Featured Research

from universities, journals, and other organizations

Cell-Cell Communication In The Flower Is Unlocked

Date:
September 12, 2001
Source:
Cornell University
Summary:
Familiarity breeds contempt. Nonfamiliarity produces seed. Just as humans have a natural aversion toward marrying kin, some food crop plants have genes that allow them to avoid being fertilized by "self-related" pollen. Now Cornell University's biologists have solved one more piece of the puzzle of how plants' self-incompatibility works on the molecular level.

ITHACA, N.Y. -- Familiarity breeds contempt. Nonfamiliarity produces seed.

Just as humans have a natural aversion toward marrying kin, some food crop plants have genes that allow them to avoid being fertilized by "self-related" pollen. Now Cornell University's biologists have solved one more piece of the puzzle of how plants' self-incompatibility works on the molecular level.

The discovery, as reported in the today's journal Science , could enable genetic engineers to short-circuit the reproduction process and more easily hybridize improved varieties of plants.

Many commercial crops are genetic hybrids. Obtaining seed to plant commercial quantities of these crops, such as tomatoes, for example, requires the labor-intensive work of manual crossing. Without the process of manual crossing, the plants would not have the desired qualities of hybrids. But nature has come up with an efficient system for making hybrid seed, which, when understood at the molecular level, can have applications on a commercial scale. This process, termed self-incompatibility, "prevents inbreeding and promotes out-crossing and variability in plants," says June Nasrallah, Cornell professor of plant biology, and the lead author on the Science paper.

In addition to Nasrallah, co-authors of "Allele-Specific Receptor-Ligand Interactions in Brassica Self-Incompatibility" include Mikhail Nasrallah, Cornell professor of plant biology; Aardra Kachroo, Cornell postdoctoral researcher in plant biology; and Christel R. Schopfer, a former Cornell postdoctoral researcher who now conducts research in Germany.

Funding for the research was provided by a four-year grant from the National Institutes of Health for the purpose of understanding cellular communication systems. The Nasrallah group examined the reproductive processes of Brassica plants. Like humans and animal species, plants use eggs and sperm in order to make seed and multiply. On the plant's pistil is the stigma, which is the site for capturing pollen. Pollen, which carries the male sperm, is released by stamens and is carried by wind or insects, and it is drawn to a plant's stigma.

If genetically unrelated (nonmatching) pollen lands on the stigma, the pollen germinates and produces a pollen tube that then runs through the plant's pistil and into the plant's ovaries. Fertilized eggs then develop into seed ready to be grown in a garden or a producer's field.

However, if "self-related" pollen lands on the stigma, the stigma's outer (epidermal) layer genetically recognizes the type of pollen and precipitates a self-incompatible reaction that inhibits the pollen tubes from growing. The Cornell group found that pollen recognition is based on highly specific lock-and-key interactions between receptors (the lock) on the stigma surface and ligands (the key) on the pollen surface. "If the pollen is matching kin, the receptor on the stigma is activated to prevent pollen tube growth," says Kachroo. "If the pollen is nonmatching, the receptor is not activated and pollen tubes can grow."

With this revelation, scientists are one step closer to understanding the reproductive barriers of flowering plants and their evolution. "The potential is to finally grasp -- at the molecular level -- which genes are needed for pollen rejection," says Mikhail Nasrallah. "The ability to silence, mutate and transfer the genes that control the self-incompatibility barrier could be a boon to breeders. Even self-fertilizing crops like tomatoes and rice can benefit from increased genetic variability."


Story Source:

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


Cite This Page:

Cornell University. "Cell-Cell Communication In The Flower Is Unlocked." ScienceDaily. ScienceDaily, 12 September 2001. <www.sciencedaily.com/releases/2001/09/010907080218.htm>.
Cornell University. (2001, September 12). Cell-Cell Communication In The Flower Is Unlocked. ScienceDaily. Retrieved September 16, 2014 from www.sciencedaily.com/releases/2001/09/010907080218.htm
Cornell University. "Cell-Cell Communication In The Flower Is Unlocked." ScienceDaily. www.sciencedaily.com/releases/2001/09/010907080218.htm (accessed September 16, 2014).

Share This



More Plants & Animals News

Tuesday, September 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Conservationists Face Uphill PR Battle With New Shark Rules

Conservationists Face Uphill PR Battle With New Shark Rules

Newsy (Sep. 14, 2014) New conservation measures for shark fishing face an uphill PR battle in the fight to slow shark extinction. Video provided by Newsy
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