Hsiang Tzu-Fan, Yamane Hisayo, Lin Yuan-Jui, Sugimori Miku, Nishiyama Soichiro, Nagasaka Kyoka, Nakano Ryohei, Tao Ryutaro
Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
Experimental Farm, Graduate School of Agriculture, Kyoto University, Kyoto 619-0218, Japan.
DNA Res. 2024 Dec 27;32(1). doi: 10.1093/dnares/dsae034.
Bud dormancy is a vital physiological process in woody perennials, facilitating their adaptation to seasonal environmental changes. Satisfying genotype-specific chilling requirements (CR) and heat requirements (HR) through exposure to specific chilling and warm temperatures is essential for dormancy release and the subsequent resumption of growth. The genetic mechanisms regulating bud dormancy traits in Prunus mume remain unclear. In this study, we first assembled the genome of 'Nanko', the leading P. mume cultivar in Japan, in a haplotype-resolved manner. Using an F1 segregating population from a cross between 'Nanko' (high-chill) and 'SC' (low-chill), a cultivar adapted to subtropical conditions, we identified quantitative trait loci (QTLs) for vegetative bud dormancy traits on chromosome 4 (LG4 QTLs) in the 'Nanko' genome and for CR and HR on chromosome 7 (LG7 QTL) in the 'SC' genome. A notable 5.6 Mb chromosome inversion was overlapped with LG4 QTL interval in one of the 'Nanko' haplotypes. We also identified candidate genes based on haplotyping, differential expression between the parents or the presence of trait-correlated variants in coding regions. Notably, genes such as PmuMAIN, PmuNAC2, PmuDOG1, PmuSUI1, PmuATG8CL, PmubZIP44, and PmuSAUR50 were identified. This study provides valuable insights into the genetic regulation of vegetative bud dormancy in Prunus species.
芽休眠是木本多年生植物的一个重要生理过程，有助于它们适应季节性环境变化。通过暴露于特定的低温和温暖温度来满足基因型特异性的低温需求（CR）和高温需求（HR），对于休眠解除和随后的生长恢复至关重要。梅树中调控芽休眠性状的遗传机制仍不清楚。在本研究中，我们首先以单倍型解析的方式组装了日本主要梅品种‘南光’的基因组。利用‘南光’（高需冷量）和‘SC’（低需冷量）（一个适应亚热带条件的品种）杂交产生的F1分离群体，我们在‘南光’基因组的第4号染色体上鉴定了营养芽休眠性状的数量性状位点（QTLs）（LG4 QTLs），在‘SC’基因组的第7号染色体上鉴定了低温需求和高温需求的QTL（LG7 QTL）。在‘南光’的一个单倍型中，一个显著的5.6 Mb染色体倒位与LG4 QTL区间重叠。我们还基于单倍型分析、亲本间差异表达或编码区中与性状相关变异的存在鉴定了候选基因。值得注意的是，鉴定出了PmuMAIN、PmuNAC2、PmuDOG1、PmuSUI1、PmuATG8CL、PmubZIP44和PmuSAUR50等基因。本研究为李属植物营养芽休眠的遗传调控提供了有价值的见解。
