Stress-induced curcin-L promoter in leaves of <Emphasis Type="Italic">Jatropha curcas</Emphasis> L. and characterization in transgenic tobacco

Ribosome-inactivating proteins (RIPs) represent a type of protein that universally inactivates the ribosome thus inhibiting protein biosynthesis. Curcin-L was a type I RIP found in Jatropha curcas L.. Its expression could be activated in leaves by treatments with abscisic acid, salicylic acid, polyethylene glycol, temperature 4, 45°C and ultraviolet light. A 654 bp fragment of a 5′ flanking region preceding the curcin-L gene, designated CP2, was cloned from the J. curcas genome and its expression pattern was studied via the expression of the β-glucuronidase (GUS) gene in transgenic tobacco. Analysis of GUS activities showed that the CP2 was leaf specific, and was able to drive the expression of the reporter gene under stress-induction conditions. Analysis of a series of 5′-deletions of the CP2 suggested that several promoter motifs were necessary to respond to environmental stresses.