Transcription factors TgbHLH95 and TgbZIP44 cotarget terpene biosynthesis geneTgGPPSinTorreya grandisnuts

• DOI: 10.1093/plphys/kiad385
• Publication Date: 2023-07-03T19:00:11Z
• Authors: Zuying Zhang; Liu Tao; Lingling Gao; Yadi Gao; Jinwei Suo; Weiyu Yu; Yuanyuan Hu; Chunyan Wei; Mohamed A Farag; Jiasheng Wu; Lili Song
• Keywords: Monoterpene; Terpene; Bimolecular fluorescence complementation; Protein-fragment complementation assay

Abstract Terpenes are volatile compounds responsible for aroma and the postharvest quality of commercially important xiangfei (Torreya grandis) nuts, there is interest in understanding regulation their biosynthesis. Here, a transcriptomics analysis nuts after harvest identified 156 genes associated with terpenoid metabolic pathway. A geranyl diphosphate (GPP) synthase (TgGPPS) involved production monoterpene precursor GPP was targeted functional characterization, its transcript levels positively correlated terpene levels. Furthermore, transient overexpression TgGPPS tobacco (Nicotiana tabacum) leaves or tomato (Solanum lycopersicum) fruit led to accumulation. Analysis differentially expressed transcription factors one basic helix-loop-helix protein (TgbHLH95) leucine zipper (TgbZIP44) as potential regulators. TgbHLH95 showed significant transactivation promoter, accumulation, whereas TgbZIP44 directly bound an ACGT-containing element determined by yeast 1-hybrid test electrophoretic mobility shift assay. Bimolecular fluorescence complementation, firefly luciferase complementation imaging, co-immunoprecipitation, GST pull-down assays confirmed direct protein–protein interaction between vivo vitro, combination these proteins induced promoter up 4.7-fold assays. These results indicate that TgbHLH95/TgbZIP44 complex activates upregulates biosynthesis harvest, thereby contributing aroma.