Herself's Houseplants

Killing plants so you don't have to

So what exactly is that stuff in the pitcher of your pitcher plant?

You know that carnivorous plants eat bugs. The pitcher part of the plant acts as a stomach. Some scientists in Japan have recently figured out what chemicals they use to do this.

Japanese scientists now report completely deciphering this complex cocktail of digestive and antibacterial enzymes. Their study is scheduled for the February issue of ACS’ Journal of Proteome Research.Unlike other plants that absorb nutrients from the soil, carnivorous plants growing in nutrient-poor soils have special organs to capture insects, digest them and absorb the nitrogen and phosphorous their environment sorely lacks. The identity of all the myriad proteins involved in this evolutionary marvel — some of which could have beneficial applications in medicine and agriculture — has been a mystery until now.

Tatsuro Hamada and Naoya Hatano used cutting-edge proteomic analysis to identify all of the components. They isolated and sequenced the proteins, then compared each with existing proteins to find structural matches.

Hamada and Hatano detected seven proteins that exist mainly in the pitcher fluid of N. alata — three of which can only be found in this species — including useful enzymes that may inhibit bacterial growth and rotting as the plant slowly digests its prey. [ read more Secret of the carnivorous pitcher plant’s slurp]

Also reporting on this story in more detail is Nature…

The fluid at the base of the trap had long been thought to contain digestive enzymes. Previous research had confirmed this, but exactly which enzymes were present was anyone’s guess. “Digestion in pitcher plants has been actively studied for more than 150 years and we still don’t know how it works [because] it is such a complex process,” says Chris Frazier at the University of New Mexico in Albuquerque.

Now, Naoya Hatano from the Harima Institute in Riken and Tatsuro Hamada from Ishikawa Prefectural University in Japan have identified seven proteins in the carnivorous plant’s fluid. They grew the carnivorous plants in their lab, and collected the fluid from newly opened pitchers to prevent contamination from recently captured insects. Then they used polyacrylamide gel electrophoresis to separate out the proteins, and mass spectrometry to identify what type of enzymes the proteins were likely to be. Because some of the enzymes they found were unfamiliar, they searched protein databases to find enzymes with similar structures and noted that some of them were probably not digestive at all. [ read more Little lab of horrors ]