Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sundews just want to be loved

18.08.2010
Why do some insect-eating plants like sundews keep their flowers so far away from their traps? New research suggests that it isn't a clever trick to keep pollinators safe, it's about getting pollinated

Sex can be complicated at the best of times, but plants have an extra difficulty. If you're a plant who relies on insects to pollinate your flowers and reproduce, you will want your flowerstalks to be long. That way your flowers are on display to insects above the crowd. But if your stalk is too long, you'll stand out to herbivores, and you flower will end up as someone's lunch.

It used to be thought that carnivorous plants like Sundews had the opposite problem. They reproduce better if they avoid eating insects that pollinate them, so a long stalk prevents an unfortunate meal. Simply looking at a plant, it's impossible to tell if the stalks evolved for sex or safety, but Bruce Anderson at the University of Stellenbosch has now found an answer to be published in the October issue of the Annals of Botany.

He examined two Sundews, Drosera cistiflora, which has a long stalk above its rosette of traps and Drosera pauciflora, which is more upright and has a shorter flower stalk. Both plants attract the same pollinators, so Anderson reasoned if a longer stalk is safer, D. pauciflora should accidentally catch more pollinators in its traps. To test his idea he observed the pollination of 500 plants of each species. Then he examined a sample of the traps to see what they had caught. Anderson said: "The pollinators all tended to be quite large, over 5mm. Most of them were monkey beetles. But the traps had a different catch. It's harder to say what many of them were exactly, because the Sundews left their bodies in poor condition, but they were small. Most were less than 2mm long. Only one plant had caught a pollinator. Statistically the length of the flower stems made no difference to the safety of the pollinators."

"But just because the stems didn't affect safety, it doesn't automatically follow that the other explanation, attracting pollinators, must be right by default. So I tested that too."

Flowers were cut from D. pauciflora and placed in test tubes. Some were set so the flowers were at normal height, while the other test tubes were buried so that the flower was barely above ground level. Anserson said: "Doing this meant there were few variables in the experiment. The flowers were identical. The only difference was their height. This way it's possible to simulate how well a Sundew that hadn't evolved a long stem could attract insects."

The results were emphatic. The taller flowers had ten times the number of visitors than the short flowers.

Anderson said: "There have been a few people who've suggested that the flower stalks are for attracting pollinators. However, the standard explanation in most textbooks is that the stems are to protect pollinators. It's a good story. It sounds like the kind of elegant solution that evolution comes up with. Now we have the hard data from these experiments and it shows that explanation is wrong. It's not about food, it's about sex. Sundews want to improve their chances of pollination and maximise their reproductive success."

Dr. David Frost | EurekAlert!
Further information:
http://www.le.ac.uk

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Researchers invent tiny, light-powered wires to modulate brain's electrical signals

21.02.2018 | Life Sciences

The “Holy Grail” of peptide chemistry: Making peptide active agents available orally

21.02.2018 | Life Sciences

Atomic structure of ultrasound material not what anyone expected

21.02.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>