Identification of G-Box Sequence as an Essential Element for Methyl Jasmonate Response of Potato Proteinase Inhibitor II Promoter

Abstract

The potato proteinase inhibitor II promoter was studied to identify cis-acting regulatory sequences involved in methyl jasmonate (MJ) response using transgenic tobacco plants carrying various lengths of the promoter fused to a chloramphenicol acetyltransferase reporter gene. An internal fragment between -625 and -520 was sufficient to confer a response to MJ, wounding, or sucrose when it was placed upstream of the nos promoter -101, which contains the CAAT-TATA region. Deletion of the proteinase inhibitor II promoter sequence upstream of -611 did not affect the MJ response, but a further deletion to -573 eliminated the response. The 3'-deletion study showed that the DNA sequence downstream from -520 is dispensable. However, 3'-deletion mutant -574 did not respond to the MJ treatment. These results indicated that an element essential for the MJ response is located at the -574/-573 region where the G-box sequence (CACGTGG) is located. The G-box sequence was not required for the sucrose enhancer effect, suggesting that the MJ response mechanism is different from that of sucrose.