https://www.science.org/doi/10.1126/sciadv.aav5495Many aggregating animals use aposematic signals to advertise their toxicity to predators. However, the coordination between aposematic signals and toxins is poorly understood. Here, we reveal that phenylacetonitrile (PAN) acts as an olfactory aposematic signal and precursor of hypertoxic hydrogen cyanide (HCN) to protect gregarious locusts from predation. We found that PAN biosynthesis from phenylalanine is catalyzed by CYP305M2, a novel gene encoding a cytochrome P450 enzyme in gregarious locusts. The RNA interference (RNAi) knockdown of CYP305M2 increases the vulnerability of gregarious locusts to bird predation. By contrast, the elevation of PAN levels through supplementation with synthetic PAN increases the resistance of solitary locusts to predation. When locusts are attacked by birds, PAN is converted to HCN, which causes food poisoning in birds. Our results indicate that locusts develop a defense mechanism wherein an aposematic compound is converted to hypertoxic cyanide in resistance to predation by natural enemies.
https://zhuanlan.zhihu.com/p/90254456
中科院动物研究所康乐院士率领的飞蝗（Locusta migratoria）研究团队结合生物化学、分子生物学和行为生态学的研究方法对群居飞蝗防御天敌的机制进行了深入研究。研究团队发现群居型飞蝗大量释放挥发物性化合物苯乙腈（Phenylacetonitrile），而散居型几乎不合成苯乙腈，它是两型飞蝗差别最大的信息化合物。该化合物对种群密度变化响应十分灵敏，群居散居化处理后释放量大幅下降，而散居群居化处理后会急剧产生苯乙腈。
苯乙腈是苯丙氨酸代谢途径的一个中间化合物，最终生物合成剧毒化合氢氰酸（Hydrogen cyanide）。
他们测定了群居和散居飞蝗挥发物中的氢氰酸的含量。结果显示健康的飞蝗并不释放氢氰酸，但受到鸟攻击后的群居型飞蝗释放大量氢氰酸。当给散居飞蝗补充苯乙腈后，受扰动的散居型飞蝗也可以产生氢氰酸。
来源：农业虫害鼠害综合治理研究国家重点实验室
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: 没有你说的这种毒素说法，纯扯淡
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