CaWRKY50 Acts as a Negative Regulator in Response to Colletotrichum scovillei Infection in Pepper

Abstract

Chili anthracnose is one of the most common and destructive fungal pathogens that affects the yield and quality of pepper. Although WRKY proteins play crucial roles in pepper resistance to a variety of pathogens, the mechanism of their resistance to anthracnose is still unknown. In this study, we found that CaWRKY50 expression was obviously induced by Colletotrichum scovillei infection and salicylic acid (SA) treatments. CaWRKY50-silencing enhanced pepper resistance to C. scovillei, while transient overexpression of CaWRKY50 in pepper increased susceptibility to C. scovillei. We further found that overexpression of CaWRKY50 in tomatoes significantly decreased resistance to C. scovillei by SA and reactive oxygen species (ROS) signaling pathways. Moreover, CaWRKY50 suppressed the expression of two SA-related genes, CaEDS1 (enhanced disease susceptibility 1) and CaSAMT1 (salicylate carboxymethyltransferase 1), by directly binding to the W-box motif in their promoters. Additionally, we demonstrated that CaWRKY50 interacts with CaWRKY42 and CaMIEL1 in the nucleus. Thus, our findings revealed that CaWRKY50 plays a negative role in pepper resistance to C. scovillei through the SA-mediated signaling pathway and the antioxidant defense system. These results provide a theoretical foundation for molecular breeding of pepper varieties resistant to anthracnose.

The Laccase Family Gene CsLAC37 Participates in Resistance to Colletotrichum gloeosporioides Infection in Tea Plants

“…H 2 O 2 is a critical component of ROS, and its production increased when the host cell was damaged [ 34 ]. In plants, excessive endogenous ROS can damage host cells and peroxidases (PODs), which play a pivotal role in plant immunity by scavenging ROS accumulation [ 35 , 36 ]. Taken together, the results of AsODN treatment displayed that CsLAC37 may play a positive regulatory role in resistance to C. gloeosporioides infections.…”

Comparative Transcriptomics Analysis Reveals the Differences in Transcription between Resistant and Susceptible Pepper (Capsicum annuum L.) Varieties in Response to Anthracnose

“…Similarly, the expression of CaWRKY27 [ 26 ], CaWRKY6 [ 45 ], CaWRKY22 [ 46 ], CaWRKY41 [ 47 ], CaWRKY30 [ 48 ], CaWRKY28 [ 49 ], and CaWRKY27b [ 43 ] positively regulates resistance to an R. solanacearum infection; however, the expression of CaWRKY58 [ 50 ] and CaWRKY40b [ 51 ] has the opposite effect. The CaWRKY50 TF negatively regulates the resistance of pepper to Colletotrichum scovillei through its effects on SA-mediated signaling and the antioxidant defense system [ 52 ]. The WRKY TFs can bind specifically to W-box cis-elements (TTGACC/T) in promoters to regulate the expression of defense-related genes.…”