Chalcone synthase promoter activity and sanguinarine accumulation in transgenic Eschscholzia californica suspension cultures.

摘要

To investigate the influence of exogenous addition of methyl jasmonate (MeJA) in the elicitation process and to quantify the relationship between chalcone synthase promoter induction and sanguinarine accumulation in suspension-cultured cells, Eschscholtzia californica and Nicotiana tobacum were genetically transformed with a chimeric gene via Agrobacterium tumefaciens Bo542. The chimeric gene which consisted of a bean ( Phaseolus vulgaris L.) chalcone synthase (CHS) or the cauliflower mosaic virus (CaMV 35S) promoter fused transcriptionally to a bacterial β-glucorunidase (GUS) reporter gene was strongly expressed in transgenic suspension cultures of tobacco and California poppy and further induced by a yeast elicitor, methyl jasmonate (MeJA) and ethanol.; Exogenous addition of MeJA and ethanol induced the CHS promoter in transgenic tobacco, and induced the CHS promoter and sanguinarine accumulation in California poppy suspension cultures in a dose-dependent manner. Induction kinetics show similar patterns of transgene expression with yeast, MeJA and ethanol in transgenic tobacco suspension cultures. Expression was measurable within 15–20 min, reached its maximum 2–3hr post-elicitation and declined to baseline levels within 5 hr. Repeated yeast and ethanol elicitation showed repeated CHS activation with lower CHS activity at the second elicitation but MeJA showed no further CHS activation.; CHS and CaMV 35S promoters respond to MeJA elicitation to a similar extent, indicating that the cis-elements necessary for promoter activation is probably conserved or there is a central signal transduction pathway involved in the transcriptional activation of defense-related genes. The induction of CHS and CaMV 358 by MeJA and ethanol treatment provoking the elicitation process is strictly correlated with the accumulation of sanguinarine in transgenic California poppy. A strong correlation was shown between CHS promoter induction and sanguinarine accumulation in California poppy suspension cultures.