背景回顾：Exploding seed pods evolved in the Arabidopsis relative Cardamine hirsuta via morphomechanical innovations that allow the storage and rapid release of elastic energy. Asymmetric lignin deposition within endocarp b cell walls is one such innovation that is required for explosive seed dispersal and evolved in association with the trait. 

提出问题：However, the genetic control of this novel lignin pattern is unknown. 

结果1-LAC-不对称性木质素沉积：Here, we identify three lignin-polymerizing laccases, LAC4, 11, and 17, that precisely colocalize with, and are redundantly required for, asymmetric lignification of endocarp b cells. 

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结果2-突变体筛选-SPL7-细胞壁木质素沉积：By screening for C. hirsuta mutants with less lignified fruit valves, we found that loss of function of the transcription factor gene SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE 7 (SPL7) caused a reduction in endocarp b cell-wall lignification and a consequent reduction in seed dispersal range. 

结果3-SPL7-铜稳态-漆酶活性：SPL7 is a conserved regulator of copper homeostasis and is both necessary and sufficient for copper to accumulate in the fruit. Laccases are copper-requiring enzymes. We discovered that laccase activity in endocarp b cell walls depends on the SPL7 pathway to acclimate to copper deficiency and provide sufficient copper for lignin polymerization. 

结论：Hence, SPL7 links mineral nutrition to efficient dispersal of the next generation.

 摘 要 

拟南芥近缘植物碎米芥演化出了会发生爆裂的荚果，该过程涉及到了形态力学上的创新，能够储存并快速释放弹性能。内果皮b细胞壁上的不对称木质素沉积是爆裂种子传播所需的创新之一，并与该性状共演化。然而，控制这一新的木质素沉积模式的遗传机制仍不清楚。本文中，作者鉴定到了三个木质素聚合漆酶，即LAC4/11/7，这三个漆酶与内果皮b细胞中的不对称木质化精确共定位，并且是内果皮b细胞中不对称木质化所必需的。通过筛选果瓣木质化程度低的碎米芥突变体，作者发现转录因子SPL7的功能丧失会导致内果皮b细胞壁木质化减少，从而导致其种子传播范围缩小。SPL7是一个作用于铜稳态的保守调节子，对于果实中铜的积累是充分且必须的。同时，漆酶是一种需要铜的酶。作者发现内果皮b细胞壁中漆酶的活性依赖于SPL7途径来适应铜缺乏，并为木质素聚合提供充足的铜。因此，SPL7将矿物营养和种子传播关联在一起。