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!
Closing in on advanced prostate cancer
13.12.2017 | Institute for Research in Biomedicine (IRB Barcelona)
Visualizing single molecules in whole cells with a new spin
13.12.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
13.12.2017 | Health and Medicine
13.12.2017 | Physics and Astronomy
13.12.2017 | Life Sciences