Kishimoto Kyutaro, Matsui Kenji, Ozawa Rika, Takabayashi Junji
CREST, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan.
Phytochemistry. 2006 Jul;67(14):1520-9. doi: 10.1016/j.phytochem.2006.05.027. Epub 2006 Jun 30.
Since volatile allo-ocimene enhances resistance of Arabidopsis thaliana against Botrytis cinerea, we attempted to dissect the factors involved in this induced resistance. The penetration of B. cinerea hyphae into Arabidopsis epidermis and the growth of hyphae after penetration were suppressed on allo-ocimene-treated leaves. allo-Ocimene also induced lignification on cell walls and veins of the leaves. The treatment induced accumulation of antifungal substances including the Arabidopsis phytoalexin, camalexin. Induction of lignification and accumulation of camalexin elicited by B. cinerea infection on Arabidopsis leaves after treating with allo-ocimene was faster and more intense than that observed with the leaves that had not been treated with this volatile. This suggested that allo-ocimene could prime defensive responses in Arabidopsis. allo-Ocimene enhanced resistance against B. cinerea in an ethylene resistant mutant (etr1-1), a jasmonic acid resistant mutant (jar1-1) and a salicylic acid resistant mutant (npr1-1). Thus, it is suggested that a signaling pathway independent for ETR1, JAR1 and NPR1 was operative to induce the resistance. The series of responses observed after allo-ocimene-treatment was mostly similar to that observed after C6-aldehyde-treatment. The effect of C6-aldehyde-treatment has been largely accounted to the chemical reactivities of the compounds; however, from this result it can be suggested that resistance responses of Arabidopsis could be induced by the volatiles mostly independent on their reactivities and that a common signaling pathway unaffected by the reactivities of compound was activated by the volatiles.
由于挥发性的别罗勒烯增强了拟南芥对灰霉病菌的抗性，我们试图剖析这种诱导抗性所涉及的因素。在别罗勒烯处理过的叶片上，灰霉病菌菌丝对拟南芥表皮的穿透以及穿透后菌丝的生长均受到抑制。别罗勒烯还诱导了叶片细胞壁和叶脉的木质化。该处理诱导了包括拟南芥植保素——camalexin在内的抗真菌物质的积累。用别罗勒烯处理后，灰霉病菌感染拟南芥叶片所引发的木质化诱导和camalexin积累，比未用这种挥发物处理的叶片观察到的情况更快且更强烈。这表明别罗勒烯可以引发拟南芥的防御反应。别罗勒烯在乙烯抗性突变体（etr1 - 1）、茉莉酸抗性突变体（jar1 - 1）和水杨酸抗性突变体（npr1 - 1）中增强了对灰霉病菌的抗性。因此，表明一条独立于ETR1、JAR1和NPR1的信号通路在起作用以诱导抗性。别罗勒烯处理后观察到的一系列反应大多与C6 - 醛处理后观察到的相似。C6 - 醛处理的效果在很大程度上归因于化合物的化学反应性；然而，从这个结果可以推测，拟南芥的抗性反应可能主要由挥发物诱导，而与其化学反应性无关，并且一条不受化合物化学反应性影响的共同信号通路被挥发物激活。
