Table 1.
Summary of all discussed bacteria, predicted function, and secreted molecules in this review. Some molecules are secreted from different bacteria.
| Bacterial strain | Molecules | Predicted function | References |
|---|---|---|---|
| Plant growth promoting | |||
| Enterobacter, Bacillus, Pseudomonas | Organic acids | Phosphate solubilization | Jha et al., 2012; Goswami et al., 2014 |
| Pseudomonas spp. GRP3A, PRS9, Pseudomonas chlororaphis ATCC 9446 | Siderophores | Fe acquisition | Sharma and Johri, 2003; Trapet et al., 2016 |
| Azospirillum brasilense SP245 | IAA production | Induction of root hair formation | Cohen et al., 2008; Molina et al., 2018 |
| Leifsonia soli SE | Gibberellin | Induction of plant growth and seed germination | Kang et al., 2014 |
| Pseudomonas fluorescens G20-18 | Cytokinins | Suppression of disease resistance, cell elongation | Großkinsky et al., 2016 |
| Root nodulation | |||
| Rhizobium leguminosarum bv. viciae A34 | Exopolysaccharide (EPS)-glycanases PlyA and PlyB | Biofilm maturation | Russo et al., 2006; Bogino et al., 2013 |
| Sinorhizobium meliloti | TolC protein | Nodules production | Cosme et al., 2008; Srinivasan et al., 2015; Mergaert, 2018 |
| Rhizobium leguminosarum bv. trifolii R200, Rhizobium etli | RapA1 | Biofilm formation | Mongiardini et al., 2009; Ho et al., 2014; Poole et al., 2018 |
| Rhizobium leguminosarum spp. | NodO | Signaling for nodulation | Finnie et al., 1997; Krehenbrink and Allan, 2008 |
| Sinorhizobium fredii HH103 | NopD | Regulating expression of plant proteins | Hubber et al., 2004; Rodrigues et al., 2007; Nelson and Sadowsky, 2015 |
| Bradyrhizobium japonicum USDA110, Sinorhizobium fredii NGR234, HH103, USDA257 | NopL | Induction of plant immune response | Pedley and Martin, 2005; Zhang et al., 2011 |
| Bradyrhizobium japonicum USDA110, Sinorhizobium fredii NGR234, HH103 | NopM | Ubiquitination process | Rohde et al., 2007; Burkinshaw and Strynadka, 2014; Zheng and Shabek, 2017 |
| Rhizobium etli CNPAF512, Sinorhizobium fredii NGR234, HH103, USDA257 | NopP | Phosphorylated by plant kinases | Bartsev et al., 2004; Skorpil et al., 2005; Gourion et al., 2015 |
| Sinorhizobium fredii NGR234 | NopT | Cysteine protease activity | Dai et al., 2008; Kambara et al., 2009; Gourion et al., 2015; Nelson and Sadowsky, 2015 |
| Rhizobium sp. NGR234 | NopJ | Inactivates MAP kinases | Mukherjee et al., 2006; Kambara et al., 2009; Gourion et al., 2015 |
| Mesorhizobium loti R7A | Msi059 | Regulating expression of plant proteins | Rodrigues et al., 2007; Nelson and Sadowsky, 2015 |
| Mesorhizobium loti R7A | Msi061 | Protein degradation of VirE2 and Vip1 | Nelson and Sadowsky, 2015 |
| Bradyrhizobium strain ORS3257 | ErnA | An unknown function in the plant nucleus | Teulet et al., 2019 |
| Biocontrol | |||
| Pseudomonas spp., Bacillus spp. | Antibiotics | Virulence against phytopathogens | Guilleroux and Osbourn, 2004; Daval et al., 2011; Cao et al., 2018 |
| Pseudomonas fluorescens Pf29Apr | DAPG | Downregulation of pathogenic enzymes | Daval et al., 2011 |
| Pseudomonas fluorescens MFE01 | T6SS related- toxins | Virulence against phytopathogens | Decoin et al., 2014 |
| Pseudomonas brassocaecearum Q8r1–96 | RopAA, RopB, RopM, DAPG | Induction of plant immune responses | Mavrodi et al., 2011 |
| Bacillus subtilis BBG111 | Cyclic lipopeptides (CLCPs) | Induction of plant immune responses | Ongena et al., 2005; García-Gutiérrez et al., 2013; Farace et al., 2015 |
| Bacillus velezensis | Lipopeptide compounds | Antifungal | Cao et al., 2018 |