ADVERTISEMENT

Wood Spirit, An Alert Signal For Plants Under Attack

There is a plant-protecting spirit blowing through the air. If you breathe in carefully now you will smell… wood spirit! Long believed to be a simple by-product of degradation of a plant cell wall, new results show that methanol is a signal that tells surrounding plants to activate their defenses against pathogens and predators.

Methanol is the simplest of alcohols (Figure 1), formerly called wood spirit because obtained by distilling wood. Many chemical syntheses use methanol, and its derivatives are widely used in the production of many dyeing products, resins, pharmaceuticals, and synthetic perfumes. Very recently, it was shown that the leaf tissue of flowering plants produces such significant amounts of methanol that it is now considered as one of the most significant organic compounds in the atmosphere.

ADVERTISEMENT
Figure 1: Methanol molecule, CH3OH. Image courtesy François Bouteau.

Methanol was long considered as a by-product of a plant’s response to mechanical wounding or other stresses that damage the cell wall. Indeed, the source of metabolic methanol formation in plants is the demethylation of cell wall pectins by pectin methylesterases (PMEs). However, it has been shown recently that gaseous methanol emitted by a wounded plant induces defense reactions, not only in its intact leaves but also in neighboring plants.

In order to identify the molecular mechanisms underlying methanol-induced plant defenses, we studied early plant cell responses to exogenously supplied methanol applied as liquid or a volatile. We observed that methanol induces various well-known signaling events related to plant defenses such as cytosolic Ca2+ variations, generation of reactive oxygen species (ROS), and ion fluxes through the plant cell membrane (Figure 2). Moreover, we showed that in tobacco, Arabidopsis, and sunflower, methanol induces the synthesis of ethylene (C2H4), one of the most important volatile plant hormones. The methanol-induced synthesis of ethylene depends on the well-known signaling events induced by methanol treatment.

Strikingly, ethylene is also a volatile involved in plant defenses. In the 1990s in South Africa, it was shown that the acacia could warn its congeners via ethylene. By recognizing a bite or shredding attack, the acacia leaf releases ethylene, which radiates within a radius of 6 m. This gaseous stimulus allows the neighboring acacias to start producing tannins even before the arrival of the pest, the kudu antelope, saving them valuable time. The increasing amounts of tannins make acacias more and more toxic, up to doses that are lethal for browsing animal.

Therefore, methanol is not only a by-product of PME activities. Our study shows that it participates together with ethylene to a volatile communication network, allowing plants to defend against pathogens and predators. In addition, it has not escaped our notice that methanol is used as a drug solvent in a wide array of experiments in plants. Our results raise the question of whether, depending on the dose used, some of the effects detected in these previous studies are due to the drug applied or the solvent.

ADVERTISEMENT
Figure 2: Methanol-induced early plant responses. Image courtesy François Bouteau.

These findings are described in the article entitled Methanol induces cytosolic calcium variations, membrane depolarization and ethylene production in arabidopsis and tobacco, recently published in the journal Annals of Botany. This research was conducted by Delphine Arbelet-Bonnin, Tingting Zhao, Patrick Laurenti and François Bouteau.

Reference:

  1. Daniel Tran, Aurélien Dauphin, Patrice Meimoun, Takashi Kadono, Hieu TH Nguyen, Delphine Arbelet-Bonnin, Tingting Zhao, Rafik Errakhi, Arnaud Lehner, Tomonori Kawano, François Bouteau. Methanol induces cytosolic calcium variations, membrane depolarization and ethylene production in arabidopsis and tobacco. Annals of Botany, Volume 122, Issue 5, 3 November 2018, Pages 849–860, https://academic.oup.com/aob/article/122/5/849/4944430

Comments

READ THIS NEXT

My Science Life: Dr. Stephen Johnston – University Of Alberta Earth & Atmospheric Sciences

Welcome to the My Science Life feature of Dr. Stephen Johnston, Chair / Professor in Tectonics at the Earth & […]

A Novel Method For Fluoride Detection

Paracelsus’ old adage “the dose makes the poison” is well exemplified by fluoride. Many people know that fluoride is commonly […]

Phosphorus Recovery – A Voyage From Sewage Sludge To Johannes Vermeer

What is phosphorus recovery about? Phosphorus as a nutrient – importance for our society ADVERTISEMENT Phosphorus is a chemical element. […]

An Alternative To Petroleum-Based Plastic Packaging

Packaging is a crucial tool in containing and protecting food as it moves through the supply chain to the consumer. […]

How Ethanol And Heavy Metals In Alcohol Sachets Are Affecting Uganda’s Acoli People

Excessive consumption of ethanol, the intoxicating agent in alcoholic drinks, and the ingestion of heavy metals in contaminated foods and […]

Using Social Information Cascade To Spread Information

One of the most spectacular scenes one can witness in a tropical rainforest is the swarming of army-ants as they […]

Early Drinking = Later Sickness: A Study In Twins

Adolescents that start drinking early have been shown to have a much higher likelihood to become addicted later on. The […]

Science Trends is a popular source of science news and education around the world. We cover everything from solar power cell technology to climate change to cancer research. We help hundreds of thousands of people every month learn about the world we live in and the latest scientific breakthroughs. Want to know more?