34 コムギにおいてジャスモン酸によって誘導されるDIMBOA-Glc 4-O-メチルトランスフェラーゼの精製及び性状解析

抄録

S-Adenosyl-L-methionine:DIMBOA-Glc (2-(2,4-dihydroxy-7-methoxy-l,4-benzoxazin-3-onc)-β-D-glucopyranose) 4-O-methyltransferase was purified from JA (jasmonic acid)-treated wheat leaves. This methyltransferase catalyzed the methylation of the hydroxyl group at position 4 of DIMBOA-Glc with S-Adenosyl-L-methionine as the methyl donor to form HDMBOA-Glc (2-(2-hydroxy-4,7-dimethoxy-l,4-benzoxazin-3-one)-β-D-glucopyranose). The activity reached a maximum 9 hours after treatment with JA, and then decreased gradually. The optimum pH and temperature was 7.5 and 35℃, respectively. The activity increased by the application of 1 mM EDTA (ethylenediamine tetra acetate), while heavy metal ions (1 mM) inhibited the activity completely.