Open AccessMycoRed: Betalain pigments enable in vivo real-time visualisation of arbuscular mycorrhizal colonisation
Author(s) -
Alfonso Timoneda,
T. S. Yunusov,
ClĂŠment Quan,
Aleksandr Gavrin,
Samuel F. Brockington,
Sebastián Schornack
Publication year - 2021
Publication title -
plos biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.127
H-Index - 271
eISSN - 1545-7885
pISSN - 1544-9173
DOI - 10.1371/journal.pbio.3001326
Subject(s) - biology , colonisation , symbiosis , betalain , medicago truncatula , botany , glomeromycota , rhizophagus irregularis , arbuscular mycorrhiza , mutualism (biology) , mycorrhiza , arbuscular mycorrhizal , pigment , ecology , colonization , bacteria , genetics , chemistry , organic chemistry
Arbuscular mycorrhiza (AM) are mutualistic interactions formed between soil fungi and plant roots. AM symbiosis is a fundamental and widespread trait in plants with the potential to sustainably enhance future crop yields. However, improving AM fungal association in crop species requires a fundamental understanding of host colonisation dynamics across varying agronomic and ecological contexts. To this end, we demonstrate the use of betalain pigments as in vivo visual markers for the occurrence and distribution of AM fungal colonisation by Rhizophagus irregularis in Medicago truncatula and Nicotiana benthamiana roots. Using established and novel AM-responsive promoters, we assembled multigene reporter constructs that enable the AM-controlled expression of the core betalain synthesis genes. We show that betalain colouration is specifically induced in root tissues and cells where fungal colonisation has occurred. In a rhizotron setup, we also demonstrate that betalain staining allows for the noninvasive tracing of fungal colonisation along the root system over time. We present MycoRed, a useful innovative method that will expand and complement currently used fungal visualisation techniques to advance knowledge in the field of AM symbiosis.