NIa-Pro of sugarcane mosaic virus targets Corn Cysteine Protease 1 (CCP1) to undermine salicylic acid-mediated defense in maize

• DOI: 10.1371/journal.ppat.1012086
• Publication Date: 2024-03-14T17:47:40Z
• Authors: Wen Yuan; Xi Chen; Kaitong Du; Tong Jiang; Mengfei Li; Yanyong Cao; Xiangdong Li; Gunther Doehlemann; Zaifeng Fan; Tao Zhou
• Keywords: Cysteine protease

Papain-like cysteine proteases (PLCPs) play pivotal roles in plant defense against pathogen invasions. While pathogens can secrete effectors to target and inhibit PLCP activities, the of PLCPs plant-virus interactions mechanisms through which viruses neutralize activities remain largely uncharted. Here, we demonstrate that expression activity a maize CCP1 (Corn Cysteine Protease), is upregulated following sugarcane mosaic virus (SCMV) infection. Transient silencing led reduction thereby promoting SCMV infection maize. Furthermore, knockdown resulted diminished salicylic acid (SA) levels suppressed SA-responsive pathogenesis-related genes. This suggests plays role modulating SA signaling pathway. Interestingly, NIa-Pro, primary protease SCMV, was found interact with CCP1, subsequently inhibiting its activity. A specific motif within NIa-Pro termed inhibitor identified as essential for interaction suppression We have also discovered key amino acids responsible between are crucial virulence SCMV. In conclusion, our findings offer compelling evidence undermines CCP1. Together, these shed new light on mechanism(s) controlling arms races plant.