Navigation Links
CSHL-Mexican team coaxes sexually reproducing plant to brink of asexual reproduction
Date:3/8/2010

Cold Spring Harbor, NY -- One seemingly insurmountable obstacle to the dream of virtually limitless yields of staple crops like corn, wheat and rice is the dependence of those plants on sexual reproduction. When male and female gametes -- sperm and egg -- combine randomly to generate a genetically unique seed, valuable parental traits painstakingly selected by breeders are erased. But what if plants like these could be engineered to reproduce asexually -- an abilty of a subset of plants, for example the common dandelion?

In a paper to appear online in Nature February 7, plant geneticists at Cold Spring Harbor Laboratory (CSHL) and the National Polytechnic Institute in Mexico report moving a step closer to the goal of turning plants that normally reproduce sexually into asexual reproducers, an outcome that would have profound implications for agriculture globally.

In sexually reproducing plants, the sex cells, or gametes, each bear one half of the organism's genetic legacy, which is combined in their progeny, a single seed. These unique offspring stand in contrast to the offspring of asexual reproducers like the dandelion, which are clones of the parent genetically identical. For years, Jean-Philippe Vielle-Calzada, Ph.D., who led the Mexican team, has sought to generate viable seeds in the absence of a fusion of sperm and egg. His team experimented with a type of asexual reproduction called apomixis, using the small mustard plant Arabidopsis thaliana -- normally a sexual reproducer -- as a testbed.

The key technique was shutting down the activity of a protein called Argonaute 9. By doing this, the scientists tricked an Arabidopsis ovule into manufacturing multiple gametes, rather than one, as it usually does. Instead of carrying half the plant's genetic legacy, these extra gametes carried the full load of genetic material. The plant, in some respects, had cloned itself, raising the possibility that some or perhaps all plants have the potential to reproduce asexually. If so, the secret of unlocking that potential, it would appear, is the ability to repress the activity of Argonaute 9.

Argonaute 9 binds small interfering RNA (siRNA), which are studied by the team at CSHL led by Rob Martienssen, PhD. The new results build on the discovery by Martienssen's team last year of a similar mechanism in the male gametes of the plant, found in its pollen grains. They showed that siRNAs were passed from the cells immediately surrounding the gametes, called companion cells, into the adjacent sperm cells. The siRNAs inactivated, or silenced, specific DNA sequences in the sperm. Importantly, those sequences marked the position of transposons, the "jumping genes" discovered by CSHL Nobel laureate Barbara McClintock 60 years ago. If activated, they have the ability to jump around the genome, wreaking havoc.

In fact, says Martienssen, "it has long been speculated that transposons and sex co-evolved. But it has remained a mystery as to how transposons promote sexual reproduction. In the work we're reporting today, it appears that Argonaute 9 inhibits asexual reproduction -- apparently by silencing transposons." Martienssen says his lab will be pursuing the relationship between transposons and sex in collaboration with the Mexican team.


'/>"/>

Contact: Peter Tarr
tarr@cshl.edu
917-435-5068
Cold Spring Harbor Laboratory
Source:Eurekalert

Related biology news :

1. Scientists demonstrate feasibility of preventing malaria parasite from becoming sexually mature
2. Are female mountain goats sexually conflicted over size of mate?
3. Reproducing early and often is the key to rapid evolution in plants
4. Circadian clock controls plant growth hormone
5. Layered approach may yield stronger, more successful bone implants
6. Clearance of hepatitis C viral infection after liver transplantation
7. Device helps patients survive, regain function til transplant
8. How the plant immune system can drive the formation of new species
9. The American Society of Plant Biologists announces 2007 awards
10. UCR plant cell biologist to study how plant stem cells maintain and change their identity
11. A study proposes a new universal rule to explain the equilibrium of plant populations
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/9/2016)... , June 9, 2016 ... deploy Teleste,s video security solution to ensure the safety of ... during the major tournament Teleste, an ... systems and services, announced today that its video security solution ... to back up public safety across the country. The ...
(Date:6/2/2016)... LONDON , June 2, 2016 ... Systems, Manned Platforms, Unmanned Systems, Physical Infrastructure, Support & ... intelligence provider visiongain offers comprehensive analysis of ... that this market will generate revenues of $17.98 billion ... Systems acquired DVTEL Inc, a leader in software and ...
(Date:5/12/2016)... 2016 WearablesResearch.com , a brand of ... results from the Q1 wave of its quarterly wearables ... consumers, receptivity to a program where they would receive ... insurance company. "We were surprised to see ... Michael LaColla , CEO of Troubadour Research, "primarily because ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... Ginkgo Bioworks , a leading organism design company ... as one of the World Economic Forum,s Technology ... companies. Ginkgo Bioworks is engineering biology to manufacture ... the nutrition, health and consumer goods sectors. The ... Fortune 500 companies to design microbes for their ...
(Date:6/23/2016)... ... June 23, 2016 , ... Mosio, a leader in ... Trials Patient Recruitment and Retention Tips.” Partnering with experienced clinical research professionals, Mosio ... practical tips, tools, and strategies for clinical researchers. , “The landscape of how ...
(Date:6/23/2016)... 2016 Houston Methodist Willowbrook Hospital has ... Association to serve as their official health care ... Willowbrook will provide sponsorship support, athletic training services, ... coaches, volunteers, athletes and families. "We ... Association and to bring Houston Methodist quality services ...
(Date:6/23/2016)... ... , ... Supplyframe, the Industry Network for electronics hardware design ... Located in Pasadena, Calif., the Design Lab’s mission is to bring together inventors ... and brought to market. , The Design Lab is Supplyframe’s physical representation of ...
Breaking Biology Technology: