Caterpillar attack triggers accumulation of the toxic maize protein RIP2
Caterpillar attack triggers accumulation of the toxic maize protein RIP2
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DOI：
10.1111/nph.12581
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发表时间：
2014-02-01
期刊：
影响因子：
9.4
通讯作者：
Luthe, Dawn S.
中科院分区：
文献类型：
--
作者：
Chuang, Wen-Po;Herde, Marco;Luthe, Dawn S.
一些植物源的抗草食动物防御蛋白被昆虫取食诱导，在毛虫肠道中抵抗消化，并在粪便中被消除。我们已经确定了几个玉米蛋白在秋季粘虫（草地贪夜蛾）的粪便，可能发挥作用，在草食动物防御。此外，这些蛋白质之一，核糖体失活蛋白2（RIP2）的毒性进行了评估，并调节其积累的因素进行了determined.To了解RIP2蛋白质积累的调节因素，玉米（玉米）植物秋粘虫幼虫侵染或外源激素处理。重组RIP2蛋白对秋粘虫的毒力测定结果表明，RIP2蛋白是以一种无活性的酶原形式在毛虫肠道中合成的。此外，毛虫喂养，而不是机械创伤，诱导叶片RIP2蛋白积累。定量实时PCR表明，RIP2转录迅速诱导（1小时）和免疫印迹分析表明，RIP2蛋白积累攻击后不久，并在叶片中存在长达4天后，毛虫去除。几种植物激素，包括茉莉酸甲酯，乙烯和脱落酸，调节RIP2蛋白的表达。此外，纯化的重组RIP2蛋白对秋粘虫的生物测定显着延迟毛虫的生长。我们的结论是，有毒蛋白RIP2是诱导毛虫进食，是一个潜在的蛋白质，保护玉米对咀嚼食草动物。
Some plant-derived anti-herbivore defensive proteins are induced by insect feeding, resist digestion in the caterpillar gut and are eliminated in the frass. We have identified several maize proteins in fall armyworm (Spodoptera frugiperda) frass that potentially play a role in herbivore defense. Furthermore, the toxicity of one of these proteins, ribosome-inactivating protein 2 (RIP2), was assessed and factors regulating its accumulation were determined.To understand factors regulating RIP2 protein accumulation, maize (Zea mays) plants were infested with fall armyworm larvae or treated with exogenous hormones. The toxicity of recombinant RIP2 protein against fall armyworm was tested.The results show that RIP2 protein is synthesized as an inactive proenzyme that can be processed in the caterpillar gut. Also, caterpillar feeding, but not mechanical wounding, induced foliar RIP2 protein accumulation. Quantitative real-time PCR indicated that RIP2 transcripts were rapidly induced (1 h) and immunoblot analysis indicated that RIP2 protein accumulated soon after attack and was present in the leaf for up to 4 d after caterpillar removal. Several phytohormones, including methyl jasmonate, ethylene, and abscisic acid, regulated RIP2 protein expression. Furthermore, bioassays of purified recombinant RIP2 protein against fall armyworm significantly retarded caterpillar growth.We conclude that the toxic protein RIP2 is induced by caterpillar feeding and is one of a potential suite of proteins that defend maize against chewing herbivores.