Understanding genomic diversity in Pseudomonas syringae throughout the forest and on the trees

Abstract

This article is a Commentary on Hulin et al., 219: 672–696.

Host Range Determinants of Pseudomonas savastanoi Pathovars of Woody Hosts Revealed by Comparative Genomics and Cross-Pathogenicity Tests

“…Genomics-based methods offer unprecedented resolution to analyze strain diversity and evolutionary relationships within the P. syringae complex, besides identifying candidate genes involved in pathogenicity and host range definition ( Lindeberg et al., 2009 ; Baltrus et al., 2011 ; Bartoli et al., 2015 ; Monteil et al., 2016 ; Baltrus et al., 2017 ; Dillon et al., 2019a ; Dillon et al., 2019b ). However, understanding the biological meaning of the observed genomic differences depends on the availability of experimental data confirming specific phenotypes, such as virulence and host range ( Baltrus and Orth, 2018 ). Specifically, testing more than one hundred P. syringae strains on different hosts showed that the host range is an overlapping continuum, with closely related strains exhibiting from extremely narrow to very broad host ranges ( Morris et al., 2019 ).…”

Liebig review: The role of mineral nutrients in the development of Pseudomonas syringae diseases—Lessons learned and implications for disease control in woody plants

“…Findings from these experiments are not necessarily applicable to perennial species. Plant defense mechanisms can be highly species‐specific, and also pathovars of Ps and perhaps even different strains from the same pathovar can differ in virulence factors and pathogenicity mechanisms (Baltrus & Orth, 2018; Hulin et al., 2020; Preston, 2000; Ruinelli et al., 2019). ‐Few plant nutritionists specialize in fruit tree nutrition, and even fewer work on interactions between plant nutrients and pathogen susceptibility.…”