Pseudomonas putida BP25 alters root phenotype and triggers salicyclic acid signaling as a feedback loop in regulating endophytic colonization in Arabidopsis thaliana

Abstract

Endophytic Pseudomonas putida BP25 (PpBP25) triggered density dependent alterations on Arabidopsis thaliana Col-0 growth. Endogenous colonization of PpBP25 was found regulated within Arabidopsis that caused induction and repression of 131 and 74 plant genes, respectively. Induced genes like WRKY33, ATRLP19, ATL2, ATEXO70 B2, pEARLI, RPS2, CBP60G, PLA2, CRK18, ATFBSI, DREB2A, TIR, RAP2.4, and MOSI were components of defense and salicyclic acid(SA) signaling. Development associated genes were found significantly repressed. Based activation of Phytohormone signaling with their associated fitness costs on plant growth was observed. The data suggests that PpBP25 colonization triggered expression of defense genes that restricted its own population in a feedback loop besides causing altered root phenotype.