Positively Regulates Pepper Immunity by Targeting against Inoculation through Modulating Defense-Related Genes.

The WRKY transcription factors (TFs) network is composed of WRKY TFs' subset, which performs a critical role in immunity regulation of plants. However, functions of WRKY TFs' network remain unclear, particularly in non-model plants such as pepper ( L.). This study functionally characterized CaWRKY30-a member of group III Pepper WRKY protein-for immunity of pepper against infection. The was detected in nucleus, and its transcriptional expression levels were significantly upregulated by inoculation (RSI), and foliar application ethylene (ET), abscisic acid (ABA), and salicylic acid (SA). Virus induced gene silencing (VIGS) of amplified pepper's vulnerability to RSI. Additionally, the silencing of by VIGS compromised HR-like cell death triggered by RSI and downregulated defense-associated marker genes, like , , , , , and . Conversely, transient over-expression of in pepper leaves instigated HR-like cell death and upregulated defense-related maker genes. Furthermore, transient over-expression of upregulated transcriptional levels of , , , and . On the other hand, transient over-expression of , , , and upregulated transcriptional expression levels of . The results recommend that newly characterized positively regulates pepper's immunity against attack, which is governed by synergistically mediated signaling by phytohormones like ET, ABA, and SA, and transcriptionally assimilating into WRKY TFs networks, consisting of , , , and . Collectively, our data will facilitate to explicate the underlying mechanism of crosstalk between pepper's immunity and response to RSI.