Navigation Links
Milkweed's evolutionary approach to caterpillars: Counter appetite with fast repair
Date:7/22/2008

The adage that your enemies know your weaknesses best is especially true in the case of plants and predators that have co-evolved: As the predators evolve new strategies for attack, plants counter with their own unique defenses.

Milkweed is the latest example of this response, according to Cornell research suggesting that plant may be shifting away from elaborate defenses against specialized caterpillars toward a more energy-efficient approach. Genetic analysis reveals an evolutionary trend for milkweed plants away from resisting predators to putting more effort into repairing themselves faster than caterpillars -- particularly the monarch butterfly caterpillar -- can eat them.

"An important question with co-evolution is where does it end?" said Anurag Agrawal, Cornell associate professor of ecology and evolutionary biology and lead author of a paper in the current issue of the Proceedings of the National Academy of Sciences. "One answer is when it becomes too costly. Some plants seem to have shifted away from resisting herbivory [plant eating] and have taken that same energy and used it to repair themselves."

The paper is important because it sheds light on key theories of co-evolution, claiming that pressure by foraging insects makes plants diversify as they evolve new defensive strategies and that such diversification follows trends in one direction or another, said Agrawal.

Milkweed species have evolved elaborate resistance strategies to fight off caterpillars that eat their leaves. These include hairs on their leaves, heart poisons called cardenolides in their tissues and milky-white toxic latex that pours from the plants' tubes. A caterpillar's bite into a milkweed leaf leads to a flood of latex that is "like getting a gallon of sticky paint thrown into your face," said Agrawal.

Some caterpillars, in turn, have adapted by shaving the leaf, cutting a leaf's veins in a circle and then eating in the middle where the latex doesn't flow. Also, the monarch caterpillar has become immune to the cardenolides.

Using DNA sequence data to look at relationships between 38 species of milkweed, Agrawal and colleague Mark Fishbein, a Portland State University biologist, found evolutionary declines in milkweed's three most important resistance traits (hairs, cardenolides and latex) and an escalation in the plant's ability to regrow.

Agrawal was surprised, he said, to find that the plant became more tolerant rather than more diverse in its defenses. The reason, he speculated, could be because as its predators have become so specialized, the plant was better off choosing a new defensive tactic "to tolerate the herbivory damage instead of resisting it." It is unknown whether such strategies have also evolved in animals trying to evade parasites.

The findings address questions about plant evolution, biodiversity and keystone species and may give plant scientists clues about profitable pest control strategies.


'/>"/>

Contact: Blaine Friedlander
bpf2@cornell.edu
607-254-8093
Cornell University Communications
Source:Eurekalert

Related biology news :

1. Revolutionary chefs? Not likely, shows physics research
2. Crossed (evolutionary) signals?
3. Mechanism and function of humor identified by new evolutionary theory
4. Revolutionary CO2 maps zoom in on greenhouse gas sources
5. M2SYS Introduces Revolutionary Biometric Artificial Intelligence Technology to Significantly Reduce Fingerprint Software False Reject Rates
6. Lemurs evolutionary history may shed light on our own
7. Dartmouth researchers find the root of the evolutionary emergence of vertebrates
8. Oldest Australian crayfish fossils provide missing evolutionary link
9. New book reveals an evolutionary journey of the human body
10. Scientists find missing evolutionary link using tiny fungus crystal
11. Primitive early relative of armadillos helps rewrite evolutionary family tree
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/13/2017)... , April 13, 2017 UBM,s Advanced ... will feature emerging and evolving technology through ... Innovation Summits will run alongside the expo portion of ... sessions, panels and demonstrations focused on trending topics within ... advanced design and manufacturing event will take place June ...
(Date:4/11/2017)... No two people are believed to ... York University Tandon School of Engineering and Michigan ... partial similarities between prints are common enough that ... and other electronic devices can be more vulnerable ... in the fact that fingerprint-based authentication systems feature ...
(Date:4/5/2017)... -- Today HYPR Corp. , leading innovator in ... the HYPR platform is officially FIDO® Certified . ... that empowers biometric authentication across Fortune 500 enterprises and ... 15 million users across the financial services industry, however ... suites and physical access represent a growing portion of ...
Breaking Biology News(10 mins):
(Date:7/18/2017)... ... July 18, 2017 , ... Blood centers traditionally see a dangerous drop of ... is a struggle for community blood centers as high schools are out and many ... Commerce is teaming up with the South Texas Blood & Tissue Center ...
(Date:7/17/2017)... ... July 17, 2017 , ... ... clinical trial solutions, today announced safety software company AB Cube has joined ... Solutions business segment to advance technology innovation across life sciences and healthcare. ...
(Date:7/17/2017)... ... 17, 2017 , ... DuPont Pioneer today announced the launch ... (openinnovation.pioneer.com) dedicated to connecting third-party innovators with DuPont Pioneer scientists is now available ... biologicals and digital solutions. , “DuPont Pioneer is building on its long history ...
(Date:7/14/2017)... , ... July 13, 2017 , ... Dr. Joshua Mondlick ... dental implants into his practice, Mondlick Perio, in the Phoenix area. Dr. ... world's first and only FDA cleared laser treatment to re-grow bone and with significantly ...
Breaking Biology Technology: