Venus flytrap carnivorous lifestyle builds on herbivore defense strategies

Abstract

Although the concept of botanical carnivory has been known since Darwin's time, the molecular mechanisms that allow animal feeding remain unknown, primarily due to a complete lack of genomic information. Here, we show that the transcriptomic landscape of the Dionaea trap is dramatically shifted toward signal transduction and nutrient transport upon insect feeding, with touch hormone signaling and protein secretion prevailing. At the same time, a massive induction of general defense responses is accompanied by the repression of cell death–related genes/processes. We hypothesize that the carnivory syndrome of Dionaea evolved by exaptation of ancient defense pathways, replacing cell death with nutrient acquisition.

Long-read sequencing uncovers the adaptive topography of a carnivorous plant genome

“…Several other significantly enriched GOs are associated with this gene family. Cysteine proteases have been identified as major functional components of Venus flytrap (Dionaea muscipula) digestive fluid (72), reported in three D. muscipula transcriptomes (70,73,74), and structurally annotated for both Cape sundew (Drosera capensis) draft genome sequences (75,76) and D. muscipula (77). We found tandem clusters of homologous proteaseencoding genes in the U. gibba genome that had demonstrably undergone tandem duplication both before and after the most recent WGD event in U. gibba's evolutionary history (Fig.…”

Genome of the pitcher plant Cephalotus reveals genetic changes associated with carnivory

“…Previous studies on several digestive enzymes of Nepenthes spp., Drosera spp., Dionaea muscipula and Cephalotus indicate that pathogenesis-related proteins were co-opted for digestive function as well as for preventing microbial colonization of digestive fluid (refs [16][17][18][19] and refs in Supplementary Table 24). To further investigate the origin and evolution of digestive enzymes of Cephalotus and three other distantly related carnivorous plants (Drosera adelae, N. alata and Sarracenia purpurea), we sequenced fragments of digestive fluid proteins and identified 35 corresponding genes (Fig.…”

Insect haptoelectrical stimulation of Venus flytrap triggers exocytosis in gland cells

“…If a second one fires within 20 s, it triggers rapid trap closure. In case an insect is trapped and struggles to escape, two and more haptoelectric stimuli activate jasmonate (JA) signaling and biosynthesis (3,6,7). From the fifth strike on, glands raise their expression levels of hydrolase and nutrient transporter genes.…”

“…From the fifth strike on, glands raise their expression levels of hydrolase and nutrient transporter genes. When mechanostimulation is replaced by application of coronatine (COR), a mimic of the biologically active JA hormone JA-Ile, it can substitute for the mechanoelectric stimulation of the flytrap (7). Haptoelectric signaling and touch hormone activation turn the closed trap into a "green stomach," flooding the entrapped prey with an acidic digestive fluid (3,6,13).…”

“…Growing on mineral-deficient soils, the carnivorous Venus flytrap (Dionaea muscipula) lures, captures, and digests small arthropods (3)(4)(5)(6)(7)(8) to feed on the nutrients extracted from their flesh (9)(10)(11)(12). Closure of the bilobed snap trap is initiated by mechanical stimulation of trigger hairs located at the inner trap surface.…”