College of Life Science, Engineering Research Center of the Chinese Ministry of Education for Bioreactor and Pharmaceutical Development, Jilin Agricultural University, Changchun, 130118, China.
Plant Cell Rep. 2023 Jan;42(1):57-72. doi: 10.1007/s00299-022-02936-0. Epub 2022 Oct 30.
The nuclear Factor YB of Carthamus tinctorius L. increased the content of unsaturated fatty acids by regulating the expression of genes involved in fatty acid synthesis and oil accumulation. Safflower (Carthamus tinctorius L.) seed oil is rich in linoleic acid and is widely used in food and medicine. Therefore, key genes regulating oil synthesis were mined through genetic engineering to provide genetic resources for improving oil content. Based on the conserved domain of the NF-YB, we screened and identified 14 CtNF-YB transcription factors in the safflower genome and divided them into three subfamilies through phylogenetic analysis. Regulatory motif analysis of the CtNF-YB promoter revealed specific cis-regulatory elements related to abiotic stress, growth, and development. Expression analysis of CtNF-YB family genes showed that non-Leafy Cotyledon 1(non-LEC1) genes were highly expressed in roots, leaves, and flowers; Leafy Cotyledon 1(LEC1) genes were highly expressed during early seed development; and Dr1-like genes were highly expressed in roots, stems, and leaves. CtNF-YB12 was identified as a LEC1 transcription factor based on phylogeny and BLAST alignment. Heterologous CtNF-YB12 expression in Arabidopsis thaliana increased seed pod length and seed size. Moreover, CtNF-YB12 overexpression increased the oil content of seeds, upregulated genes involved in fatty acid biosynthesis and glycolysis, and altered the content of unsaturated fatty acids, including oleic acid (C18:1), linoleic acid (C18:2), and linolenic acid (C18:3), as well as of sucrose, fructose, and glucose. CtNF-YB12 may increase the oil content by regulating key enzyme genes of oil synthesis, so it can be used as a reliable target.
红花（Carthamus tinctorius L.）种子油富含亚油酸，广泛应用于食品和医药领域。因此，通过基因工程挖掘调控油合成的关键基因，可为提高油含量提供遗传资源。基于 NF-YB 的保守结构域，我们从红花基因组中筛选并鉴定了 14 个 CtNF-YB 转录因子，并通过系统发育分析将其分为三个亚家族。CtNF-YB 启动子调控元件分析揭示了与非生物胁迫、生长和发育相关的特定顺式调控元件。CtNF-YB 家族基因的表达分析表明，非叶状胚乳 1（non-LEC1）基因在根、叶和花中高表达；叶状胚乳 1（LEC1）基因在早期种子发育中高表达；而 Dr1 样基因在根、茎和叶中高表达。基于系统发育和 BLAST 比对，鉴定 CtNF-YB12 为 LEC1 转录因子。在拟南芥中异源表达 CtNF-YB12 可增加种子荚的长度和种子大小。此外，CtNF-YB12 的过表达增加了种子的油含量，上调了脂肪酸生物合成和糖酵解途径中的基因，并改变了不饱和脂肪酸（包括油酸（C18:1）、亚油酸（C18:2）和亚麻酸（C18:3））以及蔗糖、果糖和葡萄糖的含量。CtNF-YB12 可能通过调控油合成关键酶基因来增加油含量，因此可以作为一个可靠的目标。
