Table 2.
Examples of mechanisms of plant growth promotion by PGPF.
| Gene/Product | Function | Species | Reference |
|---|---|---|---|
| aph /acid phosphatase | - increased P availability via phosphates solubilization | Aspergillus, Trichoderma, Penicillium | [238,239] |
| AMT1; AMT2; AAT9/ ammonium transporter; amino acid transporter | - improved N acquisition | Tulasnella calospora | [240] |
| AQPF /aquaporin | - transport of water to the host - enhanced drought stress resistance |
Glomus intraradices | [241] |
| Phy /phytase | - increased P availability via solubilization of inositol | Aspergillus, Trichoderma, Penicillium | [238,239,242] |
| acdS /ACC deaminase | - degradation of ethylene precursor and protects against elevated ethylene levels - ameliorates stress effects and promotes root growth |
Trichoderma asperellum, Penicillium citrinum, Trichoderma gamsii | [243] |
| Hyd; Qid /hydrophobins | - allows for adhesion of hyphae to the surface of roots and protects hyphae against antifungal compounds - functions as MAMP (microbe-associated molecular pattern) and triggers plant response involved with symbiont recognition |
Trichoderma asperellum, Trichoderma
harzianum |
[244,245] |
| MST2/ monosaccharide transporter2 | - development of arbuscules - facilitates root colonization |
Glomus sp. | [246] |
| Tex1 /non-ribosomal peptided synthase | - synthesis of trichovirin II (peptaibol) which activates the plant immune system | Trichoderma virens | [247] |
| Thctf1 /transriptional factor | - regulates the synthesis of 6-pentyl-2H-pyran-2-one (6-PP) (VOC) which exhibits antifungal activity | Trichoderma sp. | [248] |
| Thph1; Thph2/cellulases | - cellulolytic activity - triggers plant immune system |
Trichoderma harzianum | [236] |
| sidD/siderophores synthase | - synthesis of siderophores - improved Fe acquisition - defense against pathogens |
Trichoderma reesei, Trichoderma virens | [249] |
|
Sm1; Sm2; Ep1; Swo
/ cerato-platanins; swollenin |
- fungal elicitors and upregulation of genes involved in JA signaling (modulation of the immune system) - swollenin disrupts the plant cell wall structure and enables penetration of the apoplast |
Trichoderma citrinoviride, Trichoderma virens | [250,251,252] |