Cardiac glycosides protect wormseed wallflower (Erysimum cheiranthoides) against some, but not all, glucosinolate-adapted herbivores.
Cardiac glycosides protect wormseed wallflower (Erysimum cheiranthoides) against some, but not all, glucosinolate-adapted herbivores.
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强心苷可以保护蠕虫壁花（Erysimum cheiranthoides）免受某些但不是全部适应芥子油苷的食草动物的侵害。
DOI：
10.1101/2023.09.19.558517
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Jander,Georg
中科院分区：
文献类型：
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作者：
Younkin,GordonC;Alani,MartinL;Capador,AnamaríaPáez;Fischer,HillaryD;Mirzaei,Mahdieh;Hastings,AmyP;Agrawal,AnuragA;Jander,Georg
像其他成员一样，墙花属（糖芥属）的植物产生芥子油苷，这是对广泛的食草动物的有效防御。糖芥作为一种新近进化的第二道防线，产生强心苷，其是动物体内Na+，K+-ATP酶的变构抑制剂。强心苷的生物合成已经在包括毛地黄（洋地黄属，车前草科）和乳草（夹竹桃科）在内的不同谱系中进化，但完整的生物合成途径尚未在任何物种中描述。我们鉴定并产生了参与wormseed wallflower（Erysium cheiranthoidesL.）中强心苷生物合成的两种细胞色素P450单加氧酶的CRISPR/Cas9敲除：EcCYP 87 A126，其从固醇前体切割侧链以启动强心苷生物合成，以及EcCYP 716 A418，其在强心苷羟基化中起作用。在EcCYP 87 A126敲除株系中，强心苷的产生被消除，有效地逆转了糖芥从食草动物中的逃逸。对于多面手食草动物绿色桃蚜（Myzus persicaeSuzler）和甘蓝夜蛾（Trichoplusia niHübner），强心苷似乎在很大程度上与硫代葡萄糖酸盐冗余，在选择测定中有一定影响，但对昆虫性能几乎没有影响。相比之下，以十字花科植物为食的甘蓝蝴蝶（Pieris rapaeL.），它们不会产卵或以野生型E为食。cheiranthoides，能够完成其生活周期的cardenolide-freeE。突变系。因此，我们的研究表明，在体内，强心苷的生产允许糖芥逃脱一个专业的草食动物。
Like other members of the Brassicaceae, plants in the wallflower genus (Erysimum) produce glucosinolates, which are potent defenses against a wide range of herbivores. As a more recently evolved second line of defense,Erysimumproduces cardiac glycosides, which are allosteric inhibitors of Na+,K+-ATPases in animals. Cardiac glycoside biosynthesis has evolved in diverse lineages including foxglove (Digitalis, Plantaginaceae) and milkweeds (Apocynaceae), but the full biosynthetic pathway has not been described in any species. We identify and generate CRISPR/Cas9 knockouts of two cytochrome P450 monooxygenases involved in cardiac glycoside biosynthesis in wormseed wallflower (Erysimum cheiranthoidesL.):EcCYP87A126, which cleaves the side chain from sterol precursors to initiate cardiac glycoside biosynthesis, andEcCYP716A418, which has a role in cardiac glycoside hydroxylation. In theEcCYP87A126 knockout lines, cardiac glycoside production is eliminated, effectively reversingErysimum’s escape from herbivory. For the generalist herbivores green peach aphid (Myzus persicaeSuzler) and cabbage looper (Trichoplusia niHübner), cardiac glycosides appear to be largely redundant with glucosinolates, having some effect in choice assays but little to no effect on insect performance. By contrast, the crucifer-feeding specialist cabbage butterfly (Pieris rapaeL.), which will not oviposit or feed on wildtypeE. cheiranthoides, is able to complete its life cycle on cardenolide-freeE. cheiranthoidesmutant lines. Thus, our study demonstratesin vivothat cardiac glycoside production allowsErysimumto escape from a specialist herbivore.