Featured Research

from universities, journals, and other organizations

Seed size is controlled by maternally produced small RNAs, scientists find

Date:
April 11, 2012
Source:
University of Texas at Austin
Summary:
Seed size is controlled by small RNA molecules inherited from a plant's mother, a discovery that has implications for agriculture and understanding plant evolution.

Small RNAs affect development of seeds. Arabidopsis seeds 3, 4, 5, 6 and 7 days (left to right) after pollination. Seeds in the second row are from a cross between a diploid mother and tetraploid father. Seeds in the third row are from a cross between a tetraploid mother and diploid father. Seeds in the third row (5 to 6 days after pollination) are much smaller as a result of increased maternally inherited small RNAs.
Credit: Image courtesy of University of Texas at Austin

Seed size is controlled by small RNA molecules inherited from a plant's mother, a discovery from scientists at The University of Texas at Austin that has implications for agriculture and understanding plant evolution.

Related Articles


"Crop seeds provide nearly 70 to 80 percent of calories and 60 to 70 percent of all proteins consumed by the human population," said Z. Jeff Chen, the D.J. Sibley Centennial Professor in Plant Molecular Genetics at The University of Texas at Austin. "Seed production is obviously very important for agriculture and plant evolution."

Chen and his colleagues, including David Baulcombe at the University of Cambridge, provide the first genetic evidence that seed development is controlled by maternally inherited "small interfering RNAs," or siRNAs.

They published their research April 3 in the journal PNAS.

SiRNAs are known to control a number of aspects of growth and development in plants and animals. The researchers used Arabidopsis, a rapidly growing flowering plant in the mustard family, for the study.

In this case, the researchers found that the siRNAs influence the development of a seed's endosperm, which is the part of the seed that provides nutrients to the developing plant embryo, much like the placenta in mammals. The endosperm is also the source for most of the nutritional content of the seed for humans and animals.

Despite the importance of the endosperm, little has been known about the molecular mechanisms that govern its growth.

In flowering plant seeds, the embryo is formed by fusion of one paternal and one maternal genome, while the endosperm combines one paternal and two maternal genomes. This process of embryo and endosperm formation is known as "double fertilization."

The scientists found that when a female plant with a duplicate genome (known as a tetraploid) is crossed with a male plant with a normal genome (called a diploid), not only is there an increase in the maternal genome in their offspring's seed endosperm, but there is also an associated increase in maternal siRNAs.

Those maternal siRNAs decrease the expression of genes that lead to larger endosperm growth, meaning that the siRNAs create smaller seeds.

"Now we understand that siRNAs play a large role in sensing maternal and paternal genome imbalance and controlling seed development, and that maternal control is important," said Chen.

The researchers are working to find out how exactly siRNAs regulate gene expression in the endosperm and embryo and how they control seed size. These new findings will enable scientists to develop biotechnological tools for improving seed production and crop yield.

But Chen cautioned that "bigger isn't always better." In fact, in his experiments, seeds lacking the control of the maternally inherited siRNAs grew so large that they collapsed.

Chen's research is funded by the National Science Foundation Genetic Mechanisms program. It was also the result of a Fulbright Award he received to do research with Baulcombe, a Royal Society research professor, at Cambridge. Baulcombe is widely recognized for his pioneering and seminal research discovering the role of siRNAs in gene silencing in plants.


Story Source:

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


Journal Reference:

  1. J. Lu, C. Zhang, D. C. Baulcombe, Z. J. Chen. Maternal siRNAs as regulators of parental genome imbalance and gene expression in endosperm of Arabidopsis seeds. Proceedings of the National Academy of Sciences, 2012; 109 (14): 5529 DOI: 10.1073/pnas.1203094109

Cite This Page:

University of Texas at Austin. "Seed size is controlled by maternally produced small RNAs, scientists find." ScienceDaily. ScienceDaily, 11 April 2012. <www.sciencedaily.com/releases/2012/04/120411132214.htm>.
University of Texas at Austin. (2012, April 11). Seed size is controlled by maternally produced small RNAs, scientists find. ScienceDaily. Retrieved November 1, 2014 from www.sciencedaily.com/releases/2012/04/120411132214.htm
University of Texas at Austin. "Seed size is controlled by maternally produced small RNAs, scientists find." ScienceDaily. www.sciencedaily.com/releases/2012/04/120411132214.htm (accessed November 1, 2014).

Share This



More Plants & Animals News

Saturday, November 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Watch Baby Goose Survive A 400-Foot Cliff Dive

Watch Baby Goose Survive A 400-Foot Cliff Dive

Buzz60 (Oct. 31, 2014) For its nature series Life Story, the BBC profiled the barnacle goose, whose chicks must make a daredevil 400-foot cliff dive from their nests to find food. Jen Markham has the astonishing video. Video provided by Buzz60
Powered by NewsLook.com
World's Salamanders At Risk From Flesh-Eating Fungus

World's Salamanders At Risk From Flesh-Eating Fungus

Newsy (Oct. 31, 2014) The import of salamanders around the globe is thought to be contributing to the spread of a deadly fungus. Video provided by Newsy
Powered by NewsLook.com
Alcoholic Drinks In The E.U. Could Get Calorie Labels

Alcoholic Drinks In The E.U. Could Get Calorie Labels

Newsy (Oct. 31, 2014) A health group in the United Kingdom has called for mandatory calorie labels on alcoholic beverages in the European Union. Video provided by Newsy
Powered by NewsLook.com
Malaria Threat in Liberia as Fight Against Ebola Rages

Malaria Threat in Liberia as Fight Against Ebola Rages

AFP (Oct. 31, 2014) Focus on treating the Ebola epidemic in Liberia means that treatment for malaria, itself a killer, is hard to come by. MSF are now undertaking the mass distribution of antimalarials in Monrovia. Duration: 00:38 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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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