A Novel Role of Salt- and Drought-Induced RING 1 Protein in Modulating Plant Defense Against Hemibiotrophic and Necrotrophic Pathogens.

Many plant-encoded E3 ligases are known to be involved in plant defense. Here, we report a novel role of E3 ligase SALT- AND DROUGHT-INDUCED RING FINGER1 (SDIR1) in plant immunity. Even though SDIR1 is reasonably well-characterized, its role in biotic stress response is not known. The silencing of in reduced the multiplication of the virulent bacterial pathogen pv. . The mutant is resistant to virulent pathogens, whereas overexpression lines are susceptible to both host and nonhost hemibiotrophic bacterial pathogens. However, mutant and overexpression lines showed hypersusceptibility and resistance, respectively, against the necrotrophic pathogen . The mutant of SDIR1 target protein, i.e., SDIR-interacting protein 1 (SDIR1P1), also showed resistance to host and nonhost pathogens. In overexpression plants, transcripts of transcription factors were less accumulated and the levels of jasmonic acid (JA) and abscisic acid were increased. In the mutant, JA signaling genes and were downregulated. These data suggest that SDIR1 is a susceptibility factor and its activation or overexpression enhances disease caused by pv. DC3000 in . Our results show a novel role of SDIR1 in modulating plant defense gene expression and plant immunity.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.