Independent evolution of the iridoid biosynthetic pathway in plants and insects.
Independent evolution of the iridoid biosynthetic pathway in plants and insects.
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DOI：
10.1073/pnas.2216444119
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发表时间：
2022-11-29
影响因子：
11.1
通讯作者：
Pickett, John A.
中科院分区：
文献类型：
--
作者：
Pickett, John A.
利用异戊二烯类环烯醚萜类生物合成途径的生物技术开发对于廉价获取许多药物和食品生产至关重要，特别是在提供马头草苷方面，马头草苷是龙葵素合成酶的底物(1)，是抗癌药物长春花碱的合成途径(2)，以及对食用植物病毒病原体的蚜虫载体进行可持续管理，作为包含蚜虫性信息素的荆芥内酯和荆芥内酯的特定异构体（3,4）。最近报道的蚜虫环烯醚萜类途径的阐明(5)（图5）。1)加上Sarah O 'Connor在工作中对植物的早期阐释（参见参考文献5）（图5）。1)最终证明该途径在植物和昆虫中的独立进化。因此，作为来自植物和动物各自王国的相同化合物的不同生物合成途径的代表，这一发现是进一步研究的独特进化例子，也具有生物技术开发的价值，为构建生产系统提供了替代酶学，包括合成生物学。蚜虫的性信息素在1987年被化学鉴定，发表在《自然》(3)杂志上的报告在情人节那天引起了公众媒体的极大兴趣。这也与nepetalactone成分有关，(4aS, 7S, 7aR)-nepetalactone在Nepeta属（Lamiaceae）植物中很常见，以前已知猫和大多数其他Felidae成员的兴奋行为。第二种信息素化合物(1R, 4aS, 7S, 7aR)-nepetalactol的绝对立体化学通过x射线晶体学在3,5 -二硝基苯甲酸酯上建立(4)，其形式是还原的nepetalactol，对行为活性至关重要。随着越来越多的蚜虫性信息素被鉴定为含有这种化学物质(6)，在科学会议上广泛提出了一种可能性，即从植物中隔离是蚜虫中这种化学物质的起源。对这些观点的反驳现在以豌豆蚜虫Acyrthosiphon pisum为例的蚜虫生物合成途径的明确建立达到了顶峰(5)。因此，通过转录组学的方法，从雌性后腿的表达，称为信息素的产生位点(3)，并结合系统发育分析，初步确定了蚜虫环烯酰胺途径的候选基因。通过异种表达对这些基因进行功能表征，并对产物进行严格的化学分析，从而确定了其生物合成途径。令人惊讶的是，该途径涉及与植物中相同的中间化合物，但涉及的所有六种酶与植物途径中的酶不同（图1）。中间化合物包括8-氧基戊二醛，然后作为还原环化反应的一部分，还原成8-氧基戊二醛的烯醇互变异构体显然是为环化成戊基戊二醇而设定的。这一步包括
Biotechnological exploitation of the isoprenoidal iridoid biosynthetic pathway is crucial for cheap access to many drugs and food production, specifically in the provision of loganin, the substrate for secologaninin synthase (1) in the route to the anticancer drug vinblastine (2), and for sustainable management of the aphid vectors of food plant viral pathogens, as specific isomers of nepetalactone and nepetalactol comprising the aphid sex pheromones (3, 4). The newly reported elucidation of the iridoid pathway in aphids (5)(Fig. 1) plus the earlier elucidation in plants in work also led by Sarah O’Connor (see references in ref. 5)(Fig. 1) conclusively demonstrate the independent evolution of this pathway in plants and insects. Thus, as representing separate biosynthetic pathways to the same compounds from the respective kingdoms of plants and animals, this discovery is a unique evolutionary example for further study and also of value in biotechnological exploitation by offering alternative enzymology for constructing production systems including by synthetic biology.The aphid sex pheromones were chemically characterized in 1987 and the report in Nature (3), published on St Valentine’s Day, stimulated a great deal of public media interest. This is related also to the component,(4aS, 7S, 7aR)-nepetalactone, common to plants in the Nepeta genus (Lamiaceae) being previously known to confer excitatory behavior in cats and most other members of the Felidae. The absolute stereochemistry of the second pheromonal compound,(1R, 4aS, 7S, 7aR)-nepetalactol, formally the reduced nepetalactone and essential for behavioral activity, was established via X-ray crystallography on the 3, 5-dinitrobenzoate ester (4). Following the growing number of aphid sex pheromones identified as comprising this chemistry (6), the possibility was widely raised at scientific meetings that sequestration from plants was the origin of this chemistry in aphids. The refutation of such ideas has now culminated in the unequivocal establishment of the aphid biosynthetic pathway as exemplified by the pea aphid, Acyrthosiphon pisum (5). Thus, by a transcriptomics approach from expression in the female hindlegs, known as the site of pheromone production (3), and coupled phylogenetic analysis, candidate genes for the aphid iridoid pathway were tentatively identified. Functional characterization of these genes by heterologous expression and rigorous chemical analysis of the products then confirmed the biosynthetic pathway to the nepetalactone. Surprisingly the route involves the same intermediate compounds as in plants but with all of the six enzymes involved being different from those in the plant pathway (Fig. 1). The intermediate compounds include 8-oxogeranial, and then as part of the reductive cyclization reaction, the reduction to what is formally the enol tautomer of 8-oxocitronellal clearly set for the cyclization to the nepetalactol. This step involves
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DOI：
10.1073/pnas.2211254119
发表时间：
2022-10-18
影响因子：
11.1
作者：
通讯作者：
--
影响因子：
3.2
作者：
通讯作者：
--
影响因子：
4.9
作者：
Touchet, Sabrina;Chamberlain, Keith;Allemann, Rudolf K.
通讯作者：
Allemann, Rudolf K.
影响因子：
1.8
作者：
DAWSON, GW;JANES, NF;WILLIAMS, DJ
通讯作者：
WILLIAMS, DJ
影响因子：
64.8
作者：
DAWSON, GW;GRIFFITHS, DC;WOODCOCK, CM
通讯作者：
WOODCOCK, CM