AUG 26, 2019 02:49 PM PDT

Invasive Tumbleweed Demonstrates the Advantage of Extra Chromosomes

WRITTEN BY: Carmen Leitch

The massive tumbleweed  Salsola ryanii is a species that was once thought to be going extinct. Researchers have found that this tumbleweed is more likely to expand into new regions, however, and is here to stay. This tumbleweed carries two copies of its parents’ chromosomes. While that’s been thought of as a biological advantage for plants, this work shows that the offspring can grow faster and larger than its parents. The findings have been reported in the journal AoB Plants.

"Salsola ryanii is a nasty species replacing other nasty species of tumbleweed in the U.S.," noted study co-author Norman Ellstrand, a University of California Riverside (UCR) Distinguished Professor of Genetics. "It's healthier than earlier versions, and now we know why."

Almost all mammals, including humans, are diploid organisms, which means they carry two sets of chromosomes; one set comes from the female parent, and one from the male. In humans, if an egg that mistakenly carries two sets of chromosomes is fertilized, the resulting zygote is unlikely to survive.

In plants, however, it’s far more common for organisms to carry more than two sets of chromosomes - called polyploidy. Many common domesticated crops like apples, peanuts, and wheat are polyploid. Polyploidy can easily occur when two parents have similar chromosomes or when there is a genome duplication event. It’s often been assumed to confer some biological benefit in plants, otherwise, polyploidy would be rejected and it wouldn’t be seen so often.

"Typically, when something is new, and it's the only one of its kind, that's a disadvantage. There's nobody exactly like you to mate with," explained study co-author Shana Welles, a graduate student at the time of this research who is currently a postdoctoral fellow at Chapman University.

Commandos from Cannon Air Force Base, N.M., clear tumbleweeds from a residential area in Clovis, N.M., 2014. / Credit: U.S. Air Force/Senior Airman Ericka Engblom

The evolutionary advantage of polyploidy had not been demonstrated, until this research. The scientists showed that a hybrid tumbleweed with more sets of chromosomes than its parents also grows more vigorously.

A tumbleweed that can grow higher faster is not something people living in the West are looking forward to. They can damage property and agriculture, and cause car accidents. Tumbleweeds buried the town of Victorville, California last year; they reached the second story of some buildings.

The range of  Salsola ryanii is now expanding from its current small area. Climate change may encourage its growth, which tends to be in later winter. This work may help get it under control.

"It's one of the only things that's still green in late summer," Welles said. "They may be well-positioned to take advantage of summer rains if climate changes make those more prevalent. An ounce of prevention is a pound of cure."


Sources: AAAS/Eurekalert! Via UCR, AoB Plants

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
JAN 22, 2020
Cancer
JAN 22, 2020
At-home urine test detects prostate cancer
Peeing on a stick may not just be for pregnancy-detection anymore – an at-home urine test could also detect prostate cancer in the near future. New r...
JAN 22, 2020
Genetics & Genomics
JAN 22, 2020
A New Threat to Christmas Trees is Discovered
Fraser firs are farmed to supply us with great-smelling Christmas trees that hold their needles, but they are also susceptible to molds....
JAN 22, 2020
Genetics & Genomics
JAN 22, 2020
Outbreak of Drug-Resistant Infections Linked to Pet Store Puppies
The CDC is warning people about an outbreak of drug-resistant bacteria that's been linked to store-bought puppies....
JAN 22, 2020
Genetics & Genomics
JAN 22, 2020
A New Type of Muscle Cell That Could be a Target for Gene Therapy is ID'ed
Muscles have a supply of restorative stem cells called satellite cells, and now they have identified a new type....
JAN 22, 2020
Genetics & Genomics
JAN 22, 2020
Perfect for Urban Farming: Gene-Edited Tomatoes that Grow like Grapes
A team of researchers from New York’s Cold Spring Harbor Laboratory have created a new strain of tomatoes that can grow from bushes rather than vines...
JAN 22, 2020
Cancer
JAN 22, 2020
A gene for leukemia triggers the growth of stem blood cells
New research from the University of Colorado Cancer Center has identified a way to make hematopoietic stem cells from a gene that causes a type of leukemia...
Loading Comments...