Neomycin Inhibition of (+)-7-Iso-Jasmonoyl-L-Isoleucine Accumulation and Signaling

作者：Vadassery Jyothilakshmi; Reichelt Michael; Jimenez Aleman Guillermo H; Boland Wilhelm; Mithoefer Axel

来源：Journal of Chemical Ecology, 2014, 40(7): 676-686.

DOI：10.1007/s10886-014-0448-7

• Herbivory
• Jasmonates
• Neomycin
• Plant defense
• Spodoptera littoralis

The majority of plant defenses against insect herbivores are coordinated by jasmonate (jasmonic acid, JA; (+)-7-iso-jasmonoyl-L-isoleucine, JA-Ile)-dependent signaling cascades. Insect feeding and mimicking herbivory by application of oral secretions (OS) from the insect induced both cytosolic Ca2+ and jasmonate-phytohormone elevation in plants. Here it is shown that in Arabidopsis thaliana upon treatment with OS from lepidopteran Spodoptera littoralis larvae, the antibiotic neomycin selectively blocked the accumulation of OS-induced Ca2+ elevation and level of the bioactive JA-Ile, in contrast to JA level. Furthermore, neomycin treatment affected the downstream expression of JA-Ile-responsive genes, VSP2 and LOX2, in Arabidopsis. The neomycin-dependent reduced JA-Ile level is partially due to increased CYP94B3 expression and subsequent JA-Ile turn-over to12-hydroxy-JA-Ile. It is neither due to the inhibition of the enzymatic conjugation process nor to substrate availability. Thus, blocking Ca2+ elevation specifically controls JA-Ile accumulation and signaling, offering an insight into role of calcium in defense against insect herbivory.

• 出版日期2014-7