Zhao Xiaoqing, Yi Liuxi, Zuo Yongchun, Gao Fengyun, Cheng Yuchen, Zhang Hui, Zhou Yu, Jia Xiaoyun, Su Shaofeng, Zhang Dejian, Zhang Xiangqian, Ren Yongfeng, Mu Yanxin, Jin Xiaolei, Li Qiang, Bateer Siqin, Lu Zhanyuan
Inner Mongolia Academy of Agricultural & Animal Husbandry Sciences, Hohhot 010031, China.
Agricultural College, Inner Mongolia Agricultural University, Hohhot 010019, China.
Plants (Basel). 2023 Jul 26;12(15):2773. doi: 10.3390/plants12152773.
Flax is an economic crop with a long history. It is grown worldwide and is mainly used for edible oil, industry, and textiles. Here, we reported a high-quality genome assembly for "Neiya No. 9", a popular variety widely grown in China. Combining PacBio long reads, Hi-C sequencing, and a genetic map reported previously, a genome assembly of 473.55 Mb was constructed, which covers ~94.7% of the flax genome. These sequences were anchored onto 15 chromosomes. The N50 lengths of the contig and scaffold were 0.91 Mb and 31.72 Mb, respectively. A total of 32,786 protein-coding genes were annotated, and 95.9% of complete BUSCOs were found. Through morphological and cytological observation, the male sterility of flax was considered dominant nuclear sterility. Through GWAS analysis, the gene (cysteine synthase gene) was found to be closest to the most significant SNP, and the expression level of this gene was significantly lower in male sterile plants than in fertile plants. Among the significant SNPs identified in the GWAS analysis, only two were located in the coding region, and these two SNPs caused changes in the protein encoded by (cysteine protease gene). It was speculated that these two genes may be related to male sterility in flax. This is the first time the molecular mechanism of male sterility in flax has been reported. The high-quality genome assembly and the male sterility genes revealed, provided a solid foundation for flax breeding.
亚麻是一种历史悠久的经济作物。它在全球范围内种植，主要用于食用油、工业和纺织。在此，我们报道了对“内亚9号”的高质量基因组组装，“内亚9号”是在中国广泛种植的一个流行品种。结合PacBio长读长测序、Hi-C测序以及先前报道的遗传图谱，构建了一个473.55 Mb的基因组组装，覆盖了亚麻基因组的约94.7%。这些序列被锚定到15条染色体上。重叠群和支架的N50长度分别为0.91 Mb和31.72 Mb。共注释了32786个蛋白质编码基因，发现了95.9%的完整BUSCO。通过形态学和细胞学观察，亚麻的雄性不育被认为是显性核不育。通过全基因组关联研究（GWAS）分析，发现基因（半胱氨酸合酶基因）最接近最显著的单核苷酸多态性（SNP），并且该基因在雄性不育植株中的表达水平显著低于可育植株。在GWAS分析中鉴定出的显著SNP中，只有两个位于编码区，这两个SNP导致了（半胱氨酸蛋白酶基因）编码的蛋白质发生变化。推测这两个基因可能与亚麻的雄性不育有关。这是首次报道亚麻雄性不育的分子机制。所揭示的高质量基因组组装和雄性不育基因，为亚麻育种提供了坚实的基础。
