Zhao Kunkun, Zhang Jingjing, Fan Yi, Du Xufa, Zhu Shuliang, Li Zhongfeng, Qiu Ding, Cao Zenghui, Ma Qian, Li Yaoyao, Cao Di, Hu Sasa, Zhao Kai, Gong Fangping, Ren Rui, Ma Xingli, Zhang Xingguo, Yin Dongmei
College of Agronomy & Peanut Functional Genome and Molecular Breeding Engineering, Henan Agricultural University, Zhengzhou, 450046, China.
J Integr Plant Biol. 2025 May;67(5):1364-1378. doi: 10.1111/jipb.13847. Epub 2025 Jan 24.
Seed color is a key agronomic trait in crops such as peanut, where it is a vital indicator of both nutritional and commercial value. In recent years, peanuts with darker seed coats have gained market attention due to their high anthocyanin content. Here, we used bulk segregant analysis to identify the gene associated with the purplish-red coat trait and identified a novel gene encoding a basic/helix-loop-helix transcription factor, PURPLE RED SEED COAT1 (PSC1), which regulates the accumulation of anthocyanins in the seed coat. Specifically, we found that a 35-bp insertion in the PSC1 promoter increased the abundance of PSC1 mRNA. Transcriptomic and metabolomic analyses indicated that the purplish-red color of the seed coat was the result of decreased expression of anthocyanidin reductase (ANR), leading to increased accumulation of delphinidin, cyanidin, and pelargonidin derivatives. Further analysis revealed that PSC1 interacts with AhMYB7 to form a complex that specifically binds to the ANR promoter to suppress its expression, resulting in increased anthocyanin accumulation. Moreover, overexpression of PSC1 increased anthocyanin content in Arabidopsis thaliana and peanut callus. Our study reveals a new gene that controls seed coat color by regulating anthocyanin metabolism and provides a valuable genetic resource for breeding peanuts with a purplish-red seed coat.
种皮颜色是花生等作物的关键农艺性状，它是营养和商业价值的重要指标。近年来，种皮颜色较深的花生因其高花青素含量而受到市场关注。在这里，我们使用混合分组分析法来鉴定与紫红色种皮性状相关的基因，并鉴定出一个编码碱性/螺旋-环-螺旋转录因子的新基因——紫红色种皮1（PSC1），该基因调控种皮中花青素的积累。具体而言，我们发现PSC1启动子中的一个35bp插入增加了PSC1 mRNA的丰度。转录组学和代谢组学分析表明，种皮的紫红色是花青素还原酶（ANR）表达降低的结果，导致飞燕草素、矢车菊素和天竺葵素衍生物的积累增加。进一步分析表明，PSC1与AhMYB7相互作用形成复合物，该复合物特异性结合ANR启动子以抑制其表达，从而导致花青素积累增加。此外，PSC1的过表达增加了拟南芥和花生愈伤组织中的花青素含量。我们的研究揭示了一个通过调控花青素代谢来控制种皮颜色的新基因，并为培育具有紫红色种皮的花生提供了宝贵的遗传资源。
