Université de Toulouse, UPS, Laboratoire de Recherche en Sciences Végétales Castanet-Tolosan, France ; CNRS, Laboratoire de Recherche en Sciences Végétales Castanet-Tolosan, France.
Natex Biotech Toulouse, France.
Front Plant Sci. 2014 Sep 23;5:477. doi: 10.3389/fpls.2014.00477. eCollection 2014.
Essential oil from Gaultheria procumbens is mainly composed of methylsalicylate (MeSA) (>96%), a compound which can be metabolized in plant tissues to salicylic acid, a phytohormone inducing plant immunity against microbial pathogens. The potential use of G. procumbens essential oil as a biocontrol agent was evaluated on the model plant Arabidopsis thaliana. Expression of a selection of defense genes was detected 1, 6, and 24 h after essential oil treatment (0.1 ml/L) using a high-throughput qPCR-based microfluidic technology. Control treatments included methyl jasmonate and a commercialized salicylic acid (SA) analog, benzo(1,2,3)-thiadiazole-7carbothiolic acid (BTH). Strong induction of defense markers known to be regulated by the SA pathway was observed after the treatment with G. procumbens essential oil. Treatment induced the accumulation of total SA in the wild-type Arabidopsis line Col-0 and analysis of the Arabidopsis line sid2, mutated in a SA biosynthetic gene, revealed that approximately 30% of MeSA sprayed on the leaves penetrated inside plant tissues and was demethylated by endogenous esterases. Induction of plant resistance by G. procumbens essential oil was tested following inoculation with a GFP-expressing strain of the Arabidopsis fungal pathogen Colletotrichum higginsianum. Fluorescence measurement of infected tissues revealed that treatments led to a strong reduction (60%) of pathogen development and that the efficacy of the G. procumbens essential oil was similar to the commercial product BION(®). Together, these results show that the G. procubens essential oil is a natural source of MeSA which can be formulated to develop new biocontrol products.
透骨香挥发油主要由水杨酸甲酯（MeSA）（>96%）组成，该化合物可在植物组织中代谢为水杨酸，水杨酸是一种诱导植物对微生物病原体产生免疫力的植物激素。透骨香挥发油作为一种生物防治剂的潜在用途在模式植物拟南芥上进行了评估。使用高通量基于 qPCR 的微流控技术，在精油处理（0.1ml/L）后 1、6 和 24 小时检测了一系列防御基因的表达。对照处理包括茉莉酸甲酯和商业化的水杨酸（SA）类似物，苯并（1,2,3）噻二唑-7-羧酸（BTH）。在用透骨香挥发油处理后，观察到已知受 SA 途径调控的防御标记物的强烈诱导。处理诱导了野生型拟南芥品系 Col-0 中总 SA 的积累，并且对突变体 SA 生物合成基因的拟南芥品系 sid2 的分析表明，约 30%喷洒在叶片上的 MeSA 穿透植物组织内部，并被内源性酯酶去甲基化。在用 GFP 表达的拟南芥真菌病原体炭疽菌 Colletotrichum higginsianum 接种后，测试了透骨香挥发油对植物抗性的诱导。感染组织的荧光测量表明，处理导致病原体发育强烈减少（60%），并且透骨香挥发油的功效与商业产品 BION(®)相似。总之，这些结果表明，透骨香挥发油是 MeSA 的天然来源，可以被配制成开发新的生物防治产品。
