Expression of Lipoxygenase in Wounded Tubers of Solanum tuberosum L
Expression of Lipoxygenase in Wounded Tubers of Solanum tuberosum L
复制标题
马铃薯受伤块茎中脂氧合酶的表达
作者：
A. Geerts;D. Feltkamp;S. Rosahl
马铃薯脂肪氧合酶cDNA克隆。研究了脂肪氧合酶在马铃薯发育和创伤反应中的作用。序列分析和推导的氨基酸序列的比较表明，与其他植物脂氧合酶的同源性较高。在大肠杆菌中的cDNA序列的表达和随后的细菌蛋白质提取物的分析表明，使用亚油酸，亚麻酸，或花生四烯酸作为底物的脂氧合酶活性。马铃薯脂肪氧合酶基因在块茎组织中含量最高，在根中含量较低，在叶、叶柄和茎中几乎检测不到。在块茎中的脂肪氧合酶表达的诱导损伤依赖于各种参数。而脂氧合酶转录水平增加光盘从存储的块茎在有氧条件下孵育，块茎从生长中的植物没有积累脂氧合酶转录响应受伤。块茎光盘在缓冲液中孵育没有导致脂肪氧合酶RNA水平的增加，然而，茉莉酸甲酯刺激脂肪氧合酶的表达后24小时在存储的块茎。蛋白酶抑制剂II mRNA在储存的块茎中以及在来自生长的块茎的圆盘中减少。
A lipoxygenase cDNA clone from Solanum tuberosum L. was analyzed to study the role of lipoxygenases in potato development and wound response. Sequence analysis and comparison of the deduced amino acid sequence revealed high homology to other plant lipoxygenases. Expression of the cDNA sequences in Escherichia coli and subsequent analysis of bacterial protein extracts showed lipoxygenase activity using linoleic, linolenic, or arachidonic acid as substrates. Transcripts encoding the potato lipoxygenase were most abundant in tuber tissue, lower in roots, and hardly detectable in leaves, petioles, and stems. The induction of lipoxygenase expression in tubers by wounding was dependent on various parameters. Whereas lipoxygenase transcript levels increased in discs from stored tubers incubated under aerobic conditions, tubers taken from a growing plant did not accumulate lipoxygenase transcripts in response to wounding. Incubation of tuber discs in buffer did not lead to an increase in lipoxygenase RNA levels; however, methyl jasmonate stimulated lipoxygenase expression after 24 h in stored tubers. Proteinase inhibitor II mRNAs decreased in stored tubers as well as in discs from growing tubers.