Genome-wide quantification of Pseudomonas syringae B728a gene fitness in multiple host plants

Authors: Helmann, Tyler; DEUTSCHBAUER, ADAM - Lawrence Berkeley National Laboratory; LINDOW, STEVEN - University Of California

Submitted to: International Conference on Pseudomonas syringae Pathovars
Publication Type: Abstract Only
Publication Acceptance Date: 6/16/2020
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Diverse traits are necessary for bacterial colonization of plant hosts, ranging from specific virulence traits to those more generally required for bacterial growth both in the apoplast and on leaf surfaces. There is, however, little information as to the distinct genetic requirements for bacteria to colonize different plant hosts. Here, we utilize Randomly Barcoded TnSeq (RB-TnSeq) to identify the genes that contribute to the ability of Pseudomonas syringae strain B728a to grow within three different plant species spanning two families. We generated a mutant population containing over 280,000 uniquely barcoded transposon insertional mutant strains, with a median insertion density of 21 insertions per gene. This massive heterogeneous mutant population was used to interrogate the contribution of most of the individual genes in P. syringae to its ability to grow within common bean, lima bean and pepper. Most genes contributed at similar magnitudes to apoplastic fitness. However, 50 genes significantly differed in their fitness contributions to growth when compared across hosts. These genes encoded proteins in various functional categories including polysaccharide synthesis and transport, amino acid metabolism and transport, cofactor metabolism, and phytotoxin synthesis and transport. Six genes that encoded hypothetical proteins also contributed differentially to growth in these hosts. This dataset represents a valuable resource for the exploration of broadly important and host-specific virulence genes.