背景回顾：Grafting has been adopted for a wide range of crops to enhance productivity and resilience; for example, grafting of Solanaceous crops couples disease-resistant rootstocks with scions that produce high-quality fruit. 

提出问题：However, incompatibility severely limits the application of grafting and graft incompatibility remains poorly understood.

研究问题：In grafts, immediate incompatibility results in rapid death, but delayed incompatibility can take months or even years to manifest, creating a significant economic burden for perennial crop production. 

主要研究：To gain insight into the genetic mechanisms underlying this phenomenon, we developed a model system using heterografting of tomato (Solanum lycopersicum) and pepper (Capsicum annuum). These grafted plants express signs of anatomical junction failure within the first week of grafting. 

结果1-解剖学观察：By generating a detailed timeline for junction formation, we were able to pinpoint the cellular basis for this delayed incompatibility. 

结果2-基因调控网络：Furthermore, we inferred gene regulatory networks for compatible self-grafts and incompatible heterografts based on these key anatomical events, which predict core regulators for grafting. 

结果3-维管发育与WOX4：Finally, we examined the role of vascular development in graft formation and uncovered SlWOX4 as a potential regulator of graft compatibility. 

结果4-基因功能试验：Following this predicted regulator up with functional analysis, we show that Slwox4 homografts fail to form xylem bridges across the junction, demonstrating that indeed, SlWOX4 is essential for vascular reconnection during grafting, and may function as an early indicator of graft failure.

 摘 要 

嫁接已被广泛应用于各种作物，以增加作物产量和恢复力；例如，茄科作物中通常会将能够产生优质果实的接穗嫁接到抗病性强的砧木上。但是，嫁接不亲和严重限制了该项技术的实际应用，其机理还不甚清楚。在嫁接中，即时的不亲和性会导致嫁接植株的快速死亡，但延迟的不亲和性可能需要数月甚至数年的时间才能表现出来，从而给多年生作物的生产造成巨大的经济负担。为了深度挖掘该现象的分子机理，作者利用番茄和辣椒之间的异源嫁接建立了一个研究嫁接的模式系统。这些嫁接植物会在嫁接后的第一周内表现出解剖结构上连接失败的迹象。作者通过连续观察连接形成，从而精确定位这种延迟不相容性的细胞学基础。另外，作者根据所观察到的关键解剖事件，推断出相容性自身嫁接和不相容性异源移植物的基因调控网络，预测了嫁接的核心调控因子。最终，作者鉴定了维管发育在嫁接过程中的作用，发现SlWOX4作为嫁接亲和性的关键调控子发挥作用。紧接着的基因功能分析，作者发现Slwox4突变体的自身嫁接会因为连接处木质部桥的形成缺陷，导致嫁接失败，说明SlWOX4基因对于嫁接中维管的重新连接是必须的，并且可能是嫁接失败的早期指示信号。