On the cover: Common pond skaters (Gerris lacustris) on the surface of a river in the Lake District, UK. These predatory insects exploit the high surface tension of water to skate across the water's surface, a process facilitated by their long, hydrophobic legs and the distribution of their weight over a large surface area, providing a clear example of how physical principles impact biology. Our special issue on the collaboration between physics and biology brings together reviews, essays, primers, and other formats to showcase the various ways in which physical concepts and approaches have enhanced our understanding of the living world. Photo: Ashley Cooper/Getty Images.
PLANT PHYSIOLOGY:北林揭示一个平衡植物免疫反应与生长发育的WRKY转录因子
免疫反应会破坏植物的生长发育过程。本研究发现来自杨树的转录因子PagWRKY33a/b参与了对植物免疫反应调控过程。抑制PagWRKY33a/b会提高植物对Colletotrichum gloeosporioides的抗性。而过表达株系的抗性反应虽然低于突变株，但是仍然高于野生型。
PagWRKY33a/b可以结合到N requirement gene 1.1 (NRG1.1) and Gibberellic Acid-Stimulated in Arabidopsis (GASA14)的启动子上来诱导它们的表达，这一方面可以激活植物的免疫反应，另一方面可以抑制免疫反应对植物生长发育带来的负面影响。oxPagWRKY33a/nrg1.1降低了对 C. gloeosporioides的抗性.
PagWRKY33a/b被Mitogen-Activated Protein Kinase Kinase 1 (MKK1)磷酸化而激活，从而抑制了Respiratory Burst Oxidase Homolog D (RBOHD) and Respiratory Burst Oxidase Homolog I (RBOHI) 的表达, wrky33a/b double mutants中活性氧水平显著增加，从而诱导PagNRG1.1. wrky33a/b/nrg1.1 and wrky33a/b/rbohd triple mutants的防卫反应被抑制。
此外，PagWRKY33还受到Ring Finger Protein 5 (PagRNF5)泛素化修饰，从而平衡植物免疫反应与生长发育。
The working model of WRKY33 overexpression and mutants. WRKY33, as the direct upstream of GASA14, was induced by the transcriptional upregulation caused by the fungus C. gloeosporioides, participates in the signal transduction of GA, promotes the growth and development of poplar, and alleviates the pressure exerted by immunity on plant growth. In addition, WRKY33 was the direct upstream activator of NRG1.1, enhancing its transcription and improving resistance to C. gloeosporioides. WRKY33 also serves as a direct phosphorylation target of MKK1 in MAPK cascade members. Phosphorylated WRKY33 has an enhanced ability to bind downstream, while the expression of MKK1 is downregulated by induction of C. gloeosporioides. E3 ubiquitin ligase RNF5 is induced to degrade WRKY33, regulate WRKY33 protein stability, ensure the balance between immunity and growth. When the function of WRKY33 was compromised, there was an increase in SA accumulation, a burst of ROS, and the transcription of NRG1.1 was ectopic activated, leading to a gain of function that triggers the autoimmune response. Simultaneously, the transcription of GASA14 was downregulated, sacrificing growth to provide the plant with a defense response. Dotted arrows indicate the reduction or interruption, line arrows indicate promotion, and red crosses indicate interruption.
原文：Transcription factor PagWRKY33 regulates gibberellin signaling and immune receptor pathways in Populus
