Laboratory of Entomology, Wageningen University, Wageningen, The Netherlands.
J Chem Ecol. 2009 Sep;35(9):1021-31. doi: 10.1007/s10886-009-9696-3. Epub 2009 Oct 2.
The oxylipin pathway is commonly involved in induced plant defenses, and is the main signal-transduction pathway induced by insect folivory. Herbivory induces the production of several oxylipins, and consequently alters the so-called 'oxylipin signature' in the plant. Jasmonic acid (JA), as well as pathway intermediates are known to induce plant defenses. Indirect defense against herbivorous insects comprises the production of herbivore-induced plant volatiles (HIPVs). To unravel the precise oxylipin signal-transduction underlying the production of HIPVs in Arabidopsis thaliana and the resulting attraction of parasitoid wasps, we used a multidisciplinary approach that includes molecular genetics, metabolite analysis, and behavioral analysis. Mutant plants affected in the jasmonate pathway (18:0 and/or 16:0 -oxylipin routes; mutants dde2-2, fad5, opr3) were studied to assess the effects of JA and its oxylipin intermediates 12-oxo-phytodienoate (OPDA) and dinor-OPDA (dnOPDA) on HIPV emission and parasitoid (Diadegma semiclausum) attraction. Interference with the production of the oxylipins JA and OPDA altered the emission of HIPVs, in particular terpenoids and the phenylpropanoid methyl salicylate, which affected parasitoid attraction. Our data show that the herbivore-induced attraction of parasitoid wasps to Arabidopsis plants depends on HIPVs that are induced through the 18:0 oxylipin-derivative JA. Furthermore, our study shows that the 16:0-oxylipin route towards dnOPDA does not play a role in HIPV induction, and that the role of 18:0 derived oxylipin-intermediates, such as OPDA, is either absent or limited.
类二十烷酸途径通常参与植物的诱导防御，也是昆虫取食诱导的主要信号转导途径。取食诱导几种类二十烷酸的产生，从而改变植物中的所谓“类二十烷酸特征”。茉莉酸（JA）以及途径中间产物已知可诱导植物防御。对草食性昆虫的间接防御包括产生草食性诱导的植物挥发物（HIPVs）。为了阐明拟南芥中产生 HIPVs 的精确类二十烷酸信号转导以及由此产生的寄生蜂的吸引力，我们使用了一种多学科的方法，包括分子遗传学、代谢物分析和行为分析。研究了茉莉酸途径（18:0 和/或 16:0-氧化脂途径；突变体 dde2-2、 fad5、opr3）中受影响的突变体植物，以评估 JA 及其类二十烷酸中间体 12-氧-植二烯酸（OPDA）和二降-OPDA（dnOPDA）对 HIPV 发射和寄生蜂（Diadegma semiclausum）吸引力的影响。干扰类二十烷酸 JA 和 OPDA 的产生改变了 HIPV 的释放，特别是萜类化合物和苯丙烷甲酯水杨酸，这影响了寄生蜂的吸引力。我们的数据表明，草食性昆虫对拟南芥植物的诱导吸引取决于通过 18:0 氧化脂衍生物 JA 诱导的 HIPVs。此外，我们的研究表明，16:0-氧化脂途径向 dnOPDA 不起诱导 HIPV 的作用，并且 18:0 衍生的氧化脂中间产物，如 OPDA，没有作用或作用有限。
