How multiple-genome plants reproduce

decrease font size  Resize text   increase font size       Printer-friendly version of this article Printer-friendly version of this article

A study out of Harvard and Purdue universities is starting to unravel the genetic mechanisms that allow some plants to duplicate their entire genomes and continue to reproduce.

Most plants, including crops, at some point in history have duplicated their genomes, giving them two or more copies of each of the instructions to build the plant. These plants have few problems reproducing normally.

When scientists manipulate individuals and induce duplicate genomes, however, it is difficult - sometimes impossible - for the organism to sexually reproduce. Being able to create polyploids, organisms with three or more genomes, such as the crops peanut, strawberry, banana, canola, cotton, wheat and others, may allow scientists to improve those crops more quickly through breeding and create new polyploidy crop species. Breeding programs that use new polyploids are cumbersome because many do not reproduce easily.

"The machinery that divides the genome during sex is designed to pull paired chromosomes apart and create two cells from one. When you have four chromosomes to work with, they aren't always divided correctly," said Brian Dilkes, a Purdue assistant professor of horticulture and co-author of the findings published in the journal PLoS Genetics. "What this paper demonstrates is that we can use evolution as a tool to find the genes that allow plants to tolerate being tetraploids, which have four copies of their genomes."

The scientists found a species that does reproduce as both a diploid and tetraploid - Arabidopsis arenosa, a cousin of the standard research plant Arabidopsis thaliana. By comparing the DNA sequences of the whole genomes of plants, they detected the genetic differences between the tetraploid and diploid versions of the species.

Many genes known to play a role in meiosis, or cell division, were different in the tetraploids as compared to the diploids. In particular, the gene Asynaptic1, which controls the organization of chromosome pairs during reproduction, was mutated in tetraploids.

Of the plants tested, 95 percent of the tetraploids shared the same mutation in Asynaptic1, while 95 percent of the diploids did not contain this variant. This suggests that the mutation in Asynaptic1 is involved in the adaptation of the meiotic machinery needed to work with four copies of the genome.

"We're actually learning the mechanisms that were used in evolution to solve challenges faced by plants dealing with tetraploidy," Dilkes said. "With this understanding we will be able to manipulate crops and crop relatives to accelerate plant breeding and the inclusion of a wider genetic base in the improvement of many existing crops."

Dilkes' laboratory at Purdue was involved in analyzing the DNA of each plant tested to determine whether it was a diploid or tetraploid. He said the work would continue to determine which genes and mutations allow for sexual reproduction in tetraploid plants.

Kirsten Bomblies, an assistant professor of organismic and evolutionary biology at Harvard and principal investigator for the project, said the results are also important for human health.

"Several of the genes have been shown to be critical for survival of tetraploid, but not diploid yeast, and they are also implicated in human polyploid cancers and genome instability syndromes," Bomblies said.

The research was funded by the Purdue University College of Agriculture. Bomblies was supported by a Harvard University William F. Milton Fund award.


Prev 1 2 Next All



Buyers Guide

Doyle Equipment Manufacturing Co.
Doyle Equipment Manufacturing prides themselves as being “The King of the Rotary’s” with their Direct Drive Rotary Blend Systems. With numerous setup possibilities and sizes, ranging from a  more...
A.J. Sackett Sons & Company
Sackett Blend Towers feature the H.I.M, High Intensity Mixer, the next generation of blending and coating technology which supports Precision Fertilizer Blending®. Its unique design allows  more...
R&R Manufacturing Inc.
The R&R Minuteman Blend System is the original proven performer. Fast, precise blending with a compact foot print. Significantly lower horsepower requirement. Low inload height with large  more...
Junge Control Inc.
Junge Control Inc. creates state-of-the-art product blending and measuring solutions that allow you to totally maximize operating efficiency with amazing accuracy and repeatability, superior  more...
Yargus Manufacturing
The flagship blending system for the Layco product line is the fully automated Layco DW System™. The advanced technology of the Layco DW (Declining Weight) system results in a blending  more...
Yargus Manufacturing
The LAYCOTE™ Automated Coating System provides a new level of coating accuracy for a stand-alone coating system or for coating (impregnating) in an automated blending system. The unique  more...
John Deere
The DN345 Drawn Dry Spreader can carry more than 12 tons of fertilizer and 17.5 tons of lime. Designed to operate at field speeds up to 20 MPH with full loads and the G4 spreader uniformly  more...
Force Unlimited
The Pro-Force is a multi-purpose spreader with a wider apron and steeper sides. Our Pro-Force has the most aggressive 30” spinner on the market, and is capable of spreading higher rates of  more...
BBI Spreaders
MagnaSpread 2 & MagnaSpread 3 — With BBI’s patented multi-bin technology, these spreaders operate multiple hoppers guided by independent, variable-rate technology. These models are built on  more...


Comments (0) Leave a comment 

Name
e-Mail (required)
Location

Comment:

characters left


Kinze 1500 Grain Cart

The Kinze 1500 Grain Cart is engineered for speed and reliability required of custom harvesters. Load up to 1500 bushels ... Read More

View all Products in this segment

View All Buyers Guides

Feedback Form
Feedback Form