イネにおけるエリシター化合物を利用した天敵誘引物質の放出制御技術の開発

在27财年，我们继续测量水稻和高粱的挥发性有机化合物(VOC)排放。在这两种植物中，我们测定了以萜类化合物、芳香化合物和绿叶挥发物为主的VOCs的全光谱。在两种单子叶植物中，挥发性有机化合物非常相似，主要是倍半萜和单萜类。食草动物取食和昼夜条件是影响VOC排放的主要因素，化学诱导物(BTH)和植物基因对VOC排放的影响更大。为了了解单子叶植物在控制和胁迫(草食、伤害)条件下VOCs差异排放的分子基础，我们启动了VOC生物合成直接相关基因的克隆和基因表达研究。为了将不同的VOCs与植物对昆虫的间接防御联系起来，我们还监测了不同遗传背景的高粱植株(导致不同的VOCs)，并在田间条件下调查了它们对食草动物的危害。虽然BTx602来源的高粱植株的VOCs排放量较高，但与敏感的NOG基因型(高危害与低VOCs)相比，BTx602来源的高粱植株在田间受到欧洲二化螟(Ostrinia Nubilaris)的危害较小。我们可以提出这样的假设，即BTx602中的高VOCs可能有助于这些植物招收更多的玉米象天敌，从而减少这一臭名昭著的害虫在这些植物上的成功建立。目前正在准备几份总结我们成果的出版物。

In FY 27, we continued measuring volatile organic compound (VOC) emissions from rice (Oryza sativa) and sorghum (Sorghum bicolor). In both plants, we determined whole spectrum of VOCs dominated by terpenoids, aromatic compounds and green leaf volatiles. In both monocot species, the VOCs were quite similar, dominated by sesquiterpenes and monoterpens. Herbivore feeding and diurnal conditions were main factors influencing VOC emissions, which was further affected by chemical inducers (BTH) and plant genotype. In order to understand the molecular basis of differential emissions of VOCs from monocot plants, both under control and stress conditions (herbivory, wounding), we initiated cloning and investigated gene expression of those genes directly involved in VOC biosynthesis. In order to correlate differential VOCs with plant indirect defense against insects, we also monitored sorghum plants of different genetic backgrounds (resulting in differential VOCs), and investigated their herbivore damage under field conditions. Although direct relationship still needs to be established, sorghum plants of BTx602 origin, which had higher emissions of VOCs, had lower damage from European stem borer (Ostrinia nubilalis) in the field, compared to susceptible NOG genotype (high damage vs. low VOCs). We could propose hypothesis that high VOCs in BTx602 may help these plants to recruit a higher number of natural enemies of O. nubilalis, and thus reduce the successful establishment of this notorious pest on these plants. Several publications summarizing our results are now under preparation.