Featured Research

from universities, journals, and other organizations

Probiotics supercharge plants' immunity to disease

Date:
August 27, 2012
Source:
University of Delaware
Summary:
Pathogens can slip through leaf pores and begin infecting a plant. However, new research shows that this invasion is halted when a beneficial bacterium is present in the soil where the plant is rooted.

At left, a magnified stomata (pore and surrounding guard cell) on a plant leaf is shown being attacked by pathogens. However, when the beneficial bacterium Bacillus subtilis is added to the plant's soil, the bacteria signal the stomata to close, cutting off the pathogens' access to the plant interior.
Credit: Image courtesy of University of Delaware

With the help of beneficial bacteria, plants can slam the door when disease pathogens come knocking, University of Delaware researchers have discovered.

Related Articles


A scientific team under the leadership of Harsh Bais, assistant professor of plant and soil sciences in UD's College of Agriculture and Natural Resources, found that when pathogens attempt to invade a plant through the tiny open pores in its leaves, a surprising ally comes to the rescue. Soil bacteria at the plant's roots signal the leaf pores to close, thwarting infection.

The fascinating defense response is documented in video and micrographs of live plants taken by confocal and scanning electron microscopes at UD's Bio-Imaging Center at the Delaware Biotechnology Institute.

The research, which explored the interaction between the soil bacterium Bacillus subtilis and the laboratory plant Arabidopsis thaliana, is published in the August issue of The Plant Journal. The findings underscore both the importance of root-based processes in plant defense and the potential for bolstering plant immunity naturally through the emerging field of probiotics.

Postdoctoral researcher Amutha Sampath Kumar is the lead author of the journal article. In addition to Bais, the co-authors include postdoctoral researcher Venkatachalam Lakshmanan, researchers Jeffrey L. Caplan, Deborah Powell and Kirk J. Czymmek of UD's Bio-Imaging Center, and Delphis F. Levia, associate professor of geography. The National Science Foundation, University of Delaware Research Foundation and Delaware Experimental Program to Stimulate Competitive Research (EPSCoR) provided funding for the study.

Millions of stomata, consisting of microscopic pores surrounded by guard cells, cover the above-ground parts of plants, from the stems to the flower petals. The pores resemble tiny mouths, or doors, which the guard cells open and close to allow carbon dioxide, oxygen, water and minerals in and out of the plant.

Pathogens also can slip through these stomata and begin infecting the plant. However, as Bais's team confirmed, this invasion is halted when the beneficial bacterium Bacillus subtilis is present in the soil where the plant is rooted. The finding was based on tests of approximately 3,000 Arabidopsis plants inoculated with the foliar pathogen Pseudomonas syringae pathovar tomato DC3000 (PstDC3000) during a year-long period.

When a foliar pathogen attacks, as shown in previous research by Bais and his group, the plant recruits Bacillus subtilis to help and facilitates its multiplication. The Bacillus subtilis bacteria bind to the plant's roots and invoke abscisic acid and salicylic acid signaling pathways to close the stomata.

Abscisic acid and salicylic acid are both important hormones involved in plant defense. When a plant encounters adverse environmental conditions, such as drought, for example, abscisic acid triggers the stomata to shut tightly to prevent the plant from dehydrating.

In addition to ramping up plant disease resistance, the use of this rhizobacteria to promote drought tolerance in plants could be a very promising avenue, Bais notes.

"Many bacterial pathogens invade plants primarily through stomata on the leaf surface," Bais says. "But how do plants fight off infection? In our studies of the whole plant, we see this active enlistment by Bacillus subtilis, from root to shoot."

Strikingly, the research team's data revealed that of different root-associated soil bacteria tested, only Bacillus species were effective in closing the stomata and for a prolonged period.

"We know only 1 to 5 percent of what this bug Bacillus subtilis can do, but the potential is exciting," Bais notes, pointing out that there is increasing commercial interest in inoculating crop seeds with beneficial bacteria to reduce pathogen infection. "Just as you can boost your immune system, plants also could be supercharged for immunity."


Story Source:

The above story is based on materials provided by University of Delaware. The original article was written by Tracey Bryant. Note: Materials may be edited for content and length.


Journal Reference:

  1. Amutha Sampath Kumar, Venkatachalam Lakshmanan, Jeffrey L. Caplan, Deborah Powell, Kirk J. Czymmek, Delphis F. Levia, Harsh P. Bais. Rhizobacteria Bacillus subtilis restricts foliar pathogen entry through stomata. The Plant Journal, 2012; DOI: 10.1111/j.1365-313X.2012.05116.x

Cite This Page:

University of Delaware. "Probiotics supercharge plants' immunity to disease." ScienceDaily. ScienceDaily, 27 August 2012. <www.sciencedaily.com/releases/2012/08/120827130647.htm>.
University of Delaware. (2012, August 27). Probiotics supercharge plants' immunity to disease. ScienceDaily. Retrieved October 24, 2014 from www.sciencedaily.com/releases/2012/08/120827130647.htm
University of Delaware. "Probiotics supercharge plants' immunity to disease." ScienceDaily. www.sciencedaily.com/releases/2012/08/120827130647.htm (accessed October 24, 2014).

Share This



More Plants & Animals News

Friday, October 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Black Bear Cub Goes Sunday Shopping

Black Bear Cub Goes Sunday Shopping

Reuters - Light News Video Online (Oct. 23, 2014) Price check on honey? Bear cub startles Oregon drugstore shoppers. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Dances With Wolves in China's Wild West

Dances With Wolves in China's Wild West

AFP (Oct. 23, 2014) One man is on a mission to boost the population of wolves in China's violence-wracked far west. The animal - symbol of the Uighur minority there - is under threat with a massive human resettlement program in the region. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
Breakfast Debate: To Eat Or Not To Eat?

Breakfast Debate: To Eat Or Not To Eat?

Newsy (Oct. 23, 2014) Conflicting studies published in the same week re-ignited the debate over whether we should be eating breakfast. Video provided by Newsy
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