Featured Research

from universities, journals, and other organizations

Plants Defy Mendel's Inheritance Laws, May Prompt Textbook Changes

Date:
March 23, 2005
Source:
Purdue University
Summary:
Contrary to inheritance laws the scientific world has accepted for more than 100 years, some plants revert to normal traits carried by their grandparents, bypassing genetic abnormalities carried by both parents.

This mutant plant has a malfunctioning gene that prevents its flowers from opening. Purdue University scientists found that 10 percent of the offspring of two such mutant plants don't have this malformation, but rather are like the normal grandparents. This chain of inheritance defies accepted scientific beliefs. (Purdue University photo from the laboratory of Robert Pruitt)

WEST LAFAYETTE, Ind. - Contrary to inheritance laws the scientific world has accepted for more than 100 years, some plants revert to normal traits carried by their grandparents, bypassing genetic abnormalities carried by both parents.

These mutant parent plants apparently have hidden templates containing genetic information from the preceding generation that can be transferred to their offspring, even though the traits aren't evident in the parents, according to Purdue University researchers. This discovery flies in the face of the scientific laws of inheritance first described by Gregor Mendel in the mid-1800s and still taught in classrooms around the world today.

"This means that inheritance can happen more flexibly than we thought in the past," said Robert Pruitt, a Purdue Department of Botany and Plant Pathology molecular geneticist. "While Mendel's laws that we learned in high school still are fundamentally correct, they're not absolute.

"If the inheritance mechanism we found in the research plant Arabidopsis exists in animals, too, it's possible that it will be an avenue for gene therapy to treat or cure diseases in both plants and animals."

The study is published in the March 24 issue of the journal Nature.

Pruitt and collaborator Susan Lolle found that Arabidopsis in which each parent plant had two copies of a mutant gene could produce progeny that didn't show the parents' deformity, but rather were normal like the grandparents. Under Mendelian laws, the offspring should have shown the same mutation.

The first clue that the classic inheritance rules didn't always apply was the discovery of normal flowers on some offspring of mutant plants. In the deformed parents, the flowers were fused into tight balls. But in the grandparents and 10 percent of the grandchildren, the buds become 1-millimeter-long, bright white flowers that fully opened and radiated out from the center of a cluster.

"If you take this mutant Arabidopsis, which has two copies of the altered gene, let it seed and then plant the seeds, 90 percent of the offspring will look like the parent, but 10 percent will look like the normal grandparents," Pruitt said. "Our genetic training tells us that's just not possible. This challenges everything we believe.

"We've done a lot of experiments, described in this paper, that show none of the simple explanations account for this skipping of generations by an inherited trait."

The scientists kept the plants in isolation so they couldn't accidentally crossbreed with plants that didn't have the mutated gene, called hothead, that causes organ fusion like that seen in the flowers. The researchers used molecular markers - bits of DNA that help identify and locate genes in organisms - to determine whether a plant carried normal or mutant copies of the genes.

"It seems that these hothead-containing plants keep a cryptic copy of everything that was in the previous generation, even though it doesn't show up in the DNA, it's not in the chromosome," Pruitt said. "Some other type of gene sequence information that we don't really understand yet is modifying the inherited traits."

Although the hothead gene tipped the researchers off to this unconventional inheritance cycle, Pruitt believes that this particular DNA sequence is just a trigger for the phenomenon. He suspects that a number of other genes and the proteins they produce are involved in activating this process.

"We need to understand more about the molecular mechanics of how this process works," Pruitt said. "Then we will know exactly what role this gene plays."

Pruitt's team already knows that animals don't have hothead genes, either normal or mutated, so the scientists must investigate which genes might affect this novel inheritance in both plants and animals.

"There are probably a lot of other triggers yet to be discovered, and this mechanism for inheritance may require a different trigger to make it work in animals," he said.

Once scientists understand more about the mechanism, they then may be able to manipulate it to modify genes already in plants and animals in order to correct mutations that cause diseases and abnormal growth.

Though further research is required to learn how this form of inheritance happens and how it can help improve plants or animals through gene therapy, Pruitt said the discovery has opened an important new line of thinking.

The other researchers involved with this study were Jennifer Victor, a former Purdue graduate student now at Butler University; and Jessica Young, a botany and plant pathology laboratory technician. Lolle, a Purdue research scientist, is currently at the National Science Foundation.

The National Science Foundation provided funding for this research.


Story Source:

The above story is based on materials provided by Purdue University. Note: Materials may be edited for content and length.


Cite This Page:

Purdue University. "Plants Defy Mendel's Inheritance Laws, May Prompt Textbook Changes." ScienceDaily. ScienceDaily, 23 March 2005. <www.sciencedaily.com/releases/2005/03/050323115547.htm>.
Purdue University. (2005, March 23). Plants Defy Mendel's Inheritance Laws, May Prompt Textbook Changes. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2005/03/050323115547.htm
Purdue University. "Plants Defy Mendel's Inheritance Laws, May Prompt Textbook Changes." ScienceDaily. www.sciencedaily.com/releases/2005/03/050323115547.htm (accessed July 30, 2014).

Share This




More Plants & Animals News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Otters Enjoy Water Slides at Japan Zoo

Raw: Otters Enjoy Water Slides at Japan Zoo

AP (July 30, 2014) River otters were hitting the water slides to beat the summer heatwave on Wednesday at Ichikawa City's Zoological and Botanical Garden. (July 30) Video provided by AP
Powered by NewsLook.com
In Virginia, the Rise of a New Space Coast

In Virginia, the Rise of a New Space Coast

AP (July 30, 2014) Every summer, tourists make the pilgrimage to Chincoteague Island, Va. to see wild ponies cross the Assateague Channel. But, it's the rockets sending to supplies to the International Space Station that are making this a year-round destination. (July 30) Video provided by AP
Powered by NewsLook.com
Rodents Rampant in Gardens Around Louvre

Rodents Rampant in Gardens Around Louvre

AP (July 29, 2014) Food scraps and other items left on the grounds by picnickers brings unwelcome visitors to the grounds of the world famous and popular Louvre Museum in Paris. (July 29) Video provided by AP
Powered by NewsLook.com
Jane Goodall Warns Great Apes Face Extinction

Jane Goodall Warns Great Apes Face Extinction

AFP (July 29, 2014) The world's great apes face extinction within decades, renowned chimpanzee expert Jane Goodall warned Tuesday in a call to arms to ensure man's closest relatives are not wiped out. Duration: 00:58 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins