Activation of the VQ Motif-Containing Protein Gene Compromised Nonhost Resistance of to Pathogens.

Nonhost resistance refers to resistance of a plant species to all genetic variants of a non-adapted pathogen. Such resistance has the potential to become broad-spectrum and durable crop disease resistance. We previously employed and a forward genetics approach to identify plant mutants susceptible to the nonhost pathogen , which resulted in identification of the T-DNA insertion mutant (). In this study, we report the identification of VQ motif-containing protein 28 (), whose expression was highly up-regulated in the mutant . Stable transgenic plants constitutively overexpressing compromised nonhost resistance (NHR) against and , and supported increased infection of . Transcriptomic analysis showed that overexpression of resulted in six differentially expressed genes (DEGs) that are involved in the response to abscisic acid (ABA). High performance liquid chromatography-mass spectrometry (HPLC-MS) detection showed that the contents of endogenous ABA, salicylic acid (SA), and jasmonate (JA) were enriched in overexpression lines. These findings suggest that overexpression of may lead to an imbalance in plant hormone homeostasis. Furthermore, transient overexpression of in rendered plants more susceptible to pathogens. Deletion mutant analysis showed that the C-terminus and VQ-motif were essential for plant susceptibility. Taken together, our results suggest that negatively regulates plant NHR to pathogens.