Featured Research

from universities, journals, and other organizations

Plant hormone regulates nectar production: Jasmonic acid triggers nectar accumulation in rapeseed flowers

Date:
March 29, 2010
Source:
Max Planck Institute for Chemical Ecology
Summary:
Plant scientists have discovered that the plant hormone jasmonic acid -- known as a signalling molecule after herbivory -- not only regulates flower development in the bud stage, but also triggers nectar production.

Rapeseed (Brassica napus) is important in agriculture not only as an oil-producing plant and a source of animal food, but also as a nectar provider for honey bees every spring.
Credit: MPI for Chemical Ecology/Kellmann

Rapeseed is one of the ten most important agricultural crops worldwide. In spring, the rapeseed fields with their bright yellow flowers are widely visible: this year winter rapeseed is being cultivated on 1.46 million hectares in Germany; at least 2.2 million tons of rapeseed oil can be expected. Beekeepers set up their beehives in the vicinity of rapeseed fields, so that the worker bees can gather nectar This ensures that the rapeseed flowers are pollinated and a high crop yield will be obtained.

During her studies, a scientist from the Max Planck Institute for Chemical Ecology has discovered that the plant hormone jasmonic acid -- known as a signalling molecule after herbivory -- not only regulates flower development in the bud stage, but also triggers nectar production.

Jasmonic acid and related molecules are constituents of molecular signal transduction chains in plant tissues. These compounds -- generally referred to as jasmonates -- are synthesized when caterpillars feed on plants; they are signaling substances and belong to the group of plant hormones. By producing jasmonates the plant regulates its defense against herbivores e.g. by stimulating the synthesis of toxins. Moreover, previous studies have shown that jasmonates regulate the production of "extrafloral nectar." This particular nectar, which is produced by special glands called "extrafloral nectaries," has nothing to do with pollination, but attracts ants to the herbivore-attacked plants as defenders against their pests. The sugars in the nectar reward the ants for defending the plant. The same principle applies to floral nectar: nectar production in the flowers attracts and rewards pollinators which in turn contribute substantially to the seed yield. However, up to now, it has not been clear how nectar production is regulated in the flowers.

Different effects in flowers and leaves

Radhika Venkatesan, PhD student at the International Max Planck Research School in Jena, studied Brassica napus, a widespread and agriculturally important plant species. She found that when its flower tissues produced jasmonates during an early developmental stage, nectar production was immediately activated, regardless of whether the plant had been attacked by herbivores or not. "When we put caterpillars on the rapeseed leaves to elicit jasmonic acid production, the nectar secretion of the flowers was not affected," the researcher says. Spraying jasmonic acid on the green leaves also did not have an impact on the production of nectar in the flowers. However, when the scientist sprayed jasmonic acid directly on the flowers, nectar production increased dramatically. This clearly indicates that jasmonic acid has different functions in the different plant tissues: whereas the hormone activates defense mechanisms against herbivores in the leaves and the shoot of the plant, it regulates nectar production in the flower tissue.

The correlation between the production of jasmonic acid and nectar accumulation was demonstrated in experiments with an inhibitor: if the flowers had been treated with an inhibitor of jasmonic acid synthesis, the so-called phenidone, nectar production failed. If the substance was sprayed on young, still closed flower buds, however, their opening was inhibited, which confirms the importance of jasmonic acid also during the development of the flowers.

"The fact that jasmonic acid regulates so many functions, such as plant defense and pollination, is extremely interesting and raises new questions, especially concerning the evolution of these control mechanisms," says Martin Heil, the leader of the study. Wilhelm Boland, director at the Max Planck Institute in Jena, emphasizes: "The more we know about the hormonal effects on flower development and nectar production in agricultural crops like rapeseed, the better we can use this knowledge to ensure high yields." Even beekeepers could benefit from increased nectar production. [JWK, AO]


Story Source:

The above story is based on materials provided by Max Planck Institute for Chemical Ecology. Note: Materials may be edited for content and length.


Journal Reference:

  1. Venkatesan Radhika, Christian Kost, Wilhelm Boland, Martin Heil, Abidur Rahman. The Role of Jasmonates in Floral Nectar Secretion. PLoS ONE, 2010; 5 (2): e9265 DOI: 10.1371/journal.pone.0009265

Cite This Page:

Max Planck Institute for Chemical Ecology. "Plant hormone regulates nectar production: Jasmonic acid triggers nectar accumulation in rapeseed flowers." ScienceDaily. ScienceDaily, 29 March 2010. <www.sciencedaily.com/releases/2010/03/100329103654.htm>.
Max Planck Institute for Chemical Ecology. (2010, March 29). Plant hormone regulates nectar production: Jasmonic acid triggers nectar accumulation in rapeseed flowers. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2010/03/100329103654.htm
Max Planck Institute for Chemical Ecology. "Plant hormone regulates nectar production: Jasmonic acid triggers nectar accumulation in rapeseed flowers." ScienceDaily. www.sciencedaily.com/releases/2010/03/100329103654.htm (accessed October 1, 2014).

Share This



More Plants & Animals News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Attacking Superbugs

Attacking Superbugs

Ivanhoe (Oct. 1, 2014) — Two weapons hospitals can use to attack superbugs. Scientists in Ireland created a new gel resistant to superbugs, and a robot that can disinfect a room in minutes. Video provided by Ivanhoe
Powered by NewsLook.com
Cultural Learning In Wild Chimps Observed For The First Time

Cultural Learning In Wild Chimps Observed For The First Time

Newsy (Oct. 1, 2014) — Cultural transmission — the passing of knowledge from one animal to another — has been caught on camera with chimps teaching other chimps. Video provided by Newsy
Powered by NewsLook.com
Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Newsy (Sep. 30, 2014) — A new study published by the World Wide Fund for Nature found that more than half of the world's wildlife population has declined since 1970. Video provided by Newsy
Powered by NewsLook.com
Annual Dog Surfing Competition Draws California Crowds

Annual Dog Surfing Competition Draws California Crowds

AFP (Sep. 30, 2014) — The best canine surfers gathered for Huntington Beach's annual dog surfing competition, "Surf City, Surf Dog." Duration: 01:15 Video provided by AFP
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