Table 1.
Summary of auxin transport proteins implicated in root–microbe interactions.
| Gene/Protein | Host Organism | Type of Interaction | Role/Phenotype | Reference |
|---|---|---|---|---|
| AtAUX1 | Arabidopsis thaliana | Heterodera schachtii | - AUX1 expression was localized to feeding sites | [135] |
| AtPIN1 AtPIN2 |
Arabidopsis thaliana | Heterodera schachtii | - Reduced H. schachtii development in infected roots of pin1/tgg1 and pin2 mutants | [122] |
| AtAUX1
AtLAX1 AtLAX2 AtLAX3 |
Arabidopsis thaliana | Heterodera schachtii | - AtLAX3 interacts with cyst nematode effector Hs19C07 | [137] |
| - aux1lax1 and aux1lax1lax2lax3 mutants show reduced infection by H. schachtii | ||||
| AtPIN1
AtPIN2 AtPIN3 AtPIN4 AtPIN7 |
Arabidopsis thaliana | Heterodera schachtii | - PIN1, 2, 3, 4 genes are expressed in developing feeding structures, but at different times | [138] |
| - PIN3 and PIN4 are redirected to lateral sides of feeding cells | ||||
| - Mutants of all five PIN genes show reduced infection | ||||
| AtLAX3 AtAUX1 |
Arabidopsis thaliana | Meloidogyne incognita | - AtLAX3 and AtAUX1 expression induced in developing root galls | [136] |
| PtaPIN2, 4,9,12 | Poplar (Populus tremula × Populus alba) | Laccaria bicolor (Ectomycorrhiza) | - Gene expression upregulated during early interaction | [21] |
| PtaAUX6 | Poplar | Laccaria bicolor (Ectomycorrhiza) | - Gene expression upregulated during early interaction | [21] |
| AtPIN2 | Arabidopsis thaliana (nonhost) | Laccaria bicolor (Ectomycorrhiza) | - LR induction reduced by 40% in Atpin2 mutant | [21] |
| AtAUX1 | Arabidopsis thaliana (nonhost) | Tuber borchii (Ectomychorizza) | - Reduced inhibition of primary root development in Ataux1-7 mutant compared to WT | [141] |
| CgPIN1 | Casuarina glauca | Frankia inoculation | - Localized to uninfected cells adjacent to Frankia-infected cells | [142] |
| - Exports IAA into Frankia-infected cells | ||||
| CgAUX1 | Casuarina glauca | Frankia inoculation | - Localized to Frankia-infected cells | [143] |
| - Likely imports IAA into Frankia-infected cells | ||||
| DtAUX1 | Discaria trinervis | Frankia inoculation | -Localized to nodule meristem | [144] |
| MtPIN2 | Medicago truncatula | Sinorhizobium meliloti inoculation | - Expressed in peripheral vasculature in early nodule primordium | [145] |
| - Expressed at the base of mature nodule | ||||
| - Knockdown of MtPIN2 reduced nodulation | ||||
| MtPIN3 | Medicago truncatula | Sinorhizobium meliloti inoculation | - Knockdown of MtPIN3 reduced nodulation | [107] |
| MtPIN4 | Medicago truncatula | Sinorhizobium meliloti inoculation | - Knockdown of MtPIN4 reduced nodulation | [43] |
| Sinorhizobium meliloti nod factor treatment | - Increased expression after nod factor treatment | [146] | ||
| MtPIN10 | Medicago truncatula | Sinorhizobium meliloti nod factor treatment | - Increased expression after nod factor treatment | [147] |
| MtLAX1-3 | Medicago truncatula | Sinorhizobium meliloti inoculation | - Transcripts are localized to early dividing cells and to cells near the vasculature of early nodule primordium | [148] |
| LjABCB1 | Lotus japonicus | Mesorhizobium loti inoculation | - Localized to uninfected cells adjacent to Rhizobia-infected cells | [149] |
| - Exports IAA from uninfected cells into adjacent Rhizobia-infected cells |