A novel TIR-NBS-LRR gene regulates immune response to Phytophthora root rot in soybean

Abstract

Phytophthora root rot (PRR), caused by Phytophthora sojae, is a devastating disease of soybean. The NBS-LRR gene family is a class of plant genes involved in disease resistance. miRNA mediates plant response to biotic stresses by regulating the expression of target genes at the transcriptional or post-translational level. Glyma.16G135500, encoding an NBS-LRR-type protein, is a target of gma-miR1510 that responds to pathogen infections. We cloned and overexpressed Glyma.16G135500 (naming it GmTNL16) and knocked down miR1510 using short tandem target mimic technology to identify the roles of the GmTNL16/gma-miR1510 pair in the interaction of soybean and the oomycete. By overexpressing GmTNL16 in transgenic hairy roots of soybean, we showed that biomass of P. sojae was lower in overexpressing hairy roots than in control roots. Thus, miR1510 expression was reduced upon P. sojae infection, reflecting the induced expression of GmTNL16 conferring resistance to P. sojae in soybean. Differentially expressed genes were enriched in plant-pathogen interaction, plant hormone signal transduction, and secondary metabolism by RNA sequencing analyze. In particular, jasmonate and salicylic acid pathway-associated genes, including JAZ, COI1, TGA, and PR, responded to P. sojae infection. All of these results indicate that the GmTNL16/gma-miR1510 pair participates in soybean defense response via the JA and SA pathways.