Wheat Plants and Their Microbiota Respond to Climate Stress in Different Ways, Study Shows

Climate change is posing a serious threat to agriculture, especially to staple crops like wheat. Extreme weather events such as droughts, floods, and heat waves can reduce the growth and yield of wheat plants, as well as make them more vulnerable to diseases and pests.

However, wheat plants are not alone in their struggle.

They have a diverse community of microorganisms living in and around them, called the microbiota, that can help them cope with climate stress.

A team of researchers from four non-university research institutions in Germany has been studying how wheat plants and their microbiota interact under different stress conditions, and how they use volatile organic compounds (VOCs) to communicate and defend themselves.

Their findings could provide insights for plant breeding and crop management to enhance the resilience of wheat plants to climate change.

How Microbes Can Help Wheat Plants Survive Floods and Droughts

(Photo : VLADIMIR NIKOLAYEV/AFP via Getty Images)

One of the main challenges that wheat plants face under climate change is water stress, either too much or too little.

The researchers found that floods and droughts not only affect the growth and yield of wheat plants but also change the composition of their microbiota.

In particular, more pathogenic microbes colonize the early growth stages of wheat plants under water stress, making them more susceptible to disease.

However, the researchers also discovered that beneficial bacteria can accumulate in the root zone of wheat plants during flooding, promoting the uptake of nutrients and vitamins by the plant.

The plant itself also changes its metabolism to cope with water stress. The researchers showed that the amino acid alanine plays a central role in maintaining nitrogen supply and metabolism in the stressed plants.

"Presumably, the altered microbiota then makes more supporting vitamins available to support the weakened wheat metabolism in the root zone," explained project coordinator Steffen Kolb from ZALF.

The researchers used systems biology methods to study the changes in plant metabolism and microbiota under water stress.

They also analyzed the VOCs emitted by the plant and its microbes, which are important for their interaction and defense.

They found that water stress alters the VOC profile of wheat plants, affecting their communication with the microbiota and their resistance to pests.

Also Read: Climate and Food Grains: New Wheat Gene Info Will Increase Adaptability

How Wheat Plants Use VOCs to Fight Pests

Another threat that wheat plants face under climate change is pest infestation, such as aphids. These insects can damage the plant by sucking its sap and transmitting viruses.

To defend themselves, wheat plants produce VOCs that can repel aphids or attract their natural enemies.

The researchers studied how pest infestation affects the VOC production of wheat plants and their microbiota, using mass spectrometry to measure the complex mixtures of VOCs.

They found that pest infestation induces a defense response in wheat plants, increasing the emission of certain VOCs that can deter aphids or attract parasitoids.

However, they also observed that some microbes can interfere with this defense mechanism by producing VOCs that mask or counteract the plant's signals.

This suggested that there is a complex interplay between wheat plants, their microbiota, and their pests, mediated by VOCs.

The researchers developed a new tool for data analysis of VOC mixtures using mass spectrometry, which will speed up follow-up studies on plant-microbe interactions.

They also compared different varieties of wheat plants in terms of their VOC production and pest resistance, which could provide information for breeding more resilient crops.

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