Station Biologique de Roscoff, UMR 7139 CNRS-UPMC & LIA-DIAMS, Roscoff, France.
J Chem Ecol. 2011 Jul;37(7):677-86. doi: 10.1007/s10886-011-9981-9. Epub 2011 Jun 15.
The red alga Gracilaria chilensis is commercially farmed for the production of agar hydrocolloids, but some susceptible algae in farms suffer from intense epiphyte growth. We investigated the induced chemical defense response of G. chilensis against epiphytes and demonstrated that an extract of an epiphyte-challenged alga can trigger a defense response. The hormonally active metabolites were purified by RP-HPLC. Treatment with the extract or the purified fraction changed the chemical profile of the alga and increased resistance against epiphyte spores. Semi-quantitative RT-PCR and enzyme assays demonstrated that this metabolic response occurs after an increase in lipoxygenase and phospholipase A2 activity. Although this suggests the involvement of regulatory oxylipins, neither jasmonic acid nor the algal metabolite prostaglandin E2 triggers comparable defense responses.
智利红藻是商业养殖的琼脂水胶体的来源，但一些养殖场中的敏感藻类会受到强烈的附生藻生长的影响。我们研究了智利红藻对附生藻的诱导化学防御反应，并证明了一种受附生藻挑战的藻类提取物可以引发防御反应。用 RP-HPLC 对具有生物活性的代谢物进行了纯化。用提取物或纯化部分处理会改变藻类的化学特征，并提高其对附生藻孢子的抗性。半定量 RT-PCR 和酶分析表明，这种代谢反应发生在脂氧合酶和磷脂酶 A2 活性增加之后。尽管这表明调节性氧化脂素的参与，但茉莉酸和藻类代谢物前列腺素 E2 都不能引发类似的防御反应。
