College of Agronomy/Institute of Molecular Agriculture and Bioenergy, Shanxi Agricultural University, Shanxi Engineering Research Center for Genetics and Metabolism of Special Crops, Taigu, Shanxi, China.
College of Biological Science and Technology, Jinzhong University, Jinzhong, Shanxi, China.
Int J Biol Macromol. 2024 Jun;270(Pt 1):132273. doi: 10.1016/j.ijbiomac.2024.132273. Epub 2024 May 9.
The basic leucine zipper (bZIP) transcription factors (TFs) function importantly in numerous life processes in plants. However, bZIP members and their biological roles remain unknown in Camelina sativa, a worldwide promising oil crop. Here, 220 CsbZIP proteins were identified in camelina and classified into thirteen groups. Two and 347 pairs of tandem and segmental duplication genes were detected to be underwent purification selection, with segmental duplication as the main driven-force of CsbZIP gene family expansion. Most CsbZIP genes displayed a tissue-specific expression pattern. Particularly, CsbZIP-A12 significantly positively correlated with many FA/oil biosynthesis-related genes, indicating CsbZIP-A12 may regulate lipid biosynthesis. Notably, yeast one-hybrid (Y1H), β-Glucuronidase (GUS), dual-luciferase (LUC) and EMSA assays evidenced that CsbZIP-A12 located in nucleus interacted with the promoters of CsSAD2-3 and CsFAD3-3 genes responsible for unsaturated fatty acid (UFA) synthesis, thus activating their transcriptions. Overexpression of CsbZIP-A12 led to an increase of total lipid by 3.275 % compared to the control, followed with oleic and α-linolenic acid levels enhanced by 3.4 % and 5.195 %, and up-regulated the expressions of CsSAD2-3, CsFAD3-3 and CsPDAT2-3 in camelina seeds. Furthermore, heterogeneous expression of CsbZIP-A12 significantly up-regulated the expressions of NtSAD2, NtFAD3 and NtPDAT genes in tobacco plants, thereby improving the levels of total lipids and UFAs in both leaves and seeds without negative effects on other agronomic traits. Together, our findings suggest that CsbZIP-A12 upregulates FA/oil biosynthesis by activating CsSAD2-3 and CsFAD3-3 as well as possible other related genes. These data lay a foundation for further functional analyses of CsbZIPs, providing new insights into the TF-based lipid metabolic engineering to increase vegetable oil yield and health-beneficial quality in oilseeds.
基本亮氨酸拉链 (bZIP) 转录因子 (TF) 在植物的许多生命过程中发挥着重要作用。然而，bZIP 成员及其生物学功能在全世界有前途的油用作物荠蓝中尚不清楚。在这里，在荠蓝中鉴定了 220 种 CsbZIP 蛋白，并将其分为 13 组。检测到两个和 347 对串联和片段重复基因经历了纯化选择，以片段重复作为 CsbZIP 基因家族扩张的主要驱动力。大多数 CsbZIP 基因表现出组织特异性表达模式。特别是，CsbZIP-A12 与许多 FA/油生物合成相关基因显著正相关，表明 CsbZIP-A12 可能调节脂质生物合成。值得注意的是，酵母单杂交 (Y1H)、β-葡萄糖醛酸酶 (GUS)、双荧光素酶 (LUC) 和 EMSA 实验证明，CsbZIP-A12 位于细胞核内与负责不饱和脂肪酸 (UFA) 合成的 CsSAD2-3 和 CsFAD3-3 基因的启动子相互作用，从而激活它们的转录。与对照相比，CsbZIP-A12 的过表达导致总脂质增加了 3.275%，油酸和α-亚麻酸水平分别提高了 3.4%和 5.195%，并上调了荠蓝种子中 CsSAD2-3、CsFAD3-3 和 CsPDAT2-3 的表达。此外，CsbZIP-A12 的异源表达显著上调了烟草植物中 NtSAD2、NtFAD3 和 NtPDAT 基因的表达，从而提高了叶片和种子中总脂质和 UFA 的水平，而对其他农艺性状没有负面影响。总之，我们的研究结果表明，CsbZIP-A12 通过激活 CsSAD2-3 和 CsFAD3-3 以及可能的其他相关基因来上调 FA/油生物合成。这些数据为进一步研究 CsbZIP 的功能奠定了基础，为基于 TF 的脂质代谢工程提供了新的见解，以提高油籽中蔬菜油的产量和有益健康的质量。
