OBJECTIVETo analyze the content of periplocin in different part of the Periploca sepium in vitro plantlet and study its dynamic variation during the process of differentiation.

METHODThe seeds were generated seedling under aseptic condition, and the cut hypocotyl was induced to form the callus and adventitious buds on the MS culture medium with the hormone of IBA 0.1 mg x L(-1) + BA 1 mg x L(-1). The seedling was cut down when the buds grew up to 3 cm and then the root was cultured in the 1/2 MS culture medium with the hormone of IBA 0.5 mg x L(-1) to form intact plantlet. Different parts of it were collected and the content of periplocin was measured during the process of differentiation.

RESULTThe contents of periplocin varied widely in different parts during the process of differentiation, with the highest in the roots and then callus, stem and leaf of intact plantlet, stem and leaf of plantlet without root from high to low.

CONCLUSIONThe periplocin of the secondary metabolite is more likely to be produced and accumulated in root and callus. Periplocin in stem and leaf is probably transported by conducting tissue.

Periploca ; chemistry ; growth & development ; metabolism ; Saponins ; analysis ; metabolism ; Tissue Culture Techniques

Hevea brasiliensis is the main source of natural rubber. Restricted by its tropical climate conditions, the planting area in China is limited, resulted in a low self-sufficiency. Periploca sepium which can produce natural rubber is a potential substitute plant. cis-prenyltransferase (CPT), small rubber particle protein (SRPP) and rubber elongation factor (REF) are key enzymes involved in the biosynthesis of cis-1, 4-polyisoprene, the main component of natural rubber. In this study, we cloned the promoter sequences of CPT, SRPP and REF through chromosome walking strategy. The spatial expression patterns of the three promoters were analyzed using GUS (β-glucuronidase) as a reporter gene driven by the promoters through Agrobacterium-mediated genetic transformation. The results showed that GUS driven by CPT, SRPP or REF promoter was expressed in leaves and stems, especially in the leaf vein and vascular bundle. The GUS activity in stems was higher than that in leaf. This study provided a basis for analyzing the biosynthesis mechanism of natural rubber and breeding new varieties of high yield natural rubber.
Peptide Elongation Factors/genetics* ; Plant Proteins/metabolism* ; Periploca/metabolism* ; Rubber ; Plant Breeding ; Cloning, Molecular

OBJECTIVETo study the characteristics of the growth and periplocin accumulation of the adventitious roots of Periploca sepium, and on this basis, study the effect of Ag+ and La3+ elicitors on the growth and periplocin accumulation of the adventitious roots.

METHODThe adventitious roots were sampled every four days, and the dry weight and the contents of the periplocin were measured. The curves of the growth and periplocin accumulation of the roots were plotted. The Ag+ and La3+ elicitors with different concentrations were added to the medium when the adventitious roots grew in the stable phase to study the optimal concentration which was good to synthesize the periplocin. Besides, the optimal concentration of Ag+ and La3+ elicitors was added to the different growth phases to study the effect of the elicitors on the growth and periplocin synthesis of adventitious roots.

RESULTThe characteristics of the growth of adventitious roots of P. sepium showed a typical growth S-Curve, which displayed a half-coupling relationship with the metabolism of periplocin. The optimal concentrations of Ag+ and La3+ elicitors were both 0.05 mmol L(-1). Besides, it was the best period for the Ag+ and La3+ elicitors to elicit the synthesis of periplocin when in the terminally exponential phase.

CONCLUSIONThe growth of adventitious roots and the accumulation of periplocin show a half-coupling relationship. Besides, the concentration and additive time of Ag and La3+ elicitors obviously influences the growth of adventitious roots and synthesis of periplocin.

Drugs, Chinese Herbal ; analysis ; metabolism ; Lanthanum ; metabolism ; Periploca ; chemistry ; growth & development ; metabolism ; Plant Roots ; chemistry ; growth & development ; metabolism ; Saponins ; analysis ; metabolism ; Silver ; metabolism