Jiang Haixia, Guo Dongliang, Liu Yuanyuan, Zhu Leilei, Xie Fang, Xie Liqiong
Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, China.
Front Plant Sci. 2022 Oct 25;13:1015399. doi: 10.3389/fpls.2022.1015399. eCollection 2022.
Seed size is a key determinant of crop yields. Understanding the regulatory mechanisms of seed size is beneficial for improving flax seed yield. In this study, the development of large flax seeds lagged behind that of small seeds, and 1,751 protein-coding genes were differentially expressed in early seeds, torpedo-stage embryos, and endosperms of CIli2719 and Z11637 using RNA sequencing. Homologous alignment revealed that 129 differentially expressed genes (DEGs) in flax were homologous with 71 known seed size-related genes in and rice ( L.). These DEGs controlled seed size through multiple processes and factors, among which phytohormone pathways and transcription factors were the most important. Moreover, 54 DEGs were found to be associated with seed size and weight in a DEG-based association study. Nucleotide diversity (π) analysis of seed size-related candidate DEGs by homologous alignment and association analysis showed that the π values decreased significantly during flax acclimation from oil to fiber flax, suggesting that some seed size-related candidate genes were selected in this acclimation process. These results provide important resources and genetic foundation for further research on seed size regulation and seed improvement in flax.
种子大小是作物产量的关键决定因素。了解种子大小的调控机制有助于提高亚麻籽产量。在本研究中，大粒亚麻种子的发育落后于小粒种子，利用RNA测序技术在CIli2719和Z11637的早期种子、鱼雷期胚和胚乳中发现1751个蛋白质编码基因差异表达。同源比对显示，亚麻中有129个差异表达基因（DEGs）与拟南芥和水稻（Oryza sativa L.）中71个已知的种子大小相关基因同源。这些DEGs通过多个过程和因素控制种子大小，其中植物激素途径和转录因子最为重要。此外，在基于DEG的关联研究中发现54个DEGs与种子大小和重量相关。通过同源比对和关联分析对种子大小相关候选DEGs进行核苷酸多样性（π）分析，结果表明，在亚麻从油用型向纤维型驯化过程中，π值显著降低，这表明在该驯化过程中一些种子大小相关候选基因被选择。这些结果为进一步研究亚麻种子大小调控和种子改良提供了重要资源和遗传基础。
