Somatic embryo induction and Agrobacterium-mediated transformation of embryonic callus tissue in Phoebe bournei, an endangered woody species in Lauraceae

Abstract

Phoebe bournei, a plant species endemic to China, is a precious timber tree and widely used in landscaping. This tree contains numerous secondary metabolites, underscoring its potential economic value. However, studies on this species, including molecular genetic research, remain limited. In this study, both a somatic embryogenesis (SE) technical system and Agrobacterium-mediated genetic transformation were successfully employed in P. bournei for the first time. The SE technical system was constructed using immature embryos as original material. The primary embryo and embryonic callus induction rates were 30.66% and 41.67%, respectively. The highest rate of embryonic callus proliferation was 3.84. The maximum maturity coefficient and germination rate were 53.44/g and 39%, respectively. Agrobacterium-mediated genetic transformation was performed using the SE technical system, and the highest transformation rate was 11.24%. The results presented here are the first to demonstrate an efficient approach to achieve numerous P. bournei plantlets, which serves as the basis for artificial cultivation and resource conservation. Furthermore, the genetic transformation platform constructed in this study will facilitate assessment of gene function and molecular regulation.