Login


Greater understanding of plant hormone results in stem cells that grow shoots

Researchers at Dartmouth College have identified how a well-known plant hormone targets genes to regulate plant growth and development. The finding could allow scientists to establish organ-growing stem cells for grains like rice and corn, and may ultimately lead to solutions to stubborn agricultural problems.

The study, appearing in the Proceedings of the National Academy of Sciences, describes how cytokinin activates the transcription factor ARR10 to control gene expression in the Arabidopsis plant - a member of the mustard family commonly used as a model in plant biology.

Cytokinin is a hormone that regulates numerous processes in plants, including cell division, growth of shoots and roots, grain yield and greening.

"The question has always been how cytokinin regulates so many different processes within a plant," said Eric Schaller, a professor of biological sciences at Dartmouth College. "Now we know the genes that are the primary targets of cytokinin, and we can provide the toolbox for manipulating the plant hormone response."

According to the paper, results from the analysis "shed light on the physiological role of the type-B ARRs in regulating the cytokinin response, the mechanism of type-B ARR activation, and the basis by which cytokinin regulates diverse aspects of growth and development as well as responses to biotic and abiotic factors."

As part of the study, conducted in collaboration with the University of North Carolina Charlotte and the University of North Carolina at Chapel Hill, researchers were able to use the new understanding of how cytokinin works to grow shoots in tissue culture under conditions in which these plant organs normally do not form.

To make the plant tissues grow shoots in vitro, the research team increased the cytokinin sensitivity in the Arabidopsis plant. This resulted in activation of the WUSCHEL target gene, which is a key regulator of shoot development. The result confirms understanding of how to establish stem cells that lead to different types of organ growth.

"What we have done is activate the plant to make a stem cell center for a shoot to form," said Schaller. "By finding the direct targets of what is impacted by cytokinin, we can fine-tune our focus in the future."

According to Schaller, this research sets the stage for further work that could help improve yield of important agricultural products like rice and corn.

Read the paper.

Article source: Dartmouth College.

News

How gene silencing works in plants

The group of Myriam Calonje Macaya from the Institute of Plant Biochemistry and Photosynthesis (IBVF), a mixed centre from the University of Seville and the Spanish National Research Council (CSIS), in collaboration with the group of Franziska Turck from the Max Planck Institute for Plant Breeding Research from Cologne, have recently published a study in Genome Biology that means an advance in the knowledge of epigenetic regulation by means of Polycomb-group proteins in plants.


Symbiosis: Butter for my honey

Textbooks tell us that, in arbuscular mycorrhizal symbioses, the host plant supplies its fungal symbionts solely with sugars, in return for inorganic nutrients. New findings by Ludwig-Maximilians-Universitaet (LMU) in Munich researchers now show that lipids are also on the menu.


Researchers find corn gene conferring resistance to multiple plant leaf diseases

Researchers at North Carolina State University have found a specific gene in corn that appears to be associated with resistance to two and possibly three different plant leaf diseases.