Characterization and cDNA-microarray expression analysis of 12-oxophytodienoate reductases reveals differential roles for octadecanoid biosynthesis in the local versus the systemic wound response.
Characterization and cDNA-microarray expression analysis of 12-oxophytodienoate reductases reveals differential roles for octadecanoid biosynthesis in the local versus the systemic wound response.
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DOI：
10.1046/j.1365-313x.2002.01449.x
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发表时间：
2002-11
期刊：
影响因子：
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通讯作者：
J. Strassner;F. Schaller;Ursula B. Frick;G. Howe;E. Weiler;N. Amrhein;P. Macheroux;A. Schaller
中科院分区：
文献类型：
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作者：
J. Strassner;F. Schaller;Ursula B. Frick;G. Howe;E. Weiler;N. Amrhein;P. Macheroux;A. Schaller
12-氧代植物二烯酸还原酶（Oxophytodienoate reductases，OPRs）属于黄素依赖性氧化还原酶家族。随着两个新的番茄异构体在这里报道，三个OPR现在已经在番茄和拟南芥的特点。这些异构体中只有一种（OPR 3）直接参与茉莉酸生物合成的十八烷途径，因为只有OPR 3还原茉莉酸的生物前体12-氧代植物二烯酸的9 S，13 S-立体异构体。在番茄和拟南芥中分析了OPR的亚细胞定位。OPR 3蛋白和活性始终存在于过氧化物酶体中，在过氧化物酶体中它们与催化茉莉酸形成的最后步骤的β-氧化酶共定位。因此，十八烷途径仅限于质体和过氧化物酶体，与以前的假设相反，不涉及胞质隔室。使用包含233个cDNA探针的微阵列分析了番茄（Lycopersicon esculentum，Le）OPR 3在防御相关基因背景下的表达。发现LeOPR 3在创伤后上调，其诱导动力学类似于其他十八烷酸途径酶。与伤口反应蛋白（如蛋白酶抑制剂）基因的诱导相反，十八烷途径转录本的积累被发现在受伤的叶片中更迅速和短暂，但在未受伤的系统性叶片中几乎检测不到。与表达数据一致，发现OPDA和JA在受伤的番茄植物的叶片中局部而非系统地积累。因此，十八烷途径的转录激活和JA积累到高水平不是激活系统组织中防御基因表达所必需的。
12-Oxophytodienoate reductases (OPRs) belong to a family of flavin-dependent oxidoreductases. With two new tomato isoforms reported here, three OPRs have now been characterized in both tomato and Arabidopsis. Only one of these isoforms (OPR3) participates directly in the octadecanoid pathway for jasmonic acid biosynthesis, as only OPR3 reduces the 9S,13S-stereoisomer of 12-oxophytodienoic acid, the biological precursor of jasmonic acid. The subcellular localization of OPRs was analyzed in tomato and Arabidopsis. The OPR3 protein and activity were consistently found in peroxisomes where they co-localize with the enzymes of beta-oxidation which catalyze the final steps in the formation of jasmonic acid. The octadecanoid pathway is thus confined to plastids and peroxisomes and, in contrast to previous assumptions, does not involve the cytosolic compartment. The expression of tomato (Lycopersicon esculentum,Le) OPR3 was analyzed in the context of defense-related genes using a microarray comprising 233 cDNA probes. LeOPR3 was found to be up-regulated after wounding with induction kinetics resembling those of other octadecanoid pathway enzymes. In contrast to the induction of genes for wound response proteins (e.g. proteinase inhibitors), the accumulation of octadecanoid pathway transcripts was found to be more rapid and transient in wounded leaves, but hardly detectable in unwounded, systemic leaves. Consistent with the expression data, OPDA and JA were found to accumulate locally but not systemically in the leaves of wounded tomato plants. The transcriptional activation of the octadecanoid pathway and the accumulation of JA to high levels are, thus not required for the activation of defense gene expression in systemic tissues.