Tang Yanyan, Zhou Xiantao, Li Xin, Zhou Cai, Wang Wenlin, Zhou Mo, Hu Zhicheng, Li Xiaobei, Zhang Kaiyuan, Wang Siming, Zhang Zhihao, Chen Hao, Wang Jingshan, Qiao Lixian
College of Agronomy, Qingdao Agricultural University, Qingdao, 266109, Shandong, China.
Institute of Crop Sciences, Fujian Research Station of Crop Gene Resource & Germplasm Enhancement, Fujian Academy of Agricultural Sciences, Fuzhou, China.
Theor Appl Genet. 2025 May 13;138(6):117. doi: 10.1007/s00122-025-04903-1.
AhRt3, which governs the red testa of peanut, was narrowed down to a 125.30 kb region, and one gene encoding anthocyanin reductase was identified as the putative candidate gene. Testa color is a special characteristic of peanuts (Arachis hypogaea L.), and those with dark testa have been focused on recent years owing to their high-anthocyanin content and increased antioxidant nutritional value. However, the genetic mechanisms underlying this trait remain limited. To identify the gene responsible for the red testa color in peanuts, an F population was constructed by crossing YH91 (pink testa) with JHT1 (red testa). Genetic analysis revealed that the red testa was controlled by a single dominant gene named AhRt3 (Arachis hypogaea Red Testa 3). Through bulked segregant analysis sequencing, AhRt3 was preliminarily mapped to the chromosome Arahy.03 and subsequently narrowed to a 125.30 kb genomic region containing 12 potential candidate genes. RNA-seq analysis revealed that 4,880 genes were differentially expressed in the seed testa, with only the candidate gene Arahy.W8TDEC exhibiting higher expression levels in JHT1 than in YH91. Additionally, sequence variation, functional annotation, and expression profiling confirmed that Arahy.W8TDEC, which encodes an anthocyanin reductase, may be a candidate gene for AhRt3. The structural variation involving an inversion between the sixth exon and the 3'UTR of Arahy.W8TDEC resulted in altered amino acids closely associated with the red testa phenotype in peanuts. In conclusion, this study highlights the role of a novel gene in regulating red testa and contributes valuable insights into the genetic basis of seed testa in peanuts.
控制花生红色种皮的AhRt3基因被定位到一个125.30 kb的区域，并鉴定出一个编码花青素还原酶的基因作为推定的候选基因。种皮颜色是花生（Arachis hypogaea L.）的一个特殊特征，近年来，深色种皮的花生因其高花青素含量和增加的抗氧化营养价值而受到关注。然而，该性状的遗传机制仍然有限。为了鉴定控制花生红色种皮颜色的基因，通过将YH91（粉色种皮）与JHT1（红色种皮）杂交构建了一个F群体。遗传分析表明，红色种皮由一个名为AhRt3（花生红色种皮3）的单显性基因控制。通过混合分组分析法测序，AhRt3基因初步定位到Arahy.03染色体上，随后缩小到一个包含12个潜在候选基因的125.30 kb基因组区域。RNA测序分析表明，4880个基因在种子种皮中差异表达，只有候选基因Arahy.W8TDEC在JHT1中的表达水平高于YH91。此外，序列变异、功能注释和表达谱分析证实，编码花青素还原酶的Arahy.W8TDEC可能是AhRt3的候选基因。涉及Arahy.W8TDEC第六外显子与3'UTR之间倒位的结构变异导致了与花生红色种皮表型密切相关的氨基酸改变。总之，本研究突出了一个新基因在调节红色种皮中的作用，并为花生种子种皮的遗传基础提供了有价值的见解。
