Venus flytrap's molecular mechanisms The Venus flytrap (Dionaea muscipula) is a carnivorous plant that depends on a diet of insects to supplement the poor mineral nutrition of the soil it grows in. Despite being known since the time of Darwin, the molecular basis of the plant's carnivorous lifestyle has remained largely unexplored. Climate Change and Environment © Shutterstock The CARNIVOROM (Molecular basis of carnivory excitability, movement, and endocrinology of plant traps) project was established to fill the gap in scientific knowledge. It employed a multidisciplinary approach based on a state-of-the-art combination of genomics, bioinformatics, molecular biology, protein biochemistry and biophysics. Although Dionaea shows the typical morphological and physiological properties of a green plant, it has also evolved highly specialised leaf-like structures called a snap trap. The trap-forming leaf is used to catch and digest prey and to absorb their valuable nutrients. High-throughput RNA sequencing was used to show that the final transcriptome of the Venus flytrap comprises 45 147 potential unigenes, which each contains sequences that represent a unique gene. Transcriptomic analysis revealed that the plant has the typical genetic make-up of a flowering plant. In addition, no novel genes leading to the development of carnivory were identified. Researchers hypothesised that the function of the snap trap relies mainly on a unique combination of genes already expressed in other organs. This assumption was supported by analysing the molecular processes occurring multicellular glands covering the inside of the trap. Once activated, the glands are able to digest prey and take up nutrients. The active glands also showed signs of a stress response normally associated with wounding and/or pathogen signalling in non-carnivorous plants. This included the secretion of hydrolysing enzymes, ER-quality control and the generation of reactive oxygen species. However, Dionaea actively suppressed programmed cell death and activated nutrient transport, in contrast to non-carnivorous plants. CARNIVOROM provided new insights into electrical and carnivorous activity in plants, which can be used as a model for understanding the evolution of the human nervous and endocrine systems. Keywords Dionaea muscipula, carnivory, transcriptome, venus flytrap, carnivorous, CARNIVOROM, snap trap, nutrients, unigenes
