Key positive factor of disease resistance. Plays an essential role in benzothiadiazole (BTH)-induced resistance to the blast fungus disease caused by Magnaporthe oryzae (PubMed:20924648). Involved in defense response against the bacterial blight disease caused by Xanthomonas oryzae pv. oryzae (Xoo). Over-expression of NPR1/NH1 confers disease resistance to Xoo, but also enhances herbivore susceptibility (PubMed:17309686). Functions as a transcriptional coactivator of TGA2.1 and LG2 in vitro (PubMed:22353606). Involved in defense response against herbivore. Plants silencing NPR1/NH1 have increased herbivore-induced trypsin proteinase inhibitors and volatiles, which reduces the performance of the striped stem borer (SSB) Chilo suppressalis (PubMed:22694163). Oligomer in an uninduced state; disulfide-linked. Forms activated monomer upon changes in cellular redox potential (PubMed:17309686). Interacts with TGA2.1, TGA2.2, TGA2.3, LG2, TGAL1 and TGAL4 (PubMed:24919709). Interacts with NRR, RH1, RH2 and RH3 (PubMed:22353606, PubMed:24919709). Accumulation in nucleus when present as monomer. By mechanical wounding, treatment with jasmonic acid (JA), salicylic acid (SA) and benzothiadiazole (BTH), and in response to infestation by the rice striped stem borer Chilo suppressalis and rice leaf folder Cnaphalocrocis medinalis.