Genome-wide analysis of NDR1/HIN1-like genes in pepper ( L.) and functional characterization of under biotic and abiotic stresses.

Plant NDR1/HIN1-like () genes play an important role in triggering plant defenses in response to biotic stresses. In this study, we performed a genome-wide identification of the genes in pepper ( L.) and characterized the functional roles of these genes in response to abiotic stresses and infection by different pathogens. Phylogenetic analysis revealed that s can be classified into five distinct subgroups, with each group containing generic and specific motifs. Regulatory element analysis showed that the majority of the promoter regions of the identified s contain jasmonic acid (JA)-responsive and salicylic acid (SA)-responsive elements, and transcriptomic analysis revealed that genes are expressed in all the examined tissues of pepper. The , , , , , and genes were significantly upregulated under abiotic stress as well as in response to different pathogens, such as TMV, and . In addition, we found that CaNHL4 localizes to the plasma membrane. -silenced pepper plants display significantly increased susceptibility to TMV, and , exhibiting reduced expression of JA-related and SA-related genes and reduced ROS production. However, transient overexpression of in pepper increases the expression of JA-related and SA-related genes, enhances the accumulation of ROS, and inhibits the infection of these three pathogens. Collectively, for the first time, we identified the genes in pepper and demonstrated that is involved in the production of ROS and that it also regulates the expression of JA-related and SA-related genes in response to different pathogens, suggesting that members of the CaNHL family play an essential role in the disease resistance of pepper.