Anthocyanins are the most widely produced secondary metabolites in plants, and they play an important role in plant growth and reproduction. The nitrogen source is an important factor affecting anthocyanin production, but the nitrogen concentrations on metabolism and the underlying genetic basis remain unclear. In this study, in vitro anthocyanin induction was conducted on Malus spectabilis. The leaf explants were cultivated in media containing different nitrogen concentrations. The results suggested that when the nitrogen contents decreased in limit, the color of leaf explants turned from green to red, and increased anthocyanin accumulation led to a change in phenotype. Furthermore, the content of other flavonoids, such as dihydroquercetin, epicatechin, and catechin, increased under low nitrogen conditions. The transcription levels of the general flavonoid pathway genes, from phenylalanine ammonia lyase (PAL) to anthocyanidin synthase (ANS), were associated with the concentration of corresponding flavonoid compounds and phenotype changes. In particular, the expression level of ANS increased substantially under a low nitrogen treatment, which was significantly and positively correlated with the anthocyanin levels (R² = 0.72, P < 0.05). The increased expression patterns of anthocyanin pathway genes were similar to that of the transcription factor MYB10. We further verified MYB10 played an important role in the anthocyanin pathway in leaves of Malus spectabilis. These results suggested that we can improve the desirable ornamental plant phenotypes by controlling nitrogen content. This process may offer clues to further development of new agricultural practices.

花青素是植物中产生最广泛的次级代谢产物，它们在植物的生长和繁殖中起重要作用。氮源是影响花青素生产的重要因素，但代谢中的氮浓度和潜在的遗传基础仍不清楚。在这项研究中，对大果海棠进行了花青素的体外诱导。在含有不同氮浓度的培养基中培养叶片外植体。结果表明，当氮含量降低到极限时，叶片外植体的颜色从绿色变为红色，花青素积累的增加导致表型发生变化。此外，在低氮条件下，其他类黄酮（例如二氢槲皮素，表儿茶素和儿茶素）的含量也会增加。从苯丙氨酸氨裂合酶（PAL）到花青素合酶（ANS）的一般类黄酮途径基因的转录水平与相应类黄酮化合物的浓度和表型变化有关。特别是ANS的表达水平在低氮处理下，其显着增加，与花青素水平显着正相关（R ²  = 0.72，P <0.05）。花青素途径基因的增加表达模式与转录因子MYB10相似。我们进一步验证MYB10的花青素途径的叶发挥了重要作用海棠。这些结果表明，我们可以通过控制氮含量来改善所需的观赏植物表型。这一过程可能为进一步发展新的农业实践提供线索。