MycoRed: Betalain pigments enable in vivo real-time visualisation of arbuscular mycorrhizal colonisation
Fig 5
Betalains can be produced in Nicotiana benthamiana roots as a response to AM fungi colonisation.
(a) Schematic of the multigene vectors constructed for inducible betalain expression in N. benthamiana roots where only the first gene of the betalain biosynthesis pathway is controlled by AM symbiosis–specific promoters. Expression of NbPT5b-p1 (b) and NbBCP1b-p1 (c) in whole root systems of N. benthamiana T1 plants 4 weeks after inoculation with Rhizophagus irregularis. Right: Root images are filtered for red colour. (d–g) Confocal microscopy of red NbPT5b-p1 (d and e) and NbBCP1b-p1 (f and g) transgenic root sections which were cut and stained with WGA-FITC to visualise fungal structures. (d and f) colour-filtered for red; (e and g) FITC green fluorescence. Scale bar (b and c), 1 cm; scale bar (d–g), 100 μm. AM, arbuscular mycorrhiza; WGA, wheat germ agglutinin.