Table 4.
Effects of microbes in modulating root system architecture
| Microbes | Function | Effects | References |
|---|---|---|---|
| Azospirillum brasilense | IAA production | Increased in root elongation, root surface area, root dry matter and development of LRs | El-Khawas and Adachi (1999) |
| Azospirillum brasilense Sp245 | Enhances the expression of ethylene receptors | Increasing numbers of LRs | Vargas et al. (2012) |
| Azospirillum brasilense CA-10 | IAA production | Enhanced PG (polygalacturonase) activity in roots, better root morphogenesis | Sekar et al. (2000) |
| Azospirillum lipoferum 4B | Alters rice secondary metabolite profiles | Increased the number of roots, total root length and root surface | Chamam et al. (2013) |
| Azospirillum B510 | |||
| Azospirillum irakense | Induces polygalacturonase expression | Modification of root tissue structural properties | Sekar et al. (2000) and Dobbelaere et al. (2002) |
| Acanthamoeba castellanii (Protozoa) and Betaproteobacteria | Nutrient solubilization | Elongated (L-type) laterals, branched root systems | Kreuzer et al. (2006) |
| Bacillus altitudinis strain FD48 | IAA production | Modifies the early events of root architecture | Ambreetha et al. (2018) |
| Bacillus altitudinis (strain FD48) | Modulates the expression of AUX/IAA family genes | Modifies the root architecture | Ambreetha et al. (2018) |
| Bacillus amyloliquefaciens RWL-1 | ABA | LR development | Shahzad et al. (2017) |
| Bacillus amyloliquefaciens | Induces the expression of auxin-responsive OsASR6 | Root improvement | Agarwal et al. (2019) |
| Burkholderia pyrrocinia (R-46) | Auxins, siderophore production | Improves root length and diameter | Ferreira Rêgo et al. (2014) |
| Herbaspirillum seropedicae | Improves the expression of auxin and ethylene-responsive genes | LR initiation | Brusamarello-Santos et al. (2012) |
| Klebsiella pneumoniae | IAA production | Increased in root elongation, root surface area, root dry matter and development of LRs | El-Khawas and Adachi (1999) |
| Phomopsis liquidambari B3 | Enhanced auxin, cytokinin, and ethylene level | Nitrogen-mediated growth of LRs | Li et al. (2018b) |
| Pseudomonas fluorescens | Stress-related induction | Increased root length | Kandasamy et al. (2009) |
| Pseudomonas putida REN5, Pseudomonas fluorescens REN1 | IAA, ACC deaminase, siderophore production | Increase length, fresh weight and dry weight, branching | Etesami and Alikhani (2016) |
| Pseudomonas fluorescens (R-55) | Auxins, siderophore production | Improves root length and diameter | Ferreira Rêgo et al. (2014) |
| Glomus intraradices (Rhizophagus irregularis) | Affects the expression of OsCYCLOPS1 | Increases in root mass, thickness, length, and LR number, induces the formation of long LRs | Yano et al. (2008) and Gutjahr et al. (2009) |
| OsLRT1 and also alters auxin, ABA, CK, ethylene concentration | |||
| Rhizophagus irregularis | Perception of chitin oligomers | Increases growth of LRs | Chiu et al. (2018) |
| Rhizosphere isolates PGG2 and PGB4 | IAA Production | Increases root length | Ashrafuzzaman et al. (2009) |
| Trichoderma koningiopsis NBRI-PR5 and T. asperellum NBRI-K14 | Altered lignification patterns and packing of the sclerenchyma and exodermis cells | Stimulated the root growth | Anshu et al. (2022) |