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

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.