“As we better understand signaling pathways, we can make crops more resilient to flooding.”
Crops could soon be fortified against flooding, scientists say
As the climate become more unpredictable, extreme weather events are on the increase worldwide. Among them are flash droughts and flash floods, both of which can devastate crops.
When it comes to flooding, fields inundated with water invariably lead to major losses in crops, which adds to food insecurity. Already some 15% of crops are lost globally to flooding.
Scientists have been working on ways to fortify plants against flooding and in a breakthrough a team of researchers in Europe has identified a signaling molecule that can be triggered before floods to make plants more resistant to becoming waterlogged.
“The gaseous plant hormone ethylene causes the plant to switch on a kind of molecular emergency power system that helps it survive the lack of oxygen during flooding,” explain the scientists, who work at universities in the Netherlands and Germany and have published their findings in a study.
Ethylene has been shown to send a signal to a plant that gets submerged in water, triggering a defense mechanism. Waterlogged plants that are treated before flooding with the chemical have higher chances of survival, according to the researchers.
Such interventions could prove to be a key because different plant species have varying degrees of natural ability to survive underwater with some common crops succumbing fairly fast.
“In the case of potatoes, the roots die after two days due to a lack of oxygen. Rice plants are much more resistant, able to survive their entire lives in waterlogged paddy fields,” notes Sjon Hartman, a scientist at the Centre for Integrative Biological Signalling Studies of the University of Freiburg.
“Plants notice that they are surrounded by water because the gas ethylene, which all plant cells produce, can no longer escape into the air,” Hartman adds.
During an experiment the researchers simulated flooding for seedlings of Arabidopsis thaliana, popularly known as Thale cress, a small flowering plant widely used as a model organism in experiments. The seedlings were sealed in a bell jar without light or oxygen.
In seedlings that were previously exposed to ethylene gas, the root tip cells survived longer, the scientists found. The reason was that treated plants stopped growing their roots and switched energy production in the cells to oxygen-free metabolic processes.
The ethylene also caused the cells to be better protected against harmful oxygen radicals that accumulate in oxygen-deprived plants.
“Taken together, these rearrangements that ethylene triggers improve plant survival during and after flooding,” Hartman says. “As we better understand these signaling pathways, we can learn to make crops more resilient to flooding to combat climate change.”
