Login

GPC Members Login
If you have any problems or have forgotten your login please contact [email protected]


Nuclear events make a flower bloom

Flowers do more than give plants beautiful lovely colors and fragrances. They are the reproductive organs of the plant. Their formation depends on strict nuclear events that if compromised can leave the plant sterile. A new study by researchers at the Nara Institute of Science and Technology (NAIST) shows how two transcription factors, AGAMOUS and CRABS CLAW, bind sequentially to the gene YUC4, which is responsible for synthesizing the plant hormone auxin. The findings, which can be read in Nature Communications, provide an epigenetic explanation for proper formation of the gynoecium, the female reproductive organ of flowering plants.

Flowers consist of floral organs, the number of which is determined by growth and termination of the floral meristem. To study the molecular events inside the nucleus that determine the termination, NAIST Professor Toshiro Ito and his research team have been investigating epigenetic regulation by transcription factors.

"AGAMOUS is a master regulator of floral meristem termination. One of its targets is CRABS CLAW. CRABS CLAW regulates plant stem cell growth and differentiation," says lab member and Assistant Professor Nobutoshi Yamaguchi, who led the study.

Both AGAMOUS and CRABS CLAW are well known to plant scientists, but how they control common target genes has remained a mystery. Using mutated versions of Arabidopsis plants, the researchers found that AGAMOUS and CRABS CLAW bind to YUC4, but at different locations and in a specific sequence.

"The binding of CRABS CLAW happened after the binding of AGAMOUS. AGAMOUS binding opened the chromatin to expose the YUC4 promoter site. This feed-forward loop terminated the floral meristem and allowed gynoecium formation," explains Professor Toshiro Ito.

Although the bindings sites for AGAMOUS and CRABS CLAW were close to one another, the two transcription factors did not interact with one another. Instead, AGAMOUS formed a complex with CHR11 and CHR17, two known chromatin-remodeling proteins, before binding to YUC4. Thus, AGAMOUS activated CRABS CLAW, resulting in a synergistic activation of YUC4 by the two transcription factors.

Yamaguchi says the regulation of the chromatin state by AGAMOUS and CRABS CLAW provides crucial insights on plant flowering that can be exploited in agriculture.

"The feed-forward loop may be important to activate YUC4 at the correct time and place. Controlling the feed-forward loops could allow us to grow plants that produce more or bigger fruits," he says.

Read the paper: Nature Communications

Article source: NAIST

Image credit: CCO Public domain

News

Scientists engineer shortcut for photosynthetic glitch, boost crop growth 40%

Plants convert sunlight into energy through photosynthesis; however, most crops on the planet are plagued by a photosynthetic glitch, and to deal with it, evolved an energy-expensive process called photorespiration that drastically suppresses their yield potential. Researchers from the University of Illinois and U.S. Department of Agriculture Agricultural Research Service report in the journal Science that crops engineered with a photorespiratory shortcut are 40 percent more productive in real-world agronomic conditions.


Should researchers engineer a spicy tomato?

The chili pepper, from an evolutionary perspective, is the tomato's long-lost spitfire cousin. They split off from a common ancestor 19 million years ago but still share some of the same DNA. While the tomato plant went on to have a fleshy, nutrient-rich fruit yielding bountiful harvests, the more agriculturally difficult chili plant went defensive, developing capsaicinoids, the molecules that give peppers their spiciness, to ward off predators.


European wheat lacks climate resilience

The climate is not only warming, it is also becoming more variable and extreme. Such unpredictable weather can weaken global food security if major crops such as wheat are not sufficiently resilient – and if we are not properly prepared.