Geerts A, Feltkamp D, Rosahl S
Max-Planck-Institut für Züchtungsforschung, Abteilung Genetische Grundlagen der Pflanzenzüchtung, Köln, Germany.
Plant Physiol. 1994 May;105(1):269-77. doi: 10.1104/pp.105.1.269.
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.
对来自马铃薯（Solanum tuberosum L.）的一个脂氧合酶cDNA克隆进行了分析，以研究脂氧合酶在马铃薯发育和创伤反应中的作用。对推导的氨基酸序列进行序列分析和比较，发现其与其他植物脂氧合酶具有高度同源性。将cDNA序列在大肠杆菌中表达，随后对细菌蛋白提取物进行分析，结果表明以亚油酸、亚麻酸或花生四烯酸为底物时具有脂氧合酶活性。编码马铃薯脂氧合酶的转录本在块茎组织中最为丰富，在根中较低，而在叶、叶柄和茎中几乎检测不到。创伤对块茎中脂氧合酶表达的诱导取决于各种参数。在有氧条件下培养的储存块茎的圆片中，脂氧合酶转录水平增加，而取自生长植株的块茎在创伤后不会积累脂氧合酶转录本。在缓冲液中培养块茎圆片不会导致脂氧合酶RNA水平升高；然而，茉莉酸甲酯在储存块茎中培养24小时后刺激了脂氧合酶的表达。蛋白酶抑制剂II mRNA在储存块茎以及生长块茎的圆片中均减少。
