Ancient wheat varieties have a higher ability to interact with plant growth‐promoting rhizobacteria

Abstract

Plant interactions with plant growth‐promoting rhizobacteria (PGPR) are highly dependent on plant genotype. Modern plant breeding has largely sought to improve crop performance but with little focus on the optimization of plant × PGPR interactions. The interactions of the model PGPR strain Pseudomonas kilonensis F113 were therefore compared in 199 ancient and modern wheat genotypes. A reporter system, in which F113 colonization and expression of 2,4‐diacetylphloroglucinol biosynthetic genes (phl) were measured on roots was used to quantify F113 × wheat interactions under gnotobiotic conditions. Thereafter, eight wheat accessions that differed in their ability to interact with F113 were inoculated with F113 and grown in greenhouse in the absence or presence of stress. F113 colonization was linked to improved stress tolerance. Moreover, F113 colonization and phl expression were higher overall on ancient genotypes than modern genotypes. F113 colonization improved wheat performance in the four genotypes that showed the highest level of phl expression compared with the four genotypes in which phl expression was lowest. Taken together, these data suggest that recent wheat breeding strategies have had a negative impact on the ability of the plants to interact with PGPR.

Secondary metabolites from plant‐associated Pseudomonas are overproduced in biofilm

“…1). The 4 Pseudomonas strains formed small or thick aggregates of cells throughout the root system and appeared as good wheat colonizers, as already reported for F113 (Valente et al ., 2020).…”

“…One representative view for each strain was presented in Figure 1A. In addition, root colonization by the Pseudomonas strains was estimated by quantifying the mCherry fluorescence recovered from roots as previously reported (Valente et al ., 2020). Briefly, the roots were ground for 1 min with a FastPrep‐24 Classic Instrument (MP Biomedicals, Santa Ana, CA).…”

Beneficial soil-borne bacteria and fungi: a promising way to improve plant nitrogen acquisition

“…Furthermore, there clearly is genetic diversity among crop varieties for beneficial plant–microorganism associations, which suggests that, both among different species and within the same species, there are favorable alleles involved in the control of such associations ( Sawers et al , 2018 ; Valente et al , 2020 , Chandra et al , 2020 ). More ambitious studies at the genome level could be undertaken to identify which genes or loci are involved in the genetic control of plant performance in response to inoculation with N 2 -fixing bacteria and AMF ( Lehnert et al , 2018 b; Vidotti et al , 2019 ).…”

Wheat domestication has dramatically affected the root-associated microbiome

“…Breeding for higher yields in high-input agriculture may inadvertently have led to depletion of beneficial microbial taxa associated with plant roots. For example, Valente et al [22] found that ancient wheat varieties were more capable of interacting with beneficial plant growth-promoting rhizobacteria. Generally, the magnitude of genotype effects on microbial communities is significant but small [3,5,26].…”

“…Several wheat traits have changed dramatically during domestication such as root architecture and exudation of primary and secondary metabolites [19][20][21]. This may have had profound effects on root and rhizosphere microbial communities, as demonstrated in a study of plant growth-promoting bacteria associated with roots of ancient and 5 modern wheat [22]. It has further been shown that modern wheat types are less dependent on arbuscular mycorrhizae than older types and that old accessions benefits more from mycorrhizal symbiosis [23].…”