Meeting Abstract
Bladderworts are carnivorous plants that trap microscopic organisms in under-water traps. Bladderworts are remarkable among plants in two ways: they have one of the smallest nuclear haploid genomes (88 Mbp) among known angiosperms, and they are the fastest predators with traps that ingest prey within less than a millisecond. The mechanisms behind re-setting of the suction traps is energetically intensive, and known to generate Reactive Oxygen Species (ROS), which puts these plants under continuous oxidative stress. Whole genome sequencing of bladderwort has revealed that all parts of the plant express ROS-detoxification and DNA-repair enzyme genes, which supports the hypothesis that the mutagenic action of high ROS activity increases nucleotide substitution rates. The small genome might be explained by the prohibitive cost of DNA repair. In this project, we want to explore whether the trap resetting mechanism is indeed responsible for raising ROS levels in bladderworts. Profiling of plant metabolites using Nuclear Magnetic Resonance (NMR) spectroscopy has already been used to identify ROS activity in Arabidopsis via detection of stress-related compounds. The usefulness of this approach for studying bladderworts however still needs to be tested. We developed a protocol to vary the rate of trap firing and resetting to explore whether increasing trap activity modulates ROS levels. Our protocol uses two different approaches to study the effect of trap resetting activity on ROS production. First, trap age has a strong effect on spontaneous trigger frequency, causing young traps to reset more often than old traps. Second, mechanical stimulation (flow) and changing the water ionic content affects firing rates. We are currently exploring whether those firing rate changes affect ROS levels in the plant.
