Metabolism of salicylic acid in wild-type, ugt74f1 and ugt74f2 glucosyltransferase mutants of Arabidopsis thaliana
Metabolism of salicylic acid in wild-type, ugt74f1 and ugt74f2 glucosyltransferase mutants of Arabidopsis thaliana
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DOI：
10.1111/j.1399-3054.2007.01041.x
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发表时间：
2008-04-01
影响因子：
6.4
通讯作者：
Delaney, Sean P.
中科院分区：
文献类型：
--
作者：
Dean, John V.;Delaney, Sean P.
拟南芥含有两种水杨酸（SA）葡糖基转移酶，命名为UGT 74 F1和UGT 74 F2。UGT 74 F1仅形成SA 2-O-β-D-葡萄糖（SAG），而UGT 74 F2形成SAG和SA葡萄糖酯（SGE）。在试图确定每个SA葡糖基转移酶（SAGT）的体内作用，SA在ugt 74 f1和ugt 74 f2突变体的代谢进行了检查，并与野生型进行了比较。在野生型拟南芥中形成的三种主要代谢物包括SAG、SGE和2，5-二羟基苯甲酸2-O-β-D-葡萄糖（DHB 2G）。这是DHB 2G作为SA在植物中的主要代谢产物的首次描述。在ugt 74 f1突变体中形成的SA的主要代谢产物是SGE、SAG和2，5-二羟基苯甲酸5-O-β-D-葡萄糖（DHB 5G）。DHB 5G在野生型植物中没有形成。SA在ugt 74 f2突变体中的主要代谢产物为SAG和DHB 2G。ugt 74 f2突变体不能形成SGE。在未处理的野生型和ugt 74 f1突变体的体外SAGT测定期间，仅可检测到SGE。该活性是由于组成型UGT 74 F2活性。SA预处理的野生型和ugt 74 f1叶片在体外试验期间均可形成SGE和SAG。在未处理的ugt 74 f2叶的体外SAGT测定期间，既不能检测到SAG也不能检测到SGE。在SA预处理的ugt 74 f2叶片的体外SAGT测定期间仅形成SAG。SAG形成是UGT 74 F1活性的结果。这项工作表明，任何SAGT酶的活性的变化可以有一个显着的影响外源供应的SA在拟南芥中的代谢。
Arabidopsis thaliana contains two salicylic acid (SA) glucosyltransferase enzymes designated UGT74F1 and UGT74F2. UGT74F1 forms only SA 2-O-beta-D-glucose (SAG), while UGT74F2 forms both SAG and the SA glucose ester (SGE). In an attempt to determine the in vivo role of each SA glucosyltransferase (SAGT), the metabolism of SA in ugt74f1 and ugt74f2 mutants was examined and compared with that of the wild-type. The three major metabolites formed in wild-type Arabidopsis included SAG, SGE, and 2,5-dihydroxbenzoic acid 2-O-beta-D-glucose (DHB2G). This is the first description of DHB2G as a major metabolite of SA in plants. The major metabolites of SA formed in ugt74f1 mutants were SGE, SAG and 2,5-dihydroxybenzoic acid 5-O-beta-D-glucose (DHB5G). DHB5G was not formed in the wild-type plants. SAG and DHB2G were the main metabolites of SA in ugt74f2 mutants. The ugt74f2 mutant was unable to form SGE. Only SGE could be detected during in vitro SAGT assays of untreated wild-type and ugt74f1 mutants. This activity was because of constitutive UGT74F2 activity. Both SGE and SAG could be formed during in vitro assays of SA-pretreated wild-type and ugt74f1 leaves. Neither SAG nor SGE could be detected during the in vitro SAGT assays of untreated ugt74f2 leaves. Only SAG was formed during the in vitro SAGT assays of SA-pretreated ugt74f2 leaves. The SAG formation was a result of the UGT74F1 activity. This work demonstrates that changes in the activity of either SAGT enzyme can have a dramatic effect on the metabolism of exogenously supplied SA in Arabidopsis.