MycoRed: Betalain pigments enable in vivo real-time visualisation of arbuscular mycorrhizal colonisation
Fig 6
Betalain production in Nicotiana benthamiana roots as a response to AM fungi colonisation via expression of the entire betalain pathway under AM symbiosis–specific promoters.
(a) Schematic of the multigene vectors constructed for inducible betacyanin expression in N. benthamiana roots with the 3 betalain biosynthetic genes controlled by the NbPT5b or the NbBCP1 promoters. Expression of NbPT5b-p3 (b and c) and NbBCP1-p3 (d and e) in roots of N. benthamiana 4 weeks after inoculation with Rhizophagus irregularis. Betacyanin production was not visible in mock conditions for any NbPT5b-p3 or NbBCP1b-p3 roots. (c and e) are a magnification of the areas delimited by the dashed squares. Scale bar (b and d), 500 μm; scale bar (c and e), 100 μm. AM, arbuscular mycorrhiza; Ar, arbuscules; en, endodermis; ep, epidermis; ih, internal hyphae; v, vesicle.