College of Horticulture and Gardening, Yangtze University, Jingzhou, 434025, Hubei, China.
College of Horticulture and Gardening, Yangtze University, Jingzhou, 434025, Hubei, China.
J Plant Physiol. 2023 Aug;287:154054. doi: 10.1016/j.jplph.2023.154054. Epub 2023 Jul 16.
Ginkgo biloba is the oldest relict plant on Earth and an economic plant resource derived from China. Flavonoids extracted from G. biloba are beneficial to the prevention and treatment of cardiovascular and cerebrovascular diseases. Basic leucine zipper (bZIP) transcription factors (TFs) have been recognized to play important roles in plant secondary metabolism. In this study, GbbZIP08 was isolated and characterized. It encodes a protein containing 154 amino acids, which belongs to hypocotyl 5 in group H of the bZIP family. Tobacco transient expression assay indicated that GbbZIP08 was localized in the plant nucleus. GbbZIP08 overexpression showed that the contents of total flavonoids, kaempferol, and anthocyanin in transgenic tobacco were significantly higher than those in the wild type. Transcriptome sequencing analysis revealed significant upregulation of structural genes in the flavonoid biosynthesis pathway. In addition, phytohormone signal transduction pathways, such as the abscisic acid, salicylic acid, auxin, and jasmonic acid pathways, were enriched with a large number of differentially expressed genes. TFs such as MYB, AP2, WRKY, NAC, bZIP, and bHLH, were also differentially expressed. The above results indicated that GbbZIP08 overexpression promoted flavonoid accumulation and increased the transcription levels of flavonoid-synthesis-related genes in plants.
银杏是地球上最古老的孑遗植物之一，也是一种源自中国的经济植物资源。从银杏中提取的类黄酮有益于预防和治疗心脑血管疾病。基本亮氨酸拉链（bZIP）转录因子（TFs）已被认为在植物次生代谢中发挥重要作用。本研究从银杏中分离和鉴定了 GbbZIP08。它编码一个含有 154 个氨基酸的蛋白质，属于 bZIP 家族 H 亚组的下胚轴 5。烟草瞬时表达试验表明，GbbZIP08 定位于植物细胞核内。GbbZIP08 的过表达导致转基因烟草中总黄酮、山奈酚和花青素的含量明显高于野生型。转录组测序分析显示，类黄酮生物合成途径中的结构基因表达显著上调。此外，植物激素信号转导途径，如脱落酸、水杨酸、生长素和茉莉酸途径，也富集了大量差异表达基因。TFs 如 MYB、AP2、WRKY、NAC、bZIP 和 bHLH 也表现出差异表达。上述结果表明，GbbZIP08 的过表达促进了黄酮类化合物的积累，并增加了植物中黄酮类化合物合成相关基因的转录水平。
