Ava Wise

The circadian clock in plants is a crucial mechanism driving them to optimize energy use in a fluctuating environment. Recent studies have suggested the possibility of multi-species clock coordination between arbuscular mycorrhizal fungi (AMF) and their mutualistic symbiotic plant hosts. Using the tomato Solanum lycopersicum, we investigated the circadian period of tomato near-isogenic lines (NILs) and validated qPCR primers targeting the homologous clock genes of Rhizophagus irregularis, to soon determine if the fungus exhibits circadian cycling. From a subset of tomato NILs we ran leaf-movement assays through time-lapse imaging and a computational pipeline to obtain circadian period. For future RT-qPCR analysis, we extracted RNA from AMF-inoculated clover roots, synthesized cDNA, confirmed amplicons with PCR, then tested primer efficiency using a dilution series. Leaf-movement data showed significant period length variation across the NILs. Following melting point and efficiency analyses, qPCR primers for clock genes WC-1, WC-2, and housekeeping genes specifically amplified their target successfully. Future steps include performing RT-qPCR to test for the presence of a clock in AMF, continuing leaf-movement trials, and begin including leaf-movement trials with AMF presence in tomato roots. Additionally, we aim to use NILs with period length variation to examine gene expression in tomato roots with and without AMF inoculation using a RT-qPCR time course, to determine the impacts of AMF on the plant host's circadian cycle.