Nav: Home

Lab-made hormone may reveal secret lives of plants

January 22, 2018

A lab-designed hormone may unlock mysteries harbored by plants.

By developing a synthetic version of the plant hormone auxin and an engineered receptor to recognize it, Howard Hughes Medical Institute (HHMI) Investigator Keiko Torii and colleagues are poised to uncover plants' inner workings.

The new work, described January 22, 2018, in the journal Nature Chemical Biology, is "a transformative tool to understand plant growth and development," says Torii, a plant biologist at the University of Washington. That understanding may have big agricultural implications, raising the possibility, for instance, of a new way to ripen strawberries and tomatoes.

To plants, the hormone auxin is king. Among many other jobs, auxin helps sunflowers track sunlight, roots grow downward, and fruits ripen. This wide range of jobs, as well as the fact that every cell in a plant can both produce and detect auxin, makes it tricky to tease apart the hormone's various roles. "It's been a huge mystery as to how such a simple molecule can do so many different things," Torii says.

She and her colleagues set out to create a new way to study plants' responses to auxin by designing a lab-made version of the hormone that can be precisely controlled. Working with synthetic chemists in Japan, the researchers added a little bump to auxin's structure -- hydrocarbon rings that auxin doesn't normally contain. The researchers then tweaked plants' auxin receptor, a protein that sits on the outside of plant cells and detects auxin. This time, the researchers removed a bulky amino acid from the receptor, creating a perfect-sized hole that cradles the lab-made auxin. That simple switch, called a "bump and hole" strategy, "is really elegant, actually," Torii says.

Next, the researchers tested whether this matched set -- the synthetic auxin and the synthetic receptor -- could do the same jobs as the cells' natural auxin/receptor pair. The intricately designed system worked beautifully, experiments on roots showed.

Normally, roots exposed to auxin stop growing down, and instead grow sideways by activating stem cells that break out of the main root. Torii compares the process, called lateral root development, to aliens bursting through stomachs. After detecting synthetic auxin, Arabidopsis plants genetically engineered to produce the synthetic auxin receptor behaved just like normal - growing the same sideways baubles of root branches.

What's more, roots that didn't have the synthetic auxin receptor were essentially "blind" to synthetic auxin, proof that the artificial hormone is detected by only the artificial receptor. Torii and her colleagues call this switch to synthetic auxin "chemical hijacking" -- a well-controlled takeover that will now allow researchers to tease apart the tangled web of auxin's jobs in plants.

With their system up and running, the researchers tested a long-standing question in plant biology. Scientists knew that germinating seedlings use auxin to grow quickly. But the identity of the exact receptor that allows this process to happen wasn't settled.

The scientific community had a suspect in mind. Torii's team produced a plant that lacked an auxin receptor called TIR1, and instead possessed a synthetic version. When exposed to artificial auxin, these seedlings began to grow rapidly, behaving exactly as if they had the normal receptor. The results suggest that seed elongation does indeed happen through the TIR1 receptor.

Other fundamental scientific questions can be addressed with this system, Torii says, such as auxin's role in corn ripening and in opening the stomata, the structures that let plants breathe.

One day, synthetic auxin might even find a place in agriculture. Auxin is currently sprayed on fruits to hasten ripening. But in high concentrations, the hormone can act as a plant-killing herbicide. Fruits engineered to carry the synthetic receptor could be ripened with the synthetic auxin hormone, Torii says, eliminating the need to spray auxin indiscriminately. But, she cautions, much more testing needs to be done before a synthetic hormone system can be used for growing food.
-end-
Naoyuki Uchida et al. "Chemical hijacking of auxin signaling with an engineered auxin-TIR1 pair." Nature Chemical Biology. Published online January 22, 2018. doi: 10.1038/nchembio.2555.

Howard Hughes Medical Institute

Related Plants Articles:

Transgenic plants against malaria
Scientists have discovered a gene that allows to double the production of artemisinin in the Artemisia annua plant.
How plants can tell friend from foe
The plant's immune system can recognize whether a piece of RNA is an invader or not based on whether the RNA has a threaded bead-like structure at the end, say University of Tokyo researchers.
Plants at the pump
Regular, unleaded or algae? That's a choice drivers could make at the pump one day.
How do people choose what plants to use?
There are about 400,000 species of plants in the world.
Defend or grow? These plants do both
From natural ecosystems to farmers' fields, plants face a dilemma of energy use: outgrow and outcompete their neighbors for light, or defend themselves against insects and disease.
How do plants protect themselves against sunburn?
To protect themselves against UV-B, which are highly harmful, plants have developed cellular tools to detect them and build biochemical defenses.
Pea plants demonstrate ability to 'gamble' -- a first in plants
An international team of scientists from Oxford University, UK, and Tel-Hai College, Israel, has shown that pea plants can demonstrate sensitivity to risk -- namely, that they can make adaptive choices that take into account environmental variance, an ability previously unknown outside the animal kingdom.
A 'Fitbit' for plants?
Knowing what physical traits a plant has is called phenotyping.
How plants conquered the land
Research at the University of Leeds has identified a key gene that assisted the transition of plants from water to the land around 500 million years ago.
Plants are 'biting' back
Calcium phosphate is a widespread biomineral in the animal kingdom: Bones and teeth largely consist of this very tough mineral substance.

Related Plants Reading:

The Plant Paradox: The Hidden Dangers in Healthy Foods That Cause Disease and Weight Gain
by Dr. Steven R Gundry M.D. (Author)

“Dr. Gundry is a true trailblazer, always at the forefront of scientific knowledge. The Plant Paradox shows the world what pioneer thinking is about and is a must-read book for anyone interested in being as healthy as nature has designed them to be.” —Alejandro Junger MD, New York Times bestselling author of Clean, Clean Gut and Clean Eats

The Plant Paradox elegantly explains how plants defend themselves from being consumed by humans, and how eating the wrong ones at the wrong times immeasurably hurts our health.... View Details


The Plant Paradox Cookbook: 100 Delicious Recipes to Help You Lose Weight, Heal Your Gut, and Live Lectin-Free
by Dr. Steven R Gundry M.D. (Author)

From renowned cardiac surgeon and acclaimed author Dr. Steven R. Gundry, the companion cookbook to New York Times bestselling The Plant Paradox, offering 100 easy-to-follow recipes and four-color photos.  

In the New York Times bestseller The Plant Paradox, Dr. Steven Gundry introduced readers to the hidden toxins lurking in seemingly healthy foods like tomatoes, zucchini, quinoa, and brown rice: a class of plant-based proteins called lectins. Many people are familiar with one of the most predominant lectins—a substance called... View Details


Plant: Exploring the Botanical World
by Phaidon Editors (Author)

The ultimate gift for gardeners and art-lovers, featuring 300 of the most beautiful and pioneering botanical images ever

Following in the footsteps of the international bestseller Map: Exploring the World, this fresh and visually stunning survey celebrates the extraordinary beauty and diversity of plants. It combines photographs and cutting-edge micrograph scans with watercolours, drawings, and prints to bring this universally popular and captivating subject vividly to life. Carefully selected by an international panel of experts and arranged in a uniquely... View Details


How Not to Kill Your Houseplant: Survival Tips for the Horticulturally Challenged
by Veronica Peerless (Author)

Can't keep a houseplant alive, no matter how hard you try and how good your intentions are? This is the book for you. You need this book. Give plants a chance.

Help your plant live with survival tips and learn the simple ways not to kill your plants.With over 50 different types of popular houseplants, How Not to Kill Your Houseplant summarizes what type of care your plants do (or don't) need. Be on the lookout for warning signs of a sick plant, from brown spots to crispy leaves, and make sure you take the proper action to rescue your plant.

Learn the basics of... View Details


If You Plant a Seed
by Kadir Nelson (Author), Kadir Nelson (Illustrator)

Kadir Nelson, acclaimed author of Baby Bear and winner of the Caldecott Honor and the Coretta Scott King Author and Illustrator Awards, presents a resonant, gently humorous story about the power of even the smallest acts and the rewards of compassion and generosity.

With spare text and breathtaking oil paintings, If You Plant a Seed demonstrates not only the process of planting and growing for young children but also how a seed of kindness can bear sweet fruit.

View Details


The Secret Life of Plants: a Fascinating Account of the Physical, Emotional, and Spiritual Relations Between Plants and Man
by Peter Tompkins (Author), Christopher Bird (Author)

The world of plants and its relation to mankind as revealed by the latest scientific discoveries. "Plenty of hard facts and astounding scientific and practical lore."--Newsweek View Details


American Horticultural Society Encyclopedia of Plants and Flowers (American Horticultural Society)
by Christopher Brickell (Editor)

Since its first publication in 1987, the AHS Encyclopedia of Plants & Flowers has sold nearly three million copies worldwide.

Packed with 8,000 plants for every climate — inside and out — from trees, shrubs, perennials, annuals, biennials, bulbs, water plants, and cacti, the AHS Encyclopedia of Plants & Flowers is a must-have reference for all gardeners!

This fully revised and updated edition features a brighter, clearer design and improved navigation — cataloging plants by color, season, and size — that makes the book more intuitive for the reader.

The... View Details


American Horticultural Society Plant Propagation: The Fully Illustrated Plant-by-Plant Manual of Practical Techniques
by Alan Toogood (Author)

This comprehensive guide contains all the techniques you need with easy-to-follow, step-by-step explanations of how to propagate your plant. Whether you want to increase your plants by the easiest or most reliable methods of propagation, experiment with more unusual or advanced techniques, or use specialized techniques for a favorite plant group, you will find everything you need in this approachable handbook.

Want to know the best way to propagate a particular plant?  Each entry in the A-Z section of this book tells you which method of propagation to use, when to do it, and what... View Details


Urban Jungle: Living and Styling with Plants
by Igor Josifovic (Author), Judith de Graaff (Author)

Provides all your DIY ideas for styling and tips on how to plantInspiration for seasoned plant lovers as well as beginners, providing the total package on the topic of living with plantsUrban Jungle: Living and Styling with Plants is a source of inspiration, ideas and a manual for all of those who want to bring more plants into their home.

The book guides the reader through different "green" homes in five European countries and shows how beautiful, unique, creative and even artistic living with plants can be. More than that the reader finds endless ideas for styling from the... View Details


Lola Plants a Garden
by Anna McQuinn (Author), Rosalind Beardshaw (Illustrator)

How does your garden grow?Book-loving Lola is inspired by a collection of garden poems that she reads with her mommy. She wants to plant her own garden of beautiful flowers, so she and Mommy go to the library to check out books about gardening. They choose their flowers and buy their seeds. They dig and plant. And then they wait. Lola finds it hard to wait for her flowers to grow, but she spends the time creating her own flower book. Soon she has a garden full of sunflowers and invites all of her friends for cakes and punch and a story amongst the flowers.

Lola is a beloved character... View Details

Best Science Podcasts 2018

We have hand picked the best science podcasts for 2018. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Attention Please
In an age of constant information and infinite distractions, how can we pay more attention to our ... attention? This hour, TED speakers explore the battle for our awareness during the digital age. Guests include sociologist Zeynep Tufekci, podcast host Manoush Zomorodi, neuroscientist Amishi Jha, designer Tristan Harris, and computer scientist Jaron Lanier.
Now Playing: Science for the People

#475 Mother Nature is Trying to Kill You (Rebroadcast)
This week, we're learning how deadly and delightful our planet and its ecosystem can be. We're joined by biologist Dan Riskin, co-host of Discovery Canada's Daily Planet, to talk about his book "Mother Nature Is Trying to Kill You: a Lively Tour Through the Dark Side of the Natural World." And we'll talk to astronomer and author Phil Plait about Science Getaways, his company that offers educational vacation experiences for science lovers.