Unveiling the Catalytic Roles of <i>DsBBS1</i> and <i>DsBBS2</i> in the Bibenzyl Biosynthesis of <i>Dendrobium sinense</i>
Liyan Liu,
Huiyan You,
Lixuan Ye,
Qiongjian Ou,
Ying Zhao,
Jia Wang,
Jun Niu
Affiliations
Liyan Liu
Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants—Ministry of Education, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
Huiyan You
Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants—Ministry of Education, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
Lixuan Ye
Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants—Ministry of Education, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
Qiongjian Ou
Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants—Ministry of Education, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
Ying Zhao
Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants—Ministry of Education, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
Jia Wang
Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants—Ministry of Education, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
Jun Niu
Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants—Ministry of Education, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
Dendrobium sinense, an endemic medicinal herb in Hainan Island, is rich in bibenzyl compounds. However, few studies have explored the molecular mechanisms of bibenzyl biosynthesis. This study presents a comprehensive analysis of DsBBS1 and DsBBS2 function in D. sinense. A molecular docking simulation revealed high-resolution three-dimensional structural models with minor domain orientation differences. Expression analyses of DsBBS1 and DsBBS2 across various tissues indicated a consistent pattern, with the highest expression being found in the roots, implying that they play a pivotal role in bibenzyl biosynthesis. Protein expression studies identified optimal conditions for DsBBS2-HisTag expression and purification, resulting in a soluble protein with a molecular weight of approximately 45 kDa. Enzyme activity assays confirmed DsBBS2’s capacity to synthesize resveratrol, exhibiting higher Vmax and lower Km values than DsBBS1. Functional analyses in transgenic Arabidopsis demonstrated that both DsBBS1 and DsBBS2 could complement the Atchs mutant phenotype. The total flavonoid content in the DsBBS1 and DsBBS2 transgenic lines was restored to wild-type levels, while the total bibenzyl content increased. DsBBS1 and DsBBS2 are capable of catalyzing both bibenzyl and flavonoid biosynthesis in Arabidopsis. This study provides valuable insights into the molecular mechanisms underlying the biosynthesis of bibenzyl compounds in D. sinense.
