NPR1R2

NPR1R2, short for NPR1-related protein 2, is a gene encoding a member of the NPR1-like family found in plants. The NPR1-like family comprises regulatory proteins related to Nonexpressor of PR genes 1 (NPR1), a central regulator of salicylic acid–mediated defense responses. NPR1R2 was identified through sequence homology to NPR1 and is one of several paralogs in some plant species. The precise function of NPR1R2 is not fully defined; as with other NPR1-like proteins, it is thought to participate in plant immune signaling and may influence the transcriptional activation of defense genes.

In many plant systems, NPR1 and its relatives participate in the regulation of systemic acquired resistance. NPR1-like proteins can act as transcriptional coactivators, often by interacting with TGA-family transcription factors, and their activity can be modulated by cellular redox state and hormones such as salicylic acid. NPR1R2 may contribute to these pathways either as a positive regulator of defense gene expression or, in some contexts, as a fine-tuner of the response, potentially through interactions with NPR1 or other signaling components, or through regulation of NPR1 stability.

Expression of NPR1R2 is usually responsive to pathogen challenge and hormonal cues, though expression patterns are species-dependent. Post-translational regulation, including redox changes and protein turnover, is a common feature of NPR1-like proteins and is likely relevant to NPR1R2 as well.

Research for NPR1R2 is ongoing, with studies aimed at clarifying its specific roles in immunity, its regulation, and its potential utility in developing disease-resistant crops. See also NPR1, NPR3/NPR4, and salicylic acid signaling.