Traps of carnivorous pitcher plants as a habitat: composition of the fluid, biodiversity and mutualistic activities

Abstract

There is strong evidence that CPPs influence their phytotelm. Two strategies can be distinguished: (1) Nepenthes and Cephalotus produce acidic, toxic or digestive fluids and host a limited diversity of inquilines. (2) Genera without efficient enzymes such as Sarracenia or Heliamphora host diverse organisms and depend to a large extent on their symbionts for prey utilization.

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

“…Exposed sites are structurally less constrained, and substitutions in such sites are likely to change their interactions with other molecules in solution, rather than changing protein conformation [25][26][27] . During the evolution of digestive enzymes, selective pressures may have come from the digestive fluid environment, which include the presence of insect-derived substrates, high endogenous proteolytic activity, low pH and microbial invasion or symbiosis 1,11,12 . As exposed residues constitute the protein-environment interface, the convergent amino acid substitutions may have been critical factors for the convergent establishment of carnivory across the angiosperms.…”

“…Carnivorous plants attract potential prey by nectar, coloration and scent 1,11,12 . GO terms enriched in the pitcher transcriptome included 'starch metabolic process' and 'sucrose metabolic process' (Supplementary Table 22), which may be related to the production of attractive nectar.…”

“…Carnivorous plants secrete digestive enzymes for degradation of trapped animals 1,11,12 . 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).…”

Convergence in Multispecies Interactions

“…For example, both Sarracenia (Ericales: Sarraceniaceae) and Nepenthes (Caryophyllales: Nepenthaceae) pitchers host predators, filter feeders, and detritivores [51]. The food webs of pitchers from these different families on different continents are more like each other than they are like the food webs of other aquatic microcosms, even if the microcosms are in the same habitat as the pitchers [50].…”

“…The food webs of pitchers from these different families on different continents are more like each other than they are like the food webs of other aquatic microcosms, even if the microcosms are in the same habitat as the pitchers [50]. Convergence might be influenced by the plants' internal chemistry, which is similar among all pitcher plant lineages and is controlled to some extent by the plant [51][52][53].…”