Featured Research

from universities, journals, and other organizations

Calcium waves help the roots tell the shoots

Date:
April 3, 2014
Source:
University of Wisconsin-Madison
Summary:
For Simon Gilroy, sometimes seeing is believing. In this case, it was seeing the wave of calcium sweep root-to-shoot in the plants the professor of botany is studying that made him a believer. He demonstrated what long had been suspected but long had eluded scientists: that calcium is involved in rapid plant cell communication.

Simon Gilroy and colleagues showed what long had been suspected but long had eluded scientists: that calcium is involved in rapid plant cell communication, as discovered in Arabidopsis thaliana (above). No one had ever been able to see it before.
Credit: Oregon State University

For Simon Gilroy, sometimes seeing is believing. In this case, it was seeing the wave of calcium sweep root-to-shoot in the plants the University of Wisconsin-Madison professor of botany is studying that made him a believer.

Related Articles


Gilroy and colleagues, in a March 24, 2014 paper in the Proceedings of the National Academy of Sciences, showed what long had been suspected but long had eluded scientists: that calcium is involved in rapid plant cell communication.

It's a finding that has implications for those interested in how plants adapt to and thrive in changing environments. For instance, it may help agricultural scientists understand how to make more salt- or drought-tolerant plants.

"How do you think plants live?" Gilroy asks. "If I poke you, I see an instant response. You move away. Plants live in a slightly different world. They are rooted to the ground, literally, and they respond to the world either by growing or creating chemicals."

Calcium is involved in transmitting information in the cells of humans and other animals, contracting muscles, sending nerve signals and more.

In plants, scientists believed it had to also play a role in processing information and sending rapid signals so that plants can respond quickly to their environments.

Imagine you are a plant being eaten by a caterpillar: "It's like a lion chewing your leg," says Gilroy. "If an insect is chewing your leaf, you're gone unless you determine something effective immediately."

But no one had ever been able to see it before. Even Gilroy's team found it by accident.

The team was using a specific calcium sensor they thought wasn't going to work. They speculated it could serve as a control in their studies.

The sensor's brightness changes in the presence of calcium, displayed on screen as a change from green to red through a process known as fluorescence resonance energy transfer, or FRET. Typically, this particular sensor is so sensitive to calcium it is nearly always red.

But when researchers applied stress to the tip of a plant's roots -- a high concentration of sodium chloride salt -- it triggered a wave of red that traveled rapidly from the root to the top of the plant.

"We were kind of like, 'Why is it even working?' says Gilroy. "It was probably telling us we were looking in the wrong realm. It's like we could only hear the people shouting and we couldn't hear the talking."

The calcium wave, a flush of red on an otherwise green palette, traveled on a scale of milliseconds, traversing about eight plant cells per second -- too quick to be explained by simple diffusion of salt.

"It fit with a lot of our models," Gilroy says. "But the idea that it's a wave is one step beyond what our models would predict."

Within 10 minutes of applying a small amount of salt to the plants' roots, typical stress response genes were turned on in the plant.

Also turned on was the machinery to make more of a protein channel called two pore channel 1 (TPC1). Within one-to-two minutes, there was 10 times more of the building blocks needed to make the channel, which is thought to be involved in calcium signaling.

Gilroy and his team then looked at plants with a defect in TPC1. They had a much slower calcium wave -- about 25 times slower -- than plants with normal TPC1. When they studied plants expressing more of the TPC1 protein, the calcium wave moved 1.7 times faster.

Plants with more channels also grew larger and contained more chlorophyll than plants with normal or mutated TPC1 when grown in salt water.

The protein channel is present in all land plants, says Gilroy, and it's found throughout the plant. This is one of the many reasons it surprised the team to learn the calcium wave moves only through specific cells in the plant, like electrical signals moving through nerve cells in humans and other animals.

"We weren't expecting that," Gilroy says. "It means specific cell types have specific functions … there must be something special about those cells. We're really at the beginning."

The lab is now looking at the molecular machinery that makes up TPC1, to figure out how the parts of the channel work.

And now that the scientists know that calcium talks, the volume is turned up. The work is just getting started.

"We can hear the screaming," says Gilroy. "Now we're trying to see what the vocal chords are doing."


Story Source:

The above story is based on materials provided by University of Wisconsin-Madison. The original article was written by Kelly April Tyrrell. Note: Materials may be edited for content and length.


Journal Reference:

  1. W.-G. Choi, M. Toyota, S.-H. Kim, R. Hilleary, S. Gilroy. Salt stress-induced Ca2 waves are associated with rapid, long-distance root-to-shoot signaling in plants. Proceedings of the National Academy of Sciences, 2014; DOI: 10.1073/pnas.1319955111

Cite This Page:

University of Wisconsin-Madison. "Calcium waves help the roots tell the shoots." ScienceDaily. ScienceDaily, 3 April 2014. <www.sciencedaily.com/releases/2014/04/140403212400.htm>.
University of Wisconsin-Madison. (2014, April 3). Calcium waves help the roots tell the shoots. ScienceDaily. Retrieved April 19, 2015 from www.sciencedaily.com/releases/2014/04/140403212400.htm
University of Wisconsin-Madison. "Calcium waves help the roots tell the shoots." ScienceDaily. www.sciencedaily.com/releases/2014/04/140403212400.htm (accessed April 19, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Sunday, April 19, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Un-Bee-Lievable: Bees on the Loose After Washington Truck Crash

Un-Bee-Lievable: Bees on the Loose After Washington Truck Crash

Reuters - US Online Video (Apr. 17, 2015) A truck carrying honey bees overturns near Lynnwood, Washington, spreading boxes of live bees across the highway. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Our Love Of Puppy Dog Eyes Explained By Science

Our Love Of Puppy Dog Eyes Explained By Science

Newsy (Apr. 17, 2015) Researchers found a spike in oxytocin occurs in both humans and dogs when they gaze into each other&apos;s eyes. Video provided by Newsy
Powered by NewsLook.com
Dog Flu Spreading in Midwestern States

Dog Flu Spreading in Midwestern States

AP (Apr. 17, 2015) Dog flu is spreading in several Midwestern states. Dog daycare centers and veterinary offices are taking precautions. (April 17) Video provided by AP
Powered by NewsLook.com
Raw: Rare Whale Spotted in Gulf of Mexico

Raw: Rare Whale Spotted in Gulf of Mexico

AP (Apr. 17, 2015) Researchers from the E/V Nautilus had quite a surprise Tuesday, when a curious sperm whale swam around their remotely operated vehicle in the Gulf of Mexico. Cameras captured the encounter. (April 17) Video provided by AP
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