147322
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发表时间：
2010-01-01
期刊：
影响因子：
7.4
通讯作者：
Bovy, Arnaud
中科院分区：
文献类型：
--
作者：
Ballester, Ana-Rosa;Molthoff, Jos;Bovy, Arnaud
番茄果实的颜色主要由类胡萝卜素和类黄酮决定。对番茄Moneyberg与野生种茄Solanum chmielewskii杂交获得的渐渗系（IL）群体进行表型分析，发现3个具有粉红色果实颜色的IL。这些品系具有纯合的S。chmielewskii基因渗入1号染色体的短臂上，与已知导致无色表皮的Y（黄色）突变的位置一致，因此当与红色果肉结合时，导致粉红色的果实。代谢分析表明，粉红色的水果缺乏成熟依赖积累的黄色类黄酮柚皮素查尔酮在果皮中，而类胡萝卜素水平不受影响。所有编码生物合成酶的基因的表达参与生产的黄酮醇芦丁从柚皮素查耳酮下调粉红色的水果，这表明潜在的粉红色表型的候选基因编码的调控蛋白，如转录因子，而不是生物合成酶。26 MYB和碱性螺旋-环-螺旋转录因子puridium参与调控类苯丙素和/或类黄酮途径中的基因转录，只有MYB 12基因的表达水平与成熟过程中粉红色和红色果实基因型果皮样品中结构类黄酮基因表达的减少密切相关。遗传定位和分离分析表明，MYB 12位于第1染色体上，与粉红色的果实特征色完全分离。病毒诱导的SlMYB 12的基因沉默导致柚皮素查耳酮的积累减少，这是与IL 1b的粉红色番茄果实一致的表型。总之，生化和分子数据，基因定位，分离分析，和病毒诱导的基因沉默实验表明，MYB 12转录因子在调节番茄果实中的类黄酮途径中起着重要作用，并强烈建议，SLMYB 12是一个可能的候选人的y突变。
The color of tomato fruit is mainly determined by carotenoids and flavonoids. Phenotypic analysis of an introgression line (IL) population derived from a cross between Solanum lycopersicum 'Moneyberg' and the wild species Solanum chmielewskii revealed three ILs with a pink fruit color. These lines had a homozygous S. chmielewskii introgression on the short arm of chromosome 1, consistent with the position of the y (yellow) mutation known to result in colorless epidermis, and hence pink-colored fruit, when combined with a red flesh. Metabolic analysis showed that pink fruit lack the ripening-dependent accumulation of the yellow-colored flavonoid naringenin chalcone in the fruit peel, while carotenoid levels are not affected. The expression of all genes encoding biosynthetic enzymes involved in the production of the flavonol rutin from naringenin chalcone was down-regulated in pink fruit, suggesting that the candidate gene underlying the pink phenotype encodes a regulatory protein such as a transcription factor rather than a biosynthetic enzyme. Of 26 MYB and basic helix-loop-helix transcription factors putatively involved in regulating transcription of genes in the phenylpropanoid and/or flavonoid pathway, only the expression level of the MYB12 gene correlated well with the decrease in the expression of structural flavonoid genes in peel samples of pink- and red-fruited genotypes during ripening. Genetic mapping and segregation analysis showed that MYB12 is located on chromosome 1 and segregates perfectly with the characteristic pink fruit color. Virus-induced gene silencing of SlMYB12 resulted in a decrease in the accumulation of naringenin chalcone, a phenotype consistent with the pink- colored tomato fruit of IL1b. In conclusion, biochemical and molecular data, gene mapping, segregation analysis, and virus-induced gene silencing experiments demonstrate that the MYB12 transcription factor plays an important role in regulating the flavonoid pathway in tomato fruit and suggest strongly that SlMYB12 is a likely candidate for the y mutation.