Arbuscular mycorrhizal (AM) symbiosis is regulated by carotenoid-derived molecules, including strigolactones and other apocarotenoids. However, the role of root carotene availability remains poorly understood. Here we evaluated AM performance in tomato using two mutants showing contrasting root carotenoid profiles, i.e. cyc-b7 , an EMS-derived TILLING mutant carrying a characterized mutation in Cyc-B , and 7458-Y , an uncharac...