Researchers Determine How Plants Decide Where to Position Their Leaves and Flowers

Apr 04, 2006

One of the quests of modern biologists is to understand how cells talk to each other in order to determine where to form major organs. An international team of biologists has solved a part of this puzzle by combining state-of-the-art imaging and mathematical modeling to reveal how plants go about positioning their leaves and flowers.

In the January 31 issue of the Proceedings of the National Academy of Sciences, researchers from the California Institute of Technology, the University of California at Irvine, and Lund University in Sweden reported their success in determining how a plant hormone known as auxin affects plant organ positioning. Experts already knew that auxin played some role in the development of plant organs, but the new study employs imaging techniques and computer modeling to propose a new theory about how the mechanism works.

The research involves the growing tip of the shoot of the plant Arabidopsis thaliana, a relative of the mustard plant that has been studied intensely by modern biologists. With its simple and very well understood genome, Arabidopsis lends itself to a wide variety of experiments.

The achievement of the researchers is their demonstration of how plant cells, with purely local information about their nearest neighbors' internal concentration of auxin, can communicate to determine the position of new flowers or leaves, which form in a regular pattern, with many cells separating the newly formed primordia (the first traces of an organ or structure). The authors theorize that the template the plant uses to make the larger parts comes from two mechanisms: a polarized transport of auxin into a feedback loop and a dynamic geometry arising from the growth and division of cells.

To capture the development, Beadle Professor of Biology Elliot Meyerowitz, division chair of the biology division at Caltech, and his team used green fluorescent proteins to mark specific cell types in the plant's meristem, the plant tissue in which regulated cell division, pattern formation, and differentiation give rise to plant parts like leaves and flowers.

The marked proteins allowed the group to image the cell's lineages through meristem development and differentiation leading to specific arrangement of leaves and reproductive growth, and also to follow changes in the concentration and movement of auxin.

Although the study applies specifically to the Arabidopsis plant, Meyerowitz says the mechanism is probably similar for other plants and even other biological systems in which patterning occurs in the course of development.

In addition to Meyerowitz, the paper's authors are Henrik Jönsson of Lund University, Marcus G. Heisler of Caltech's Division of Biology, Bruce E. Shapiro of Caltech's Biological Network Modeling Center, and Eric Mjolsness of UC Irvine's Institute of Genomics and Bioinformatics and department of computer science.

Source: Caltech

Explore further: Oceans apart: Study reveals insights into the evolution of languages

add to favorites email to friend print save as pdf

Related Stories

How does your garden grow?

Jul 01, 2014

Growing plants in a microscope is helping scientists to view roots developing in 3D and in real time. "With the growth conditions under our control, we can explore how roots respond to different environmental ...

Evolution of a bimetallic nanocatalyst

Jun 06, 2014

(Phys.org) —Atomic-scale snapshots of a bimetallic nanoparticle catalyst in action have provided insights that could help improve the industrial process by which fuels and chemicals are synthesized from ...

Recommended for you

Modern population boom traced to pre-industrial roots

1 hour ago

The foundation of the human population explosion, commonly attributed to a sudden surge in industrialization and public health during the 18th and 19th centuries, was actually laid as far back as 2,000 years ...

Researcher looks at the future of higher education

1 hour ago

Most forecasts about the future of higher education have focused on how the institutions themselves will be affected – including the possibility of less demand for classes on campus and fewer tenured faculty members as ...

Now we know why it's so hard to deceive children

2 hours ago

Daily interactions require bargaining, be it for food, money or even making plans. These situations inevitably lead to a conflict of interest as both parties seek to maximise their gains. To deal with them, ...

How financial decisions are made

4 hours ago

Jayant Kale didn't grow up dreaming of becoming a leading expert in corporate finance and mutual fund investment. But he's happy he invested in that market early in life.

User comments : 0