背景回顾：For millions of years, plants evolve plenty of structurally diverse secondary metabolites (SM) to support their sessile lifestyles through continuous biochemical pathway innovation. 

提出问题：While new genes commonly drive the evolution of plant SM pathway, how a full biosynthetic pathway evolves remains poorly understood. The evolution of pathway involves recruiting new genes along the reaction cascade forwardly, backwardly, or in a patchwork manner.

结果1：With three chromosome-scale Papaver genome assemblies, we here reveal whole-genome duplications (WGDs) apparently accelerate chromosomal rearrangements with a nonrandom distribution towards SM optimization. 

结果2：A burst of structural variants involving fusions, translocations and duplications within 7.7 million years have assembled nine genes into the benzylisoquinoline alkaloids gene cluster, following a punctuated patchwork model. 

结果3：Biosynthetic gene copies and their total expression matter to morphinan production. 

结论：Our results demonstrate how new genes have been recruited from a WGD-induced repertoire of unregulated enzymes with promiscuous reactivities to innovate efficient metabolic pathways with spatiotemporal constraint.

 摘 要 

数百万年来，植物通过不同的生化途径创新，演化出许多结构多样的次生代谢物，以支撑其固着生活方式。虽然，新基因通常会驱动植物次生代谢物途径的演化，但植物如何演化出一条完整的生物合成途径还不清楚。一条新途径的演化包括将基因招募到反应级联上，这种反应级联在方向性上可能是向前、向后，抑或是以拼凑方式进行。本文中，作者报道了三个罂粟的染色体水平基因组组装，发现全基因组复制明显加速了罂粟的染色体重排，并以非随机分布的方式最优化罂粟的次生代谢物合成。在770万年内，一系列涉及融合、易位和复制的结构变异，按照间断拼凑模型将9个新基因招募到了苄基异喹啉生物碱合成基因簇中。生物合成基因拷贝数及其总表达量与吗啡喃的产生有关。本文的研究结果揭示了如何从全基因组复制诱导形成的一系列无特异性反应的、不受调控的酶中招募新基因，从而创新出具有时空限制的高效代谢途径。