Qu Zhaoyang, Tian Ze, Wei Liqing, Wang Chao, Kuang Lieqiong, Yan Jiaqi, Wang Furong, Wang Nian, Tu Jinxing, Wang Xinfa, Wang Hanzhong, Dun Xiaoling
Key Laboratory of Biology and Genetic Improvement of Oil Crops, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Ministry of Agriculture and Rural Affairs, Wuhan, China.
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China.
Plant Biotechnol J. 2025 Jun 18. doi: 10.1111/pbi.70184.
Seed weight (SW), which is directly influenced by silique length (SL), is a critical agronomic trait significantly affecting both the quality and yield of rapeseed. In this study, a shorter silique length (ssl) mutant was generated through ethyl methane sulfonate mutagenesis, exhibiting reduced SL and SW compared to the wild type. Utilizing a map-based cloning approach, BnaC01.CCT8, a member of the chaperonin containing T-complex polypeptide-1 (CCT) family, was identified as the gene responsible for restoring the ssl phenotype. A missense mutation from alanine to valine (A507V) in BnaC01.CCT8 was identified as crucial for its functional activity, as evidenced by the genetic complementation of BnaC01.CCT8 and BnaC01.CCT8 in the Arabidopsis cct8-2 background. Moreover, overexpression of BnaC01.CCT8 in Brassica napus significantly enhanced SL, SW and seed yield per plant. Conversely, CRISPR/Cas9-mediated bnac01.cct8 knockout lines exhibited reduced SL and SW. Transcriptome analysis and hormone content detection indicated that BnaC01.CCT8 positively regulated SL and SW primarily by modulating auxin and jasmonic acid signalling, thereby affecting the length of epidermal cells in the silique wall. Furthermore, BnaC01.CCT8 interacted with BnaA09.ARF18 (AUXIN-RESPONSE FACTOR 18), contributing to the regulation of SL and SW, while the A507V mutation disrupted this interaction. Haplotype analysis demonstrated that several SNP differences in BnaC01.CCT8 were significantly associated with variations in SL and SW among germplasm resources, revealing superior alleles of BnaC01.CCT8. The identification and functional analysis of BnaC01.CCT8 provide new insights into the mechanisms regulating SL and SW and present a valuable target for the genetic enhancement of rapeseed yield.
种子重量（SW）直接受角果长度（SL）影响，是一个关键的农艺性状，对油菜籽的品质和产量都有显著影响。在本研究中，通过甲基磺酸乙酯诱变产生了一个角果长度较短（ssl）的突变体，与野生型相比，其SL和SW均降低。利用基于图谱的克隆方法，鉴定出伴侣蛋白包含T-复合体多肽-1（CCT）家族的成员BnaC01.CCT8是负责恢复ssl表型的基因。在BnaC01.CCT8中鉴定出一个从丙氨酸到缬氨酸的错义突变（A507V）对其功能活性至关重要，这在拟南芥cct8-2背景下BnaC01.CCT8和BnaC01.CCT8的遗传互补中得到了证明。此外，在甘蓝型油菜中过表达BnaC01.CCT8显著提高了SL、SW和单株种子产量。相反，CRISPR/Cas9介导的bnac01.cct8敲除系的SL和SW降低。转录组分析和激素含量检测表明，BnaC01.CCT8主要通过调节生长素和茉莉酸信号通路来正向调控SL和SW，从而影响角果壁表皮细胞的长度。此外，BnaC01.CCT8与BnaA09.ARF18（生长素响应因子18）相互作用，有助于调控SL和SW，而A507V突变破坏了这种相互作用。单倍型分析表明，BnaC01.CCT8中的几个SNP差异与种质资源中SL和SW的变异显著相关，揭示了BnaC01.CCT8的优良等位基因。BnaC01.CCT8的鉴定和功能分析为调控SL和SW的机制提供了新的见解，并为油菜籽产量的遗传改良提供了一个有价值的靶点。
