On the cover: Sea robins are unusual fish that evolved leg-like appendages that they use to “walk” along the seafloor. In this issue, two papers from the Bellono and Kingsley labs use sea robins to investigate the origins of novel traits. In the first paper, the researchers discover that sea robins develop legs from fins using genes that are also involved in human limb formation. In the second paper, the team describes that sea robins specialize legs as sensory organs that detect chemicals and touch to find buried prey. Image by Mike Jones (https://mikejonesdive.com/).
PCE:南农揭示一个介导抗病反应的转录因子
Phytochrome Interacting Factor 4 (PIF4)参与了植物生长发育过程。pif4 mutants呈现出对病害的强抗性（spray inoculation），但是对infiltration inoculation侵染没有表现出抗性表型，说明PIF4是通过阻止病菌通过保卫细胞进入植物体内发挥作用。
该突变体中更多的气孔被关闭。将保卫细胞特异性启动子驱动PIF4的表达可以将pif4 mutants的抗性恢复到野生型状态。
PIF4过表达株系会表现出更强的抗性，这是一个与叶绿素代谢无关的过程，虽然该基因的功能丧失型突变体则会导致叶绿素水平显著提高。
小结：本研究揭示了PIF4介导的植物发育与抗性反应之间的关系。
原文：Guard Cell Activity of PIF4 Represses Disease Resistance in Arabidopsis
