Effects of transcription factor PsnWRKY70 on phyllosphere bacterial community of Populus infected by Melampsora laricis-populina

Abstract

PsnWRKY70 is an important transcription factor in plant immunity. In this study, we found that the transcription factor PsnWRKY70 can positively regulate the resistance of poplar to Melampsora laricis-populina. Meanwhile, the PsnWRKY70 gene is involved in the regulation of the composition of the phyllosphere microbiome of the poplar, thereby synergistically relieving the infection of pathogens. In this study, For β diversity analysis, principal coordinate analysis (PCoA) showed that PsnWRKY70 had little effect on phyllosphere bacterial community in healthy leaves of poplar. However, the bacterial community in leaves of transgenic PsnWRKY70 poplars changed significantly when the leaves were infected by Melampsora laricis-populina.The lefse analysis of epiphytic bacteria on infected leaves showed that Rubellimicrobium, Knoellia, Flavisolibacter, Devosia, Dyadobacter, Rhodococcus, Balneimonas, and Sphingobacterium were significantly enriched OE lines. The lefse analysis of endophytic bacteria on infected leaves showed that Erwinia and Ochrobactrum was significantly enriched in the leaves of OE lines. The PsnWRKY70 gene can recruit the strains to improve the ability of the OE lines of the transgenic poplar to resist the invasion of Melampsora laricis-populina. In summary, The results showed that PsnWRKY70 enhanced the resistance of poplar to Melampsora laricis-populina by changing the composition of bacterial community in poplar phyllosphere.