TABLE 4.
Literature comparisons of root-associated microbial functional groups considering (i) wheat of different species, wild or domesticated, (ii) landraces, ancient, or modern varieties within wheat species, and (iii) different modern cultivars within wheat species.
| Microbial function | Analysis of individual microorganisms |
Analysis of functional groups |
||||||
| Microorganism studied | (i) Wheat evolution/domestication | (ii) Genotype categories within wheat species | (iii) Wheat cultivars | Methodology used | (i) Wheat evolution/domestication | (ii) Genotype categories within wheat species | (iii) Wheat cultivars | |
| Biotic interactions | ||||||||
| DAPG synthesis | Pseudomonas brassicacearum Q8r1-96 | Okubara and Bonsall, 2008; Yang et al., 2018 | ||||||
| Pseudomonas fluorescens Q2-87 | ||||||||
| Pseudomonas ogarae F113 | Valente et al., 2020 | Valente et al., 2020 | ||||||
| PCR-RFLP and sequence analysis of Pseudomonas isolates | Mazzola et al., 2004 | |||||||
| Phenazine synthesis | Pseudomonas chlororaphis | Mahmoudi et al., 2019 | ||||||
| Synthesis of antimicrobial compound(s) | in silico prediction from rrs metabarcodes | Mahoney et al., 2017 | ||||||
| Fungal inhibition | PCR-RFLP of Pseudomonas isolates | Gu and Mazzola, 2003 | ||||||
| Rhizoctonia inhibition | Agar plate assays of Pseudomonas isolates | Mazzola and Gu, 2002 | ||||||
| Induction of root defense | Pseudomonas brassicacearum Q8r1-96 | Maketon et al., 2012 | ||||||
| Pseudomonas putida | Pérez-de-Luque et al., 2017 | |||||||
| Rhizophagus irregularis | ||||||||
| Pseudomonas brassicacearum Q8r1-96 | Okubara et al., 2010 | |||||||
| IAA synthesis | Azotobacter chroococcum | Narula et al., 2000 | ||||||
| Salkowski method and sequence analysis | Venieraki et al., 2011 | |||||||
| ACC deaminase activity | Absorbance quantification of α-ketobutyrate product | Stromberger et al., 2017 | ||||||
| Yield promotion | Azospirillum brasilense Cd | Pagnani et al., 2020 | ||||||
| Gluconacetobacter diazotrophicus Pal5 | ||||||||
| Herbaspirillum seropedicae Z67 | ||||||||
| Biogeochemical cycles | ||||||||
| Malate production | in silico prediction from rrs metabarcodes | Mahoney et al., 2017 | ||||||
| Degradation of organic compound | Biolog™ plate assays | Siciliano et al., 1998 | ||||||
| Cellulose decomposition | Counts on cellulose Congo Red medium | Zuo et al., 2014 | ||||||
| Urease, catalase, sucrose, and dehydrogenase synthesis | Colorimetric assays of potential enzymatic activities | Zuo et al., 2014 | ||||||
| Nitrogen metabolism | Metabarcoding (rrs) predicted gene functioning | Mahoney et al., 2017 | ||||||
| N2 fixation | Counts on N-free Ashby’s medium | Zuo et al., 2014 | ||||||
| Acetylene reduction assays and nifH sequence analysis | Venieraki et al., 2011 | |||||||
| qPCR (nifH) | Spor et al., 2020 | Rilling et al., 2018 | ||||||
| Nitrification | Counts on improved Stephenson’s medium | Zuo et al., 2014 | ||||||
| qPCR (amoA) | Spor et al., 2020 | |||||||
| Denitrification | Measurement of nitrate reductase potential activity | Gill et al., 2006 | ||||||
| qPCR (nirK/nirS, nosZI/nosZII) | Spor et al., 2020 | |||||||
| Sulfur metabolism | in silico prediction from rrs metabarcodes | Mahoney et al., 2017 | ||||||
| Phosphorus metabolism | in silico prediction from rrs metabarcodes | Mahoney et al., 2017 | ||||||
| Phosphate solubilization | Azotobacter chroococcum | Narula et al., 2000 | ||||||
These comparisons were carried out at the level of individual microorganisms (whereby one or several microorganisms was/were inoculated on wheat) or entire functional groups (i.e., taking into account most or all microorganisms potentially contributing to a given microbial function). RFLP, Restriction Fragment Length Polymorphism. List of references is available in Supplementary Material 1.