Conditioning plants for arbuscular mycorrhizal symbiosis through DWARF14-LIKE signalling

The evolutionarily ancient alpha/beta hydrolase DWARF14-LIKE (D14L) is indispensable for the perception of beneficial arbuscular mycorrhizal (AM) fungi in the rhizosphere, and for a range of developmental processes. Variants of D14L recognise natural strigolactones and the smoke constituent karrikin, both classified as butenolides, and additional unknown ligand(s), critical for symbiosis and development. Recent advances in the understanding of downstream effects of D14L signalling include biochemical evidence for the degradation of the repressor SMAX1. Indeed, genetic removal of rice SMAX1 leads to the de-repression of symbiosis programmes and to the simultaneous increase in strigolactone production. As strigolactones are key to attraction of the fungus in the rhizosphere, the D14L signalling pathway appears to coordinate fungal stimulation and root symbiotic competency. Here, we discuss the possible integrative roles of D14L signalling in conditioning plants for AM symbiosis.

Automated summary

The evolutionarily ancient alpha/beta hydrolase DWARF14-LIKE (D14L) plays a crucial role in the perception of beneficial arbuscular mycorrhizal (AM) fungi and various developmental processes, recognizing natural strigolactones and other unknown ligands critical for symbiosis and development. Recent research has shown that D14L signaling pathway coordinates fungal stimulation and root symbiotic competency by degrading the repressor SMAX1, leading to increased strigolactone production. This pathway appears to play an integrative role in conditioning plants for AM symbiosis.