Regeneration of Transgenic Carica papaya and Biochemical Analysis of Arabidopsis thaliana Containing the Stilbene Synthase Gene for Resistance to Phytophthora palmivora

Abstract

Papaya (Carica papaya L.) is an important tropical fruit crop due to its productivity and high nutrient content. Production of papaya is diminished by infection by the oomycete pathogen Phytophthora palmivora, which causes root, stem and fruit rot. To increase resistance to this important pathogen, papaya was previously engineered with the Vst1 gene from grapevine, which codes for the enzyme stilbene synthase, under the control of 4 different native papaya promoters. Stilbene synthase catalyzes the biosynthesis of the antimicrobial compound resveratrol. In this study, papaya were regenerated from somatic embryos to normal papaya plants using auxins 2, 4-dichlorophenoxyacetic acid and indole 3-butyric acid, as well as the cytokinin 6-benzylaminopurine. Additionally, Arabidopsis thaliana plants that were previously transformed with the same genetic constructs were used as heterologous models to investigate phenotypic and metabolic effects of ectopic Vst1 expression and biosynthesis of the resveratrol derivative picied.